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The effect of ethanol on alcohol‐responsive essential tremor: A positron emission tomography study
Author(s) -
Boecker Henning,
Wills Adrian J.,
CeballosBaumann Andres,
Samuel Michael,
Thompson Philip D.,
Findley Leslie J.,
Brooks David J.
Publication year - 1996
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.410390515
Subject(s) - cerebral blood flow , medicine , cerebellum , anesthesia , cerebellar vermis , essential tremor , inferior olivary nucleus , postural tremor , positron emission tomography , nuclear medicine , physical medicine and rehabilitation
We used H 2 15 O positron emission tomography (PET) to investigate the effect of ethyl alcohol on regional cerebral blood flow in 6 patients with alcohol‐responsive essential tremor and 6 age‐matched control subjects. The patients were scanned while at rest and during involuntary postural tremor of the extended right arm. Normal control subjects were scanned at rest and during passive wrist oscillation of the right arm at tremor frequency. Regional cerebral blood flow associated with these conditions was measured before and after oral administration of 2 to 3 units of alcohol. The mean blood alcohol level was 35.3 ± 20.0 mg/dl in the patient group and caused marked suppression of tremor; it was 33.9 ± 12.9 mg/dl in the control group. Similar to previous PET studies on essential tremor patients, tremor compared with rest was associated with bilateral cerebellar activation including the cerebellar vermis. This pattern of activation differed from passive wrist oscillation where ipsilateral cerebellar activation was observed. Ethanol ingestion led to bilateral decreases of cerebellar blood flow in both tremor patients and normal subjects, and this was associated with suppression of tremor in the patients. Alcohol‐associated increases of regional cerebral blood flow were observed in the inferior olivary nuclei in the patients but not in the control subjects. We conclude that alcohol‐induced suppression of essential tremor is mediated via a reduction of cerebellar synaptic overactivity resulting in increased afferent input to the inferior olivary nuclei.