Cerebrospinal fluid GABA levels in involuntary movement disorders

Abstract

GABA was measured in Cerebrospinal fluid (CSF) from patients with involuntary movement disorders to evaluate the selectivity and specificity of CSF GABA levels in diseases of the basal ganglia and cerebellum. GABA was measured by ion-exchange/fluorometric method from the first 12 ml of CSF. The results showed the mean ( ± SD) CSF GABA levels to be 233 ± 78 pmol/ml in normal controls, 141 ± 60 pmol/ ml in Hungtinton's disease, 130 ± 48 pmol/ ml in Parkinson's disease, 125 ± 89 pmol/ ml in Cerebellar degeneration and 125 ± 43 pmol/ ml in Essential tremor. Statistical comparison using the Student's t-test showed that CSF GABA level was significantly reduced in patients with Huntington's disease, Parkinson's disease, Cerebellar degeneration and Essential tremor when compared to normal controls. No statistically significant differences were found between Huntington's disease and other three diseases, showing that low CSF GABA levels are not specific for any one of these diseases. No clear correlation was seen between CSF GABA levels and age, duration, severity of illness, medication or symptoms in either Huntington's disease or Parkinson's disease.