Prognosis
HD has a great impact on patients' physical and psychosocial well-being, the latter being more severely affected. Even though the symptoms of HD are fairly well characterized, their progression, especially in the early and middle stages, remains unpredictable. With the approach of late-stage HD, affected individuals begin to experience speech difficulty and weight loss. In the late stage, patients lose bowel and bladder control. Clarification of disease progression is vital to improved understanding of the pathogenesis of HD and to the evaluation of therapeutic agents that are designed to slow the progression of disease.
In longitudinal analyses, longer disease duration and better neuropsychological performance at baseline were associated with a less rapid rate of decline in the Total Functional Capacity Scale score, whereas depressive symptomatology at baseline was associated with a more rapid decline in the Independence Scale score. These rates of functional decline and the co-variates that modify them should be considered in estimating statistical power and designing future therapeutic trials involving patients with HD who have early or moderately severe disease.
Patient Education
Genetic testing
Genetic testing has been available for HD for longer than any other adult-onset genetic disorder.
Predictive genetic testing presents unique issues in the legal and ethical debate concerning disclosure of information within the physician-patient relationship.
A duty to disclose information to family members has been found when the disclosure is likely to result in the ability to mitigate the damaging effects of the disease.
When evaluating a situation in which an individual is at risk of HD, the analysis must be different and necessitates an ethical and legal examination of the consequences of receipt of the information on family members, ie, those known to be at risk but who may not know they are at risk of inheriting a genetic disease.
The situation presented by HD is unique and demands a different framework for analysis, given the late onset and lack of curative or ameliorative treatment. Also, the ethical standards should be invoked when considering violating the privacy of a patient or a family member. The principles of autonomy and self-determination of family members are considered, compared with the risk of harm and the privacy interest in not knowing potentially devastating information.
The discovery of the genetic mutation causing HD made possible the use of predictive testing to identify currently unaffected carriers. Concerns have been raised that predictive testing may lead to an increase in deaths by suicide among identified carriers. [15]
There is evidence that individuals with a family history of HD are discriminated against in various ways, contributing to psychological distress. [16]
A fact that might be comforting to patients with HD (or family members) is the significantly lower prevalence of cancer among these patients. The lower prevalence of cancer among patients with HD seems to be related to intrinsic biologic factors. One explanation may be that the modified protein, huntingtin, encountered in patients with HD protects against cancer by inducing or increasing the rate of naturally occurring programmed cell death in preneoplastic cells.
When possible, the patient and the family members/caregivers should be prepared for the HD progression, from early involuntary movements and emotional changes to more overt motor symptoms and difficulty with activities of daily living.
Family therapy, support groups, and caregiver education is extremely important due to the degenerative and emotionally exhausting course of the disorder. Family therapy may encourage genetic testing and provide for support functionality to the families and caregivers. It provides for a deeper understanding of the condition and ways to deal with the deterioration as it comes about.
Coulson et al discussed the use of online support groups as a resource for those affected by HD. [17] The authors analyzed the content of more than 1000 postings on a support group's message board. They found that those diagnosed with HD, we well as those affected by HD, use the online group to exchange information on the disease and networking information, such as referrals, and to offer and seek empathy, emotional, and esteem support. Online support groups can lessen feelings of isolation by providing a community for those who are facing the unique challenges of HD. Further investigation is needed to evaluate the accuracy of informational exchanges.
For patient education resources, see the Dementia Center, as well as Huntington Disease Dementia, Dementia Overview, and Dementia Medication Overview.
Other useful websites for the patient and the family are as follows:
