Perceptual Problems

HD causes deficits in spatial perception. The mental manipulation of personal space is impaired, even early in the disease. For instance, the judgment of where the body is in relation to walls, corners or tables may be disturbed, resulting in falls and accidents.

Precautions might include carpeting the floors and removing furniture with sharp corners to the periphery of the room, where it will be out of the patient's path. Behavior problems reported by family members are often due to another kind of impaired perception, unawareness of changes due to HD, which can lead to challenges in providing care.

Unawareness

Denial is commonly considered a psychological inability to cope with distressing circumstances. We often see this in situations such as the loss of a loved one, a terminal disease, or a serious injury. This type of denial typically recedes over time as the individual begins to accept his losses.

Individuals with HD often suffer from a more recalcitrant lack of insight or self-awareness. They may be unable to recognize their own disabilities or evaluate their own behavior. This type of denial is thought to result from a disruption of the pathways between the frontal regions and the basal ganglia. It is sometimes called "organic denial," or anosognosia, and is a condition that may last a lifetime.

We recommend that "unawareness" be used to describe this type of denial in HD to distinguish it from the more familiar kind and to avoid thinking of patients with HD as suffering from a purely psychological problem.

Unawareness often plays a significant role in seemingly irrational behavior. At first unawareness may be beneficial because it keeps the individual motivated to try things and to avoid labelling himself. In this way it may prevent demoralization. On the other hand, unawareness may lead to anger and frustration when the individual cannot understand why he cannot work or live independently.

The HD patient with unawareness sometimes feels that people are unjustifiably keeping him away from activities that he could do, such as driving, working, or caring for children, and may attempt to do these things against the advice of family and friends. This type of unawareness can become dangerous.

Organic denial is also an issue for health professionals, friends, and family members, who may delay

making the diagnosis or keep the diagnosis from the affected individual because they are concerned that he "cannot handle it."

Some people interpret the unawareness as a sign that the individual does not want to know. We have not found that talking about HD to a person with unawareness will cause negative consequences.

In our clinical experience, organic denial is not easily amenable to treatment or change. Nevertheless, there are different degrees of unawareness.

It may be that the person can talk about her problems, but not acknowledge that she has HD. In such a case, one might try to address the problems while avoiding discussion of the diagnosis.

Noncompliance with therapy or nursing care should not automatically be interpreted as intentional. It may be helpful to develop a contract that includes incentives for compliance. Denial can thus be sidestepped, while behavioral goals remain the same.

For example, the goal may be to convince an unsafe driver to stop, rather than to accept the diagnosis, or acknowledge why he must stop driving.

Attention

There are many different types of attention. In persons with HD, simple attention often remains intact. In contrast, sustained or complex types of attention become impaired by HD. For instance, most persons with HD will experience difficulty with what is called "divided attention," or the capacity to do two things at once.

For most people, divided attention is impaired when we are tired, sick, or stressed. In HD, divided attention is compromised most of the time, regardless of extra stress. Consequently, a person may complain that he can't "pay attention" as well as he used to.

Divided attention is needed to drive a car while listening to the radio, talking to the kids in the back seat, or talking on the cell phone. When divided attention is impaired it is recommended that patients try to do only one thing at a time. For instance, an HD-affected person should turn off radios, television, and telephones, and limit conversations while cooking dinner.

When swallowing becomes a problem, mealtime distractions should be minimized and the patient should concentrate on chewing and swallowing to limit choking.