Parkinson’s gait is a distinctive symptom of Parkinson’s disease (PD). It is characterized by short, shuffling steps while walking. As PD progresses, this halting gait becomes more and more problematic, often leading to freezing in place. The cause of gait disorders in Parkinson’s disease is not well-understood, but the medical community generally agrees that the neurotransmitter dopamine is involved.
The disease is a degenerative neurological disorder that affects about 4 to 6.5 million people worldwide, approximately 1% of adults. It usually affects more men than women and typically begins in middle age. Though the specific cause is not known, some risk factors include a genetic predisposition and exposure to environmental toxins. Having a family member with Parkinson’s increases the risk of developing this disorder, but the overall likelihood of having PD is about 5%.
Parkinson’s gait is not usually evident until the disorder has progressed. The earliest symptom of Parkinson’s is typically a rubbing together of the forefinger and thumb on one hand, a behavior generally known as “pill rolling.” This involuntary and persistent muscle movement typically radiates to the other side of the body as time passes. As neurological connections degenerate, voluntary and involuntary movements become more difficult. This often leads to the unsteady, halting walk of the Parkinson’s patient known as Parkinson’s gait.
Freezing of gait, also known as FOG, often occurs in people who have had Parkinson’s disease for over five years. This form of Parkinson’s gait presents as a sudden freezing during walking. The person is unable to move automatically or to initiate movement forward. FOG is probably the most debilitating of the Parkinson’s gait disorders, since it typically causes the person to fall and become injured.
The gait disorders of Parkinson’s are generally disabling, robbing the PD patient of his or her independence. Not being able to walk steadily and predictably puts the person at greater risk for injury and places increasingly severe limitations on mobility and autonomy.
In addition to difficulties with the voluntary movements of walking, involuntary movements may become difficult or impossible. People with Parkinson’s may be unable to swing their arms as they walk or even blink their eyes. Speech sometimes becomes unintelligible as the muscles needed to form words are not under the patient’s control.
Most medical experts agree that dopamine, a neurotransmitter crucial for initiating movement, is involved in Parkinson’s disease, although it is not clear how. The Parkinson’s patient may produce too little dopamine or be unable to utilize the dopamine he does have. Another neurotransmitter called norepinephrine which helps regulate the autonomic nervous system has been found to be low in most Parkinson’s patients. It is not clear whether the decrease in these chemical messengers cause or are caused by Parkinson’s.