Parkinson’s disease is a relatively common neurodegenerative disease. It was first described by James Parkinson in his now classical essay titled ” The Shaking Palsy”. James Parkinson was an astute observer and his longitudinal description of the disease which now bears his name was on the basis of just a single patient.
Like other neurodegenerative diseases, Parkinson’s disease starts in the later age groups (60’s and onwards). Sometimes it may start in the younger age groups especially if there is a family history of the disease. This is referred to as Familial Parkinson’s Disease.
Typical Parkinson’s disease has a clinical triad consisting of:
a) rigidity (patient’s are rigid–when you passively move their limbs you experience increased resistance. Rigidity is a condition in which the tone of the body is increased. Tone refers to the resistance offered to passive movement of a limb across the joint)
b) bradykinesia or akinesia: as the name suggests, this means that the patient’s are bradykinetic. They have paucity of spontaneous movements, when they walk they do not have the characteristic arm swing which describes the human walk.
c) resting tremor: Parkinson’s disease (PD) patient’s have a characteristic tremor in their hands and feet. The tremor is a resting tremor meaning that it is most prominent when they are relaxed and their arms are at complete rest (when you walk, your arms are at rest by the side of your body and the tremor can be clearly seen).
Other features of Parkinson’s disease (PD):
d) PD patient’s have a typical disturbance of gait and posture. They seem off balance and are prone to falls. They walk bend forward in short quick steps (as if chasing something). This characteristic gait of PD patient’s has been referred to as festinating gait. If you accidently push a PD patient to the side or backward or forward, they are unable to compensate and may fall down. Falls and the disturbance in gait and posture is an important cause of morbidity in PD patient’s. When PD patient’s turn they do not turn in one smooth motion rather thay turn with small steps.
e) PD patient’s have a mask like face. They do not have the characteristic facial expressions which so define when humans talk. They may not blink while speaking ( sort of staring look), do not smile or frown.
f) PD patient’s may notice a change in their writing. Typically the hand writing becomes smaller and smaller and more illegible. This is referred to as micrographia.
g) The voice of PD patient’s is monotonous and lacks the variations in the pitch and tone which defines human speech.
A point to note here is that unlike Alzheimer’s disease, PD patient’s usually have no impairment in memory at least in the early to middle stages of the disease. Later on in the disease course, they may develop cognitive impairments, this condition is referred to as Parkinson’s disease dementia (PDD) or dementia associated with Parkinson’s disease.