Neuropathy of metachromatic leukodystrophy: Improvement with immunomodulation

A 4-year-old child with metachromatic leukodystrophy was initially diagnosed with chronic immune demyelinating polyneuropathy and treated with immunosuppressive therapy. Physical examination revealed diffuse, distal >proximal weakness and areflexia. Electrodiagnostic studies revealed nerve conduction velocities that were slowed to variable degrees in different nerves. In the 18 months after institution of immunomodulating therapy, she had functionally significant improvement and a quantitative increase in her strength. Treatment was discontinued at age 6 years when the patient developed urinary incontinence, followed by loss of motor and cognitive skills. We conclude that immunomodulation early in the course of metachromatic leukodystrophy presenting as a neuropathy may result in temporary functional improvement. Whether the immunomodulation altered the disease progression or had direct effects on the function of the dysmyelinated axons is not known.