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A. Definitionsnavigator

  1. Tremor is a rhythmical oscillation of ANY body part
  2. Chorea - involuntary, non-rhythmic, quick, flicking motions of (distal) extremities
  3. Myoclonus - muscular contractions with clonic motions
  4. Dystonia - involuntary, often painful, contractions of entire muscle groups
  5. Cerebellar Disease
    1. Intention tremor - akinetic tremor; oscillation increases as target is approached
    2. Dysmetria - cannot gauge targets, distance; overshoot and undershoot on ballistic motion
  6. Tardive Dyskinesia - late effects of anti-dopaminergic agents; dystonic motions
  7. Asteryxis - sudden, irregular loss of tone ("liver flap")
  8. Hemibellismus - large magnitude limb motions often associated with subthalamic infarcts

B. Classification of Tremors navigator

  1. Postural (Action) Tremor
    1. Most prevalent type of tremor
    2. Essential Tremor (see below)
    3. Alcoholic Tremor
    4. Orthostatic Tremor - torso, lower limbs, 14-18 Hz, relieved by walking
    5. Basal Ganglia Lesion Tremor (often at rest): Parkinson's, Wilson's Diseases, Dystonia
    6. Tremor with Peripheral Neuropathy: Hereditary or Acquired
    7. Post-traumatic Tremor
    8. Parkinson's and Wilson's diseases can also cause action tremor
    9. Hyperthyroidism
    10. Physiologic Tremor (rapid rate, 8-12 Hz; Hz=Herz=cycles per second)
  2. Rest Tremor
    1. Parkinson's Disease (slow rate, 4-6 Hz)
    2. Wilson's Disease: wing-beating tremor (proximal tremor at shoulders)
  3. Intention Tremor
    1. Coarse terminal tremor occurs as limb approaches a target
    2. Cerebellar Tremor (3-5 Hz)
    3. Often accompanied by ataxic gait, nystagmus, slurred speech (cerebellar signs)
    4. Multiple Sclerosis (cerebellar lesions)
  4. Rubral Tremor
    1. Midbrain or Holmes tremor
    2. Mixture of rest and intention tremor
    3. Lesions usally in red nucleus area
    4. Lesions cause interruption of nigrostriatal and bracium conjunctival pathways
  5. Task Specific Tremor
    1. Primary writing tremor
    2. Vocal tremor
  6. Cortical Tremor
  7. Drug Inudced Tremors (see below)

C. Essential Tremor [1,3]navigator

  1. Most common action tremor, affects 5-10 million in USA
  2. Any age of onset, with increases over months to years
  3. Autosomal dominant inheritance with family history very common
  4. Usually bilateral, often postural tremor
  5. Rapid motion most commonly, ~10 cycles per second (10 Hz median; 4-12 Hz range)
  6. Diagnosis of Classic Essential Tremor
    1. Bilateral postural or kinetic tremor of hands and forearms; OR
    2. Isolated head tremor without evidence of dystonia
    3. No other disease to explain tremors and no recent neurologic trauma
    4. No use of drugs that cause tremors
    5. HIstory or presence of psychogenic tremor
    6. Sudden onset or stepwise progression
    7. Primary orthostatic tremor
    8. Isolated position-specific or task-specific tremors or primary writing tremor
    9. Isolated tremor in voice, tongue, chin or legs
  7. Treatment
    1. Intermittent: as needed alcohol, ß-adrenergic blocker, or benzodiazepine
    2. First line chronic: non-selective ß-adrenergic blocker such as propranolol or nadolol
    3. Alternative first line chronic: Primidone (Mysoline®),
    4. Second line: may combine ß-adrenergic blocker and primidone
    5. Third line: Benzodiazapine (clonazepam, alprazolam), gabapentin (Neurontin®), topiramate
    6. Botulinum toxin may be used
    7. Invasive Surgery: deep brain stimulation of thalamus, thalamotomy

D. Parkinsonian Tremor navigator

  1. Age of onset usually >60 years
  2. Family history uncommon
  3. Usually asymmetric, with unilateral involvement common earlier in course
  4. Decreases with posture or complete relaxation
  5. Onset in weeks-months
  6. Pill Rolling tremor, 4-6 per second (Hertz)
  7. Treatment
    1. Anti-cholinergics very effective
    2. L-DOPA therapy
    3. Pergolide (Pramipexole®), Bromocriptine (Parlodel®) or other dopamine agonists

E. Dystonia [4,5,6] navigator

  1. Types
    1. Generalized: more common in children, usually congenital / hereditary, dystonia throughout
    2. Focal: more common in adults and more common overall, dystonia usually 1-2 regions only
    3. Segmental: two or more adjacent regions
    4. Multifocal: two or more nonadjacent regions
    5. Hemidystonia: ipsilateral arm and leg
  2. Symptoms
    1. Twisting postures
    2. Tremors
    3. Pain resulting from sustained muscle contractions
    4. Meige Syndrome - oral and ocular spasm
    5. Laryngeal or pharyngeal spasm
    6. Torticollis - head twisting
    7. Blepharospasm - tremor of the eye (orbicularis oculus muscle)
  3. Therapy Overview
    1. Dopamine responsive dystonia - usually with parkinsonism
    2. Anticholinergics: cyclobenzaprine (Flexeril®), anti-histamines
    3. Anticholinergics with baclofen (Lioresal®) may be dramatically effective in children
    4. Botulinum Toxin injection - mainly for adults with focal dystonia
    5. Bilateral deep brain stimulation of globus pallidus - very good efficacy in refractory generalized and in segmental dystonia [5,7]
    6. Most common side effect with bilateral deep brain stimulation was dysarthria [7]
    7. 4 of 40 patients undergoing deep brain stimulation had infections at stimulator site [7]

F. Intention Tremor navigator

  1. Usually due to cerebellar lesion, often from multiple sclerosis
  2. May also be caused by lesions involving cerebellar inflow or outflow tracts (red nucleus)
  3. Tremor occurs with planned motion
    1. Impairment of feedback loops controlling directed motor movements
    2. Leads to undershoot and overshoot of intended targets
    3. Oscillations increase with approach to target objects
  4. Treatment
    1. Serotonergic agents
    2. Isoniazid - for patients with multiple sclerosis
    3. Weighted implants or wrist and ankle weights

G. Cortical Tremornavigator

  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

H. Drug Inudced Tremorsnavigator

  1. Usually with enhanced physiologic tremor
  2. Usually pathologic mixture of pathologic and kinetic tremor
  3. Rest termor and inention tremor may occur
  4. Each drug different and dependent on severity of intoxication
  5. Acetylcholine, Anticholinesterases
  6. Neuroleptics, Lithium
  7. Levodopa
  8. Tricyclic Antidepressants
  9. Caffeine
  10. Cigarettes (nicotine)
  11. Amphetamines
  12. Adrenaline (including Primatene®)
  13. ß-Adrenergic Agonists
  14. Theophylline
  15. Glucocorticoids (prednisone, hydrocortisone, others)
  16. Fluorouracil (5-FU)
  17. Amiodarone
  18. Alcohol

I. Tardive Dyskinesia navigator

  1. "Late abnormal motions"
  2. Occurs with high dose dopamine receptor blocking (neuroleptic) agents over long period
  3. Probably occurs due to dopamine receptor supersensitivity
  4. Treatment
    1. Very difficult to treat
    2. Reserpine (depletes brain dopamine) may help
    3. Increasing neuroleptic dose can block dyskinesia
    4. Occasionally spontaneously resolves

References navigator

  1. Pahwa R and Lyons KE. 2003. Am J Med. 115(2):134 abstract
  2. Sandroni P and Young RR. 1994. Am Fam Phys. 50(7):1505 abstract
  3. Louis ED. 2001. NEJM. 345(12):887 abstract
  4. Greene P. 2005. NEJM. 352(5):498 abstract
  5. Vidailhet M, Vercueil L, H JL, et al. 2005. NEJM. 352(3):459
  6. Tarsy D and Simon DK. 2006. NEJM. 355(8):818 abstract
  7. Kupsch A, Benecke R, Muller J, et al. 2006. NEJM. 355(19):1978 abstract