Background: Hematopoietic stem cell transplantation (HSCT) may slow the progression of Krabbe disease (KD) if performed early in the disease. The authors' studies indicate that more than 90% of patients with KD have severe abnormalities in peripheral nerve conduction.

Objective: To assess the effect of HSCT on nerve conduction in patients with KD.

Methods: The authors performed serial nerve conduction studies (NCS) in 12 patients with KD after HSCT. The average follow-up was 18 months (6 months to 3 years) after HSCT. Pretransplant NCS were not available in two patients; all others (10 of 12) had significant pretransplant abnormalities.

Results: After HSCT, previously absent F-waves (1 patient) and sural sensory responses (SNR) (3 patients) were found recordable. All patients continued to have recordable SNR after HSCT, and these became normal in 7 of 12 patients. Distal motor nerve latency became normal in 6 of 17 and motor nerve conduction velocity (CV) in 2 of 17 nerves; F-wave latencies (FWL) improved in 6 of 17 nerves, but did not become normal in any. There was greater improvement in nerve conduction abnormalities if the transplant was performed earlier in life. After an initial improvement, there was subsequent worsening of motor latencies (2 of 12), motor CV (2 of 12), FWL (3 of 12), and SSR (1 of 12), indicating that benefit from HSCT may be temporary.

Conclusions: Serial nerve conduction studies are useful in following the course of peripheral neuropathy in Krabbe disease. Hematopoietic stem cell transplantation is followed by improvement in peripheral nerve conduction abnormalities in these patients, suggesting remyelination of the nerves.