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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

A Comparison of Screening and N-30 Mode in Frequency Doubling Technology Perimetry

FDT is known as a comfortable and convenient device, and there was no restriction in pupil size and refractive error within 7 diopters.To compare the effectiveness of secreening and N-30 mode in FDT, new field analyzer. Twenty-three POAG or ocular hypertension patients(43 eyes)were included in this study. All subjects underwent FDT screening and N-30 15 minutes apart on same day within 1 month after HFA C30-2 test. Mean age of the subjects was 49.77+/-11.61 years. Fifteen men and nine woman were included in this study. Test duration was 52.3+/-6.2 seconds with FDT screening, 5.46+/-0.32 minutes with FDT N-30, and 14.46+/-1.88 minutes with HFA C30-2.In global indexes MD and PSD of FDT N-30 were well correlated with MD, PSD, and CPSD of HFA C30-2 respectively(p<0.01). In diagnosing glaucoma, sensitivity of FDT screening and N-30 was 75% and 88%respectively, and specificity of screening and N-30 was 94%and 82%respectively. In detecting defect in each test location, sensitivity of FDT screening and N-30 was 68.6%and 81.6%respectively, and specificity of screening and N-30 was 94.5%and 83.8%respectively. FDT N-30 mode appears to be superior to FDT screening mode in screening and diagnosing glaucoma as there are high correlation with HFA C30-2, good sensitivity, and specificity inspite of longer test duration.