Huntington's Disease: A Case Study

//This page is currently under revision by Queen's MScPT students in the course PT858 lab group 6. The scope of this article is to describe the characteristics and care related to the earliest clinical stage of Huntington's Disease.

Title: Huntington's Disease: A Case Study

Abstract

This is a fictional case study involving a 41-year-old male presenting with early-stage Huntington’s disease. Our case study encompasses the presentation of the patient, appropriate interventions, interdisciplinary care and functional outcomes one year after the initial visit. This patient presented with difficulty manipulating and gripping objects in his workplace as a teacher. Cognitive effects were also noted, including apathy and emotional outbursts. We concentrated on his patient-specific goals in tandem with the understanding that he has a progressive disease that will require ongoing and proactive treatment. Aerobic training was introduced as well as respiratory muscle training to combat the eventual symptoms of respiratory failure. Other interdisciplinary professionals were involved in his care and referrals were made at the follow-up visit to a speech-language pathologist and social worker. The patient’s outcomes for fine motor tasks were significantly reduced one year later; however, aerobic capacity increased over time due to physiotherapy interventions.  

Outcome

We followed up with Mr. Magee one year later and have summarized the results of his assessment below:

• Initial 6MWT distance of 450.7 meters increased by 34.2 meters to 484.9 meters.
• Upon observation, chorea has become more proximal in upper extremities only, affecting the elbow joint bilaterally in addition to previous symptoms at the wrist and fingers.
• BBS score has decreased from 54 to 44 (increased risk of falls in typical population)

• Mr. McGee’s progressive decline in speech function has necessitated referral to Speech Language Pathologist.
• Mr. McGee’s condition has put tremendous strain on his family’s mental health and well-being. His ongoing interdisciplinary care services are very costly, and these financial stresses have been negatively contributing to his family’s functioning. These factors suggest that Mr. McGee is a strong candidate for referral to a Social Worker.
• PSFS scores for:

• Holding and writing with chalk: 7 (initial: 9)  
• Handwriting on paper: 5 (initial: 8)

• Typing on the keyboard: 6 (initial:9)
• Overall average: 6 (initial: 8.67)

Referrals

1. Speech language therapist for assessment of speech impairment and assistive strategies.
2. Social worker for familial support, counselling, and advocacy in accessing financial support
3. In-home community physiotherapy care from advanced practice neuro physiotherapist for continuation of physiotherapy services

Discharge

Discharge is not yet indicated for this patient, as Huntington’s disease is progressive and will worsen with time. Mr. McGee is currently managing his symptoms well and can continue physiotherapy treatment as needed.

Discussion

Rex McGee is a 41-year-old male diagnosed with early-stage Huntington’s disease. During the initial assessment, Mr. McGee presented with chorea in distal upper extremities and reported behavioural symptoms such as apathy. He showed limitations in activity measured by the outcome measures PSFS, TUG, BBS, 6MWT, and Borg-10. Treatment interventions were aimed at improving patient-stated functional tasks such as typing on a keyboard or writing on a chalkboard (e.g., handwriting task). Interventions also included treatments that would be beneficial for Mr. McGee in the future, as Huntington’s disease is a progressive degenerative disease (e.g., aerobic exercise, respiratory muscle training [20]).  

The following treatments were implemented at the patient’s initial visit: respiratory training, aerobic training, postural and balance training, education on conservation of energy during movement, and training on functional reach and grasp activities. Respiratory muscle training was advised due to the inevitable effects of Huntington’s disease on respiratory muscles and the resultant atrophy [20]. Aerobic and functional reach and grasp activities were related to the patient’s individual goals of walking with his family and being able to manipulate objects at work. Since the patient reported having difficulty with fatigue, he was educated on energy conservation during movement to enable more efficient movement. Balance and postural muscle training were initiated for the same purpose, to achieve more functional movement and limit the risks of fatigue, in preparation for eventual atrophy of respiratory muscles. Busse (19) suggests that physiotherapy intervention soon after diagnosis of early to middle stages of Huntington's disease can have a positive impact on motor and functional performance and may even slow the decline. Therefore, implementing these treatments early in the disease will inevitably be beneficial for Mr. McGee.

Evidence-based clinical recommendations for patient management of Huntington’s disease continue to evolve as further research is developed. Physiotherapy interventions for Huntington's disease focus on maintenance of physical activity, physical functioning, and reduction of impairments secondary to mobility limitations [18]. Physiotherapy interventions that emphasize physical activity and exercise translate to patient perceptions of improved gait and balance, improved self-confidence and self-efficacy, and improved mindfulness and communication, especially when interventions emphasize personal enjoyment, meaningfulness, and relevance as much as possible [18]. The progressive nature of Huntington’s disease necessitates interdisciplinary care and continual engagement within the circle of care so that the patient and their family are optimally supported.  

Self-study Questions

1. Which of the following measurement scales is considered the gold standard for assessing the progression of Huntington's disease motor symptoms?

1. MDS-UPDRS
2. MDS-UHDRS
3. 6MWT
4. TUG

Huntington’s disease is characterized by progressive degenerative changes in which of the following systems?

1. Cognitive
2. Behavioural
3. Movement
4. A and C
5. All of the above

Based on what you know of the genetic nature of Huntington's disease, which is the correct statement below? Huntington’s disease is...

1. Autosomal recessive
2. Allosomal recessive
3. Autosomal dominant
4. Allosomal dominant

Answers: (1) A (2) E (3) C

Explanation for (3): The gene for HD is found on chromosome #4 therefore it is autosomal. Allosomal (‘sex chromosomes’) are only for the chromosome pair #23. HD is a dominant gene, meaning that only one of the two chromosomes in a pair possessing the HD gene will express the disease.

References

https://physio-pedia.com/Queen's_University_Neuromotor_Function_Project