II. Definitions
- Tremor
- Body part involuntarily oscillates around point in space
 
 
III. Epidemiology
- Tremor Prevalence increases with age
 
IV. Differential Diagnosis
V. Characteristics
- Frequency
- Slow Tremor: 3-5 Hz (e.g. Rest Tremor)
 - Intermediate: 5-8 Hz (e.g. Isometric Tremor)
 - Rapid Tremor: 9-12 Hz (e.g. Postural Tremor)
 
 - Amplitude
- Fine Tremor: Barely noticeable (e.g. Postural Tremor)
 - Medium
 - Coarse Tremor: Large displacement (e.g. Rest Tremor)
 
 
VI. Classification
- Background
- Tremor causes cross-over categories (rest, postural, action)
 - Many Postural Tremors also have Rest Tremor and Action Tremor features
 
 - 
                          Rest Tremor
                          
- Most cases are due to Parkinsonism (although severe Essential Tremor can mimic this)
 - Patient attempts to maintain body position at rest (despite support against gravity)
 - Provoked by stress or distraction (e.g. counting backwards) or moving another body part (e.g. walking)
 - Rest Tremor decreases with voluntary movement
 
 - 
                          Postural Tremor
                          
- Patient attempts to maintain Posture against gravity (stretch hands out in front of them)
 - Essential Tremor
 - Physiologic Tremor or Enhanced Physiologic Tremor
 - Drug-Induced Tremor
 - Other causes
 
 - 
                          Action Tremor
                          
- 
                              Isometric Tremor
                              
- Muscle Contraction against rigid item (e.g. grasping with fist)
 
 - 
                              Kinetic Tremor
                              
- Occurs with any form of voluntary movement
 
 - 
                              Intention Tremor (subtype of Kinetic Tremor)
- Tremor amplifies as target is reached
 - Exercise high index of suspicion for cerbellar lesion (see Cerebellar Tremor)
 
 - 
                              Task-specific tremor (subtype of Kinetic Tremor)
- Tremor on performing highly skilled activity (e.g. writing, speaking, playing music)
 
 
 - 
                              Isometric Tremor
                              
 
VII. Examination
- Characterize Tremor
- Record part of body with Tremor
 - Provocative and palliative factors
 - Tremor frequency (fast or slow Tremor)
 - Tremor amplitude (coarse or fine Tremor)
 
 - Observe with hands resting in lap (Rest Tremor)
 - Observe writing or drinking (Action Tremor)
 - Perform Finger-Nose-Finger Test (Intention Tremor)
 - Draw a spiral (Archimedes Spiral in Essential Tremor)
 - Focus exam based on Tremor type
 
VIII. Labs
- Individualize work-up per Tremor type
 - Basic metabolic panel
 - Liver Function Tests
 - Complete Blood Count (CBC)
 - Thyroid Function Tests
 
IX. Evaluation
- Step 1: Enhanced Physiologic Tremor
- Consider Thyroid Stimulating Hormone, Serum Glucose, Liver Function Tests
 - Manage by avoiding provocative factors
 
 - Step 2: Drug-Induced Tremor
- Eliminate or reduce dose of offending agent
 
 - Step 3: Psychogenic Tremor (e.g. relieved with distraction)
- See Psychogenic Tremor for management
 
 - Step 4a: Patient under age 40
- Wilson's Disease
- Low serum ceruloplasmin and high 24 hour urinary Copper
 
 - Associated Neurologic findings
- Evaluate with MRI Brain and labs above
 
 - Essential Tremor
- Diagnosis of exclusion if other causes excluded
 - Trial on Beta Blocker
 
 
 - Wilson's Disease
 - Step 4b: Patient over age 40
- Rest Tremor
- Parkinsonism likely
 - If rigidity, Bradykinesia or postural instability then trial on Parkinsonism treatment
 
 - Action Tremor
- Consider Alcohol Tremor
 - Postural Tremor
 - Intention Tremor or Cerebellar Tremor
- Obtain MRI Brain
 - Evaluate for Multiple Sclerosis, Cerebrovascular Accident, Brain Tumor
 
 
 
 - Rest Tremor
 
X. Causes (See specific Tremor types)
- Physiologic Tremor
 - Drug-Induced Tremor
 - Pathologic Tremor
- Essential Tremor
 - Parkinson's Disease
 - Multiple Sclerosis
 - Brain Tumor
 - Brain Abscess
 - Peripheral Neuropathy
 - Pheochromocytoma
 - Psychogenic Tremor
 - Thyrotoxicosis
 - Alcohol Abuse or Drug-Induced Tremor
 - Hypoglycemia (Tremor 3 hours after eating)
 - Panic Disorder
 - Dystonic Tremor
 - Wilson Disease (wing-beating Tremor)
 
 
XI. Resources
- International Tremor Foundation
- Overland Park, Kansas
 - Phone: (913) 341-3880
 
 - See Parkinson's Disease Resources
 
XII. Reference
- Crawford (2011) Am Fam Physician 97(3): 180-6 [PubMed]
 - Crawford (2018) Am Fam Physician 83(6): 697-702 [PubMed]
 - Charles (1999) Am Fam Physician 59(6):1565-72 [PubMed]
 - Habib-ur-Rehman (2000) Arch Intern Med 160(16):2438-44 [PubMed]
 - Smaga (2003) Am Fam Physician 68:1545-52 [PubMed]
 - Velickovic (2002) Geriatrics 57(7):32-6 [PubMed]