Clinical Research Directory

Inclusion Criteria: * men and women at risk for HD, who have been tested for the HD gene mutation, and who have not been diagnosed with symptoms of HD (CAG ≥36 for CAG-expanded group or CAG \<36 for CAG-norm group). Exclusion Criteria: * diagnosis of manifest HD (at least 50% confidence by neurologist that symptoms are present); * clinical evidence of unstable medical or psychiatric illness (including substance abuse); * history of sever learning disability or mental retardation; * history of other CNS disease or event (e.g., seizures or head trauma); * current treatment with antipsychotic medications, including the traditional neuroleptics such as haloperidol as well as the atypical antipsychotics risperidone, clozapine, quetiapine, and olanzapine; * treatment with phenothiazine-derivative antiemetic medications such as prochlorperazine, metoclopramide, promethazine, and Inapsine on a regular basis (greater than 3 times per month); Specific exclusion criteria for the lumbar puncture: * Current use of anti-coagulants * Current use of anti-platelets * Unable to provide consent for him/herself