Clinicopathological MRI and CSF Correlates in Huntington's Disease.

Inclusion Criteria:

• Native Dutch/Flemish speaker
• Ability to undergo MRI scanning;
• Written informed consent must be obtained from the participant. And in addition: If the participant is a pre-manifest HD gene carrier:
• CAG expansion ≥ 40;
• UHDRS Total Motor Score (TMS) ≤ 5;
• Total Functional Capacity (TFC) = 13;
• Diagnostic Confidence Score < 4. If the participant is an early-manifest HD gene carrier:
• CAG expansion ≥ 36;
• Diagnostic Confidence Score = 4;
• HD stage I: TFC scores between 11 and 13 inclusive. If the participant is a moderate manifest HD gene carrier:
• CAG expansion ≥ 36;
• Diagnostic Confidence Score = 4;
• HD stage II: TFC scores between 7 and 11 inclusive. If the participant is a control subject:
• Partner/spouse of a patient not at risk of HD OR sibling with genetic test resultsavailable that show a normal CAG repeat length for both HTT alleles (<36);
• No other known cognitive, neurological or psychiatric disorders.

Exclusion Criteria:

• Additional major comorbidities not related to HD (e.g. cardiovascular diseases,coagulopathy, hypertension, diabetes mellitus, and/or other neurological disorders);
• History of severe head injury;
• Status of the participant after brain surgery;
• Past erythrocyte transfusions;
• Use of investigational drugs or participation in a clinical drug trial within 30 daysprior to study visit;
• Current intoxication, drug or alcohol abuse or dependence;
• Pregnancy;
• Inability to understand the information about the protocol;
• Severe physical restrictions (completely wheelchair dependent);
• Severe chorea that, in the investigator's judgment, precludes the patient'sparticipation in and completion of the MRI and/or lumbar puncture.
• Contra-indication to MRI scanning, such as:
• Claustrophobia;
• Pacemakers and defibrillators;
• Nerve stimulators;
• Intracranial clips;
• Intraorbital or intraocular metallic fragments;
• Cochlear implants;
• Ferromagnetic implants;
• Hydrocephalus pump;
• Intra-utrine device (not all types);
• Permanent make-up;
• Tattoos above the shoulders (not all).
• Contraindications for a lumbar puncture, including:
• Screening blood test results outside normal ranges(white cell count, neutrophilcount, lymphocyte count, hemoglobin, platelets, Prothrombin time (PT), activatedpartial thromboplastin time (APTT), C-reactive protein (CRP) and serum ferritin)if only marginally decreased or increased this will be decided by the clinicalPI;
• Signs and symptoms of increased intracranial pressure which will be confirmed onthe 7T MRI (T1 and FLAIR scan) or by a fundoscopy;
• Local infections of the skin;
• Use of anti-coagulant drugs within the last 14 days prior lumbar puncture.