The symptoms of HD can be clustered into 3 major groups:
Physical Symptoms
Cognitive Symptoms
Personality or Emotional Symptoms
‘SYMPTOM WATCHING’
There is no specific order or sequence to the symptoms for HD. Just as we are all individuals, the expression of and response to HD is different for each person. However, the symptoms begin gradually - the early signs are mild and can increase so slowly that they may go unnoticed and it is only much later, when looking back, that relatives realise all has not been well for some years. Generally speaking, the older the age of onset, the slower the condition will progress.
Early physical symptoms may include some mild twitching of the fingers and toes and perhaps the face or limbs. He or she may feel a little less coordinated, fumbling or knocking things over.
As the disease progresses, walking may become more challenging and, as coordination decreases, people affected by HD may begin to trip, bump into objects or people in their path, or fall.
The twitching gradually becomes more jerky and exaggerated. This movement of the arms and legs is referred to as ‘chorea’. It can be exhausting for the individual with HD, who has no voluntary control over these movements. Chorea is the most common symptom, although a small number of people with HD have no chorea at all.
As the disease progresses, speech becomes slurred and increasingly difficult to understand, and swallowing is difficult and uncoordinated.
The term ‘cognitive’ refers to tasks of the brain concerned with knowing, thinking, planning, judging and remembering. In the early stages of HD, there may be little evidence that these functions have been affected, but gradually, some subtle changes will be detected.
Short-term memory may be reduced.
Tasks requiring intense concentration or much planning and judgement may become more difficult.
While HD does impact upon memory, concentration, planning and judgement, it does not affect a person’s orientation. In other words, people affected by HD can be expected to know and recognise the people about them as well as know where they are and what day it is.
As with the physical and cognitive symptoms, changes to personality will initially be quite subtle.
In the early stages of HD, a person may be more irritable or moody than previously. The person may display unreasonable outbursts of anger that are out of character for the individual. Depression is common in about one third of all people affected by HD. As the disease progresses, apathy may be demonstrated or the individual may become more impulsive. Some people with HD laugh or smile at inappropriate times or may feel like crying for no apparent reason. Usually, the changes are an exaggeration of an existing personality trait; for example, a person who worries about things may become over anxious.
The illness has its ups and downs and some days the involuntary movements and irritability are less. This changing state is confusing and frustrating for both sufferers and their families/carers.
The illness usually lasts 15 - 20 years, although it may be considerably longer.
The expression of Huntington disease varies from person to person. While some of the cognitive or emotional symptoms may be quite pronounced for one person, they may be much less for another. However, for all people, HD is progressive.
For those people who are at risk for Huntington disease, the practice of ‘symptom watching’ is common. Symptom watching occurs when people are carefully noting all that they do in an effort to try to detect symptoms of the condition. Much anxiety and energy can be expended monitoring behaviour and feelings, observing movements or worrying about a one-off fumbling incident.
Symptom watching is a natural and understandable response to being at risk for Huntington disease but it can also be very stressful. Many of the early symptoms for HD such as fumbling, moodiness or forgetfulness are also experienced by members of the wider population (not at risk for HD). Particularly when they are under stress. Those at risk for Huntington disease may misinterpret such feelings, behaviours or actions as HD. If this happens, they may find themselves entering a confusing cycle with anxiety leading to irritability, fumbling and/or forgetfulness with each of these again being interpreted as symptoms of HD.
