Cortical evoked potentials in hepatolenticular degeneration

The diagnostic value of sensory evoked potentials in pediatric Wilson disease

We studied the sensory evoked potentials in pediatric Wilson disease to verify their subclinical neurologic involvement and to elucidate the role of cirrhosis in abnormal evoked potentials in non-neurologic Wilson disease. Thirty children (17 male, 13 female), diagnosed with Wilson disease before 18 years, were enrolled. The mean age during studies was 15.8 +/- 6.3 years, and disease duration since diagnosis was 3.0 +/- 3.3 years. In 12 neurologic Wilson disease cases, there were prolonged interpeak latencies of brainstem auditory evoked potentials III-V, I-V, somatosensory evoked potentials N13-N20 (P < 0.01 vs controls and non-neurologic cases), and P100 latency (P < 0.01 vs controls). All 12 patients had at least one abnormal evoked potential, including 91.7% brainstem auditory, 58.3% somatosensory, and 25% visual evoked potentials. In 18 non-neurologic Wilson disease cases, there were still prolonged interpeak latencies for brainstem auditory evoked potentials I-V and somatosensory evoked potentials N13-N20 (P < 0.05 vs controls), with 27.8% of them having at least one abnormal evoked potential, including 16.6% brainstem auditory, 5.6% somatosensory, and 11.1% visual evoked potentials. In those with non-neurologic Wilson disease, there were no significant differences in all the evoked potential parameters between the cirrhotic and non-cirrhotic patients.

Visual pathway abnormalities Wilson's disease: an electrophysiological study using electroretinography and visual evoked potentials

The pathogenesis of the pattern reversal visual evoked potential (PRVEP) abnormalities in patients with Wilson's disease (WD) has not been investigated earlier. Since electroretinography (ERG) assesses the functional integrity of the retina, it was used along with PRVEP to localize the abnormalities in PRVEP in Wilson's patients. Ten newly diagnosed Wilson's disease patients underwent PRVEP and flash ERG soon after the diagnosis was established. The PRVEP latencies were prolonged in comparison with the controls (P<0.001). Photopic and scotopic A waves and oscillatory potentials were prolonged (P<0. 02) with reduction in amplitudes of photopic A and B waves (P<0.001). Six of these patients were subjected to repeat PRVEP and flash ERG after the clinical improvement with specific therapy. Comparison of the pre and post-treatment visual electrophysiological studies revealed significant reduction in latencies of PRVEP and flash ERG A wave (P<0.05) with increase in amplitudes of P100 of PRVEP (P<0.05), A and B waves of flash ERG (P<0.01). These findings confirm the reported PRVEP changes in WD and in addition demonstrate the reversibility of the retinal dysfunction which partially contributes to the PRVEP abnormalities. To the best of our knowledge this is the first study of ERG in patients with Wilson's disease in the literature. Further, there have been no earlier reports in the literature evaluating the effect of specific treatment on the PRVEP and ERG in Wilson's disease.

Evoked potentials in patients with non-neurological Wilson's disease

In Wilson's disease neurological manifestations result from the damage in the basal ganglia, even if a widespread degeneration of the brain occurs. The few studies performed using evoked potentials with the aim of identifying subclinical dysfunction in the three major sensory pathways have never shown abnormalities in patients without neurological manifestations. To verify this observation we studied 12 patients suffering from Wilson's disease in a pre-neurological stage by using pattern visual evoked potentials (VEPs), somatosensory evoked potentials (SEPs) to median nerve stimulation and brainstem auditory evoked potentials (BAEPs). Four of these patients had not yet been treated with penicillamine or trientine (triethylenetetramine dihydrochloride), while the remaining 8 patients were on treatment for at least 1 year. In 3 patients of this second group and in 1 patient of the first group we observed a significant (3 SD over the mean) increase in P100 wave latency, while SEPs and BAEPs were found to be abnormal in only 1 patient, respectively.

Visual and brain stem auditory evoked responses in Wilson's disease

Sensory evoked potentials were studied in 15 patients with Wilson's disease. Thirteen patients were investigated with pattern reversal visual stimulation. A prolonged P 100 latency of the VEP was present in 7 patients. Brain stem auditory responses were evoked in 12 patients. Prolongation of III-V and I-V interpeak latency was found in 8 patients. The evoked potential studies demonstrated subclinical disturbances in optic and caudal brainstem auditory pathways. Further studies are in progress to evaluate the role of these techniques in monitoring the therapy of newly diagnosed cases.

An EEG study of Wilson's disease. Findings in patients and heterozygous relatives

The correlation of clinical and EEG findings was studied in 40 patients with Wilson's disease and their 57 heterozygous relations (25 children, 30 parents and 2 siblings). EEG changes in Wilson's disease were found in 84% (50% mild, 34% moderate) with but a slight predominance in patients with neurological involvement. The relatively high rate of pathological EEG findings in the hepatic or asymptomatic forms suggested the presence of subclinical CNS damage even in these cases. Diffuse episodic abnormalities were a dominant feature in all the groups under observation. As for the heterozygous relatives, a significant increase in pathological EEG findings (80-28% mild, 52% moderate to severe) was found in the heterozygous children. The changes often correlated with the clinical detection of minimal brain damage. The grossest EEG changes were seen in the youngest age group (under 10 years of age) with a subsequent tendency to abatement. In 2 cases there was an extinction of specific epileptic graphoelements which may have been the result of long-term penicillamine administration. In the adult heterozygous population (parents and siblings) there was no significant increase in the rate of pathological EEG findings compared with our control group. The authors discuss the problem of control mechanisms which have a role to play in the normalization of biochemical and probably also clinical and EEG findings in the heterozygotes.

Visual (VEP) and somatosensory (SSEP) evoked potentials in Huntington's chorea

In 13 patients suffering from Huntington's chorea (H.Ch.) VEPs and SSEPs were investigated in comparison with 9 clinically unaffected offsprings and 40 normal adults. (1) The mean amplitude of VEPs was reduced in all patients and in 4 out of 9 offsprings. (2) Latencies of P100 in VEPs were normal in all subjects. (3) The late components were reduced in amplitude and rather irregular in shape. (4) The latencies of SSEPs were slightly prolonged, less marked in the early peaks and more pronounced in the later ones. (5) The late components after 70--100 msec were often attenuated or even absent. (6) The mean amplitude of P1/N2 was remarkably reduced. (7) Interhemispheric asymmetries were pronounced in 3 out of 9 offsprings.