Nerve conduction changes in patients with mitochondrial diseases treated with dichloroacetate

Serial measurements of nerve conduction velocities and amplitudes were performed in 27 patients with congenital lactic acidemia over 1 year of sodium dichloroacetate (DCA) administration. Patients were treated with oral thiamine (100 mg) and DCA (initial dose of 50 mg/kg) daily. Nerve conduction velocity and response amplitude were measured in the median, radial, tibial, and sural nerves at 0, 3, 6, and 12 months, and plasma DCA pharmacokinetics were measured at 3 and 12 months. Baseline electrophysiologic parameters in this population were generally below normal but as a group were within 2 standard deviations of normal means. Although symptoms of neuropathy were reported by only three patients or their families, nerve conduction declined in 12 patients with normal baseline studies, and worsening of nerve conduction occurred in the two who had abnormalities at baseline. Peripheral neuropathy appears to be a common side effect during chronic DCA treatment, even with coadministration of oral thiamine. Nerve conduction should be monitored during DCA treatment.