Exam 2: Huntington's Disease Presentation Flashcards
What is Huntington’s Disease?
Huntington’s Disease (HD) is “…an inherited disorder that causes
nerve cells in parts of the brain to gradually break down and die.
The disease attacks areas of the brain that help to control
voluntary (intentional) movement, as well as other areas. People
living with HD develop uncontrollable dance-like movements
(chorea) and abnormal body postures, as well as problems with
behavior, emotion, thinking, etc.
Anatomical & Physiological Aspects of HD
Motor / Physical Symptoms
○ Voluntary Movement Difficulties:
■ Bradykinesia - slowness of movement
■ Akinesia - delayed start of movement
■ Uncoordinated movement
■ Motor impersistence- inability to sustain a movement
■ Difficulty with rapidly alternating movements
■ Difficulties performing sequences of movements
○ Involuntary Movement Difficultes:
■ Chorea- brief, irregular movements
■ Dystonia - abnormal, sustained positioning of a part of the body
Stages of HD
○ Early
■ Symptoms may include minor involuntary
movements, subtle loss of coordination
■ Eye tremors
■ ADLs
○ Middle
■ Increasing difficulty with voluntary motor tasks
■ Problems with swallowing, balance, falls, and
weight loss
■ Loose some ability to do ADLs
○ Late
DNA
Deoxyribonucleic Acid: Molecule that
carries genetic information for the
development and function of an organism
Amino Acid: Molecules that
combine to form proteins.
● Break down food
● Grow
● Repair tissues
● Other bodily functions
Essential Amino Acids vs.
Nonessential Amino Acids
Etiology
CAG = Glutamine
CAG = Glutamine -> Mutation in the
gene for the
huntingtin protein
Etiology Cont.
No risk: <27 CAG repeats
Low risk, but can pass on gene: 27-35 CAG repeats
High risk, presence of HD: >36 CAG repeats
Dominant mutation:
50% chance of inheritance from 1 parent with HD gene
(NINDS, 2023)
Onset:
● Symptoms typically develop in the 30’s & 40’s
● Mild clumsiness, cognitive impairment, psychiatric symptoms,
changes in behavior
● Juvenile Huntington’s disease (~60 CAG repeats)
Risk Factors: N/A
● Gender?
● SES?
Effects on Speech & Voice
“Speech that is slurred and/or uncoordinated due to CNS or PNS problems that affect one or
more of the following: respiration, phonation, resonance, and articulation ”
● Hyperkinetic Dysarthria:
○ Extraneous, involuntary movements
○ Affects various speech elements: voice (prosody, hoarseness, volume, pitch,
hypophonia); speech (rate, fluency, irregularity in articulation, slurred speech,
intelligibility)
Effects on Cognition
● Impaired cognitive domains include
○ Executive function, mental flexibility, psychomotor performance, attention,
working memory, and emotional recognition
● Psychiatric and behavioral symptoms include
○ Irritability, depression, suicidal ideas or attempts, anxiety, apathy, obsession,
paranoia and hallucinations
● Disorientation in time and space can occur
● Visuospatial and visual perceptual impairments
It has been found that psychopathology and cognitive dysfunction may precede the
onset of motor symptoms in many patients.
Neuropathology and environmental stress influence the occurrence of psychiatric
symptoms.
Effects on Language
● Word finding difficulties
● Reduced vocabulary
● Decreased syntax complexity
● Delay in understanding/processing of spoken language
Individuals with H.D. typically use simple language and respond to others
slowly due to these deficits. Communication with those with H.D. require time
and patience.
“Speech and language difficulties in Huntington’s disease: a qualitative study of patients and
professional caregiver experiences”
● Study included 7 individuals with H.D. and 7 professional caregivers
● Interviews were conducted with each participant
● Results emphasized that those with H.D. are aware of their language, speech and cognitive
deficits. The interviews highlighted specific challenges, situations and experiences the
participants found difficult
Effects on Swallowing
Dysphagia is a medical condition characterized by difficulty or discomfort in swallowing
food or liquids. In HD patients, dysphagia is a well-recognized feature that can lead to
malnutrition and aspiration pneumonia, a common cause of death in HD.
Dysphagia in HD patients may result from the impairment of motor and sensory
components:
● Altered coordination
● Inadequate timing of swallowing events
● Poor oral control
● Delayed pharyngeal response
● Uncoordinated laryngeal closure
● Ineffective or uncoordinated protective mechanisms
● Pharyngeal residue
Symptoms of Dysphagia in HD
patients
The major cause of Aspiration Pneumonia is silent Aspiration, a condition in which
food or liquid enters the airway without any signs of symptoms, such as coughing or
choking
According to the study by Schindler et al. (2020): Silent aspiration was found in 7.7%
of HD patients in early-stage, 11.8% in moderate-stage and 27.8% in advanced-
stage.
Another study by Manor et al. (2018) found that the main manifestation of dysphagia
in HD is oropharyngeal dysphagia. The severity of decline in both cognition and motor
function together with the severity of the HD in general correlated with the severity
of dysphagia.
Dysphagia symptoms that HD patients experience includes:
● Tongue protrusion
● Delayed swallowing reflex
● Solid food residues
HDQLIFE
The
Huntington Disease Health-Related Quality
of Life (HDQLIFE), a measurement system
designed to capture health-related quality
of life across several domains including
swallowing dysfunction. The swallowing
domain examines the impact that
difficulties with swallowing or choking have on eating and overall well-being.
Assessment on Swallowing
The Yale (Yale Pharyngeal Residue Severity Rating Scale) is a used to assess the severity of pharyngeal residue after
swallowing. The scale ranges from 1 (no residue) to 5 (severe
residue). YALE score is one of the parameters used to evaluate
the efficacy of swallowing in HD patients using FEES.
FEES visualizes the anatomy of the pharynx and larynx, and can
detect signs of dysphagia. It could be more sensitive than VFSS to identify tracheal aspiration and post-swallow residue, which are closely related with aspiration pneumonia.
Treatment
International Guidelines for the Treatment of
Huntington’s Disease.
-The European Huntington’s Disease Network (EHDN) provides scientific and
consensual guidelines from 15 European experts from the national and steering
committees and 73 additional experts from 25 other countries
● Occupational Therapy:
○ Strategies and protective measures for continuing ADLs
● Physical Therapy:
○ Body motor function, balance, mobility
● Speech-Language Therapy:
○ Oral motor function, cognition, expressive and receptive
language, speech sounds, voicing, swallowing strategies
● Psychologists & Psychiatrists
