INTRODUCTION AND PHYSIOTHERAPEUTIC MANAGEMENT OF HUNTINGTON DISEASE

Introduction: Huntington Disease is a neurodegenerative disease, which is inherited and causes brain cells that are called neurons, to die in various areas of the brain. These areas are specifically the ones which help in controlling voluntary movements.

1. HD is an inherited autosomal dominant disease
2. It is a Progressive hereditary disorder in which symptoms can develop at any time of age but usually appears in adult life .(30s or40s)
3. It is generally characterised by Movement disorder (CHOREA), Dementia and Personality disorder. Symptoms vary from person to person

Movement disorders related with Huntington’s disease can include both involuntary movement problems as well as voluntary movement impairments .

1. Involuntary jerky movements or writhing movements(Chorea)
2. Rigidity or muscle contractures (Dystonia )
3. Abnormal or slow eye movements
4. Difficulty in swallowing or speech
5. Impaired gait , posture and balance

Impairment in voluntary movement may result in greater impact on Person’s ability to work , perform ADL ( activity of daily living) and communication rather than impairment in involuntary movements

1. Difficulty in organizing ,focusing on tasks, prioritizing
2. Difficulty in learning new information
3. Slowness in processing thoughts or finding words
4. Lack of awareness of ones own behaviors and abilities
5. Acting without thinking and sexual promiscuity, lack of impulse control that can result in outbursts
6. Lack of flexibility or tendency to get stuck on a thought , behaviour or action

The most common psychiatric disorder associated with HD is depression ,this doesn’t imply that it is a charachteristic features to diagnose HD.

1. Feeling of irritability , sadness or apathy
2. Social disconnection
3. Insomnia
4. Fatigue and loss of energy
5. Frequent thoughts of death, dying or suicide

It occurs due to mutation of HTT GENE .The function of this gene to form a protein called Huntingtin ,which play a crucial role in the neuron in the brain.

The mutation of HTT gene involves a DNA segment called CAG trinucleotide . The segment consist of three DNA building blocks which appear multiple time in a row.

1. Presymptomatic
2. Prodarmal
3. Early
4. Advanced

Intially ,damage to the brain is regionally specific with dorsal striatum in the subcortical basal gangalia being primarily affected The caudate nucleus , Putamen ,Globus pallidus ,Subthalamic nucleus, Substantia nigra collectively form Basal ganglia which in coordination control and inhibit unwanted movements .

Basal ganglia has special type of neuron which is inhibitory in nature know as Striatal medium spiny neurons and inhibits unwanted movements . In this disease we can see denegeneration of medium spiny neurons which results in the uncoordinated surge of movements which leads to chorea like or dancing like phenomena .(Striatal medium spiny neurons are the most valuable , particularly ones with pojections towards the external globus pallidus) .

The CAG repeats give rise to glutamine residues ,and excessive of glutamine residues can lead to aggregation of these proteins which lead to degeneration of medium spiny neurons .

Genetic basis of Huntington disease include inheritance pattern which is an autosomal dominant disorder .

If one individual has one faulty chromosome that is one has mutated Huntington gene and is married to a normal women so that it is likely that two out of four of their offspring would have HD(That means a person need only one copy of the nontypical gene to develop the disorder).

Choreic movements are the most striking and diagnostic feature of the disease. The somatic muscles are affected randomly and choreic movement flow from one part to another .Proximal , distal and axial muscles are involved . In early stage there is slight grimacing of the face , intermittent movement of eyebrows and forehead ,shrugging of shoulder, jerky movements of limbs. As the disease progresses, walking is associated with intense arm swing and leg movement which cause dancing ,prancing and stuttering type of gait .

Motor impersistence or inhibitory pauses during voluntary movements (contraction ) accounts for milkmaid grip , dropping of objects and inability to keep the tongue steadily protruded. Choreic movement may disappear and be replaced by muscular rigidity and dystonia .

To improve pre - symptomatic stage therapist have to improve exercise capacity

Exercise in early stage of HD should include Goal setting and home exercise programs.

1. Aerobic exercise – It can be simple walking as well, 3-5 times in week for 30 mins , intensity 65-85% of maximum heart rate , 55-66% of max heart rate for deconditioned individual.
2. Resistance exercise-To maintain muscle strength and improve aerobic capacity .Frequency and duration 8-12 repetition per exercise , one set of 8-10 exercise that conditions large muscles.

1. Stratergy training in daily activities:- In executive dysfunction – for example a person forgets the steps to make coffee or even steps in motor action (getting up from the chair )
2. Sensory stimulation – in the form of deep tissue resistance to increase proprioception .
3. Cueing :Visual or physical prompts for walking

1. To test balance ,therapist can use time up and go test –in this patient stand up from chair and walks for 3 meter and again sit on the chair ,If time exceeds from 12 sec patient is prone to fall.

-Anticipatory –in this a person knows that there is going to be destabilizing force and how they avoid falls is the catch.

-Reactive – in this a person steps on an obstacle and how they will balance, is the catch .

1. Obstacle crossing
2. Fall prevention –Internal and external factors
3. Safe fall techniques

1. In this problem of contracture is a major issue .
2. Prevent further cognitive and psychological deterioration
3. Improve strength
4. Balance strategies
5. Motivate patients to regain some control of their lives by adopting a healthy lifestyle.
6. Weight control
7. Pain management –introducing patient to pain neuroscience education ,in this they can learn how pain is perceived and can desensitized by ones thought process.

1. Prevent or limit soft tissue adaptive changes
2. Minimize risk of infection and skin breakdown
3. Maximize independence in sitting and facilitate appropriate positioning.
4. Maximize functional ability – eating , reaching task , dressing , self positioning , transfers.

1. Functional exercise and ADL training , positioning to manage breathlessness
2. Breathing exercises – glossopharyngeal breathing
3. Airway clearance techniques
4. Postural management
5. Consultation for appropriate walking aids eg . wheeled walker / rollator ( cardiovascular exercise training ).

1. Minimize risk of aspiration / respiratory infection
2. Minimize risk of red sore
3. Maintain upright sitting position
4. Maintain/ increase range of motion
5. Maintain existing ADLs.
6. Positioning , ROM, Respiratory care.