Mental Flexibility

HE sufferers may sometimes seem rather inflexible and mentally rigid. They may adhere to set behaviour patterns or routines and appear unwilling to adapt to new situations or altered circumstances. They are not being deliberately obstinate. The brain changes that occur in HD can impair the ability to think flexibly and to adapt easily to novel situations. Patients generally feel most comfortable and confident in highly familiar situations, involving a fixed routine. If the patients appears to need routine, then it is worthwhile trying to accommodate this; it does not mean that variety or a stimulating environment is inevitably sacrificed, it is simply that a structure is imposed on the patient’s day so that he/she knows what will happen and when.

Doing Two Tasks at Once

Many everyday situations involve people doing more than one activity at a time e.g. answering the children’s questions while cooking or watching the television while doing the ironing. Doing two things at once requires the mental flexibility to switch attention rapidly between tasks - however engrossed in the television programme one may be it is essential to keep switching attention back to the ironing to avoid burning the clothes. HD can impair rapid switching of attention, making it difficult for sufferers to carry out two tasks at once effectively. In contrast many HD sufferers are very good at sustaining attention on a single task, provided they are not distracted. "One thing at a time" is a good general rule. Overloading what the patient can cope with at one time may be one source of patient’s irritability and disruptive behaviour.

It is worth remembering that a physical activity such as walking, requires much more conscious attention for the HD sufferer than for other people. An HD patient may find it difficult to carry on a conversation at the same time as walking and may sometimes be noted to stop walking before answering a question. This is because both activities require conscious attention. To carry out both simultaneously would require rapid switching of attention from one to the other. The HD patient who has difficulty rapidly switching attention is obliged to stop one activity before embarking on the other.

Quality of Performance

It is not uncommon for HD sufferers to carry out everyday tasks less efficiently than before. For example, in writing a letter a patient may miss out words; in washing dishes, plates may not be properly cleaned. Indeed, for many sufferers reduced efficiency is the precipitant of medical retirement from work. The poorer quality of performance on tasks may be a source of irritation to patients’ families who may perceive the sufferer as being ‘slapdash’ or ‘not bothered’. It is not the case that the patient is simply not trying. In fact many patients put an enormous amount of effort into their activities. The errors arise as a result of the changes that take place in the brain. HD patients do not forget how to do a task. What becomes impaired is the ability to self motivate and check the results of one’s own performance. The patient is often is aware of errors that are apparent to others.

Encouraging the patient to carry out tasks is a good thing. However, it is worth being aware of - and trying to accommodate - the patient’s possible limitations. In the case of the patient who lacks initiative, it falls on other family members to act as a ‘stimulator to action’. So too, in the case of a patient who carries out tasks inefficiently ‘checking’ procedures are dependent upon others.