Motor Disturbances

Early motor signs of HD typically include the gradual onset of clumsiness, balance difficulties, and brief, random, "fidgeting" movements. At first, chorea or frequent, irregular, purposeless, jerky motions, may be incorporated into intentional actions, potentially masking symptoms and delaying recognition of the condition. Early during the course of HD, chorea may be limited to the fingers or toes. However, these movements become more noticeable over time and may extend to the arms, legs, face, and trunk. Under certain circumstances, such as stress or a highly emotional state, choreic movements may become more pronounced. As the disease advances, chorea tends to become widespread or generalized. Movements essentially blend or flow into one another, causing them to appear relatively slow and writhing in nature (athetosis). In addition, involuntary movements may develop a dystonic quality in which there may be unusual twisting motions and alternating or fixed postures resulting from sustained muscle contractions.

Many HD patients develop a distinctive manner of walking (gait) that may be unsteady, disjointed, or lurching. The gait has also been described as "dance-like" in nature. As the disease progresses, other findings may include:

• Clumsy fine motor movements
• Postural instability
• Inability to sustain certain voluntary movements
• Poor control of the tongue and diaphragm
• Difficulty swallowing (dysphagia)
• Poorly articulated, slurred speech (dysarthria)
• A strained, hoarse, or inappropriately loud voice

Oculomotor abnormalities are also associated with HD. Some patients develop impaired control of certain voluntary eye movements related to focusing on objects in the visual field during movement (abnormal saccades). Some patients with advanced disease may also develop muscle stiffness (rigidity) and relative slowness of movement (bradykinesia). These findings are usually associated with juvenile HD.

	Advanced Disease