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The risk of melanoma is higher in patients with Parkinson's disease (PD) than in the general population. Whether the association is disease related or treatment related is unclear. The objective of this study was to assess melanoma prevalence in PD patients in Israel using active dermatologic screening. Consecutive patients with idiopathic PD were recruited by 12 Israeli centers. A movement disorder specialist assessed the severity of PD and obtained a medical, neurological, and medication history. Subsequently, a dermatologist assessed melanoma risk factors, recorded a dermatologic history, proactively performed a whole-body skin examination, and biopsied suspicious skin lesions. Of the enrolled patients (n = 1,395, mean age 69.5 ± 10.6 years, mean PD duration 7.3 ± 6.0 years), 95.3% were treated with dopaminergic agents. Biopsies revealed 8 patients with melanoma in situ and 1 with invasive malignant melanoma; 14 patients reported a melanoma prior to enrollment. The observed 5-year limited duration prevalence of melanoma in PD patients was 4.4 times greater (95% CI 2.6-7.6) than expected from melanoma prevalence in an age- and sex-matched cohort from the Israel National Cancer Registry. The increase was accounted for by an elevated prevalence of melanoma in situ [relative risk 12.5 (95% CI 6.7-23.2)]. Occurrence of melanoma did not correlate with levodopa therapy or time of onset of PD. Melanoma prevalence in PD patients was higher than expected in the general Israeli population. This was not related to levodopa treatment. PD patients should be actively screened for melanoma on a routine basis.

Essential tremor (ET) is the most prevalent extrapyramidal disorder, yet its diagnosis is still controversial. This article introduces new findings that pertain to this diagnostic problem. Twenty‐three patients with ET were studied. Patients with parkinsonism, cerebellar signs, severe head injury, or those under neuroleptic medication were excluded. Twenty‐five normal subjects served as control subjects. Visuomotor tests involving tracking and tracing along three different paths with both the right and left hands, were used. Performance was assessed by measuring test duration, directional error, the proportion of the cumulative test time during which directional error exceeded half the maximal possible level (PT50%), the mean distance from the model path, the velocity of the hand movement, and the number of tracking interruptions. In 15 of 23 patients performance was the same as in the control subjects. These patients were defined as having a “simple condition” of ET (ETs). Considerable visuomotor impairment was found in eight patients who were regarded as having a “complex condition” of ET (ETc). Patients with ETc had significantly lower tracking speed, more tracking interruptions, longer test duration, greater directional error, greater PT50%, and greater distance from path than patients with ETs or control subjects. Most patients with ET appear to have normal visuomotor capabilities (ETs) but some display significant visuomotor disturbances (ETc). Considering the presence of similar impairments in patients with early Parkinson's disease and the increased prevalence of parkinsonism in patients with ET, it is possible that preclinical parkinsonism exists in patients with ETc. Further follow up of patients with ETc is necessary to verify this possibility.

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