Motor and cognitive improvements in patients with Huntington's disease after neural transplantation

Background Huntington's disease is a neurodegenerative disease of genetic o rigin that mainly affects the striatum. It has severe motor and cognitive c onsequences and, up to now, no treatment. Motor and cognitive functions can be restored in experimental animal models by means of intrastriatal transp lantation of fetal striatal neuroblasts. We explored whether grafts of huma n fetal striatal tissue could survive and have detectable effects in five p atients with mild to moderate Huntington's disease. Methods After 2 years of preoperative assessment, patients were grafted wit h human fetal neuroblasts into the right striatum then, after a year, the l eft striatum. Final results were assessed 1 year later on the basis of neur ological, neuropsychological, neurophysiological, and psychiatric tests, Th e results obtained were compared with those of a cohort of 22 untreated pat ients at similar stages of the disease who were followed up in parallel. Re peated magnetic resonance imaging (MRI) and positron emission tomography (P ET) scanning with fluorine-18-labelled fluorodeoxyglucose was also done to assess metabolic activity. Findings The final PFT-scan assessment showed increased metabolic activity in various subnuclei of the striatum in three of five patients, contrasting with the progressive decline recorded in the two other patients in the ser ies, as seen in patients with untreated Huntington's disease. Small areas o f even higher metabolic activity, coregistering with spherical hyposignals on MRI were also present in the same three patients, suggesting that grafts were functional. Accordingly, motor and cognitive functions were improved or maintained within the normal range, and functional benefits were seen in daily-life activities in these three patients, but not in the other two. Interpretation Fetal neural allografts could be associated with functional, motor, and cognitive improvements in patients with Huntington's disease.