Motor,Signs and Symptoms Of Parkinson's disease

Tremor is the most apparent and well-known symptom. It is the most common; though around 30% of individuals with PD do not have tremor at disease onset, most develop it as the disease progresses. It is usually a rest tremor: maximal when the limb is at rest and disappearing with voluntary movement and sleep. It affects to a greater extent the most distal part of the limb and at onset typically appears in only a single arm or leg, becoming bilateral later. Frequency of PD tremor is between 4 and 6 hertz (cycles per second). A feature of tremor is pill-rolling, the tendency of the index finger of the hand to get into contact with the thumb and perform together a circular movement. The term derives from the similarity between the movement in PD patients and the earlier pharmaceutical technique of manually making pills.

Bradykinesia (slowness of movement) is another characteristic feature of PD, and is associated with difficulties along the whole course of the movement process, from planning to initiation and finally execution of a movement. Performance of sequential and simultaneous movement is hindered. Bradykinesia is commonly a very disabling symptom in the early stages of the disease. Initial manifestations are problems when performing daily tasks which require fine motor control such as writing, sewing or getting dressed. Clinical evaluation is based in similar tasks such as alternating movements between both hands or both feet. Bradykinesia is not equal for all movements or times. It is modified by the activity or emotional state of the subject, to the point that some patients are barely able to walk yet can still ride a bicycle. Generally patients have less difficulty when some sort of external cue is provided.

Rigidity is stiffness and resistance to limb movement caused by increased muscle tone, an excessive and continuous contraction of muscles. In parkinsonism the rigidity can be uniform (lead-pipe rigidity) or ratchety (cogwheel rigidity). The combination of tremor and increased tone is considered to be at the origin of cogwheel rigidity. Rigidity may be associated with joint pain; such pain being a frequent initial manifestation of the disease. In early stages of Parkinson's disease, rigidity is often asymmetrical and it tends to affect the neck and shoulder muscles prior to the muscles of the face and extremities. With the progression of the disease, rigidity typically affects the whole body and reduces the ability to move.

Postural instability is typical in the late stages of the disease, leading to impaired balance and frequent falls, and secondarily to bone fractures. Instability is often absent in the initial stages, especially in younger people. Up to 40% of the patients may experience falls and around 10% may have falls weekly, with number of falls being related to the severity of PD.

Other recognized motor signs and symptoms include gait and posture disturbances such as festination (rapid shuffling steps and a forward-flexed posture when walking), speech and swallowing disturbances including voice disorders, mask-like face expression or small handwriting, although the range of possible motor problems that can appear is large.