Unified Huntington's disease rating scale: clinical practice and a critical approach.

The purpose of this study was to test the usefulness of the Unified Huntington's Disease Rating Scale (UHDRS) in clinical practice. The UHDRS was used to examine 45 persons with genetically diagnosed Huntington's disease (HD) in various stages. The rate of motor involvement, cognitive deficit and reliance on nursing care rose in linear proportion to HD duration. The severity of motor involvement correlated significantly with all UHDRS subscales except for that of behavioral disorders, the rate of these disorders being unrelated to any of the parameters under study. The number of CAG triplets was inversely correlated with the age at onset of HD. Being considerably time consuming, administration of the whole UHDRS calls for interdisciplinary co-operation. For valid data acquisition, the participation of caregivers is also essential. In clinical practice it is advisable regularly to monitor the patient's conditions and the efficacy of treatment using the UHDRS motor, functional and behavioral subscales. Cognitive tests present difficulties but, in view of the progressive cognitive deterioration in HD, they are very useful in the early stage of the disease. The UHDRS does not assess impaired voluntary motor activity, or furnish information relating to therapy, dysphagia, weight loss, sexual problems or drug abuse.