Thursday, December 24, 2009

Morvan syndrome aka "Choree Fibrillaire"

Four cardinal features of Morvan syndrome are

1. Neuromyotonia or myokymia

2. Dysautonomia (esp hyperhidrosis, hypersalivation, labile hypertension). Weight loss is common.

3. Severe insomnia

4. Fluctuating encephalopathy with vivid hallucinations

Other notes-- MRI and random eeg is often normal. Patients are usually young males, EMG and PSG are not normal, and VGKC's are often present. Differential includes FFI, CJD, rabies virus, and Lewy body disease. The key clinical finding that differentiates is the dysautonomia and neuromyotonia. Often is fatal, but Ligouri et al. reversed one case with plasma exchange.

Ligouri R, Vincent A, Clover L, et al. Morvan's syndrome. Peripheral and central nervous system and cardiac involvement with antibodies to voltage gated potassium channels. Brain 124: 2417, 2001.

Note-- there is a second "Morvan's disease" that refers to atrophic changes in bone, skin, muscles of hand in syringomyelia.

Clinical spectrum of disease of VGKC

Voltage gated calcium channels are seen in a variety of neurologic diseases. They include

1. Autoimmune neuromyotonia (formerly Isaac's syndrome)
2. Morvan's syndrome (encephalopathy and myotonia). Augustus Morvan (1870) "la choree fibrillaire." see separate post on Morvan's in this blog
3. Encephalopathy without neuromuscular excitability--clinical syndrome consists of a) clinically indistinguishable from paraneoplastic limbic encephalitis (PLE) b) subacute cognitive impairment with behavioral changes and temporal lobe seizures c) FLAIR and T2 changes in mesial temporal lobes on MRI d) temporal lobe eeg abnormalities e) association with hyponatremia f) male predominance g) dramatic response to IVIG or steroids
4. Are occassional cases with associated cancer, especially lung and thymus carcinoma, but these are typically associated with "other" paraneoplastic markers and symptoms and are minority
5. A similar presentation and responsiveness to treatment occurs in VGKC negative patients who have anti hippocampal neuropil antibodies.

Monday, December 07, 2009

Coccidiodal meningitis and brain abscesses: analysis of 71 cases at a referral

Drake KW, Adam RD.  Neurology 2009; 73:1780-1786
Most patients present with headache only (77%) while 23 % had nuchal rigidity, 39 % had mental status changes,  and one third focal signs especially gait disturbance or ataxia, may be due to hydrocephalus.   Risk factors are HIV/chronic steroids but not diabetes.  Also, liver failure, hem/lymph malignancies, and ESRD.  Increased risk for males (2:1), Hispanic, black and Asian patients in endemic areas (black patients have 6:1 risk).  CSF had mononuclear pleocytosis, 69 % had abnormally low glucose, occasionally high protein or eosinophils.  CSF antibody/culture often negative on presentation (50 %), but in those patients, serum antibody test is usually positive. Also CSF cultures or brain biopsy occasionally used for diagnosis.   Imaging may show basilar meningitis or hydrocephalus and vasculitic infarcts.  Many patients had antecedent illnesses, including respiratory, that may or may not have been diagnosed as coccidio  or occasionally  osteomyelitis, lymphadenitis, skin lesions, and soft tissue masses.  Treatment is with azoles, esp. fluconazole which has supplanted amphotericin and others.  Relapse can occur years or even decades later if azole therapy is stopped.  Shunts are frequently needed for treatment of hydrocephalus.  Prognosis is now good for those compliant with therapy.