What Are the Organ Systems Affected by Huntington's Disease?

An inherited genetic condition that affects the central nervous system, Huntington's disease attacks the organs that essentially carry out the many roles of the nervous system. The disease, which typically afflicts adults in their 30s or 40s, causes advanced degeneration and loss of neurons (brain cells), and leads to a debilitating loss of motor functions followed by progressive dementia. Considered a "rare disease" by the National Institutes of Health's Office of Rare Diseases, it has no cure.

Symptoms

• Huntington's disease (HD) is characterized by two primary---and very pronounced---symptoms. The first symptoms of HD are physical, manifested in uncontrollable and random muscle movement, restlessness and poor coordination. Collectively, these difficulties with motor control are known as chorea, and will become more significant and limiting with time. Emerging in the more advanced stages of HD, the second, and most debilitating symptom of Huntington's is the deterioration of cognitive abilities, ultimately resulting in dementia.

The Brain

• Huntington's disease targets specific regions of the brain, destroying critical neurons as it progresses. Many parts of the brain that direct motor skills and cognitive abilities become severely impaired, and in some cases, atrophy. Furthermore, as the brain controls and regulates all organ systems in addition to the nervous system, deteriorating brain function can result in a variety of complications in other organs, such as the heart, musculoskeletal system or the lungs .

The Basal Ganglia

• The basal ganglia, a group of nuclei situated at the forebrain's base connected with the thalamus, are most acutely affected by Huntington's disease. Normally, this part of the brain acts to inhibit "circuits" that initiate specific movements of the body; however, Huntington's disease damages the basal ganglia, which can result in the release of these inhibitions. The result is erratic, uncontrollable body movement, as well as difficulty with walking, swallowing or even speaking.

Nerves

• Huntington's disease afflicts the nervous system.

  Nerves conduct information to and from the brain in lightning-quick impulses. There are two types of nerves, both of which are affected by Huntington's disease. Motor nerves send signals from the central nervous system to the muscular system, and sensory nerves receive input from the body's receptors and conduct them to the central nervous system. As HD aggressively assaults the central nervous system, it irreparably damages the nerves, preventing the brain from sending signals to the muscles, often resulting in chorea.

Prognosis

• Huntington's disease viciously attacks the very core of life---the central nervous system---and continues its assault for as long as the patient survives, which is usually ten to 30 years following the initial diagnosis. Death is usually due to a complication of the disease, many from chorea-related incidents such as falling or choking. Others suffer from the disease's ability to compromise all bodily organs and systems, and die from pneumonia or another infection, or from cardiac arrest. Most victims die in a state of full-blown dementia. Due to the staggering compromise in patients' quality of life, suicide claims a disproportionate number of HD patients compared to the general population.