Huntington's Disease

Huntington Disease

• Also known as Huntington Chorea
• It is an inherited neurodegenerative disease

Characteristics

• Choreiform movements: brief, purposeless, and random
• Progressive dementia: typically leads to death within 15-20 years

Symptoms

• Involuntary movements are most common however rigidity can be a feature
• Males and females are diagnosed equally
• Symptoms usually appear between 35-55 years
• Juvenile HD appears in youth 20 years and under in 10% of cases
• Late-onset HD appears in the older population 60+ in 10% of cases
• In North America, the prevalence of the disease ranges from 4 to 8 cases per 100,000 persons

Etiology

• The disease is caused by a mutation in the gene for the huntingtin protein, located on chromosome 4
• The mutation causes an excessive replication of the cytosine, adenine, and guanine (CAG) sequence
• Each child with a parent that has HD has a 50/50 chance of inheriting the HD gene
• A child who doesn’t inherit the gene will not develop the disease or pass it on
• It is inherited as an autosomal dominant disorder

Pathophysiology

• Pathologic findings show brain tissue changes
• The ventricles are enlarged due to atrophy of the basal ganglia, specifically the caudate nucleus and putamen
• This is due to the loss of small and medium-sized neurons
• The volume of the brain can decrease by 20%
• With the loss of neurons, neurotransmitters are affected
• The normal balance of excitation and inhibition responses in the basal ganglia and thalamus is disrupted

Physical Signs & Symptoms

• Weight loss
• Involuntary movements (chorea)
• Diminished coordination
• Difficulty walking, talking, and swallowing
• Impairment in voluntary movements, impacting work, ADLs, communication, and independence

Cognitive Signs & Symptoms

• Difficulty with focus, planning, recall of information, and making decisions
• Impaired insight

Emotional Signs & Symptoms

• Depression, potentially due to brain injury and changes in brain function
• Apathy
• Irritability
• Anxiety
• Obsessive behaviour

Early Stage

• An individual is still able to function well at work & home
• Early symptoms include difficulty with organizing routine and coping with new situations
• Decreased ability to recall, make decisions, and attention to detail
• Mood changes, irritability
• Minor involuntary movements ("nervous" activity, fidgeting, twitching, excessive restlessness)
• Changes in handwriting, difficulties with daily tasks like driving

Intermediate Stage

• Increased difficulties with working, managing household, but still able to deal with ADLs
• Symptoms progress from early stage
• More obvious involuntary movements (chorea)
• Increased difficulties with walking, coordination, and balance
• Challenges with speaking, can be slurred
• Problem-solving becomes more difficult
• Difficulties with swallowing
• Weight loss due to energy expenditure from choreoathetoid movements

Advanced Stage

• Individuals are not able to manage ADLs & usually require professional care
• Symptoms include a decrease in involuntary movements & increase in rigidity
• Increased difficulties with swallowing
• Diminished ability to communicate, but understanding what is being said remains possible
• Significant weight loss
• Dementia
• Bradykinesia
• Dystonia - involuntary muscle contractions

Juvenile Huntington Disorder (JHD) and Late Onset Huntington Disorder (LOHD)

• JHD follows a more rapid course, chorea is less prominent & may be absent altogether
• LOHD is diagnosed past 60 and is sometimes misdiagnosed because doctors think it is too old to develop HD
• Typical onset is 35-55

Juvenile Huntington Disorder - Initial Symptoms

• Slow, stiff movements (rigidity), sometimes tremors
• Seizures, falls, clumsiness
• Contracted & rigid muscles that affect gait (especially in young children)
• Difficulties learning in school, attention deficits
• Increase in responsive behaviours

Diagnosis

• Based on clinical symptoms, family history, and genetic testing
• There is no current diagnostic testing
• Other tests to help contribute to diagnosis
• Neurological examination
• Neuropsychological testing
• Psychiatric evaluation
• MRI, CT, genetic counseling & testing, predictive genetic tests

Treatment

• No cure, symptom management
• Medications to help control chorea-dancing gait (eg. Botox)
• Meds for psychiatric disorders: antidepressants, antipsychotics, mood-stabilizing drugs
• Psychotherapy – psychiatrist, psychologist, clinical social worker
• Speech therapy to help them talk
• Physical therapy to keep muscles and joints strong
• Occupational therapy to help with daily life, changing their living spaces etc.

Massage & Clinical Manifestations

• Classic choreiform movements: piano-playing motions in fingers, facial grimaces
• Trunk involvement, dancing gait
• May appear off balance, but the ability to balance is well preserved
• Patients who develop HD by aged 35 years often become bedridden within 15-20 years
• Patients may be argumentative, impulsive, or erratic
• Sleep disorders
• Urinary incontinence
• Muscle strength usually normal
• Tendon reflexes are usually normal

Amyotrophic Lateral Sclerosis (ALS)

• Also known as Lou Gehrig's Disease
• Progressive, fatal neurodegenerative disorder with no cure

ALS Characteristics

• LMN (Lower Motor Neuron) has decreased reflexes
• Gradual paralysis due to degeneration & scarring of the motor neurons in the lateral aspect of the spinal cord, brainstem & cerebral cortex
• Upper motor neurons from the brain extend to the brainstem & spinal cord synapse with lower motor neurons

Motor Neurons

• Lower motor neurons send nerve impulses to contract
• Motor neurons gradually breakdown & die, and muscles become weak/atrophied leading to paralysis

Areas Not Affected

• Areas of the brain controlling coordinated movements (cerebellum) and cognition (frontal cortex)
• About 80% of people die within 2-5 years of diagnosis and some can live 10+

Etiology of Dementia

• Cause is unknown
• Multifactorial based on changes in a person's genes
• 20% more common in men than women
• Mutations of a gene that produces SOD1 enzyme are linked with ALS
• This enzyme is a powerful antioxidant that protects the body from damage caused by free radicals

Risk Factors - Heredity

• 5-10% is passed on from parent to child
• Children have 50/50 chance of developing the disease

Risk Factors - Age

• Risk increases with age, most common between ages 40-60

Risk Factors - Sex

• Before age 65, men are slightly more at risk than women
• Disappears after 70

Risk Factors - Genetics

• Some studies show similarities in genetic variations in familial ALS and some in sporadic ALS, leading to more susceptibility

Environmental Risk Factors - Smoking

• Greater for women, especially post-menopause

Environmental Risk Factors - Environmental Toxin Exposure

• Some studies suggest exposure to lead, more research is needed

Environmental Risk Factors - Military Service

• Studies indicate those who have served are more at risk
• Causes are unsure such as exposure to metals, chemicals, traumatic injuries, viral infections, intense exertion

Types of ALS

• Sporadic ALS
• Familial ALS
• Bulbar ALS

Sporadic ALS

• Most common, can affect anyone, most often affects people between the ages of 40-60

Familial ALS

• From parent to child, 5-10% of cases are inherited, the rest are unknown

Bulbar ALS

• 30% of cases
• Early stages motor neuron in the corticobulbar area of the brainstem is affected, which affects muscles of the head, face, and neck. Paralysis occurs first

Symptoms - Potential Early Signs

• Tripping
• Steppage or foot drop gait (also in diabetic neuropathy and Charcots-Marie-Tooth)
• Dropping things
• Slurred or "thick" speech
• Difficulties swallowing
• Weight loss
• Decreased muscle tone
• SOB
• Increased or decreased reflexes
• Uncontrollable periods of laughing or crying

Symptoms

• No sensory deficit
• Speaking problems
• Breathing problems
• Eating problems
• Anxiety and depression
• Dementia

Upper Motor Neuron Symptoms

• Tight and stiff muscles - spasticity
• Hyperreflexia
• Positive Babinski's sign

Lower Motor Neuron Symptoms

• Muscle weakness and atrophy
• Muscle cramps
• Fleeting twitches or muscles that can be seen under the skin - fasciculations

Diagnosis

• EMG tests electrical activity of muscles at rest, diagnosis/rule out
• Nerve conduction study measures nerve's ability to send impulses
• MRI detects spinal cord tumours, herniated discs in the neck causing symptoms
• Blood and urine tests help eliminate other signs and symptoms
• Muscle biopsy is a differential diagnosis of muscle diseases

Medical Treatment

• Treatments are designed to relieve symptoms and improve the quality of life for patients
• Riluzole: taken orally, increase life expectancy by 3-6 months
• Edaravone: intravenous, reduces the decline of daily function
• Drugs to control drooling (anticholinergic), spasticity (baclofen, diazepam), constipation, fatigue, pain, depression, sleep issues, uncontrolled outburst of laughing or crying

Other Therapies

• Breathing care
• Physical therapy
• Occupational therapy
• Speech therapy
• Nutritional support
• Psychological & social support

Massage Treatment

• Prevents respiratory complications; respiratory failure and inability to eat are final stages of ALS
• Spasticity contributes to weakness; consistent slow stretching that decrease tone may benefit
• Cramps respond to daily stretching
• Ankle dorsiflexion is lost before loss of strength in plantarflexion
• Hamstring strength appears to correlate with walking and the decrease is parallel with the loss of walking ability
• Contractures should be routinely stretched taking care to support the joints as there is minimal control of muscle activity in late stages
• Abdominal muscles to help increase inspiration when diaphragm and intercostal muscles become weak

Massage Outcomes

• Maintain function of respiratory muscles
• Decrease stiffness / maintain ROM / prevent or decrease contractures
• Promote relaxation / improve mood
• Maintain joint health
• Prevent or reduce edema
• Prevent deep vein thrombosis (DVT)
• Promote muscle function
• Decrease pain