Tremors
RED FLAGS
Sudden onset
Progressive
Stepwise (suggestive of stroke or MS)
Neurological deficits
Age under 50 years in the absence of family history of essential tremor
Classification of Tremors
Static - occurs in a relaxed limb when fully supported at rest. Causes include Parkinson's disease, Parkinsonism, other extrapyramidal diseases and multiple sclerosis.
Postural/Action- occurs when a part of the body is held in a fixed position against gravity (it can also remain during movement). Types include physiological tremor, exaggerated physiological tremor (eg, thyrotoxicosis), anxiety states, alcohol abuse, drugs, heavy metal poisoning, neurological diseases, Wilson's disease, neurosyphilis, peripheral neuropathies, essential (familial) tremor and task-specific tremors such as primary writing tremor.
Kinetic/Intention or action tremor - occurs during voluntary active movement of an upper body part. If action tremor worsens as goal-directed movement approaches its intended target, this is intention tremor (indicative of a cerebellar cause). Associated with brainstem or cerebellar disease, including multiple sclerosis, spinocerebellar degenerations, vascular disease and tumours.
Examination
Assess general appearance. Note whether the face gives any clues such as oromotor dystonia (may be tardive dyskinesia) or mask-like appearance (consider Parkinsonism).
Observe the symptomatic movements. Consider whether this is tremor, chorea, dystonia or another movement disorder.
Ask the patient to hold their arms out in front of them with palms initially facing up, then down.
Ask the patient to adopt a posture or movement that they know brings on the tremor.
Look carefully at the hands and forearms. Note whether there a classical 'pill-rolling' Parkinsonian tremor.
Estimation of the frequency of the tremor is quite difficult without regular practice.
Perform a full screening peripheral neurological examination checking muscle tone, power, co-ordination, reflexes and sensation.
Observe gait, test for rigidity and bradykinesia indicating Parkinsonism.
Test cerebellar function by assessing speech (tongue-twisters), balance, finger-nose pointing and dysdiadochokinesia (inability to rapidly alternate movement - eg, pronation and supination of hand at wrist held on outstretched contralateral palm).
A screening cranial nerve examination can be useful in detecting neurological disease.
Investigations
Trials of reducing or stopping medication may be useful to determine an iatrogenic cause.
Electromyography (EMG)/accelerometry may be used as an objective neurophysiological measure of the tremor frequency but should be used only occasionally to answer specific questions about a tremor.
If there is reason to suspect metabolic derangement then U&Es, LFTs and FBC may be helpful.
Check TFTs if there is a possibility of thyroid disease.
Wilson's disease is diagnosed by measuring blood and urinary copper levels and caeruloplasmin assay. Wilson's disease should be considered in any child or young adult with unexplained liver abnormalities and also in patients with movement disorders.[5]
If underlying CNS disease is suspected then CT/MRI imaging and/or neurological referral should be considered.
Causes
Physiological tremor.
Exaggerated physiological tremor due to illness, fever, hyperthyroidism, anxiety states, etc.
Post-traumatic/post-neurosurgical tremor.
Medication/drug-induced.
Multiple sclerosis.
Parkinsonism and Parkinson's-plus syndromes
Metabolic derangement - eg, electrolyte disturbance, renal and hepatic failure.
Wilson's disease.
Cerebellar disease.
Basal ganglia lesions.
Dystonias.
Other movement disorders - eg, tardive dyskinesia, cerebrovascular disease.
Writer's cramp or tremor.
Psychogenic tremor.
Arsenic, heavy metal, organophosphate or industrial solvent poisoning.
Vitamin deficiency (especially B1).
Physiological
Pathological
Idiopathic
Anxiety
Exercise
Thyrotoxicosis
Drugs
Alcohol
Lithium
Caffeine
Phenytoin
Beta-Agonists
Cyclosporin
relapsing/remitting
progressive
fulminant
6th cranial nerve palsy common
Multiple systems atrophy (Shy Drager syndrome)
progressive supranuclear palsy
Idiopathic Parkinson's disease
usually unilateral
resting tremor, diminished on action
rigidity
bradykinesia
characteristic gait
possibly cognitive impairment
syphilis
Huntingdon's disease
drug induced eg neuroleptics and antiemetics
gradual progression
cognitive impairment
motor neuron disease
progressive
usually males, age 50+
progressive muscular atrophy, bulbar palsy