What are the presenting symptoms of Huntington's disease?

Presenting Symptoms of Huntington's Disease

The primary presenting symptoms of Huntington's disease include choreic movements, cognitive decline, and psychiatric disturbances, which together form the classic triad of manifestations in this neurodegenerative disorder. 1

Motor Symptoms

• Chorea: Involuntary, flowing, non-stereotyped movements with a writhing quality are the most recognizable and characteristic motor symptoms 1
• Impaired voluntary movements: Including incoordination and gait balance problems 2
• Deficits in stepping response time: Associated with balance impairments and increased fall risk 3
• Dystonia: Particularly prominent in juvenile-onset cases 4
• Bradykinesia: Progressive slowing of movements as the disease advances 4

In juvenile-onset HD (approximately 5% of cases), the presentation differs significantly:

• Rigidity and spasticity predominate rather than chorea 1
• Motor symptoms appear before age 20 1

Cognitive Symptoms

• Progressive cognitive decline: Affecting all psychomotor processes 4
• Learning difficulties: Particularly notable in juvenile-onset cases 4
• Attention deficits: Difficulty maintaining focus and concentration 5
• Slowed thinking processes: Progressive retardation of cognitive functions 4

Psychiatric Manifestations

• Depression: Often one of the earliest psychiatric symptoms 5
• Irritability and aggression: Can be prominent and challenging to manage 5
• Anxiety: Common and may precede motor symptoms 5
• Apathy: Progressive loss of initiative and interest 4
• Psychosis: Less common but can occur as disease progresses 4
• Behavioral disturbances: Including impulsivity and personality changes 1
• Suicidal thoughts: Require careful monitoring and intervention 5

Disease Onset and Progression

• Typical age of onset is 30-50 years 4
• Juvenile onset (before age 20) is associated with:
  • Longer CAG repeats (often exceeding 55) 4
  • More rapid disease progression 1
  • Predominance of rigidity rather than chorea 1

Diagnostic Considerations

• Symptoms result from selective neuronal loss, particularly in the caudate nucleus and putamen 1
• MRI findings include progressive atrophy of the neostriatum, particularly the head of the caudate nuclei 6
• Genetic testing for CAG repeat expansion in the HTT gene is the definitive diagnostic test 1
• It's important to note that imaging may be normal early in the disease course, even when genetic testing is positive 6

Clinical Pitfalls

• Early psychiatric symptoms may be misattributed to primary psychiatric disorders rather than recognized as the initial manifestations of HD
• Subtle motor symptoms might be overlooked in the early stages of disease
• Juvenile-onset HD can be misdiagnosed due to its different presentation (rigidity rather than chorea)
• Family history may be absent or unknown in some cases, delaying diagnosis
• Cognitive symptoms may be mistaken for other forms of dementia if choreic movements are not yet prominent

Understanding this constellation of symptoms is crucial for early recognition and appropriate management of Huntington's disease, as early intervention can help improve quality of life even though there is currently no cure for the underlying disease process.