MRI abnormalities associated with Vigabatrin treatment – a longitudinal case study and an atypical case

Purpose: MRI abnormalities in basal ganglia, brain stem and cerebellum have recently been described in infants treated with vigabatrin (Pearl P et al. Epilepsia 2009;50:184–194; Wheless JW et al. Epilepsia 2009;50:195–205). The abnormalities are considered to be asymptomatic and reversible, but there is no documented evolution of MRI changes at more than 2 points in time in the literature. The pattern has never been described in patients older than 24 months.

Method: We reviewed the medical records and MRI scans in 4 children showing the typical pattern of MRI abnormalities attributed to vigabatrin (age: 0.5–5 years; maximum dosage: 95–139mg/kg/d), who have been evaluated in our institution during the last 12 months.

Results: Two children had serial MRI scans due to other abnormalities, that allow us to document the course of MRI abnormalities starting with a normal MRI before treatment and demonstrating the typical pattern after several months of therapy and its resolution with ongoing vigabatrin treatment. No specific clinical symptoms were noted. For the first time we describe the typical pattern of MRI abnormalities outside infancy in a 5-year-old boy, who showed the abnormalities associated to a

hydrocephalus due to a subependymal giant-cell astrocytomas.

Conclusion: MRI abnormalities associated with vigabatrin therapy in infants show a typical pattern without appreciable clinical symptoms. We longitudinally documented the course of these changes and their reversibility with ongoing vigabatrin treatment in two infants. The case of a 5-year-old boy with hydrocephalus demonstrates that this phenomenon is not exclusively seen in infancy and raises the suspicion of a multifactorial etiology. The typical age-dependent appearance of the phenomenon

might point to developmental processes of myelination as one potential cofactor to vigabatrin treatment.