Cerebrotendinous xanthomatosis: 11 year treatment with chenodeoxycholic acid in five patients. An electrophysiological study

We report the electrophysiological follow-up of five cerebrotendinous xanthomatosis patients treated for 11 years with chenodeoxycholic acid (CDCA). Nerve conduction velocity (NCV) was reduced in three cases. P100 latency of visual evoked potentials was delayed in four cases, interpeaks I-III and I-V of brainstem auditory evoked potentials (BAEPs) was increased in two and interpeak N13-20 of upper limb somatosensory evoked potentials (SEPs) was slowed in one. After 4 months of therapy with CDCA, NCV was normal and did not show any significant change during the 11 years of observation. Central motor conduction time of motor evoked potentials (MEPs) and N24-P40 interpeak latency of lower limb SEPs were increased in five and four cases, respectively, in spite of 2/3-year treatment with CDCA. Improvement of evoked potentials, especially of MEPs and SEPs, was slower and continued over the whole 11-year period. The size of xanthomas slightly decreased in some patients during treatment and the clinical manifestations stabilized, avoiding progressive worsening, but there was no significant improvement in neurological deficit. Two sisters of patients who never took CDCA showed progressive worsening of clinical manifestations, upper limb SEPs and BAEPs.