Tremors Flashcards
What is a tremor?
Tremor may occur as a symptom or sign of an underlying disease or as an exaggerated physiological phenomenon. It is not a diagnostic term.
It can be defined as a rhythmic oscillatory movement of a body part, resulting from the contraction of opposing muscle groups.
What is the aetiology of tremors?
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 - eg, multiple system atrophy, progressive supranuclear palsy
Metabolic derangement - e.g., electrolyte disturbance, renal and hepatic failure.
Wilson’s disease.
Cerebellar disease.
Basal ganglia lesions.
Dystonias.
Other movement disorders - e.g., tardive dyskinesia, cerebrovascular disease.
Writer’s cramp or tremor.
Psychogenic tremor.
Arsenic, heavy metal, organophosphate or industrial solvent poisoning.
Vitamin deficiency (especially B1).
What are rest tremors?
Rest tremors occur when the body part is supported against gravity - eg, hands at rest in one’s lap.
Mental stress or general movement makes rest tremors worse.
What are static tremors?
Static - occurs in a relaxed limb when fully supported at rest. Causes include Parkinson’s disease, Parkinsonism, other extrapyramidal diseases and multiple sclerosis.
What are postural tremors?
Postural - occurs when a part of the body is held in a fixed position against gravity (it can also remain during movement).
Which conditions cause postural tremors?
Types include physiological tremor, exaggerated physiological tremor (e.g., 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.
What is an action tremor?
Kinetic or action tremor - occurs during voluntary active movement of an upper body part.
What is an intention tremor?
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.
How does essential tremor present?
This is usually a distal symmetrical postural tremor of the upper limbs, usually of low amplitude with a fairly rapid frequency of 8-10 Hz.
It may initially be transient but usually progresses to become persistent.
The neck muscles may be involved, causing tremor of the head (about 40% of cases). Voice, face and jaw muscles may be involved.
Some degree of control over the tremor, exerted by concentration on a task or via execution of a skilled manual repertoire, is common.
Tremor does not occur during sleep.
Most report improvement of tremor following alcohol ingestion.
What is the classification of essential tremor?
Mild tremor, which produces no functional or psychological disability/handicap and does not require treatment.
Mild-to-moderate tremor-producing disability only where there is tremor exacerbation in stressful situations such as social occasions or public speaking. These patients can be treated intermittently as necessary for these occasions.
Those cases with persistent disability/handicap because of tremor. These patients need continued therapy to improve daily life function.
How does physiological tremor present?
Can occur in a state of normality or in an exaggerated form, due to a precipitant such as anxiety, hyperthyroidism, hypoglycaemia, caffeine excess, fever, medication, etc.
It is usually associated with certain postures. It is usually bilateral, symmetrical and non-progressive over time.
There may be a family history but this is less often than in ET. Other motor symptoms should not accompany the tremor.
How do psychogenic tremors present?
Psychogenic tremors are usually characterised by an abrupt onset, spontaneous remission, changing tremor characteristics and absence during distraction.
Which drugs make tremors worse?
Tremor may be worsened by lithium, antidepressants, bronchodilators, neuroleptics, amiodarone, procainamide, prednisolone, cinnarizine, ciclosporin, metoclopramide, methylphenidate and sodium valproate, caffeine (or other stimulants), sympathomimetics (e.g., salbutamol, L-dopa and associated anti-Parkinsonian drugs), theophylline, thyroid hormones and recreational drug use.
Withdrawal from medication, including alcohol, may also cause tremor.
What should you examine in a patient presenting with a tremor?
The presence of any hard neurological signs suggests a secondary tremor due to underlying neurological disease.
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, coordination, 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.
Which investigations are required for a patient presenting with trauma?
Trials of reducing or stopping the 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.
If underlying CNS disease is suspected then CT/MRI imaging and/or neurological referral should be considered.
