Movement disorders and nonmotor neuropsychological symptoms in children and adults with classical galactosemia.

Although movement disorders (MDs) are known complications, the exact frequency and severity remains uncertain in patients with classical galactosemia, especially in children. We determined the frequency, classification and severity of MDs in a cohort of pediatric and adult galactosemia patients, and assessed the association with nonmotor neuropsychological symptoms and daily functioning. Patients from seven centers in the United Kingdom and the Netherlands with a confirmed galactosemia diagnosis were invited to participate. A videotaped neurological examination was performed and an expert panel scored the presence, classification and severity of MDs. Disease characteristics, nonmotor neuropsychological symptoms, and daily functioning were evaluated with structured interviews and validated questionnaires (Achenbach, Vineland, Health Assessment Questionnaire, SIP68). We recruited 37 patients; 19 adults (mean age 32.6 years) and 18 children (mean age 10.7 years). Subjective self-reports revealed motor symptoms in 19/37 (51.4%), similar to the objective (video) assessment, with MDs in 18/37 patients (48.6%). The objective severity scores were moderate to severe in one third (6/37). Dystonia was the overall major feature, with additional tremor in adults, and myoclonus in children. Behavioral or psychiatric problems were present in 47.2%, mostly internalizing problems, and associated with MDs. Daily functioning was significantly impaired in the majority of patients. Only one patient received symptomatic treatment for MDs. We show that MDs and nonmotor neuropsychological symptoms are frequent in both children and adults with classical galactosemia.

Movement disorders in adult patients with classical galactosemia.

Classical galactosemia is an autosomal recessive inborn error of metabolism leading to toxic accumulation of galactose and derived metabolites. It presents with acute systemic complications in the newborn. Galactose restriction resolves these symptoms, but long-term complications, such as premature ovarian failure and neurological problems including motor dysfunction, may occur despite adequate treatment. The objective of the current study was to determine the frequency and phenotype of motor problems in adult patients with classical galactosemia. In this cross-sectional study, adult patients with a biochemically confirmed diagnosis of galactosemia attending our clinic were assessed with an interview and neurological examination and their notes retrospectively reviewed. Patients were classified according to the presence/absence of motor dysfunction on examination. Patients with motor dysfunction were further categorized according to the presence/absence of reported motor symptoms. Forty-seven patients were included. Thirty-one patients showed evidence of motor dysfunction including: tremor (23 patients), dystonia (23 patients), cerebellar signs (6 patients), and pyramidal signs (4 patients). Tremor and dystonia were often combined (16 patients). Thirteen patients reported motor symptoms, with 8 describing progressive worsening. Symptomatic treatment was effective in 4 of 5 patients. Nonmotor neurological features (cognitive, psychiatric, and speech disorders) and premature ovarian failure were more frequent in patients with motor dysfunction. Motor dysfunction is a common complication of classical galactosemia, with tremor and dystonia the most frequent findings. Up to one third of patients report motor symptoms and may benefit from appropriate treatment. Progressive worsening is not uncommon and may suggest ongoing brain damage in a subset of patients.