Upper body dyskinesia
This must be present - it is a symptom complex containing many of the following features:
· Slowness of movement (bradykinesia).
· Poverty of movement (mask-like facies, diminished arm swing).
· Difficulty in initiating movement.
· Diminished amplitude of repetitive alternative movement.
· Inordinate difficulty in accomplishing some simultaneous or sequential motor acts.
Rigidity
This is usually but not always present:
· Leadpipe rigidity, where the increase in tone is equal in flexors and extensors of all four limbs but slightly more in flexors, resulting in a part flexed 'simian' posture.
· Cog-wheel rigidity is due to superimposed or underlying tremor. Postural instability Usually a late feature.
Tremor
Absent in about one third of patients with Parkinson's disease at presentation and throughout its course in some.
· Resting, 3-5 Hz pill, pronation and supination rolling tremor of the upper limb.
· Tremor is intermittent (can usually be brought about by getting the subject to count backwards with the eyes closed and hands dangling over the armrests of the seat).
· The tremor is intensified by emotion or stress and disappears during sleep.
· The legs, head and jaw may shake as well. Jaw tremor is rare but is most distressing; the teeth may pound together until they become unbearably painful.
What are the causes of Parkinson's disease?
· True parkinsonism:
-Idiopathic (due to degeneration of the substantia nigra) - also known as Parkinson's disease.
-Drug-induced (chlorpromazine, metaclopramide, prochlorperazine).
- Anoxic brain damage such as cardiac arrest, exposure to manganese and carbon monoxide.
-Postencephalitic - as a result of encephalitis lethargica or von Economo's disease.
- 1-Methyl-4-phenyl- 1,2,3,6-tetrahydropyridine toxicity - seen in drug abusers. -Multiple system atrophy. -Progressive supranuclear atrophy.
- Familial.
-Mutation of the alpha-synuclein gene or linkage to a region on chromosome 2.
· Pseudoparkinsonism:
-Essential tremor.
-Atherosclerotic (vascular) pseudoparkinsonism (mention that in the past atherosclerosis was thought to be a cause of Parkinson's disease but this is no longer accepted as a cause).
· Hemiparkinsonism (presenting feature of a progressive space-occupying lesion).
What are the pathological changes in Parkinson's disease?
The most typical pathological hallmarks of Parkinson's disease are:
· Neuronal loss with depigmentation of the substantia nigra.
· Lewy bodies, which are eosinophilic cytoplasmic inclusions in neurons con-sisting of aggregates of normal filaments.
What is the mental status of patients with Parkinson's disease?
· In the initial stages, intellect and senses are usually preserved. Many patients have some intellectual deterioration - a slowness of thought and of memory retrieval (bradyphrenia), and subtle personality changes.
· Global dementia may develop in one fifth of patients.
· Depression occurs in one third of patients.
· Acute confusion can be precipitated by drug therapy.
Note. Parkinson's disease must be kept in mind in elderly patients presenting with a history of frequent falls.
What is the difference between rigidity, spasticity and gegenhalten?
· Rigidity indicates increased tone affecting opposing muscle groups equally and is present throughout the range of passive movement. When smooth it is called 'leadpipe' rigidity, and when intermittent is termed 'cog-wheel' rigidity. It is common in extrapyramidal syndromes, Wilson's disease and Creutzfeld-Jakob disease.
· Spasticity of the clasp-knife type is characterized by increased tone which is maximal at the beginning of movement and suddenly decreases as passive move-ment is continued. It occurs chiefly in the flexors of the upper limb and extensors of the lower limb (antigravity muscles).
· Gegenhalten, or paratonia, is where the increased muscle tone varies and becomes worse the more the patient tries to relax.
What do you understand by the 'wheelchair sign' in Parkinson's disease?
Patients with advanced disease and 'on-off' motor fluctuations require a wheelchair when 'off' and when 'on' are seen to walk about (sometimes pushing the chair!). These patients are rarely permanently wheelchair-bound; in contrast, those who never leave their wheelchair usually do not have Parkinson's disease.
How is the severity of Parkinson's disease graded?
The Hoehn-Yahr staging grades Parkinson's disease into five stages:
· Newly diagnosed disease - Stage I.
· Moderately severe disease - Stages II and III.
· Advanced disease - Stages IV and V.
In which condition is L-dopa absolutely contraindicated?
Melanoma.
What are Parkinson plus syndromes?
Some patients have other neurological deficits in addition to Parkinson's disease. Examples of these so-called 'Parkinson plus
syndromes' are:
· Steele-Richardson-Olszewski disease (akinesia, axial rigidity of the neck, bradyphrenia, supranuclear palsy).
· Multiple system atrophy. Olivopontocerebellar degeneration. Strionigral degeneration.
Progressive autonomic failure (Shy Drager syndrome).
· Basal ganglia calcification.
What is tardive dyskinesia?
Tardive dyskinesia is seen in patients taking neuroleptics. Its manifestations are orofacial dyskinesia such as smacking, chewing lip movements, discrete dystonia or choreiform movements and, rarely, rocking movements. Withdrawal of the offendingdrug will improve these symptoms over a period of 3-4 years, except in a small minority of patients.
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