Blink rate, a putative noninvasive marker of central dopamine activity, was assessed in medication-free patients with Parkinson's disease, progressive supranuclear palsy, Huntington's disease, and dystonia. The normal control rate of 24 blinks per minute was significantly higher than the rate of 12 and 4 blinks per minute recorded for patients with Parkinson's disease and progressive supranuclear palsy, respectively. The rates for patients with Huntington's disease and dystonia did not differ significantly from those of controls (36 and 26 blinks per minute, respectively).

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Twenty-four parkinsonian patients compared pergolide and bromocriptine therapy in a randomized double-blind, two-period crossover study. Both drugs were adjusted to an optimal balance between benefits and side effects. The mean daily dose and dose range for pergolide and bromocriptine were 3.3 mg (0.7 to 7.2) and 42.7 mg (5.8 to 87.5), respectively. Adjunctive medications, which for most patients included levodopa (plus carbidopa), were not altered during the study. A similar spectrum of clinical effects was found with both drugs and with lisuride, which was used to treat 13 of the patients in a previous study. Despite neurochemical differences in the antiparkinsonian ergots, their clinical utility is quite similar. We draw attention to hepatotoxicity and pleural reactions that may occur rarely with these drugs.

In normal elderly humans there is progressive motor dysfunction and loss of nigrostriatal neurons and brain dopamine similar to, although of a milder degree than, that seen in Parkinson's disease. Ten healthy elderly volunteers were given carbidopa/levodopa or placebo in a double-blind crossover study. We measured movement velocity, reaction time, tremor, visual evoked response (VER), and electroretinography (ERG). Significant changes were seen only in ERG. Motor functions and VER were unchanged. Although there appeared to be pharmacologic activity (ie, changes in ERG), levodopa, in adequate antiparkinson dosage, had no impact on the mild extrapyramidal impairment of normal elderly subjects.

Two patients had palatal myoclonus that disappeared. In one, the palatal myoclonus disappeared completely during all stages of natural sleep only to return again when he awoke, persisting as long as he remained awake. In the other patient, palatal myoclonus was continuous for 2 years, became erratic for 6 months, and then disappeared completely, although she could induce it voluntarily. These cases demonstrate that palatal myoclonus is not always: independent of the sleep-waking cycle, persistent throughout life, and independent of cortical control.