Parkinson's disease (PD)

 

A. Presentation

4 cardinal signs:

1. Tremor at rest
2. Bradykinesia
3. Rigidity
4. Postual instability (appear late)

 

S&S Can be more prominent on one side.

 

Tremor

• 4-7Hz
• decreased by action
• increased by emotion
• pill-rolling movement between thumb and forefinger

 

Bradykinesia

• Difficulty initiating movement.
• Poverty and slowing of movement.
• Impaired rapid fine finger movements

 

 

Rigidity

• Stiffness in limb movement through the ROM and is equal in opposing muscle groups -> "lead-pipe" rigidity.
• "lead-pipe" rigidity + tremor -> "cogwheel" rigidity
• Tone in one limb may increase as the opposite limb is moved actively.
• Present in limbs, neck and axial muscles.

 

Postural instability

• Stooped posture.
• Gait becomes festinant and shuffling with poor arm swinging.
• Impaired balance
• Falls common (due to failure of usual corrective reflexes)

 

Speech

• Pronunciation initially monotone, progresses to tremulous slurring dysarthria.
• Speech may be lost completely eventually.

 

Other symptoms:

• General slow down of movements and ADLs
• Lack of facial expression (hypomimia, or masked facies)
• staring expression from decreased frequency of blinking
• impaired swallowing causing drooling (sialorrhoea)
• Hypokinetic and hypophonic dysarthria
• Small handwriting (micrographia)
• Difficulties with repetitive and simultaneous movements
• Difficulties in arising from a chair and turning over in bed
• Start hesitation and freezing (i.e. sudden unpredictable inability to move)

 

Other less prominent non-motor manifestations:

• Personality changes
• Dementia (spatial disorientation, paranoia, psychosis, hallucinations)
• Bradyphrenia (slow thought processes, loss of concentration, difficulty with concept formation)
• Depression
• Sleep disturbance
• Sexual dysfunction
• Autonomic dysfunction (orthostatic hypotension, respiratory dysregulation, flushing, "drenching sweatings", constipation, sphincter and sexual dysfunction)
• Sensory symptoms (paresthesia, pain, akathisia; visual, olfactory, and vestibular dysfunction)

 

 

B. Investigation

No laboratory test

Diagnosis is clinical.

 

Out of the 4 cardinal signs, stooped posture often occurs late.

Therefore diagnosis relies on

1. presence of 2 of the 3 other signs, i.e.
   - tremour
   - bradykinesis
   - rigidity
   PLUS
2. response to levodopa.

 

 

 

C. Treatment

No disease-modifying treatment at this time.

 

Drug treatment

Treatment with levodopa and/or dopaminergic agnoist is symptomatic only, and should be avoided until they are necessary clinically because of delayed unwanted effects.

Drug treatments are directed at increasing the action of dopamine at the receptor sites, and reducing the side-effects of levodopa.

 

Levodopa

Levodopa

 

 

D. Other notes

 

 

 

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Things to revise/add later: Add treatment info

Bibliography: Kumar and Clark,

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