Neuro examination: Parkinson's disease

PARKINSON'S DISEASE

Pathology:
degeneration of dopaminergic neuron at the nigrostriatal pathway

3 cardinal features:  bradykinesia with rigidity and/or resting tremor

Features in Neurological Examination:

1. General inspection:

-> mask-like facies ('hypomimia') with reduced eye blinking rate, drooling of saliva

-> pill-rolling tremor

2. Assess gait 

-> parkinson patient has difficulty in initiating gait, but when they start walking, their gait tend to shuffle with lack of arm swing with festinating gait (and stooped posture) as if they try to find their centre of gravity, and when they made a turn, it's usually done in small steps like statue (turn 'en bloc')

3. Tone for rigidity

-> at the elbow-> lead-pipe rigidity, at the wrist-> cog-wheel rigidity 

-> in patient that are on medication, the rigidity may not be easily be demonstrated so you may need to bring out by assessing tone in one side of one limb and the other side, ask patient to move their hands up and down and pat their hand on the thigh 

4. Assess for tremor

-> by asking the patient to put their hands on the thigh with the thumb up to the ceiling. If the tremor, not presence, try to distract patient by asking them to close their eyes and count number backward, this will help to bring out the tremor. Make a note whether this is symmetrical or asymmetrical. Idiopathic will be asymetrical/unilateral while parkinsonism from other cause will be symmetrical

5. Assess for bradykinesia (slowing with decrement)

-> assess by asking the patient to tap the thumb with each finger, there will decremental of the amplitude and frequency of succession tap. Same can be demonstrated on lower limb by using heel tap

6. Assess the speech

-> monotonous, low volume

7. Assess the function

-> ie: assess the handwriting for micrographia, by asking patient to button and unbutton cloth

8. Assess for Parkinson plus features

-> vertical gaze palsy in PSP, horizontal gaze palsy in MSA

-> assess for cerebellar features 

At the end of the examination, say you want to take full history of the patient including occupational history, family history and drug history as well as full neurological and cognitive assessment.  You also want to check the standing and lying BP (to check for autonomic involvement such as in MSA).

The end