Background for Fast Fact #201 Huntington’s disease (HD) is an incurable neurodegenerative disorder inherited in an autosomal dominant fashion. It is characterized by progressive movement disorders, psychiatric manifestations, and cognitive impairment. This Fast Fact will focus on supportive and terminal care for patients with HD and their families.

Natural history and prognosis   In healthy individuals there are an average of 17-20 CAG repeats in the huntingtin gene (HTT).  When a patient gets > 40 CAG repeats, HD emerges with 100% penetrance.  Symptom onset is usually between 33 and 44 years. Subtle cognitive and motor changes may precede HD diagnosis by many years. Mean duration of illness from onset to death is 15-20 years with average age of death of 60 years. Patients show signs of progressive dementia and become unable to walk, talk, take in nutrition, and care for themselves. Life threatening complications may result from aspiration, chronic infections, poor nutrition, falls, or cardiovascular disease. One-third of all patients are institutionalized in long-term care facilities. Clinical factors associated with a shortened survival are: 

• The length of the CAG repeat in the HTT (determined via a blood draw) is likely the strongest prognostic factor – the longer the repeat, the faster disease courses.
• Age at diagnosis and the presence of cognitive impairment are additional factors.

Impact on families     HD often begins during a time when family life is most complex and therefore most disruptive to the family structure (e.g. child-rearing, career development). Children can be particularly affected: distress is aggravated by concerns about their own genetic susceptibility, and as many as 40% of children of HD patients describe HD as splitting their family apart. Careful assessments of familial coping and psychosocial needs are an integral part of ongoing care for the HD patient.

Common symptoms and supportive care    There are known treatments to slow down the progression of HD. Patients are best served by an interdisciplinary team of mental health professionals, genetic counselors, physical therapists (PT), occupational therapists (OT), pharmacists, clinicians, neurologists, etc familiar with caring for patients with HD.

Motor Manifestations. Abnormal movements usually begin with chorea, which at first manifests as short-lived, suppressible fidgety movements in the distal extremities. In time chorea usually becomes severe and leads to falls and exhaustion. As the disease advances, the chorea may burn out and lead to more difficult to treat motor phenomena like dystonia, rigidity, bradykinesia, gait problems, and loss of balance. Slurred speech, dysphagia, and swallowing difficulties are also common. 

• First-line strategies are non-pharmacologic and include gait/balance training, education, PT, OT, speech therapy, home modifications, and orthotics and leg weights to assist with upright posture.
• Chorea is the most treatable motor symptom for pharmacologic therapy. Tetrabenazine (a dopamine depleting agent) has been shown to reduce chorea in a well-designed placebo-controlled trial.  Most studies start with a dose of 12.5 mg and titrate up to a maximum dose of 300 mg per day broken up into 3 times a day dosing. Increased risk of depression is a serious concern with tetrabenazine; newer agents are being investigated and showing promise (e.g., deutetrabenazine).  Haloperidol, risperidone, and olanzapine may be used for chorea, although trials have shown mixed results. Deep brain stimulation is an emerging option for refractory chorea.

Psychiatric manifestations are present in over half of HD patients. Establishing strict routines can lessen anxiety, short-term memory deficits, intrusive thoughts, and fear of abandonment.  

• Depression affects 33-70% of patients with HD. Rates of suicide are higher than the general population. There is no proven best anti-depressant for patients with HD, but treatment of depression with SSRIs and SNRIs is established and common.
• Agitation occurs in 38-73% and can include episodes of extreme anger. A small number of patients develop psychosis.  Atypical neuroleptics like risperidone and olanzapine are commonly used.
• Other psychiatric manifestations include a) emotional lability (case reports of treatment with propranolol); b) obsessive-compulsive behaviors (SSRIs and clomipramine commonly prescribed); c) apathy (no clearly effective agents); d) anxiety from uncontrolled movements while eating (low doses of scheduled benzodiazepines or propranolol prior to meals has been described).

Cognitive deficits are common in later stages of the illness and occur gradually.  Yes/no questions may be preferable to open-ended questions for patients with cognitive impairments.  There is little evidence supporting the use of cholinesterase inhibitors or memantine in patients with HD.

Advance care planning should be performed early as possible, prior to cognitive impairment.  Of importance is establishing a health care power of attorney and documenting patient preferences regarding the use of mechanical ventilation and medically administered nutrition and hydration to their families.  Some states require clear evidence that a patient would want tube feeding withheld or withdrawn at the end of life and patients should be instructed to document this if consistent with their wishes.  See Fast Fact #12, Fast Fact #65, Fast Fact #162, and Fast Fact #178.

Terminal care    There are no evidence-based criteria for determining a 6-month prognosis in HD. Hospice care is usually considered when a patient has a Functional Assessment Staging Score of 7 or worse (meaning inability to ambulate, dress, go to the bathroom without assistance and minimal verbal capabilities) and the presence of a major illness complication like aspiration pneumonia or a stage 3 sacral ulcer. A retrospective, multi-centered study of over 100 HD patients, suggested that the hospice length of stay is longer than non-HD hospice patients and only a significant minority of HD patients die at home.  Labored breathing, excessive secretions, and restlessness are common terminal symptoms.

References

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Version History:  Originally published April 2008.  Version re-copy-edited in June 2009; then again July 2015; then again in February 2025. 
Conflicts of Interest: None to report.