Symptoms and Diagnosis
Symptoms
Huntington’s disease patients display a wide variety of symptoms throughout the progression of the disease. The number of CAG repeats in the patient’s Huntingtin genes determines the earliness of onset of these symptoms. In most cases of adult-onset Huntington’s disease, the first symptoms that are visible are largely behavioural. Diagnosis may not occur at this stage as alterations in behaviour can occur without causing suspicion. These symptoms then progress over time and increase in intensity as more physical signs of decreased motor control are introduced. As the disease progresses further into late stages often dementia sets in to provide further mental and behavioural consequences.
Behavioural
The behavioural symptoms that may become apparent in Huntington’s disease patients include;
- Anxiety
- Depression
- Hallucinations
- Paranoia
- Psychosis
- Aggression
- Addictive behaviour (drinking, gambling etc)
- Personality changes
Motor control
Symptoms concerning a loss of motor control and coordination may become apparent as the disease progresses further. These include;
- Chorea
- Lack of coordination
- Rigidity
- Postural abnormalities
- Problems swallowing
- Speech impairment
- Abnormal facial expressions
Dementia
In later stages, Huntington’s can lead to dementia due to the break down of neural tissue. This can slowly get worse over time and includes;
- Memory loss
- Impaired judgement
- Changes in speech pattern
- Changes in the individual's personality
- A state of confusion or disorientation
Other symptoms
Other symptoms which have been observed in Huntington’s disease patients include weight loss and sleep deprivation.
Juvenile HD
In the juvenile form of the disease, a much smaller range of symptoms is typically seen. Instead of the large range of symptoms which changes over time, usually predominantly physical symptoms associated with motor control are seen. These include:
- Rigidity
- Slow movements
- Tremor
Diagnosis
In diagnosing the disease, a physician will perform physical tests on the patient to determine whether any of the symptoms involved in impaired motor control are present. DNA marker studies may be carried out to determine if an excessive number of CAG repeats are present in the patient’s huntingtin gene which would signify the likelihood of the individual developing the disease.
As this is a genetic disorder, research into the family history of the patient would take place to determine if the there is a history of the disease in the family. Any evidence found would greatly increase the chance of the patient contracting the condition.
As this disease affects and causes damage in neural tissue, a full neurological examination may be necessary. This would include CT, MRI or PET scans to detect any deep brain damage which may be indicative of the presence of Huntington’s disease.