The diagnostic value of multimodal evoked potentials in the determination of subclinical neurological involvement of Wilson's disease.

Aims: Wilson's disease (WD) is a progressive degeneration of hepatolenticular tissue caused by excessive tissue-damaging copper accumulation and in which liver involvement most frequently presents in childhood. Neurological signs also accompany liver disease with time. However, subclinical neurological involvement may occur earlier and diagnostic methods that reveal this subclinical involvement are not well established. The aim of the current study is to assess the subclinical neurological involvement by using multimodality evoked potential (EP) measurements and to explore the relationship between neurological disease and the severity of liver damage.

Methods: The patient group included 28 children (mean age 11.8 ± 2.9 years, range 5.5-17) diagnosed with WD and a control group included 24 age-matched healthy children. Multimodality EP tests (Nihon Kohden Neuropack 8 4200K) of both groups were performed at the Department of Neurology Electrophysiology Laboratory of Ege University.

Results: At least one abnormal EP value was observed in 53.5% of the children in the patient group. At least on one side, there were abnormal values for visual evoked potential (VEP) P100, brainstem auditory evoked potential (BAEP) and somatosensory evoked potential (SEP), where the ratios were 25, 28.5, and 11%, respectively. Absolute latency values of patients with right-side VEP P100 and left-side BAEP I, and the interpeak latency values of right-side BAEP I-III were significantly high. The difference in right-side BAEP I-III interpeak latency between cirrhotic and noncirrhotic groups was found to be statistically significant (P<0.05).

Conclusion: The EP examinations can be an indicator of subclinical brain damage in non-neurological WD; however, cirrhosis because of WD does not cause an increase in the EP values. Detection of changes in the EP values periodically, especially at the time of diagnosis and during the treatment follow-up, may be valuable for revealing subclinical impairment.