Cause of death among patients with Parkinson's disease: a rare mortality due to cerebral haemorrhage.

Causes of death, with special reference to cerebral haemorrhage, among 240 patients with pathologically verified Parkinson's disease were investigated using the Annuals of the Pathological Autopsy Cases in Japan from 1981 to 1985. The leading causes of death were pneumonia and bronchitis (44.1%), malignant neoplasms (11.6%), heart diseases (4.1%), cerebral infarction (3.7%) and septicaemia (3.3%). Cerebral haemorrhage was the 11th most frequent cause of death, accounting for only 0.8% of deaths among the patients, whereas it was the 5th most common cause of death among the Japanese general population in 1985. The low incidence of cerebral haemorrhage as a cause of death in patients with Parkinson's disease may reflect the hypotensive effect of levodopa and a hypotensive mechanism due to reduced noradrenaline levels in the parkinsonian brain.

Hypotensive effect of long-term levodopa in patients with Parkinson's disease.

To study the hypotensive effect of L-dopa in patients with Parkinson's disease on long-term L-dopa, the blood pressure (BP) was measured in 14 patients and 6 controls before 100 mg L-dopa plus decarboxylase inhibitor and for up to 180 min after dosing. Plasma monoamines and motor functions were assessed. The mean BP was reduced between 60 and 180 min after dosing in the patients, whereas such a reduction was not observed in 5 patients from whom L-dopa was withheld and in controls who showed a high ratio of plasma dopamine compared to plasma L-dopa after dosing. The L-dopa-induced reduction in BP was thought to be due to a central nervous mechanism.