Haemodialysis alters peripheral nerve morphology in end-stage kidney disease

Objective: We explored the nerve ultrasound (US) characteristics of 15 patients with end-stage kidney disease (ESKD) and correlated these findings with clinical severity and electrophysiological parameters of neuropathy.

Methods: 15 ESKD patients on thrice-weekly high-flux haemodialysis and 15 healthy controls were enrolled. Sonographic and electrophysiologic studies were conducted before and after a single session of haemodialysis. Serial measurements of median nerve cross-sectional area (CSA) and hypoechoic fraction (HF) were performed at the same non-entrapment site in the mid-forearm. Neuropathy severity was quantified using the total neuropathy score (TNS).

Results: 86.7% of the ESKD cohort had neuropathy (TNS>1). ESKD patients had significantly higher baseline CSA (8.9±1.2mm² vs 7.5±1.0mm², p<0.05) and HF (56.0±1.0% vs 54.0±1.1%, p<0.05) compared with the control group. The CSA correlated significantly with TNS (r=0.826; p<0.0001) and other electrophysiological parameters. There was a reduction in both the CSA (8.3±1.4mm²; p<0.01) and HF (55.0±1.6%; p<0.05) after a single session of HD. A significant relationship was also found between the change in CSA and change in serum K⁺ after dialysis (r=0.782, p<0.01).

Conclusions: This study shows that peripheral nerves in ESKD patients are larger and more hypoechoic and that these morphological abnormalities may be reversed by dialysis.

Significance: US may be useful as an early marker of neuropathy in ESKD.