title: The frontal N30 component of the median-derived SEP in patients with predominantly unilateral Parkinson's disease.
abstract: There are conflicting reports concerning attenuation of the frontal N30 component of the median-derived somatosensory evoked potential in patients with Parkinson's disease (PD). We found that the mean N30 latency (28.03 +/- 2.50 msec) and amplitude (2.30 +/- 1.58 microV) obtained with stimulation of the affected arm of 10 patients with predominantly unilateral PD were not significantly different from those obtained from the unaffected arm (mean latency, 28.14 +/- 2.47 msec; mean amplitude, 2.43 +/- 1.65 microV) or from 10 age-matched controls (mean latency, 29.01 +/- 1.88 msec; mean amplitude, 1.92 +/- 0.64 microV). Three patients had an N30 of abnormal amplitude; in two, responses were absent with stimulation of either side, and in one there was a response asymmetry exceeding the normal range, with the smaller response elicited from the affected arm. Thus, only one of 10 patients had a diminished N30 consistent with the clinical findings. We conclude that the N30 is unlikely to be clinically useful in the assessment of patients with PD.
authors.affiliation: Department of Neurology, University of California, San Francisco 94143, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Garcia
authors.forename: M J
authors.initials: MJ
authors.lastname: Aminoff
authors.forename: D S
authors.initials: DS
authors.lastname: Goodin
mesh_terms: D000368:Aged; D001931:Brain Mapping; D016022:Case-Control Studies; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D011930:Reaction Time / Q000502:physiology