Faculty Bibliography

Abnormalities of GM2 ganglioside metabolism owing to hexosaminidase A (Hex A) deficiency have been associated with ALS phenotypes. The clinical features described in these ALS patients with Hex A deficiency include early onset, positive family history, and/or long disease duration. In an attempt to determine prospectively the incidence of Hex A deficiency within an ALS population, the records of The Mount Sinai Medical Center ALS Clinic were reviewed to select those patients with "atypical" ALS (total N = 52), i.e. onset before age 35, positive family history, and/or disease duration greater than 90 months. The control group (total N = 50), "typical" ALS patients, did not fulfill any of these historical criteria. Hex A activity determined in isolated peripheral blood leukocytes was normal in all typical ALS patients (mean 67.3%). Hex A deficiency was not found in any atypical ALS patients. Thus, Hex A deficiency apparently is an unusual etiology of typical or atypical ALS but is of medical and genetic importance in individual families.

We report eight patients with cryptococcal meningitis and a cerebrospinal fluid characterized by few or no white blood cells and chemistries that may be near normal. In four of these patients, only testing for cryptococcal antigen allowed the initial diagnosis. Seven of the patients had a certain diagnosis of AIDS. Six have died. Autopsies performed in two cases indicated a poor meningeal inflammatory response. Contrary to the findings in most immunodeficient patients, in AIDS cryptococcal meningitis may present with few cellular or biochemical abnormalities in the cerebrospinal fluid. In AIDS patients presenting with headache and fever or change in mental status, examination of the cerebrospinal fluid should not be limited to routine studies.

We describe eight patients with bilateral paramedian thalamic infarction on CT scanning. Clinically, these patients had infarctions of either the paramedian thalamus alone or the paramedian thalamus with a variable extension to contiguous structures. A single occlusion may result in bilateral paramedian thalamic lesions because of the common occurrence of a single trunk of origin for the paramedian thalamic arteries.

A double-blind, placebo-controlled trial of single doses of thyrotropin releasing hormone (TRH) was performed on 12 patients with amyotrophic lateral sclerosis. Each patient was given subcutaneous injections of TRH 150 mg or placebo, and IV infusions of TRH 500 mg or placebo at 72- to 96-hour intervals. Eight motor and functional ratings were scored at regular intervals after each injection. Side effects were seen in all patients and were obvious to patients and examiners, making true blinding impossible. Nevertheless, statistically significant improvement was seen only in dynametric strength 1 hour after subcutaneous injection (p less than 0.05). Significant improvement occurred, in one patient only, on subjective speech testing during IV infusion of TRH. In none of six other ratings was there a significant difference between TRH and placebo. Subjective improvement was noted by 11 of 12 patients.

Mononeuropathy multiplex and mixed sensorimotor neuropathy are known complications of systemic vasculitis and related autoimmune disorders. Autonomic dysfunction is not generally considered a neurologic complication of these diseases. We report two patients who came to neurologic attention because of autonomic dysfunction and were then discovered to have autoimmune disease. Autonomic dysfunction may be the presenting sign of autoimmune disorders, which should be considered in the differential diagnosis of acquired autonomic disturbances