Faculty Bibliography

Anticholinesterase (AChE) drugs are being prescribed off label for nonmotor symptoms in Parkinson's disease (PD). Theoretically, these drugs can impair motor function. A small literature suggests AChE therapy has little effect on clinical motor evaluation; however, no study has made objective motor kinematic measures or evaluated brain function. We hypothesized that even if clinical examination was normal in PD patients on dopamine therapy, (1) sensitive kinematic measures would be abnormal during AChE therapy or (2) normal kinematic measures would be maintained by compensatory brain activation. We carried out a randomized, double-blind, placebo-controlled trial of 8 weeks donepezil (10 mg/day) in 17 PD subjects. Subjects carried out a computerized motor task during a positron emission tomography (PET) scan before starting the drug and again after 8 weeks of donepezil or placebo. Kinematic measures of motor function and PET scans were analyzed to compare the effects of donepezil and placebo. Neither placebo nor donepezil altered motor kinematic measures. Furthermore, movement integrity while on donepezil was maintained without compensatory brain activity. Donepezil 10 mg/day can be given for nonmotor symptoms in PD without adverse motor effects or compensatory brain activity

The authors demonstrate that high-frequency electrical stimulation dorsal to the subthalamic nucleus (STN) can directly suppress levodopa-induced dyskinesias. This 63-year-old woman with idiopathic Parkinson disease underwent surgery for placement of bilateral subthalamic deep brain stimulation (DBS) electrodes to control progressive rigidity, motor fluctuations, and levodopa-induced dyskinesias. The model 3389 DBS leads were implanted with microelectrode guidance. Magnetic resonance imaging confirmed proper placement of the leads. Postoperatively the patient exhibited improvement in all of her parkinsonian symptoms; however, her right leg dyskinesias had not improved. Based on their previous experiences treating levodopa-induced dyskinesias with subthalamic stimulation through the more dorsally located contacts of the model 3387 lead, the authors withdrew the implanted 3389 lead 3 mm. Following relocation of the lead they were able to suppress the right leg dyskinesias by using the most dorsal contacts. The patient's dopaminergic medication intake increased slightly. These findings indicate that electrical stimulation dorsal to the STN can directly suppress levodopa-induced dyskinesias independent of dopaminergic medication changes. The 3389 lead may provide inadequate coverage of the subthalamic region for some patients.

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.

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.

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.