A. Postural (Action) Tremor

1. Essential Tremor (most common)
2. Alcoholic Tremor
3. Orthostatic Tremor
4. Tremor with Peripheral Neuropathy: Hereditary or Acquired
5. Post-Traumatic Tremor
6. Parkinson's Disease
7. Wilson's Disease
8. Hyperadrenergic Conditions
   1. Hyperthyroidism / Thyrotoxicosis
   2. Pheochromocytoma
9. Dystonia
   1. Action tremor in affected body part without affecting other parts
   2. May be focal, generalized, or task-specific
10. Physiologic Tremor (rapid rate, 8-12 Hz; Hz=Herz=cycles per second)

B. Rest Tremor

1. Basal Ganglia Lesion Tremors are often at rest
2. Parkinson's Disease (slow rate, 4-6 Hz)
3. Wilson's Disease: wing-beating tremor; proximal tremor at shoulders

C. Intention Tremor

1. Coarse terminal tremor occurs as limb approaches a target
2. Cerebellar Tremor (3-5 Hz): often accompanied by ataxic gait, nystagmus, slurred speech
3. Multiple Sclerosis (cerebellar lesions)
4. Rubral Tremor

D. Task Specific Tremor

1. Primary writing tremor
2. Vocal tremor

E. Cortical Tremor

1. Also called Rhythmic Cortical Myoclonus
2. Irregular high-frequency (7-14 Hz) postural and kinetic tremor
3. Cortical myoclonus
4. Giant somatosensory cortical-evoked potentials
5. Enhanced long-loop somatosensory (C-) reflexes

F. Drug Inudced Tremors

1. Acetylcholine, Anticholinesterases
2. Neuroleptics, Lithium
3. Levodopa
4. Tricyclic Antidepressants
5. Caffeine
6. Cigarettes (nicotine)
7. Amphetamines
8. Adrenaline (including Primatene®)
9. ß-Adrenergic Agonists
10. Theophylline
11. Glucocorticoids (prednisone, hydrocortisone, others)
12. Fluorouracil (5-FU)
13. Amiodarone
14. Alcohol

References

1. Pahwa R and Lyons KE. 2003. Am J Med. 115(2):134