Table 1 Key clinical features and pathophysiological basis of tremor in Parkinson’s disease, essential tremor and dystonia
From: Rest tremor revisited: Parkinson’s disease and other disorders
Parkinsonian tremor | Essential tremor | Dystonic tremor | |
|---|---|---|---|
Key clinical features | |||
Topography | Hand > others | Hands > head > voice > others | head > Hands > others |
Activation condition | Rest > postural/kinetic | Postural > kinetic > rest | Postural > kinetic > rest |
Symmetry | Asymmetrical | Symmetrical | Asymmetrical |
Suppression of tremor during movement onset | in most cases | not found | rare |
Frequency | 4-6Hz | 4-8 Hz | 7 Hz |
Amplitude | Regular | Regular | Irregular |
Potential accompanying signs | Bradykinesia, rigidity, etc | Impaired tandem gait | Dystonic posture |
Possible pathophysiological basis | |||
Triggering factor | Dopaminergic dysfunction in nigrostriatal system | Reduced inhibition in cerebellum and brainstem | Reduced inhibitory reflex at multiple levels (spinal, brainstem, and cortical, etc.) |
Activated circuit | Cerebello-thalamo-cortical circuit | ||