Motor cortical excitability in peritoneal dialysis: a single-pulse TMS study

The aim of this paper is to investigate cortical excitability in patients with end-stage renal disease receiving peritoneal dialysis (PD) without any symptoms suggestive of uremic encephalopathy. We performed transcranial magnetic stimulation for 52 PD patients and 28 normal subjects. We compared the active motor threshold (AMT), resting motor threshold (RMT), root latency, central motor conduction time (CMCT), and cortical silent period (CSP) in PD patients to those in normal subjects. AMT, RMT, CMCT, and CSP were not significantly different between PD patients and normal subjects. However, root latency was significantly prolonged in PD patients compared to normal subjects. The root latency correlated linearly with HbA1c or duration of PD in the patients. The results suggest that the corticospinal tract and the cortical and spinal excitabilities are preserved but the peripheral nerves are disturbed in PD patients. The severity of peripheral neuropathy corresponds to the severity of DM and the duration of PD. We uncovered no evidence suggestive of any subclinical abnormality of the motor cortical excitability in PD patients.