Tuesday, December 24, 2013

Statin myopathy pearls

1. Occurs in fifteen percent of those receiving statins

3.  Risk factors for include: 
      higher dose statin
      statin myopathy in a first degree relative
      older age
      small build
      concurrent systemic disease (renal, hepatic, or diabetes)
      multiple medications including fibrates, nitrates and cyt P450 metabolized drugs
genetic polymorphisms may exist

4.  Time course of onset usually one month but may be delayed years

5.  Presentation:  weak, high CK, irritability on EMG

6.  Co Q depletion may play a role, but studies have not shown CoQ is helpful

7.  Immune mediated myopathies can follow withdrawal of statin.

8.  fibrates, nitrates and ezetimibe also can cause myopathy

Head drop in neurologic disease: differential and pearls

Clinical: typically occurs in women over age 65
neck extensor weakness is usually subacute and associated with proximal arm weakness

EMG abnormal (myopathic or denervating) in cervical or thoracic paraspinal muscles but normal in limb muscles

Immunomodulators don't affect prognosis

ALS  (usually not isolated finding)
MG   ( three percent have headdrop as initial presentation)

carnitine deficiency
myotonic dystrophy
congenital myopathy
Parkinson's disease

Briemberg-Use of MRI-- in MG signal from paraspinals is normal, in isolated myopathy of neck muscles there is edema seen.The MG would be seronegative myasthenia gravis.

Tuesday, October 01, 2013

Dx of neurologic emergencies in pregnancy/postpartum

Edlow JA, Caplan LR, Obrien K, Tibbles CD. Diagnosis of acute neurological emergencies in pregnant and post-partum women.  Lancet Neurology 2013; 12: 175-185

This is a review article that is nicely written.  I am blogging some of the minutiae of the article, not necessarily the major points, that might escape otherwise.  Here are a few pearls from the article:

1.  There is 8-39 % overlap between PRES and RCVS of patients with both conditions.

2.  Suspicious for preeclampsia:  bilateral throbbing headaches with blurring and scintillating scotomata. Before ecampsia occurs with seizures, preceding symptoms may include frontal or occipital headache, blurring, photophobia, RUQ or epigastric pain, and altered mental status.  90 % occur at or after 28 weeks, and a third after delivery. 

3.  Differential of thunderclap headaches:  subarachnoid hemorrhage, PRES, RCVS, and extracranial arterial dissections. 

4.  HELLP syndrome stands for hemolysis, elevated liver function tests, low platelets.  However, TTP also can present with low platelets.  TTP is treated with plasma exchange, HELLP with magnesium and delivery of fetus. 

5.  In PRES seizures occur at onset, in CVT they occur somewhat later in course, usually after headache is established.

6.  More than 75 % of CVT cases in this group are postpartun, not during pregnancy.

7.  RCVS is associated also (in addition to postpartum state) with "vasoactive substances" including SSRIs, cocaine, phenylpropanolamine, blood products, catechol secreting tumors, and dissections.  RECURRING DAILY THUNDERCLAP HEADACHES AFTER A SINGLE THUNDERCLAP HEADACHE OVER SEVERAL WEEKS ARE NEARLY PATHOGNOMONIC.  Vomiting, confusion photophobia, and blurring are common.  Seizures almost always follow the headache. 

8.  Rare:  Air embolism: with PFO.  Associated agitation, confusion, seizures and encephalopathy in context of CV or respiratory collapse during or after labor.  Nearly any focal neurologic or generalized neuro symptoms can occur.  Two signs that are pathognomonic include air in retinal veins and mill wheel cardiac murmur. 

9.  Choriocarcinoma metastasizes to the brain in 20 percent of cases. 

10. Wernicke's encephalopathy can complicate hyperemesis gravidarum.  Eye movement problems are almost always present and is frequently a metablolic acidosis.

11.  TTP pentad is:  thrombocytopenia, microangiopathic hemolytic anemia,  fever, neurologic and renal dysfunction. 

12.  There are three differtiable pituitary disorders:  adenoma with apoplexy-- hemorrhage or infarct into the gland (headache, visual loss, opthalmoplegia and decreased consciousness);  Sheehan's syndrome ( hypopituitarism indolently presenting weeks to months after severe postpartum hemorrhage), and lymphocytic hypophysitis (headache and visual symptoms that present acutely). 


Friday, April 12, 2013

Papilledema and obstructive sleep apnea syndrome.



To characterize the pathogenesis and clinical features of optic disc edema associated with obstructive sleep apnea syndrome (SAS).


A series of 4 patients with SAS and papilledema (PE) underwent complete neuro-ophthalmologic evaluation and lumbar puncture. In 1 patient, continuous 24-hour intracranial pressure (ICP) monitoring was also performed.


All 4 patients had bilateral PE that was asymmetric in 2. Three patients had optic nerve dysfunction, asymmetric in 1, unilateral in 2. Daytime cerebrospinal fluid pressure measurements were within normal range. Nocturnal monitoring performed in one patient, however, demonstrated repeated episodes of marked ICP elevation associated with apnea and arterial oxygen desaturation.


We propose that PE in SAS is due to episodic nocturnal hypoxemia and hypercarbia resulting in increased ICP secondary to cerebral vasodilation. In these individuals, intermittent ICP elevation is sufficient to cause persistent disc edema. These patients may be at increased risk for developing visual loss secondary to PE compared with patients with obesity-related pseudotumor cerebri because of associated hypoxemia. The diagnosis of SAS PE may not be appreciated because daytime cerebrospinal fluid pressure measurements are normal and because patients tend to present with visual loss rather than with symptoms of increased ICP.

Monday, April 08, 2013

Common pitfalls in management IIH

Management Errors:
missing venous sinus thrombosis
failure to address other secondary causes (e.g., anemia, hypoxia)
relying on optic disc appearance without monitoring visual fields
being too slow to proceed to surgical intervention

Papilledema pearls

1. Cotton wool spots OFF disk may suggest hypertensive syndrome
2.  Hemorrhages off disc suggest central retinal vein occlusion
3.  New onset pulsatile tinnitus is significant finding indicating need to look for increased ICP, as well as transient obscurations, graying of vision for twenty seconds, with postural change and headache.  Field before acuity is affected, disc edema usually affected.
4.  MRI findings  may include disc enhancement, occassionally, enhanced perioptic space (40 %), flattening of posterior globe (80 %), empty sella  Get MRI/MRV
5.  Check blood pressure
6.  Blood:  CBC, electrolytes for Addison's, Ca for HPT, ANA for lupus that is it..  Lumbar puncture always.
7.  Must check visual fields  since acuity is preserved. That is affected early.
8.  Protect optic nerve function and appearance: the two goals of management of pappilledema, not normal pressure, that is not a goal.
9.  Therapy:  diamox 500 bid to start, add Lasix 40  mg q am with Kcl 20 meq.
10. Fenestration protects eye, but does not lower headache or pressure.  Consider fenestrating patients with progressive visual loss, severe loss early, patients with severe papilledema at risk for hypotension (dialysis) or patients unable to comply with monitoring vision.  Shunt is a better treatment for headache of IIH.
h't Valerie Purvin AAN 2013

Causes of pappilledema (bilateral) with good optic nerve function

increased intracranial pressure
malignant hypertension
toxins (amiodarone,cyclosporine)
sleep apnea syndrome
uveitis, eg. sarcoidosis

Tuesday, March 05, 2013

Fwd: Neurological complications of influenza

Neurological complications of influenza

Tsai JP, Baker AJ.  Neurocritical Care 18:2013; 118-130 (review article)

There are five types of encephalopathy, two benign and three malignant.  Typically they occur a mean of two weeks post influenza, and are not associated with CNS inflammation.  They include:
1)  MERS (mild encephalopathy with reversible splenial lesion)-   influenza symptoms, then prodrome of decreased level of consciousness, seizures, CSF pleocytosis, EEG abnormal, often within 103 days, and total resolution within one month with or without therapy.  Agents include infl A and B, Legionella, Staph and Strep species,  and E Coli.  Splenial lesion is thought to represent intramyelinc edema with fiber separation.
2)  HSES (hemorrhagic shock and encephalopathy syndrome (peds only)) shock, seizures, coma, DIC, diarrhea, drop HB/platelets, elevated LFT's, renal dysfunction, acidoses, negative blood and CSF cultures.  "Definite" all 9 criteria are met, "probably" is 7-8 criteria met.  Originally defined by Levin et al, 1982.  Biphasic course with improvement then deterioration may occur.  Abnormal EEG, diffuse cerebral edema, hemorrhagic necrosis occur.  Morbidity  plusmortality may > 90 percent.
3) ANE-- Acute necrotizing encephalopathy (pediatric and adults)-- most common complication of influenza.  Course is fever, URI prodrome, then rapid and severe decline in consciousness often with seizures at onset and within 1-3 days of onset of systemic symptoms.  CSF shows mild pleocytosis, limited utility.  MRI shows severe symmetric, diffusion restricting lesions in both thalami, rostral midbrain tegmentum, putamena, periventricular white matter and cerebellar hemispheres.  Decreased flow without stenosis or emboli is seen in thalamaperforators, SCA's , and deep internal and great cerebral veins.  Early steroid therapy aids survival among patients without brainstem lesions. 
4)  (AESD) Acute encephalopathy with seizures and late restricted diffusion-- predominantly a pediatric diagnosis with variable features and prognosis and several eponyms

Sunday, February 24, 2013

Pearls on carotid cavernous fistulas

from Wijdicks text on acute neurology

1.  Associations--
      remote trauma
      post transsphenoidal surgery
      post ethmoidal surgery
     post carotid surgery
     Ehlers Danlos syndrome

2.  Visual loss is due to increased intraocular pressure or reverse of flow or thrombus in superior opthalmic vein (SOV).  Balloon or coil occlusion has been reported (sometimes) to reverse blindness

3.  On angiography, immediate opacification of carotid sinus is seen after carotid injection.

4.Clinical findings include III n palsy, lid swelling, tortuous veins, dis edema and visual loss.

tests to consider in patients with encephalitis

serology- HIV, EBV, acute and convalescent phases St Louis encephalitis, eastern equine encephalitis, LaCrosse and West Nile viruses; acute and convalescent phase serum titers of myc. pneum, ricketsii ricketsiae, ehrlichia chaffensis, anaplasma phagocytophilum; rpr and fta;  lyme (ELISA and Western blot), IgG for toxoplasma; serum cryptococcal antigen; complement fixing or immunodiffusion antibodies for coccidio species

blood cultures;

Respiratory secretions pcr for myc. pneum;

CSF cultures;  IgM for St Louis, West Nile and VZV; vdrl and fta, IgG index, lyme (elisa and Western blot), CSF cryptococcal antigen; CSF histoplasma antigen;  complement fixing or immunodiffusion antibodies for coccidio species

CSF pcr's for HSVE I and II, enteroviruses, VZV, EBV, ehrlichia and anaplasma species, myco. pneum.

blood smears for morulae

culture respiratory secretions,nasopharyx, throat and stool

skin culture of rash if present for HSV and VZV

urine -- histoplasma antigen

Signs indicating causes in confused febrile patients

from  Wijdicks, The practice of emergency and critical care neurology.

Rash-- ricketsiae, aspergillus, vasculitis

petechiae-- TTP, meningococcemia, endocarditis, drug eruption, leukemia

splenomegaly-- toxo, TB, sepsis, HIV, lymphoma

pulmonary infiltrates-- legionella, fungi, TB, mycoplasma, pneumonia, tick borne, Q fever

Saturday, February 16, 2013

Meningococcal meningitis and corticosteroids

Brust JCM.  Meningococcal meningitis, dexamethasone and Class III evidence(editorial) Neurology 2012; 79: 1528-9.

The most recent Cochran review shows a benefit of adjunctive dexamthasone to mortality in Streptococcalbut not N meningitidis meningitis with benefits to adults and children in high but not low income countries ( See Brouwer MC et al, 2010).  Significantly, however, dexamethasone does no harm.  Recommendation is .6 mg/kg.day for four days.  It should be given prior to or with the first dose of antibiotic before lysis occurs.  In practice, steroids rarely are stopped when Neiss men is identified as the organism, but that does not harm the patient.