N30 Somatosensory Evoked Potential Is Negatively Correlated with Motor Function in Parkinson's Disease

The aim of this study was to investigate frontal N30 status in Parkinson's disease (PD) and to examine the correlation between the amplitude of frontal N30 and the severity of motor deficits.

The frontal N30 was compared between 17 PD patients and 18 healthy volunteers. Correlations between the amplitude of frontal N30 and the Unified Parkinson's Disease Rating Scale (UPDRS) motor score of the more severely affected side was examined.

The mean latency of the N30 was not significantly different between patients and healthy volunteers (p = 0.981), but the mean amplitude was lower in PD patients (p < 0.025). There was a significant negative correlation between the amplitude of N30 and the UPDRS motor score (r = -0.715, p = 0.013).

The frontal N30 status indicates the motor severity of PD. It can be a useful biomarker reflecting dopaminergic deficits and an objective measurement for monitoring the clinical severity of PD.