Huntington's Disease (Huntington Chorea)

• Huntington Disease is also known as Huntington Chorea.
• CNS TX 400 FT 500 PT indicates the course code in Vancouver College of Massage Therapy.

What is it?

• Huntington's Disease (HD) is an inherited, neurodegenerative disease.
• HD is characterized by choreiform movements (brief, purposeless, and random) and progressive dementia.
• It is a progressive disease, typically leading to death 15-20 years after neurological or psychological impairment onset.
• In adults, HD often leads to involuntary movements, but rigidity can also be a symptom.
• Males and females are diagnosed with HD in equal numbers.
• Symptom onset usually occurs between 35-55 years old.
• HD can appear in youth (under 20, known as Juvenile HD, 10% of cases) or later (over 60, Late Onset HA, 10% of cases)
• North America's disease prevalence ranges from 4 to 8 cases per 100,000 people.

Etiology

• A mutation in the gene for the huntingtin protein causes HD.
• The huntingtin gene is present on chromosome 4.
• A cytosine, adenine, and guanine (CAG) sequence replicates excessively due to a defect.
• Each child of a parent with HD has a 50/50 chance of inheriting the HD gene.
• A child that doesn't inherit the gene will not develop the disease or pass it on.

Pathophysiology

• HD is inherited as an autosomal dominant disorder.
• Pathological findings reveal a consistent pattern of tissue changes in the brain.
• Enlarged ventricles result from atrophy of the adjacent basal ganglia, specifically the caudate nucleus and putamen.
• This occurs due to significant loss of small and medium-sized neurons.
• Brain volume can decrease by 20%.
• Neurotransmitters are affected due to neuron loss.
• The normal balance of excitation and inhibition responses in the basal ganglia and thalamus is disrupted.

Signs & Symptoms

• Physical symptoms include weight loss, involuntary movements (chorea), diminished coordination, difficulty walking, talking, and swallowing.
• Greater impact on the ability to work, perform Activities of Daily Living (ADLs), communicate, and maintain independence due to impaired voluntary movements.
• Cognitive symptoms include difficulty with focus, planning, recall of information, making decisions, and impaired insight.
• Emotional symptoms include depression, apathy, irritability, anxiety, and obsessive behavior.
• Depression can be due to injury to the brain and subsequent changes in brain function versus reaction to diagnosis.

Signs & Symptoms - Early Stage

• In the early stage people are still able to function well at work and home.
• Difficulties organizing routine, coping effectively with new situations.
• Decreased ability to recall, make decisions, and attention to detail.
• Mood changes, irritability.
• Minor involuntary movements such as "nervous" activity, fidgeting, twitching, and excessive restlessness may be present.
• Changes in handwriting and difficulties may occur in daily tasks like driving.

Signs & Symptoms - Intermediate Stage

• Increased difficulties with working and household management, though the person can still handle ADLs.
• Symptoms progress from the early stage and include more obvious involuntary movements (chorea).
• Increased difficulties with walking, coordination, and balance.
• Challenges with speaking (slurred speech).
• Problem-solving becomes more difficult, and the thinking process declines.
• Difficulties with swallowing.
• Weight loss may occur due to energy expenditure from choreoathetoid movements.

Signs & Symptoms - Advanced Stages

• Individuals cannot manage ADLs and usually require professional care.
• Decrease in involuntary movements & increase in rigidity
• Increased difficulties swallowing
• Ability to communicate diminishes, but understanding what is being said remains possible
• Significant weight loss
• Dementia
• Bradykinesia (slow movement)
• Dystonia (involuntary muscle contractions)

Signs & Symptoms - JHD & LOHD

• Juvenile HD (JHD) follows a more rapid course, chorea is less prominent and may be absent.
• Initial symptoms of JHD include slow stiff movement (rigidity), sometimes tremors.
• Other symptoms of JHD include seizures, falls, clumsiness, contracted & rigid muscles that affect gait (especially in young children).
• Difficulties learning in school, attention deficits and increase in responsive behaviors.
• Late Onset HD (LOHD) has a diagnosis past 60, sometimes misdiagnosed because doctors believe patients are too old to develop HD (typical onset 35-55).

Diagnosis

• No diagnostic testing exists.
• A diagnosis is made based on clinical symptoms, family history, and genetic testing.
• Other tests that contribute to a diagnosis include neurological, neuropsychological, and psychiatric evaluations.
• A neurological examination tests motor, sensory, and psychiatric symptoms.
• Neuropsychological tests check memory, reasoning, mental agility, language skills, and spatial reasoning
• Psychiatric evaluation looks at emotional state, patterns of behaviors, quality of judgement, coping skills, signs of disorder thinking, evidence of substance abuse.
• MRI, CT, genetic counseling & testing, and predictive genetic tests are further contributing factors.

Treatment

• There is no cure; treatment focuses on symptom management.
• Medications can help control chorea.
• Medications for psychiatric disorders such as antidepressants, antipsychotics, and mood-stabilizing drugs.
• Psychotherapy with a psychiatrist, psychologist, or clinical social worker.
• Speech therapy.
• Physical therapy.
• Occupational therapy.

Massage & Clinical Manifestations

• Classic choreiform movements include piano-playing motions in fingers and facial grimaces.
• Trunk involvement and a "dancing gait" may be present.
• Individuals may appear off balance, but the ability to balance is well preserved.
• Patients who develop HD by age 35 often become bedridden within 15-20 years.
• Patients may be argumentative, impulsive, or erratic.
• Sleep disorders are common.
• Urinary incontinence may occur.
• Muscle strength is typically normal.
• Tendon reflexes are usually normal as well.