Saturday, July 29, 2006

ADEM in pediatrics

ADEM A Long term followup study of 84 pediatric patients.

Argentinian series of patients admitted to the National Hospital. Preceding illnesses occurred in 74 %: 35 % nonspecific RTI 12 % immunization , 11 % GI illness, rest nonspecific febrile,varicella, HSVE, mumps, rubells or undefined.

Age at onset was 5.3 years +/- 3.8 years with a male predominance. The presentation was usually hemiparesis (76 %) with unilateral or bilateral long tract signs (85 %0 and mental status changes (69%). None had oligoclonal banding. High dose coricosteroids use was associated with a good recovery and minimal/no disability. 90 % were monophasic, 10 % were biphasic. Disability was often based on optic nerve involvement at presentation.

Sunday, July 23, 2006

Xyrem facts

Gamma hydroxybutyrate (GHB) was approved for oral treatment of cataplexy in patients with narcolepsy, and also in excessive daytime somnolence in the same patients. Xyrem is a rapid acting hypnotic with a short half life, increasing the duration of stage 3 and 4 sleep. It does not cause tolerance or dependence upon abrupt cessation, but abuse has been reported with craving and severe dependence. It can cause respiratory depression and death if taken with other sedatives. It can worsen sleep apnea, cause HA/N/V/dizziness, depression, nocturnal urinary incontinence, sleepwalking, and has sodium which could be a problem in patients with CHF, CRF or HTN.

Dosing: begin at 4.5 g per night: 2.25 g at bedtime when in bed 2-4 hours after a meal and repeat 2.5-4 hours later. Titrate by 1.5 grams per night eavery 2 weeks to a total of 9 grams. Xyrem is a available as an oral solution in 180 ml bottles with 500 mg/ml.

Central pharmacy prescriptions are available at the Xyrem success program, 1866 997 3688

Nelarabine (Arranon) for ALL causes neurotoxicity

Nelarabine is a nucleoside analog approved by the FDA for treatment of patients with refractory T-cell ALL and T-cell lymphoblastic lymphoma (T-LBL). These diseases are usually treated aggressively with combination chemotherapy (vincristine, prednisone, anthracycline, asparaginase, cyclophosphamide and cytarabine). It is demythylated to ara-G (ara-GTP) which is incorporated into dna, causing apoptosis and fragmentation. 18 % of refractory patients (5/28) has a complete response. Median survival was 20 weeks. Among children, 9/39 (23%) had a CR with median survival of 13 weeks. The most common AE's are anemia, leukopenia, thrombocytopenia, HA, somnolence and GI effects, dyspnea and peripheral neuropathy. Neurotoxicity, which can be fatal, is dose limiting; paresthesia, ataxia, ocnfusion, convulsions, and coma.

Tuesday, July 18, 2006

Obturator and combined obturator/femoral neuropathy

Obturator neuropathy-- sensory symptoms, including paresthesias and pain, possibly radiating in medial thigh. Motor involvement leads to trouble walking, due to inability to adduct the thigh, so thigh will be abducted and the gait is wide based. Examination-- weakness of thigh adductors is seen. There are no deep tendon reflex changes but the adductor tendon reflex may be absent.Etiology-- extension or lateral movements of leg that stretch it through the pelvis. Most cases are due to severe trauma: gunshot wounds, pelvic fracture or major trauma, and very rarely, childbirth.

Combined obturator/femoral neuropathy-- much more common, occurs in upper plexus lesions near psoas muscle. Causes include retroperitoneal hematoma, metastatic cancer and lymphoma. Clinically the quadriceps and the adductors are both paralyzed leading to a functional deficit of the leg.

Within pelvis the obturator nerve is medial to femoral or sciatic lesions and rare cases occur due to cement extrusion after hip surgery and after pelvic fracture.

Monday, July 17, 2006

Arsenic poisoning affects upgaze

Nakamagoe et al. Upward gaze-evoked nystagmus withorganoarsenic poisoning.

The authors report 3 patients who drank well water contaminated with very high levels of an organoarsenic compound, diphenyarsenic acid, believed to originate in emetic agents used in WWII.

Clinical presentation included articulation disorder, twitching and tremors of the hands and feet, gait disturbance and oscillopsia. The patient had upbeat nystagmus and abnormal vertical smooth pursuit movements, and impaired vertical gaze-holding. The patients also had myoclonus with long tract signs, truncal and limb ataxia. MRI showed subtle midbrain changes. Symptoms improved with removal of exposure.The authors speculate that the toxin hits the rostral interstitial nucleus of Cajal.

Sunday, July 16, 2006

Neurologic causes of unilateral hearing loss

Sjogren's syndrome
Susac's syndrome- subacute encephalopathy, branch retinal a occlusion and SN hearing loss.
Giant cell arteritis
Vertebral artery dissection with PICA stroke
AICA stroke
viral/postviral infection
lyme disease
autoimmune inner ear disease
acoustic neurinoma
Meniere's disease
perilymph fistula
ototoxic drugs
other drugs

Facial pain and trigeminal neuralgia

Hentschel K et al. Facial Pain. The Neurologist 2005; 11:244-249

Pearls with trigeminal neuralgia

Up to ten percent of patients harbor an intracranial lesion.

More than half of patients achieve remission periods of 6 months or more.

Early treatment with anti HSV medicine and corticosteroids accelerates healing and reduces the duration of postherpetic pain.

The surgical procedures of choice for trigeminal neuralgia for the 30 % of patients who are refractory is a percutaneous radiofrequency or glycerol trigeminal rhizotomy. Complications include corneal anesthesia, anesthesia dolorosa, dysethesias, and masseter muscle weakness and are uncommon. Microvascular decompression is definitive, but is reserved because of the need for a craniotomy. Gamma knife radiosurgery is gaining popularity.

Rare causes of facial pain that need consideration include:

Assessing anisocoria and Horner's syndrome

The first step is to determine which pupil is abnormal. Ptosis and opthalmoparesis on the side of the larger pupil suggests a third nerve paresis on that side. Ptosis on the side with the smaller pupil suggests a Horner's syndrome. If the pupils appear equal in normal lighting, try to darken the room. Anisocoria that is more pronounced in a darker room suggests a Horner's syndrome on the side with the smaller pupil. If its more pronounced in light, it suggests a parasympathetic defect on the side with the larger pupil.

Horner's syndrome may have upper lid ptosis and sometimes reverse lower lid ptosis, giving the (false) impression of enopthalmos. Acutely there is also hyperemia or the conjunctiva. Horner's in isolation usually is a postganglionic Horner's and it usually is due to one of two conditions, cluster headache and carotid dissection, which are not confused clinically.


Botulism causes descending symmetric paralysis due to impaired neurotransmission at theneuromuscular junction and cholinergic autonomic synapses. It is due to Clostridium Botulinum, a spore forming anaerobic Gram-positive bacillus in the soil, that produces A, B, and C type neurotoxins. There are four clinical types: food borne botulism, wound botulism, and intestinal colonization in infants and in adults.
Routes of infection are ingestion of contaminated canned meats or goods, spore contaminated wound infections, especially in heroin addicts who engage in subcutaenous injections called "skin popping," and GI colonization in infants. In infants, onset is 8-36 hours after eating, in wounds 4-17 days after injury, when toxin binds and irreversibly blocks all postganglionic parasympathetic synapses, and all ganglionic synapses.

The presentation is often external opthalmoplegia and ptosis, coinciding with dilated poorly reactive pupils, paralysis of accomodation, then dysphagia, dysarthria, dysphonia, and symmetric descending paralysis. Patients should be monitored for impending cardiovascular collapse.


Diagnosis is by history and physical examination. Demonstrating toxin in GI contents, food, confirms. Equine trivalent antitoxin is suggested for adults within 24 hours, and infants may receive human immunoglobulin. Patients should be treated in the intensive care unit. Public health officials should be alerted.

Neurology review article linked describes clinical feature of type F in adults. Cases were sporadic, had incubation period of 24 hours about, and required intubation and ventilatory support for several weeks. Type F (compared to type B) were more likley to have respiratory and extremity weakness, limb weakness and absent deep tendon reflexes and require earlier intubation. Usually antitoxin was given within four days. Diagnosis was made by serum (69 %) and stool culture (80%). Misdiagnosis of cardiopulmonary and respiratory disease was common.

Myasthenia gravis and LEMS

Myasthenia gravis (MG) can mimic many of the aforesaid conditions. 75 % of patients present with ptosis or diplopia.

Diagnostic pearls-- a painless pupil sparing third nerve palsy suggests the possibility of a "pseudo-third nerve palsy" which may be due to MG. Variability, alternating quality between eyes, and presence of orbicularis oculi face weakness helps to make the diagnosis. Face weakness rules out CN palsy as a cause. Saccade velocities are preserved in the setting of limited eye movements especially with smaller eye movements (larger ones may induce fatigue). Diagnostic tests include Tensilon test, sleep test, or the ice test, or serum antibody tests or neurodriagnostic tests.

EMG/NCS pearls in MG-- typically with rep stim four to five stimuli is best; with more repair occurs and effect is harder to see. You should see a smooth tapering response with a best effect on fourth or fifth stimulus, and it should be confirmed in a second nerve. Mestinon and timespan should be held for about twelve hours prior to testing. After exercise, rest elicits repair followed by post exercise exhaustion. You may need to repeat post exercise test every 30 seconds for up to four or five minutes. Picture on NCS can be indistinguishable from LEMS. Recall though that anti VGCC is found in up to 90 % of LEMS patients. Clinical PEARL-- can check for facilitation of a DTR after exercise--if DTR returns, favoos LEMS. LEMS oftenhas a flat CMAP that returns to normal after exercise. Instability is seen on needle examination of affected muscles on EMG. At the Mayo, Tensilon is rarely done except with the LR green eye exam. Usually 3-4 nerves are tested including facial, spinal accessory. Look for finger extensor weakness in MG and if found, check radial nerve at EIP and spiral groove.

Dorsal midbrain syndrone & shunt dysfunction

Synonyms-- pretectal syndrome, Parinaud syndrome, syndrome of the superior colliculus.

Signs and symptoms classically include vertical gaze palsy, pupillary light-near dissociation, convergence-retraction nystagmus, lid retraction, and abnormalities of convergence and accomodation. Early on, however, one may see only conjugate upgaze paresis, involving only saccades and not smooth pursuit movements. Gaze evoked upbeat nystagmus, with intact reflex upgaze. Children who complain of trouble seeing near objects should be tested for upwards saccades, as these patients may be likely ot have pineal cysts or hydrocephalus, or if they have a ventriculoperitoneal shunt, shunt dysfunction.

In evaluation for shunt dysfunction, patients may have not only abnormal velocity and accuracy of upwards saccades, but also a sixth nerve palsy, nystagmus, esotropia, convergence spasm, and amblyopia consequent to visual loss from papilledema. According to Purvin et al, IT MAY TAKE CONSIDERABLE FORTITUDE TO INSIST ON THE DIAGNOSIS IN THE FACE OF ASSURANCES FROM THE RADIOLOGIST AND THE NEUROSURGEON THAT THE SHUNT IS WORKING PROPERLY.

Combined cranial neuropathies

A combination of 3rd, fourth, fifth and sixth dysfunction, on one side, especially if ocmbined with oculosympatheic dysfunction, suggests a parasellar lesion., infectious, neoplastic, inflammatory or vascular.

Tolosa Hunt syndrome-- THS is a syndrome of acute, painful opthalmoplegia due to idiopathic granulomatous disease in the cavernous sinus. Signs and symptoms include periorbital or hemicranial pain with ipsilateral effects of CN III, IV, V1, VI and Horners' syndrome. THS is a diagnosis of exclusion after other causes of cavernous sinus abnormality have been excluded. (see separate citation of evaluation for painful opthalmoplegia). MRI may be normal or abnormal and show enlargement of the cavernous sinus, enhancement of the adjacent dural wall, and abnormal soft tissue surrounding and narrowing the cavernous ICA. There may be extension of the soft tissue abnormality into the orbital apex, sphenoid sinus or floor of the middle cranial fossa. The etiology is unknown. Like orbital pseudotumor syndrome, oral corticosteroids are dramatically effective, often within 48 hours. Beware, as other conditions that mimic THS are also steroid responsive.

Causes of painful opthalmoplegia

* Aneurysmal third nerve palsy
* vasculopathic cranial palsy
* cavernous sinus disease (thrombosis, aneurysm, inflammatory(Tolosa Hunt, sarcoid, Wegener's))
* Carotid dissection
* pituitary apoloplexy
* Giant cell arteritis
* Nasopharygeal carcinoma
*Basilar meningits (infectious or neoplastic)

Suggested evaluation:

*Blood tests: CBC, ESR, metabolic profile, angiotensin converting enzyme, lysozyme, VDRL, FTA-ABS, antineurtrophilic cytoplasmic antibodies (ANCA)

*Chest X ray
*MRI with contrast and thin coronal cuts
* lumbar puncture
*Nasopahryngeal examination with "blind" biopsy

Sixth nerve palsy

Sixth nerve palsies may be complete, with a complete esotropia and abduction defect or partial. The differential includes restrictive opthalmopathy or orbitopathy affecting the medial rectus muscle. In sixth nerve palsy but not restrictive eye disease there are characteristic slowing of abducting saccades.

Although the differential is extremely broad due to the length of the nerve, there are some helpful findings. Bilateral sixth nerve palsies are common at the clivus. Other cranial neuropathies (third, fourth, first division of fifth, or an ipsilateral Horner's) suggest a cavernous sinus lesion. Headache and pappilledema suggest a "false localizing" sign if increased intracranial pressure.

Among children, the commonest etiologies are trauma and tumor, usually a pontine glioma. Among 45 young adults without trauma,aged (20-50), one third have tumor, one fourth have multiple sclerosis, 9 % have a postviral infection, 7 % have IIH, and 7 % have meningitis (Peters et al.) Among the 15 tumor patients, only 3 had an isolated sixth nerve palsy, and among 11 patients with multiple sclerosis, an isolated sixth was the presenting sign in 8 of them. Thus MRI/LP are frequently appropriate in this group.

Among older adults, especially those with vascular risk factors, a vasculopathic or ischemic cause is the commonest. Beware of a patient with a history of malignancy. Beware of GCA; consider checking a sed rate and C reactive protein. Some opthalmalogists do not recommend neuroimaging for all patients in this group, but they do suggest careful followup, and imaging if the problem progresses after 2 weeks, fails to regress by two months, or other neurologic signs and symptoms occur. BILATERAL SIXTH NERVE PALSY IS NEVER VASCULOPATHIC. Clival bony lesions may be missed on quality neuroimaging, and sometimes lumbar puncture is required to identify increased intracranial pressure or meningitis. Consider metastases!

Third nerve palsies

Associated symptoms (hemiplegia, tremor, ataxia) suggest a brainstem lesion. See separate sections on localization; this post covers emergencies primarily.

If meningismus or photophobia occur, do lumbar puncture to exclude an infiltrative lesion.

Cavernous sinus. superior orbital fissure lesions-- look for associated fourth nerve palsy, sixth nerve palsy, V1 dysfunction, or Horner's syndrome.

Isolated Third nerve palsy is vasculopathic, ie due to small vessel disease, or due to aneurysm, commonly posterior communicating artery aneurysm. Age greater than 50 and presence of major risk factors such as diabetes, hypertension, and hyperlipidemia favor vasculopathic origin. Third nerve palsy usually presents abruptly but may progress over one or two weeks. Ipsilateral retroorbital or head pain is usually present. Recovery over a period of months is typical. A small degre of anisocoria may be present (10/26 patients per Jacobson) but is almost always less than 2.5 mm.

Aneurysmal third nerve palsy includes younger patients aged 20-50 without risk factors. Pain occurs, but does not differentiate from vasculopathic third nerve palsy. However, pupillary dilatation occurs early, and occurs in 86-95 % of cases, whereas most vasculopathic cases spare the pupil. Trobe's "The Rule of the Pupil" states that in patients with an otherwise complete but pupil-sparing third nerve palsy do not have an aneurysm. IN cases of pupillary sparing aneurysms, other third nerve muscles are spared as well. If the third nerve palsy is partial, the state of the pupil does not help. 30-40 % of patients with partial third nerve palsies harbor an aneurysm. The pattern is different than in vasculopathic third nerve palsies: In vasculopathic cases there is incomplete paresis of all third nerve innervated muscles, but in partial third nerve palsies with aneurysm, patients are more likely to show weakness of just one or more but not all muscles.

MRA and CTA are extremely sensitive for the detection of aneurysms but are not yet 100 %, as they miss aneurysms smaller than 5 mm. Suggestions for on whom to perform angiography include all younger patients without risk factors, even those with low risk (pupil sparing but otherwise complete third nerve palsy). But for patients older than 50 with vascular risk factors and a pupillary sparing lesion can be managed expectantly, as the risk of an angiogram outweighs the benefit.

Third nerve palsies

Associated symptoms (hemiplegia, tremor, ataxia) suggest a brainstem lesion. See separate sections on localization; this post covers emergencies primarily.

If meningismus or photophobia occur, do lumbar puncture to exclude an infiltrative lesion.

Cavernous sinus. superior orbital fissure lesions-- look for associated fourth nerve palsy, sixth nerve palsy, V1 dysfunction, or Horner's syndrome.

Isolated Third nerve palsy is vasculopathic, ie due to small vessel disease, or due to aneurysm, commonly posterior communicating artery aneurysm. Age greater than 50 and presence of major risk factors such as diabetes, hypertension, and hyperlipidemia favor vasculopathic origin. Third nerve palsy usually presents abruptly but may progress over one or two weeks. Ipsilateral retroorbital or head pain is usually present. Recovery over a period of months is typical. A small degre of anisocoria may be present (10/26 patients per Jacobson) but is almost always less than 2.5 mm.

Aneurysmal third nerve palsy includes younger patients aged 20-50 without risk factors. Pain occurs, but does not differentiate from vasculopathic third nerve palsy. However, pupillary dilatation occurs early, and occurs in 86-95 % of cases, whereas most vasculopathic cases spare the pupil. Trobe's "The Rule of the Pupil" states that in patients with an otherwise complete but pupil-sparing third nerve palsy do not have an aneurysm. IN cases of pupillary sparing aneurysms, other third nerve muscles are spared as well. If the third nerve palsy is partial, the state of the pupil does not help. 30-40 % of patients with partial third nerve palsies harbor an aneurysm. The pattern is different than in vasculopathic third nerve palsies: In vasculopathic cases there is incomplete paresis of all third nerve innervated muscles, but in partial third nerve palsies with aneurysm, patients are more likely to show weakness of just one or more but not all muscles.

MRA and CTA are extremely sensitive for the detection of aneurysms but are not yet 100 %, as they miss aneurysms smaller than 5 mm. Suggestions for on whom to perform angiography include all younger patients without risk factors, even those with low risk (pupil sparing but otherwise complete third nerve palsy). But for patients older than 50 with vascular risk factors and a pupillary sparing lesion can be managed expectantly, as the risk of an angiogram outweighs the benefit.

Saturday, July 15, 2006

Fourth nerve (IVn.) Trochlear palsies emergency

Most trochlear palsies are not emergent. Most trochlear palsies are due to stroke, trauma, and rarely neoplasm or aneurysm. Rarer causes are GCA and increased ICP that occassionally need to be addressed. 0.02 % of low pressure headaches after lumbar puncture have an associated IV nerve palsy (Continuum August 2009).

Low flow dural based AVMS of the orbit

These non-traumatic fistulas are indirect and involve communication between small meningeal branches of the ICA or ECA and the cavernous sinus or tributaries. Symptoms are mild and subacute, compared to CCF. They include conjunctival injection, mild motility disturbance, and elevated intraocular pressure. MRI may be normal or show mild abnormality of the cavernous sinus, but often enlarged extaocular muscles or superior opthalmic veins are seen.

Carotid Cavernous Fistula CCF

This is a high flow shunting of blood from the carotid artery into the cavernous sinus. It is usually due to carotid trauma. Other causes are intracavernous aneurysm, Ehlers-Danlos syndrome, fibromuscular dysplasia, and pseudoxanthoma elasticum. Ocular signs and symptoms are pulsatile exopthalmos, periorbital congestion, opthalmoplegia (even a "frozen" globe), and increased intraocular pressure.

Two features distinguish CCF from cavernous sinus thrombosis: an audible supraorbital bruit (may or may not be present) and the presence of arterialized corkscrew episcleral veins. Marked enlargement of the superior opthalmic vein is easily visible on a CT or MRI. CCF is life threatening due to the possibility of intracranial hemorrhage or massive epistaxis. Vision loss, seizures and neurologic deficits are bad prognostic signs. Rapid diagnosis is critical. Transarterial balloon embolization is the preferred initial treatment, with a success rate over 90 %.

cavernous sinus thrombosis

This condition may also present with acute diplopia and orbital signs. Predisposing conditions for the septic variety include facial infections, especially those of the medial third of the face, especially gram positive Staphylococcus aureus. Chronic sinusitis can cause, but in this case consider gram negative staphylococci, Aspergillosis, and Mucoracea infections. Dental infections, especially the maxillary teeth , cause ten percent of infections and may be streptococci, fusobacteria, or Bacteroides species. Rarely it is caused via orbital cellulitis or hematogenous seeding, especially in immunocompromised patients. A few are due to prothrombotic conditions.

Presenting signs and symptoms are eye pain associated with proptosis, chemosis, ptosis, and opthalmoparesis. Altered sensorium, headache, nausea and vomiting are common and help to differentiate from orbital cellulitis. Fever and leukocytosis point to an infectious etiology. Eyelid edema suggests the original infection is in the ethmoid sinus, face, or dental areas. Opthalmoparesis usually starts as an isolated paresis of one muscle, often the abducens, in the setting of orbital congestion and proptosis. Fundus may show dilatation of ocular veins andlow grade disc swelling. Vision loss can be due to ischemia, low grade optic neuropathy, or neurotrophic keratopathy. CT and MRI show enlargement of superior opthalmic veins and possibly involved cavernous sinus. CSF shows evidence of infection. Mortality is 30 % in spite of therapy.

Mucormycosis Neuroopthalmology emergency

Predisposing factors: diabetes mellitus, DKA, neutropenia, chronic immunosuppression, organ transplantation, hematologic malignancy, hemodialysis, burns, treatment with deferoxamine.

Five clinical forms-- rhinal-orbital-cerebral (one form), pulmonary, disseminated, gastrointestinal, cutaneous. ROC is most common (44 %) usually due to inhaled fungal spores that generate into hyphae and invade the blood vessels causing thrombosis, infarction, and necrosis.

Signs and symptoms-- fever, headache, periorbital pain, acute opthalmoplegia, proptosis, periorbital edema, visual loss, conjunctival redness, and trigeminal anesthesia. Facial or periorbital pain is seen only in one to thirds, against earlier belief. Acute orbital cellulits may be heralded or accompanied by blood tinged nasal discharge or epistaxis. The characteristic necrotic eschar in the nose or hard palate is often missed; these are seen in only 52 % in the first 72 hours. X rays show nonspecific findings such as sinus mucosal thickening or orbital infiltration, occassionally bone destruction, opthalmic vein thrombosis, in the setting of sinusitis or orbital cellulitis. Diagnosis is based on biopsy and H & E staining. If an eschar is not seen, consider a blind nasal biopsy. Lack of pain or bleeding during the biopsy is highly suspicious for mucormycosis. Treatment should be started immediately including amphotericin, correction of risk factors, surgical debridement, and possibly hyperbaric oxygen. Bad prognostic indicators are treatment delay of more than six days, intracranial symptoms such as seizures or hemiplegia, bilateral sinus involvement, facial necrosis, underlying leukemia, or deferoxamine therapy.

Orbital Pseudotumor

Idiopathic orbital pseudotumor may affect orbital structures diffusely or focally. In orbital myositis, the disease affects one or more extraocular muscles. Secondary causes include SLE, sarcoid, Crohn's, Whipple's, lyme, Wegener's , or paraneoplastic. Mean age of occurence is 40. Usually a single muscle is involved, often a medial rectus causing limited abduction of the eye, mimicking a sixth nerve palsy. CT should be as good as MRI.

Differential diagnosis from Graves' disease is helped by MRI. Orbital myositis involves the tendon insertions, Graves' does not; orbital myositis has an acute painful onset whereas Graves' disease has a subacute painless presentation; patients typically respond quickly and dramatically to steroids, 100 mg per day for two weeks with a slow taper thereafter. Half of the patients may recur, requiring repeat treatment, other drugs or radiation.

Idiopathic Intracranial hypertension IIH

Caveats-- occurrence in a man, child, older woman, or non-obese female. Mimics include venous sinus occlusion. 21 % may have permanent vision loss (Corbett) hence removal of "benign intracranial hypertension" term. Visual field testing is important since loss of fields preceded loss of acuity. Visual field loss can be identified in 92 % (with automated field) or 96 % (with Goldmann fields) often presenting with arcuate scotoma or nasal step. Contrast sensitivity and color vision are more sensitive than acuity testing.

Identifying the subset of patients who have progressive visual loss is difficult. Consider treating aggressively those with high grade papilledema, frequent TOV's (transient obscurations of vision) and significant visual loss at presentation.

Medicine treatments are problematic. Diamox is used, 500 mg Sequels are best with a starting dose of one bid, with furosamide 40 mg per day an alternative, along with therapy of associated problems such as anemia or hypoxia.

Lumbar shunting works, but requires an average of five revisions per patient. Optic nerve sheath fenestration (ONSF) works, to save vision, but may not fix diplopia or headache.


CAVEATS Patients with malignant clinical course are the minority but need a stepped up plan of treatment. Hypertensive optic neuropathy due to accelerated or malignant hypertension can mimic IIH, but recall that treatment is NOT designed to restore normal BP but to prevent end organ damage through minor or slow adjustments of the blood pressure. Avoid sublingual drugs such as nitroglycerin. Among men, consider sleep apnea syndrome which can cause vision changes indistinguishable from IIH.

Differential of Optic Disc Edema with preserved vision

Papilledema (increased ICP) usually bilateral but may be unilateral in IIH. Most such patients do complain of headache. If severe enough, consider cerebral venous thrombosis (CVT), hydrocephalus, meningitis, or malignant hypertension. Transient obscurations of vision with postural changes that are recurrent are not specific.

Compressive or infiltrative lesion (tumor, Graves' disease, optic perineuritis)

Central retinal vein insufficiency may see optociliary shunt vessels indicating prior retinal vein event. CAVEAT if disc pallor and decreased optic nerve function are seen, consider optic meningioma. May see central retinal hemorrhages

Benign optic disc vasculitis

Toxic optic neuropathy (amiodarone, cyclosporine, methanol (retrobulbar neuritis with blocked axoplasmic flow), hypervitaminosis A (like cyclopsorine causes increased intracranial hypertension)

Malignant hypertension may see central retinal artery hemorrhages or cotton wool spots, or macular stars. May be associated with reversible posterior leukoencephalopathy.

Low grade ischemia (diabetic papillopathy, pre-AION)-- exam might show segmental optic disc swelling, disc pallor, splinter or flame shaped hemorrhages, or macular stars. Diabetic papillopathy is a diagnosis of exclusion after evaluation.

Posterior uveitis (sarcoid, granulomatous disease, birdshot choroidopathy)

Acute zonal occult outer retinopathy

Neuroretinitis-- macular stars are a defining feature.


Differential homonymous visual loss

Occipital Stroke (especially PCA,may be heralded by episodes of vision blurring or dimming with flickering. May itself indicate onset of MI or atrial fibrillation and EKG should be checked

Abnormal MRI
Radiation damage
demyelinating disease
infections (especially PML)
MELAS (mitochonidrial encephalopathy with lactic acidosis and stroke like syndromes)
reversible posterior leukoencephalopathy
(associations include eclampsia, preeclampsia, hypertensive encephalopathy, acute glomerulonephritis, porphyria, seizures, and numerous immunosuppressive drugs)Normal MRI (or at least normal in occipital area)
Jacob-Creutzfeld disease
Alzheimer's disease
nonketotic hyperglycemia

Neuroopthalmic Emergencies--Monocular visual loss

(subscription required, may purchase individual article)
Acute visual loss. Historically verify acuity, and whether the loss is retina, optic nerve or brain.
Historical points
acute angle glaucoma--Halos around lights suggests aberration of ocular media; with eye pain consider
Retinal disease-- may have micropsia (distortion of size) or metamorphopsia (of shape) which is not seen in optic nerve disorders. A discrete, sharply demarcated scotoma is characteristic of retinal disease.
Perception light flashes or photopsias, if prolonged, suggest retinal disease but if fleeting may be optic nerve disorder.
Optic nerve disorder--typically a relative afferent pupillary defect (RAPD) is present, although a small RAPD might be seen in retinal disorders occassionally. However, the retinal exam is abnormal here.

Optic perineuritis OPN contrast to ON. Patients may be older than in ON (36 % > 50), vision changes may be paracentral or arcuate, progress over weeks, have progressive vision loss, and respond dramatically to steroids, which are continued for months typically. MRI of orbits shows enhanced area is along optic nerve sheath, which is best seen on coronal images. Oral prednisone is not contraindicated.

Optic Neuritis-- ON is primarily a clinical diagnosis. It affects central vision and color vision, and progresses over days, with spontaneous recovery without treatment. Ipsilateral pain with eye movement is present. RAPD is always present. The optic disc acutely may show inflammation (papillitis) or normal (retrobulbar neuritis). MRI with contrast, especially including coronal images with fat suppression are very helpful (see images at linked site). ON shows enhancement of anterior half of optic nerve and coronal shows enhancement within the nerve substance (compare to optic perineuritis). Over 97 percent of cases enhance with MRI contrast. 95 % of patients have a good prognosis for recovery to 20/40 or better. Refer elsewhere for discussions of relation to MS and value of brain MRI or steroid treatment. Note that steroids can affect MRI enhancement. Caveats- vision loss for greater than 2 weeks, fever, other neurologic deficits require care. Rare causes-- (besides idiopathic or MS) include syphilis, sarcoid, and lyme disease. Autoimmune/ Sjogren's also can occur . CAVEAT beware of an opthalmic artery aneurysm.

Anterior ischemic optic neuropathy (AION)- more common than posterior ischemic optic neuropathy (PION). Presentation is monocular visual loss present on awakening, usually without pain. Vision loss is usually maximal at onset but one third may have progressive AION over first ten days post onset. You may see segemental disc edema and splinter hemorrhages, and small or no optic cup. In AION, divide into arteritic and nonarteritic (NAION) causes. NAION is often related to hypotension, change in hypertensive medications, vasospasm or sleep apnea syndrome (SAS). Ask about sildafenil (Viagra), decongestants. Carotid disease and emboli are uncommon, because due to laminar flow, emboli are more likely to arrive at central or branch retinal arteries. The rarer cases of carotid stenosis/occlusion may be heralded by dim vision with changes of posture or exertion, ipsilateral pain, and ipsilateral Horner's syndrome. Symptoms improve with resolution of optic edema. Contralateral symptoms may occur in 15-40 % of patients at some later point. In NAION, steroids, hyperbaric oxygen, optic neve sheath fenestration, and transvitreal radial optic neurotomy are not established. Empiric topical treatment with brimonidine tartrate (neuroprotective) or pentoxifylline have been used. ASA is used.

Arteritic AION (giant cell arteritis, temporal arteritis)- The average age at onset is 70, its rare under 60 and remote in patients under 50. Constitutional symptoms may be present for 2-3 months including loss of appetite, fever, night sweats, malaise and body aches. It may be preceded by episodes of transient monocular visual loss mimicking embolic events. Such episodic vision loss is an ominous sign of impending vision loss. The degree of vision loss may be profound including the loss of light perception. Fundoscopic exam shows a white swollen disc "pallid edema" (in contrast to hyperemic disc of NAION),a generous optic cup (contrast to nonarteric) and cotton wool spots, ipsilateral or contralateral, and central retinal or cilioretinal arterial occlusion is the sine qua non of GCA. The second eye becomes affected within about two weeks of the first. Labs such as ESR are normal in 20 %. C reactive protein is more sensitive and is not affected by anemia or plasma protein concentration (unlike ESR). Anemia, thrombocytosis (44 %) are common. Evaluation should include CBC, ESR, CRP. Investigational studies underway for IL-6. Biopsy is normal in 15-20 percent, but contralateral biopsy then has lower yield. GCA is a T cell mediated attack on the internal elastic lamina of medium and large arteries, causing ischemia. Treatment recommendations include (unproved) dexamethasone 10 mg iv push or Solumedrol one gram iv push. If vision loss is not acutely pending, oral regimen (60-100 mg/day). One regimen is 100 mg for a month, 80 mg for a month, 60 mg for a month, 40 mg for a month, then a slower taper with monitoring of lab. Vision loss is usually severe and permanent when it occurs, and it usually occurs in the first five days after initiation of treatment, and rarely with too rapid tapering. CAVEAT AION in a patient over 80 is likely to be arteritic. Ask about scalp tenderness, not just "headache." Ask about PMR,neck pain, jaw and tongue claudication (differentiate from TMJ), poor appetite and fever. A GENEROUS CUP TO DISC RATIO IS SO UNUSUAL IN NONARTERITIC AION THAT THIS FINDING ALONE SHOULD PROMPT A TA BIOPSY.

Retrobulbar optic neuropathy-- PION is usually due to GCA or hypotension, usually coupled with anemia. It may occur after lengthy surgery (back surgery), cardiac arrest or profound blood loss. CAVEAT rarely a compressive lesion at orbital apex, hyperacute retinal artery occlusion (first few hours) and acute disorders of intracranial optic nerves (aneurysms, pituitary adenomas and tumors) can mimic PION. Compressive retrobulbar neuropathy usually presents with painless vision loss, prominent dyschromatopsia, and comprises 6.5 % of patients evaluated for glaucoma (Ahmed et al. 2002). Commonest are pituitary lesions, meningiomas and aneurysms, can include pituitary apoplexy, craniopharyngiomas, chordomas, inflammatory lesions of paranasal sinuses, primary bone lesions (Paget's, osteopetrosis, fibrous dysplasia), orbital trauma (fracture, hemorrhage) , thyroid related eye diseases.

Opthalmic artery aneurysm-- usually presents with a slowly progressive optic neuropathy, but occassionally sudden expansion with hemorrhages, abrupt loss of vision, and pain mimicking ON. These are more common in women and often bilateral. The field defect may respect the vertical meridian which suggests intracranial origin which is unusual in ON. Nasal visual loss may mimic low tension glaucoma. Symptoms of SAH or older age at onset should point away from ON.

Pituitary apoplexy-- defined as hemorrhage into or infarction of a pituitary tumor. Clinical triad is headache, mental status changes and opthalmoplegia is classical. Presentation is abrupt severe headache, signs of meningeal irritation, change in mental status and vision changes. It may mimic aneurysmal SAH. Presentation may be bilateral and include oculomotor paresis (also unilateral or bilateral)involving the third, fourth and sixth cranial nerves, in that order of frequency. In most cases the tumor is not suspected. Precipitating factors can sometimes be identified and include increased blood flow to pituitary (Vasalva or hypotension), stimulation of the pituitary (pregnancy or exogenous estrogen), emboli from carotid surgery, coagulopathy, presence of thrombolytics or thrombocytopenia. Diagnosis is often missed on CT but should be apparent on MRI. Treatment includes stress dose steroids, electrolyte monitoring, and +/- surgical decompression.

Retinal artery occlusion (central retinal artery occlusion CRAO and branch retinal artery occlusion BRAO). Presentation is acute sudden, painless unilateral visual loss, possibly heralded by a flash of light. Unlike patients with AION who awaken with their deficit, patients with RAO recount what they were doing when the vision loss occurred. Many have curtain like vision loss or episodes of vision loss previously. While carotid disease is the commonest identifiable cause, only 11-45 % have carotid atherosclerosis after evaluation. Findings on examination are retinal whitening, cotton wool spots, box car segmentation of the blood column, cholesterol emoboli (yellow, from carotid artery or aortic arch) or calcific emboli (white, from heart or aorta) or platelet fibrin emboli (long and whitish, from heart or arteries). Prognosis is poor; although recanalization occurs, only 15 % recover vision. Treatment may include conservative modalities (ocular massage, paracentesis, and drugs) and invasive (thrombolytics) (see Kattah et al. Arch Opthal, 2002), The latter helped 10/12 patients but incompletely. Other modalities include pentoxifylline, and hyperbaric oxygen.

Friday, July 14, 2006

Normal Pressure hydrocephalus--Pearls

article on Normal pressure hydrocephalus, password required.
The best teaching on NPH comes from Neill Graff-Radford, whom I first encountered in Iowa City in 1988. Although Neill has a "dry" presentation, he is extremely perceptive.  That said, he has not changed his presentation much in 20 + years.

Among patients with NPH, one hopes to get a history of hypertension, and an enlarged head circumference. One looks for reasons NOT to shunt. One casts doubt upon the motives of the public information campaign. Do the Boston Naming Test (score less than 52 is bad). Ask about a history of prior alcohol use, steroid use, or exposure to the HIV virus or MS (or any other reason to suspect brain atrophy rather than hydrocephalus). Do neuropsych testing (dementia= different diagnosis). Look at the scan at the cortical gyri-- are they atrophied? Do a spinal tap-- not only to test response to removal of fluid, but to send off tau and ABeta 42 protein.

Remember, one half of the shunts work, and a third cause more problems than they are worth. The mettle of the good neurologist is to improve those odds for selected patients.

Tuesday, July 11, 2006

Capecitabine induced multifocal leukoencephalopathy

Videnovic et al. Capecitabine-induced multifocal leukoencephalopathy: A report of five cases. Neurology 2005; 65:1792-94.

5 FU is used to treat breast and colon cancer and can cause a cerebellar syndrome or rarely, an encephalopathy. Capecitabine, an oral prodrug converted to 5FU is used in advanced breast and GI malignancies (including pancreatic or colon).

All 5 patients were women 40-74 started on capecitabine 2 g/msquared and within seven days developed neurologic symptoms requiring evaluation (range 3-7 days). They included nausea, confusion, short term memory loss, HA , vertigo, ataxia, dysarthria, and body shaking. MRI showed increased signal in brachium pontis, corpus callosum, deep periventricular area and SPLENIUM OF CORPUS CALLOSUM IN ALL CASES. The lesion was nonenhancing. Neurologic status improved with discontinuation of the drug.

Clinical and Neurologic findings in NeuroSjogren's s

Delalande et al. Medicine 83:280-291 2004.

Among patients with Sjogren's syndrome (SS) 20 % have neurologic involvement. Of 82 patients (including 65 women) the mean age at onset was 53. Neurologic involvement preceded diagnosis in 81 %. 56 % had focal or multifocal CNS disorders (acute myelopathy 12, chronic myelopathy 16, MND 1, 33 brain involvement and 13 had optic neuropathy). In 10 patients the disease mimicked relapsing-remitting MS and in 13, PPMS. There were 7 cases of seizures, 9 of cognitive dysfunction and 2 of encephalopathy. 51 patients had involvement of the peripheral nervous system. The neuropathy was a symmetric sensorimotor axonal polyneuropathy with a predominance of sensory symptoms or pure sensory neuropathy (28 patients) or cranial neuropathy affecting cranial nerves V, VII or VIII (n=16). 7 had multiple mononeuropathy, 2 myositis and 1 polyradiculopathy. 30 % had oligoclonal bands, 61 % abnormal VEP's, 70 % had abnormal brain MRI's (white spots) with 40 % meeting criteria for MS. Among the 29 patients with myelopathy, 19 had T2 changes on spinal MRI.

Patients with PNS involvement had frequent (21%) anti Ro/SSA or anti La/SSB antibodies at diagnosis of SS. 52 patients were severely disabled and those were far more likely to have CNS involvement than PNS. Cytoxan treatment resulted in stabilization/partial recovery in 92 % with myelopathy and 100 % with multiple mononeuropathy.

Comment -- the disease is virtually indistinguishable from MS. Check NMO IgG as some are positive in cases of longitudinallly extensive transverse myelitis.

clinical picture of copper deficiency myelopathy

Kumar N et al. Neurology 63:33-39, 2004

The clinical information on 13 patients was reviewed. All had sensory ataxia due to dorsal column dysfunction and lower limb spasticity. All had polyneuropathy. 7/11 had high or high normal zinc levels. 3 patients had dorsal column signal change on MRI. Some had low ceruloplasmin without Wilson's disease on further testing. Most patients did not have an etiology that was clearly established. Copper supplements prevented further deterioration, but resulted in variable amounts of improvement neurologically. The picture is strikingly similar to B12 deficiency.

Hedara et al. Arch Neurol 2003; 1303-1306 Postulates this is due to zinc overload and notes many such patients have high zinc levels, although he is not able to determine why. They also are pancytopenic.

Monday, July 10, 2006

Early clinical signs of GSS syndrome(Pro102Leu)

Arata H. et al. Early clinical signs and imaging findings in Gerstmann-Straussler-Scheinker syndrome (Pro102Leu)

There are seven types of inherited prion disease,of which the above is but one accounting for about 28 % of cases. Classic signs of GSS102 are cerebellar signs and slowly progressive dementia, but the ataxia occurs late. Early findings in 11 patients (9 families) are described, including mild gait disturbance, dysesthesias and hyporeflexias of the legs, dysarthria and truncal ataxia and 9/11 had proximal leg weakness. None were demented early. MRI/EEG were normal with abnormal SPECT scans. NCS/EMG were normal. On initial exam only three patients had mild limb ataxia and three others had mild nystagmus. Several were seen/operated for lumbar disease. Two tested had increased 14,3,3, protein in CSF. The problem with orhtopedic referrals was transmission of the disease.

Hanging leg syndrome sciatic & femoral nn

Scherer et al. Hanging leg syndrome: COmbined bilateral femoral and sciatic neuropathies. Neurology 2006; 66:1124-1125.

A 43 year old man fell asleep after etoh intoxication with both legs hanging over the end of the bed. He awoke 12 hours later unable to feel or move his legs. Bowel, bladder and sexual function were normal.

Two months later with persisting paraparesis he was evaluated. He had an impression at the gluteal fold. He had paralysis of bilateral knee extensors, foot dorsiflexors, and plantar flexors with a flicker of contraction at the knee flexors. Hip flexion, abduction and adduction were normal bilaterally. He had absent DTR's in the patellae and Achilles reflexes and toes were mute.

NCS showed absent bilateral peroneal motor and sural and superfical peroneal sensory responses. and right femoral motor responses. Peroneal response recording from the tibialis anterior was absent. Needle EMG showed fibrillation potentials and positive sharp waves in bilateral vastus lateralis, anterior tibialis, medial gastrocnemius, and short and long head of the biceps femori. Lumbar paraspinal muscles showed rare denervation at one or two levels.

The mechanism suspected for femoral injuries are traction and compression of the inguinal nerve as it passes over the fulcrum of the superior pubic ramus. Compressive sciatic neuropathies occur from sitting on toilet seats or prolonged sitting in the lotus position.

Superfical siderosis

Neurology 2006 66:1144-1152 Superficial siderosis by Kumar N et al.

I love when Neurology returns to its roots and has a first class descriptive article of a clinical entity. Superficial siderosis is something that I don't think of first, but should in patients with hearing loss and long tract signs, including gait ataxia. A history of SAH, trauma or prior neurosurgical procedure was fairly rare. CSH may show xanthochromia or RBC's ( I remember as an intern at Iowa when we centrifuged the fresh CSF on the unit to differentiate a traumatic tap from xanthochromia. I wonder-- do they still do that?).). Dynamic CT myelo is suggested to localize a sac (14 of 24 cases) and direct therapeutic laminectomy Diagnosis is by MRI which shows siderosis is Sylvian fissures, cerebral convexities and interhemispheric fissure. Cerebellar atrophy and siderosis of pial surface of the spinal cord in almost all cases. Also, is seen in the roots of the cauda equina. Dural leak is also seen. Only one spinal AV fistula was seen.

Criccuolo C. et al. Ataxia with oculomotor apraxia type 2: A clinical, pathologic and genetic study. Neurology 2006; 66: 1207-1210

Criccuolo C. et al. Ataxia with oculomotor apraxia type 2: A clinical, pathologic and genetic study. Neurology 2006; 66: 1207-1210

AOA2 as it is known in short was described in Japanese and Pakistani patients aged 10-22 with elevated alphafetoprotein (AFP), peripheral neuropathy and cerebellar atrophy on MRI. Subtle cognitive changes (not MR) and EPS may be noted. Chromosomal changes are found in SETX (recessive genes) in chromosome 9q34. The same gene, when dominant mutations occur, causes a form of juvenile ALS (ALS4). SETX encodes senataxin.

This study of four families from Italy has patients screened with symptoms, but defined based on genetic screening. Age at onset was 20.3 +/- 8 years, with gait ataxia the presenting symptom in all cases. Time to wheelchair was 15 +/- 7 years with all patients nonambulatory eventually. Cerebellar features, nystagmus, eye-head dissociation, vibratory sense examination, position sense abnormality, were common. EPS gradually disappeared. Raised AFP, sensory/motor axonal neuropathy, and cerebellar atrophy were characteristic. Sural nerve biopsies showed loss of large myelinated and small fibers both. Autopsy showed general brain and cerebellar atrophy. Atheromatous disease of large cerebral vessels, loss of cerebellar Purkinje cells, demyelination of gracilis and cuneatus funiculi, and degeneration of Clarke's columns with gliosis were seen in the spinal cord.

The discussion reviews the division of the OMA's based on DNA repair defects, They are divided into single and double stranded disorders.

Saturday, July 08, 2006

status epilepticus

Status epilepticus
Daniel H. Jacobs MD
August 5, 2006


I. Definition
II Types
III Differential Diagnosis and Diagnosis
IV Treatment
V Pitfalls and Prognosis

Definition-- SE Status epilepticus (America's Working Group on Status Epilepticus) --" more than thirty minutes of continuous seizures or two or more consecutive seizures without full recovery of consciousness in between"

Generalized Status epilepticus
Absence Status epilepticus
Complex Partial Status Epilepticus
Partial status epilepticus continua
Myoclonic status epilepticus

Depends on the type of SE, age of the patient, duration of the SE, and etiology, iatrogenic complications and previous health of the patient. Mortality ranges from 3-52 % mortality reflecting that very different conditions are represented under the rubric SE. Some authors believe the true rate is 20-30 percent.

Greater Richmond Metropolitan Status Epilepticus Project analyzed 1000 cases of SE lasting median 92 minutes. There was a bimodal onset with children and the elderly overrepresented.

Children less than 16 (including infants) have a mortality of only three percent. The mortality related to febrile seizures is nearly zero, that related to other causes has only a slightly higher mortality, and that mortality that exists is related to horrible underlying diagnoses, not to SE itself. The rate of cognitive abnormalities after SE is 15-20 percent, some of which is related to the underlying diagnosis rather than the seizures. Children did have a higher rate than adults of recurrent SE.

Older people have a higher mortality who are ill, and this cohort undoubtedly includes many patients who have agonal SE after cardiac arrest and before death. Patients more than 65 having SE due to anoxia have a 92 % mortality, with similar patients of all ages having a 71 % mortality. In older adults, SE can precipitate myocardial infarction (MI), elevated cardiac enzymes and/or EKG changes in up to ten percent of patients, at any age.

Relatively high survival is associated with SE in patients with known epilepsy who experience SE due to subtherapeutic levels of antiepileptic drugs (AED's).

Duration of SE is the primary modifiable determinant of outcome. Prognosis worsens exponentially as SE lengthens to three hours, after which only small increments in mortality are seen. Earlier presentation, diagnosis and appropriate treatment can shorten duration and improve mortality.

Nonconvulsive or "subtle" SE has several types (see below) including complex partial SE, absence SE, or patients demonstrating periodic epileptiform discharges (PED's) on their EEG's. Nonconvulsive SE has a mortality of 64 % which is higher than convulsive SE, with certain subtypes representing favorable exceptions. Some epileptologists favor treating every discharge on the EEG after generalized SE, requiring obtaining EEG monitoring, in order to reduce mortality.

Unfavorable symptoms include autonomic incompetence, such as failure to achieve tachycardia and hypertension after SE, which worsens prognosis. Cardiac arrythmias may be latent and underlying, due to cocaine or other drugs, of to sympathetic discharge ("voodoo death") associated pathologically with myofibrillar necrosis rather than CAD. The choice of drug used is not related to mortality, although some drugs can produce respiratory depressions (barbiturates and benzodiazepines).

Death in epilepsy may be related to factors other than SE. Depression and suicide may be increased ninefold or more in epileptics. Sudden unexplained death with epilepsy (SUDEP) may occur at any age and has a frequency as high as 1:250, with SUDEP 18 fold higher among men and higher among patients with early (adolescent) onset of epilepsy. Low AED levels are associated with SUDEP. Autopsies may be negative. The etiology may be related to sympathetic catecholamine discharges.
Status epilepticus is a neurologic emergency. The first item is medical stablization airway-breathing-circulation. Confused patients should be given thiamine, then glucose (50 grams_, thiamine (100 mg i-v), Narcan (0.4-2.0 mg i-v), and flumazenil (if indicated) 0.2 mg i-v. Labs should be sent, including electrolytes, CBC, diff, Ca, Mg, PO4, extra red top, AED levels, tox screen/ ETOH level.
Several drugs may be used for the acute treatment of SE, but the key is knowing in detail the pharmacokinetic proporties of the chosen drugs. Lorazepam is often given first line, and is considered the most rapidly effective. The dose is 0.5-1.0 mg/kg, Unlike diazepam, is not metabolized by the liver and has a longer half life. Typically, if lorazepam is used a longer acting drug needs to be added immediately. Cerebyx can be given i-v. Unlike i-v Dilantin, Cerebyx can be given rapidly, without cardiac monitoring, can be given i-m if no i-v access is obtained, and does not cause purple hand syndrome (safer and more effective), Dosing is identical to Dilantin. IT IS NOT ONE GRAM. The dosing is 20 mg/kg, about 1500 grams in an average sized patient, and underdosing can cause recurrent seizures. In patients with verified diagnosis of overt GCSE, response rates were as follows: lorazepam, 64.9%; phenobarbital, 58.2%; diazepam and phenytoin, 55.8%; and phenytoin alone, 43.6%. In statistical comparison of the pairs, only the difference between lorazepam and phenytoin alone was significant.
If the patient has a single seizure and is able to swallow pills, they may be orally loaded with Dilantin Kapseals, 100 mg tablets in the 20 mg/kg dosing schedule. Typically for a 80 kg man, 400 mg po q 3 hours times four doses is reasonable. A Dilantin level should be checked the following morning and a daily dose ordered. LIQUID DILANTIN GIVEN THROUGH DOBHOFFS NEVER ACHIEVES THERAPEUTIC LEVELS! (Give Kapseals or i-v Cerebyx).
Alternatives: Depacon (= i-v Depakote) 20 mg/kg i-v over five minutes, phenobarbital 10-20 mg/kg i-v with monitoring over an hour. In refractory SE (ie, that which does not respond to either regimen above), a commonly used protocol is intravenous pentobarbital. A loading dose of 5 mg/kg is followed by 0.5-3 mg/kg/h titrated to cessation of seizures or a burst-suppression pattern on EEG. In a recent study of patients with refractory SE, Krishnamurthy and Drislane concluded that the survival rate was better in patients whose EEG was more suppressed. Hypotension is a risk of pentobarbital infusion. In patients who cannot tolerate pentobarbital, alternatives include continuous infusion of benzodiazepines (eg, midazolam or propofol).
1. Failure to perform EEG-- may miss nonconvulsive SE and the chance to treat. May miss pseudoseizures and overtreat patient.
2. Failure to perform lumbar puncture-- may miss meningitis
3. Failure to consider a diagnosis of herpes encephalitis-- must be treated early
4. Using above medications incorrectly
5. Failure to order EEG monitoring on admission if patient is not back to normal-- similar to 1-- may miss ongoing SE
6. Discharge from ER prior to patient returning to baseline cognitively-- may miss HSVE
7. Failure to consider differential diagnosis-- intoxication, locked in syndrome, psychogenic SE etc.
Complex partial status epilepticus
Favorable neurologic outcomes of CPSE have been reported regardless of whether medical treatment was successful. Few reports indicate serious sequelae complicating CPSE. Thus, the question of how aggressively to treat CPSE remains controversial. In general, pending a good, randomized trial, CPSE should be treated similarly to GCSE, except that treatment should stop before the use of general anesthesia (eg, pentobarbital coma).
In acute stages and for diagnosis, treatment with an intravenous benzodiazepine may be helpful. Often, out-of-hospital treatment with rectal or oral benzodiazepines aborts an episode. Williamson believes that, since most patients with CPSE have a history of epilepsy, concomitant AED therapy should be optimized.
Walker and Shorvon reported that, although most episodes of CPSE are self-terminating, recurrent episodes are encountered, and medical treatment is often disappointing. Patients who have medically refractory localization-related epilepsy should be evaluated for surgical therapy.
Absence status epilepticus
Walker and Shorvon reported that ASE responds rapidly to intravenous benzodiazepines. D'Agostino and coworkers believe that valproate is the medication of choice for ASE. Although effective, this treatment may result in complications such as sedation and respiratory depression. Kaplan summarized a case of a female with known absence epilepsy in which hospitalization was avoided by treating ASE with intravenous valproate. Snead et al stated that the more atypical the SE, the more difficult it is to control with benzodiazepines and other forms of therapy. Patients with primary generalized epilepsy should have optimized valproate or ethosuximide therapy to prevent recurrent episodes of ASE. Thomas et al reported that long-term anticonvulsant therapy might not be necessary in adults who are middle-aged or older at the onset of de novo ASE.

Boggs JG, Towne AR, DeLorenzo RJ, Pellock JM. Status Epilepticus. In Gilchrist, James. Prognosis in Neurology, Butterworth-Heinemann, 1998.

Shinnar S, Pellock JM, Berg AT. An inception cohort of children with febrile status epilepticus: cohort characteristics and early outcome. Epilepsia 1995;36 (suppl 4):31.