Table 2.
Most common tremor disorders.
| Diagnosis | Tremor type(s) | Frequency range | Accompanying features | Pathophysiology |
|---|---|---|---|---|
| MOST COMMON TREMOR DISORDERS | ||||
| Enhanced physiologic tremor | Posture | 5–12 Hz | Increases after caffeine intake, and upon stress and anxiety | Consists of two distinct oscillations, a mechanical-reflex oscillations and a central-neurogenic oscillation (Elble, 1996) |
| Essential tremor | Posture intention rest | 4–12 Hz | Additional or isolated head tremor (Critchley, 1949), tandem gait abnormalities (Stolze et al., 2001) | Involvement of parts of the cerebello-thalamo-cortical network (Louis, 2011) |
| Parkinsonian tremor | Rest posture intention | 4–9 Hz | Bradykinesia, rigidity, postural problems | Degeneration of dopaminergic pathways (Kraus et al., 2006) |
| Dystonic tremor | Posture intention rest | 4–10 Hz | “Gestes antagonistes,” dystonic posturing of other body parts (Deuschl et al., 1998) | Unknown, but can be related to basal ganglia dysfunction observed in dystonia (Pont-Sunyer et al., 2012) |
| Psychogenic tremor | Rest posture intention | 4–12 Hz | Entrainment, increase in tremor amplitude with loading, inconsistent over time (Edwards and Schrag, 2011) | Unknown (Edwards and Schrag, 2011) |
| Toxic and drug-induced tremor | Posture intention rest | 3–12 Hz | Medication/drug use, exposure to heavy metals, symptoms of metabolic disorders (Puschmann and Wszolek, 2011) | Various mechanisms (Morgan and Sethi, 2005) |
| Cerebellar tremor | Intention | 2–5 Hz | Eye-movement abnormalities, dysmetria, dyssynergia, trunk titubation (Degardin et al., 2012) | Lesions of the lateral cerebellar nuclei, the superior cerebellar peduncle, or the pathways where they are involved (Pont-Sunyer et al., 2012) |
| Task-specific tremor | Posture intention | 4–8 Hz | Occurs during specific task (i.e., writing; Bain, 2011) | May be related to essential tremor or dystonia (writer’s cramp; Bain, 2011) |
| Holmes’ tremor | Rest intention posture | 2–5 Hz | Evidence of lesions of the central nervous system (Deuschl et al., 1998), neurological signs associated with lesions | Lesions in the dopaminergic nigrostriatal and cerebello-thalamic pathways (Seidel et al., 2009) |
| Cortical myoclonic tremor | Posture intention | 6–20 Hz | (Family) history of epileptic seizures (van Rootselaar et al., 2006) | GABAA-ergic dysfunction within the cerebral cortex (van Rootselaar et al., 2007) |
| Neuropathic tremor | Posture | 4–12 Hz | Muscle weakness, absent reflexes, glove/stocking sensory deficits (Pont-Sunyer et al., 2012) | Slow nerve conduction increases the delay of a stretch reflex response, leading to enhancement of the tremor, but central components can also be involved (Pont-Sunyer et al., 2012) |
An overview of most common tremor disorders. The tremor type(s) and frequency range columns are adapted from the MDS consensus statement (Deuschl et al., 1998).