Brain : a journal of neurology
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Multicenter Study
Grey and white matter flumazenil binding in neocortical epilepsy with normal MRI. A PET study of 44 patients.
In 20-30% of potential surgical candidates with refractory focal epilepsy, standard MRI does not identify the cause. gamma-Aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the brain. [(11)C]Flumazenil (FMZ) PET images most subtypes of GABA(A) receptors, present on most neurons. We investigated [(11)C]FMZ binding in grey and white matter in 16 normal controls and in 44 patients with refractory neocortical focal epilepsy and normal optimal MRI. Fourteen patients had unilateral frontal lobe epilepsy, five occipital lobe epilepsy (OLE), six parietal lobe epilepsy (PLE) and 19 neocortical epilepsy that was not clearly lobar. ⋯ In seven patients, the increases in FMZ binding were periventricular, in locations normally seen in periventricular nodular heterotopia on MRI. There were frontal and parietal increases in FMZ binding in grey and white matter in the PLE group and decreases in the cingulate gyrus in the OLE group. FMZ binding increases, particularly periventricular increases, were a prominent feature of MRI-negative focal epilepsies and may represent neuronal migration disturbances.
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Mutations in the parkin gene, PARK2, are a common cause of parkinsonism in familial as well as isolated cases with an age of onset <40 years and should be considered in the diagnostic work up of young-onset parkinsonism. We report a detailed clinical evaluation of a personal series of 24 patients with mutations in the parkin gene. The clinical presentation of most cases was broadly comparable to that of previous descriptions of autosomal recessive early-onset or juvenile parkinsonism and young-onset Parkinson's disease and also had similarities with phenotypes of dopa-responsive dystonia. ⋯ We emphasize a number of clinical features that can be seen in parkin disease: focal dystonia; early instability; freezing; festination or retropulsion; concurrent autonomic failure; dramatic response to anticholinergics; early or atypical L-dopa-induced dyskinesias; exquisite sensitivity to small doses of L-dopa; and recurrent psychosis, even taking L-dopa alone. We also report behavioural disorder prior to the onset of parkinsonism. Some relatives carrying a single parkin mutation without extrapyramidal symptoms or signs also had psychiatric symptoms that might be related to their carrier status.