Carbamazepine trial for Lesch-Nyhan self-mutilation.

Anticonvulsants may reduce the self-mutilation of acquired sensory neuropathy, and one report described sensory neuropathy in an older patient with Lesch-Nyhan syndrome. We performed nerve and muscle biopsies on four patients with Lesch-Nyhan syndrome and initiated an uncontrolled pilot trial to see if carbamazepine would reduce the self-mutilation in these patients. All of the boys had clinical features typical of Lesch-Nyhan syndrome, and the diagnosis was confirmed in each by enzyme analysis. No specific abnormalities were identified in either nerve or muscle. Nevertheless, self-mutilation and the need for constant restraint diminished in all four patients, though in one the effect was only transient. Two patients had increased self-mutilation when carbamazepine was stopped, then improved a second time when treatment was restarted. Sensory neuropathy was not confirmed, so any effect of carbamazepine is likely to be on the central nervous system.