Friday, October 31, 2008

More pearls of fundoscopic exam temporal pallor and atrophy

Pallor is noted in any process affecting maculopapillary bundle.  The disk is alabaster white and bound by a gray white cup.  Green light of the opthalmoscope shows the fibers as they enter the disk. 
Optic atrophy has seven major features:   1) pale aspirin-white disc.  2)  sharp margins  3) loss of lamina cribosa  4)  increased cup to disc ratio  5) decreased arterioles off disc (less than 14)  6)  small arteries and 7) gray pale retina. 
Swelling has seven features  1) Loss of disk margin, superior then inferior then temporal  Always blurred nasal margins  2)  Fat veins without pulsations   3)  Erythema off the disk  4)  loss of lamina cribosa, whole disc pushed forward  5)  Slit hemorrhages off disc margin  6)  engorged veins appear and disappear near macula   7)  Folds in retina spread towards the macula.  Last normal acuity.

Neuroopthalmology testing-- bedside pearls

Riddoch's phenomenon-- patient won't see an object in a damaged field unless it is moved.

shading of a visual field-- if larger objects are seen in a damaged field where smaller objects are missed, , suggests defect is partly caused by edema or pressure phenomenon.

Bjerrum screen (tangent screen) enlarges central meridian to 30 degrees and is most helpful for measuring central scotomata and the blind spot.

Graying of vision (finger does not appear flesh colored) or red desaturation (eg. red pin ) is appreciated before a quantifiable field defect.

Notes bitemporal upper quadrantic defect suggests chiasmal compression from above, but bitemporal lower field defect suggests compression from below.

Arcuate defect- optic nerve lesion prechiasmatic.

Bitemporal scotomata-- early bitemporal field defect or consider bilateral optic nerve lesions eg in kids.

Fundoscopic exam
Venous pulsations are seen only in the middle and not the margins of the disk unless there is a large pulse pressure such as in aortic insufficiency. severe hyperthyroidism or arteriovenous fistula.

Miscellaneous findings include commotio retina, an intense light streak seen with acute head injury of Kohlmeyer-Degos disease (arteritis with atrophic skin lesions).

Hemorrhages from papilledema occur off the disk margin (slit hemorrhages) whereas those from venous occlusion occur in the central retina and macula.

Torsten's syndrome is a hemorrhage that moves with head position following a burst aneurysm, also called preretinal or subhyaloid hemorrhage. Often can identify side of hemorrhage based on.

Lupus patients may have "grains of rice" or cytoid bodies in peripheral retina.

Renal patients may have a macular star (edema outlining the nerve sheath layer).

Hollenhorst plaque or branch point occlusion of cholesterol emboli are larger than occluded vessel birefringent and yellow.

Platelet fibrin emboli from HIT are white and multiple.

Schwartzmann 2 second mental status exam

The tests below are not thorough or well vetted, but they can be done easily at grand rounds, appear novel to the students, and are explained in Robert Schwartzman's book on the neurological examination.
He tests judgment ("What would you do if you found a letter addressed to someone else?); visual praxis (copy a hand posture after seeing it for two seconds); language/memory/frontal four part oral command, and frontal face hand test (touches patient's hand and own face and asks where am I touching you).

Monday, October 27, 2008

Transient visual loss

see also the following behavioral neurology post

Consider: noninschemic
1. opthalmic surface disorders

a. tear film abnormalities-- visual blurring occurs many times a week often at the end of the day and under one environmental circumstance. Blinking and lubricating eye helps. Patients with blepharitis may be worse in the morning due to accumulated meibomian gland secretion overnight. With dry eyes causing epithelial breakdown, there may be foreign body sensation, pain or redness with a positive Schirmer's test. Patients with rosacea frequently have opthalmic involvement. Also PD.

2. Other ocular causes-- narrow angle glaucoma causes transient blurring with halos. Recurrent spontaneous anterior chamber hemorrhages is such patients needs to be differentiated from those occurring in juvenile xanthogranuloma, malpositioned lens with iris contact, and iris neovascularization.

Patients with corneal dysfunction have episodes of blurred vision that last for hours especially in the mornings, must examine during an episode. Episodes in patients with diabetes due to hyper or hypoglycemia occur.

Ischemic Causes
Causes-- 60 % are due to carotid stenosis/occlusion. Also called TMB, amaurosis fugax, or retinal tia. In usual cases , emboli from carotid are common but low flow also occurs when collaterals from the Circle of Willis and eca are compromised. In these cases symptoms may be inducible by change in position or eating, or when distal flow is inadequate such as chronic ocular ischemia or bright light amaurosis. The latter occurs with TMB after sunlight or looking at a white wall, in the setting of carotid occlusion and is a well known phenomenon.
Risk of stroke per annum is 2 % with 1 % risk of permanent visual loss, v. 5-8 % risk of stroke with hemispheric tia's.

Symptoms are abrupt onset, painless, lasts 1-5 minutes, darkening or fogging (not blurring) of visual field, altitudinal pattern (shade closing) of vision loss, and return of vision over minutes.

Vision loss may be altitudinal, peripheral, central or even vertical. A nasal field defect may suggest emboli due to lodging in temporal retinal circulation. Rarely, scintillating scotomas occur. Pain which is rare may suggest temporal arteritis.

Neuroopthalmic signs-- the most common are retinal emboli, including cholesterol (Hollenhorst) plaques which are refractile, metallic gold appearance and indicate carotid disease and platelet fibrin emboli which are creamy white grey longitudinal intravascular opacifications that fill the lumen, and indicate either carotid thrombosis or thrombosis with recent MI. Chronic severe carotid disease leads to chronic ocular ischemia including episcleral and conjunctival injection, corneal edema, and neovascular glaucoma. Venous stasis causes microaneurysms and blot hemorrhages. Unlike diabetes they are unilateral (ipsilateral to stenosis) and mid periphery instead of posterior pole. Rarely retinal calcific emboli occur in patients with cardiac valvular disease. They are grey white and ovoid and infarct the retina.

In papilledema, episodes of grey black and white vision lasting seconds may occur. Its fleeting and associated with changes in position. This also occurs in pseudopappilledema drusen or colobomas. Gaze evoked amaurosis suggests intraorbital lesion such as glioma, nerve sheath meningioma, or intraconal mass such as cavernous hemangioma. Vision deteriorates seconds after eccentric gaze and returns to normal with straight ahead gaze.

Vision loss lasting seconds
papilledema, IIH, optic disc drusen, optic nerve sheath meningioma (need MRI with contrast),
gaze evoked (orbital tumor suspect). Get T1 image in 3 planes to differentiate MRV clot from physiologic narrowing of vessel

Vision loss can occur due to ACA aneurysm due to leakage of blood into opthalmic sheath

Sunday, October 26, 2008

Patterns of functional visual loss

taken from Liu Volpe and Galetta text p. 388
1. General observation of functionally blind-- may move into and bump objects without falling and hurting themselves; may not look at examiner speaking to them as a truly blind person might do; may wear sunglasses or mimic Stevie Wonder or other famously blind people.

2. Pupils-- should be abnormal except in cortically blind. A patient with total blindness and intact pupillary reflexes is likely to be functional. A complaint of photophobia with orbicularis oculi contraction to bright light is incompatible with an ocular cause of blindness.

3. OKN's- response is involuntary, but can be blocked by looking away from or beyond stimulus, or by excessive convergence.

4. Proprioceptive tests are performed by truly blind but not by functional. For example, looking at one's hand, bringing the tips of the fingers together from a distance, or signing one's name are better done by truly blind.

5. Mirror test-- a large mirror in front of a blind person, rocked, will produce an involuntary response if the patient is sighted and has better than hand motion vision..

6. Surprise-- atypical behaviors such as making faces, writing shocking words.

7. Evoked potentials-- a normal test can help, but an abnormal test can be ambiguous. My have in evoked fields, have characteristic hemifield loss from patient looking down.

2. Stereopsis-- requires binocular vision-- Titmus test
3. Placement of green lens should prevent visualization of Ishihara color plates


Monday, October 13, 2008

IRIS Immune reconstitution syndrome in HIV

NEUROLOGY 2009;72:835-841

Patients with low CD4 counts initiating cART therapy who then bump their CD4 counts and lower viral counts are at risk. Patients may or may not have concurrent infection. Authors describe 7 patients, with Neuro IRIS.

Presentations include trouble walking, seizure, encephalopathy, and occurred in early phase-- first 2-3 weeks after initiation of therapy (early, due to memory cells) or delayed, after 4-6 weeks phase (due to proliferation of new T lymphocytes)/ Latter tended to be a more prolonged course. Biopsy of one patient showed lots of CD8 and CD40 cells stained positive. CSF showed pleocytosis, and MRI showed diffuse white matter changes with enhancement. Lamivudine was in all cases one of the therapies used. The overall risk was 0.9 % among patients starting cART, but 1.5% when stratified with those having low CD4 count to start (<200). This is much lower than the number of non neuro IRIS cases that have been considered to be as high as 15 % although these numbers may be high.

Pearls for Multiple System Atrophy

Neurologist July 2008 14L224-237 authors Bhidayasiri R, Ling H.

MSA encompasses sporadic OPCA (MSA-C) and SND (OPC-P) with predominant Parkinsonism and both types including dysautonomia. Tremor is common but not classic pill rolling tremor. Impotence in men and urge incontinence in women are nearly universal, postural hypotension occurs in 2/3 and syncopal episodes in 15 %. Stridor and respiratory insufficiency may be presenting signs. 29 % respond to levodopa AT SOME POINT.

Red flags suggestive of MSA include early severe autonomic dysfunction, spontaneous or L dopa induced orofacial dyskinesias, which may even resemble risus sardonica in tetanus. Pisa syndrome is a form of axial dystonia, and camptocormia is forward flexion of the trunk. These are not specific and may be seen in PD. Disproportionate anterocollis may occur at any point of the disease, although rare, and botox for this can worsen dysphagia; this is a red flag. So is minipolymyoclonus, which is postural or stimulus sensitive small amplitude nonrhythmic movements of a few fingers or the whole hand. Dysarthria may be diagnostic, with a quivering, croaky strained element "reminiscent of myoclonic speech." (cit Arch Neurol 1996 53:545-548). Nighttime stridor is helpful diagnostically but poor prognostically and may present as laryngeal paresis. Sleep apnea, the "cold hand sign" and emotional incontinence comprise the other red flags.

groupings of "red flags: show six categories  early instability, rapid progression, abnormal postures, bulbar dysfunction, respiratory dysfunction, emotional incontinence.  Presence of two or more categories had high sensitivity (84 % ) and specificity (98%). see Hughes et al.  JNNP 1992; 55:181-184.

Exclusion criteria also are important, including age under 30, positive family history of MSA (PD is "OK"), frank dementia at onset, and eye movement abnormalities suggestive of PSP or CBGD.

The Quinn criteria for possible, probable and definite MSA are reviewed. International Consensus Conference Criteria of the AAN are considered better. See NEJM 2004; 351:912-924 (Case Records of the MGH).

MRI signs include atrophy of the cerebellar vermis, ponsmiddle cerebellar peduncles and lower brainstem. Signal change in the pons may resemble a "hot cross bun" (Catholics may understand this). In MSA-P, patients may have putamenal atrophy, with slit like void signal (black reflecting gliosis) which is sensitive but not specific, but is sensitive and specific if coupled with hyperintense T2 signal in the putamen. For a PD/MSA algorithm, see Arch Neurol 2002; 59:835-842). Onuf's nucleus degenerates which accounts for bladder problems. Pathologic confirmation is made by finding of alpah synuclein positive GCI's composed of misfolded alpah synuclein.

Pearls for treatment include, use of levodopa in many, the benefits of paxil 90 in one trial for motor function, botox of submandibular glands for drooling, and into adductor muscles for stridor, with concerns as above for other uses of botox. PT/OT/ST/ gait training and assistive devices are useful. Treatment of dysautonomic can include, if needed, avoiding large meal, alcohol, straining, certain meds; elastic stockings, bed tilt up at night. Drugs used for orthostasis include florinef, midodrine, desmopressin, octeotride, and eryuthorpoeitin. NGB can be treated with intermittent catheterisation, anticholinergics if detrusor hyperreflexia exists, suprapubic vibration devices, alpha adrenergic receptor antagonists, but NOT surgery. Beware of sildafenil for impotence due to hypotension. Macrogol 3350 for chronic constipation is safe and effective, increasing water content of stools. CPAP, may be needed, tracheostomy may be needed but also may be fatal due to hypercapnia. CPAP mat be contra-indicated if the epiglottis is floppy (Neurology 2011; 76:1841)

Thursday, October 09, 2008

periictal water drinking localizes as does kissing epilepsy

Peri-ictal water drinking lateralizes seizure onset to the nondominant temporal lobe

E. Trinka, MD, G. Walser, MD, I. Unterberger, MD, G. Luef, MD, T. Benke, MD, L. Bartha, PhD, M. Ortler, MD and G. Bauer, MD
From the Universitätskliniken für Neurologie, Innsbruck (Drs. Trinka, Walser, Unterberger, Luef, Benke, Bartha, and Bauer), and Universitätsklinik für Neurochirurgie (Dr. Ortler), Innsbruck, Austria.
Address correspondence and reprint requests to Eugen Trinka, MD, Universitätsklinik für Neurologie, Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria; e-mail:
The authors describe seven patients with medically refractory temporal lobe epilepsy whose seizures were associated with peri-ictal water drinking behavior. Presurgical evaluation, including video-EEG monitoring, MRI, SPECT, and neuropsychological testing, revealed a seizure onset in the nondominant temporal lobe. All patients had an excellent outcome after epilepsy surgery. Peri-ictal water  drinking may represent a lateralizing sign indicating seizure onset in the nondominant temporal lobe.

AAN 2010 PO5:210
Ictal kissing is a release phenomenon in nondominant temporal lobe epilepsy. 3 patients with ictal kissing were all righthanded women with longstanding right TLE.  Its occurrence to environmental cues suggests its a release phenomenon rather than an ictal event

ictal eye closure = pseudoseizures

Ictal eye closure is a reliable indicator for psychogenic nonepileptic seizures

Steve S. Chung, MD, Paula Gerber, MD and Kristin A. Kirlin, PhD
From the Departments of Neurology (S.S.C., P.G.) and Clinical Neuropsychology (K.A.K.), Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ.
Address correspondence and reprint requests to Dr. Steve S. Chung, Department of Neurology, 500 West Thomas Road, Suite 300, Phoenix, AZ 85013; e-mail:
Using data from video-EEG monitoring, the authors studied whether ictal eye closure was a reliable indicator of psychogenic nonepileptic seizures (PNES). Among the 52 patients with PNES, 50 consistently closed their eyes, while 152 of the 156 patients with epileptic seizures (ES) opened their eyes during seizures. These findings suggest that ictal eye closure is a highly reliable indicator for PNES, while ictal eye opening is an indicator of ES.

Monday, October 06, 2008

Photic seizures

"Pokemon incident" showed alternating red and blue light each for 12 hz caused seizures in japanese kids. 1 seizure per 10000 kids watching (as opposed to 1-3 % photosensitive) but more have sensitivity to other stimuli. Most such kids had no knowledge they had prior seizures. More females by percentage but more males by number, more young, usually generalized but sometimes focal. Brightness, esp over 100 lux; flash rate over 5-30, must go on for more than a half second and fill at least half the field, colors red flashing are the worst (advise blue sunglasses); especially moving vertical bars (stripes), and viewer factors such as covering an eye, tired, meds, exposure time. More TV seizures in Europe because there is higher flicker rate in Europe.

Posterior reversible leukoencephalopathy s (PRES) PEARLS

First described at Tufts University Department of Neurology, 1996, by Judy Hinchey, Claudia Chaves et al.

1. Associations:
cytotoxic drugs (steroids, mtx, tacrolimus, cyclosporine, imuran)
malignant hypertension
NMO (neuromyelitis optica or NMO spectrum disorder)
autoimmune disease
multiple organ dysfunction especially renal
2.  MRI pearls
--spares the calcarine cortex whereas stroke affects midline calcarine cortex
--may also affect frontal lobes, basal ganglia, brainstem, cerebellum
--no relationship between clinical severity, association, and location of lesions

3. treatment
remove drug
mag sulfate
control blood pressure

4 Review article Mayo Clin Proceedings May 2010 85:5: 427-432
120 cases in 113 patients over several years
-- may self resolve, but substantial Mortality and morbidity due to potential complications including massive infarction, hemorrhage, status epilepticus.
--hypertension present in 74 percent, but only 46 % of those had a history of chronic hypertension
--renal failure present in 57 %, but only half of those had chronic renal insufficiency
--clinical presentations included seizures in 74 % (partial or generalized, only rarely with history of seizures), 18 % with status epilepticus, 28 % with encephalopathy, 26 % with headaches, and 20 % with visual disturbances
-- Autoimmune disease was present in 45 %, of whom three fourths were women.These included TTP (27 %), SLE (18 %), hypothyroid (10 %), scleroderma (6%), Crohn's disease (6 %), ulcerative colitis or sclerosing cholangitis (4 %), RA (4%), DM ( 4%), and 1 patient each or 2 % for Graves' disease,  Hashimoto's thyroiditis, APL syndrome, anti glomerular basement disease, autoimmune hepatitis, polyarteritis nodosa, thromboangitis obliterans, polyglandular autoimmune syndrome, Sjogren's, gfrnulomatous interstitial nephritis, NMO
-- Of patients with autoimmune disease, 65 % had cerebellar involvement, and majority of septic patients had involvement of the cerebrum.
-- transplant and chemo and pediatric populations not represented in above article