Essential tremorMANAGEMENT

NEUROLOGICAL PRESENTATIONS · 12 SECTIONS

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613 items

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01Approach to the Critical Patient/attcp44

Immediate priorities

›Essential tremor is not itself an emergency and is a diagnosis of exclusion in the emergency department

›The emergency task is to exclude a dangerous mimic, not to confirm essential tremor

›Confirm airway, breathing, and circulation are intact before attributing any new tremor to a benign syndrome

›Point-of-care glucose in every patient with new or worsened tremor

›Treat a blood glucose below 4.0 mmol/l before further evaluation

›Separate long-standing action tremor from acute-onset or rapidly progressive tremor

›Years of slowly progressive bilateral hand tremor with alcohol responsiveness and family history favours essential tremor

›Onset over hours to days, or a step change in a previously stable tremor, is not essential tremor until proven otherwise

›Sudden focal tremor with other neurologic deficits suggests a structural or vascular lesion

›Identify tremor that signals systemic toxicity or withdrawal

›Fever, tachycardia, agitation, and diaphoresis with tremor suggest thyroid storm, sympathomimetic toxicity, serotonin syndrome, or alcohol withdrawal

›Hyperreflexia, inducible clonus, and rigidity with tremor point to serotonin syndrome or neuroleptic malignant syndrome

›Coarse tremor with confusion in a patient on lithium suggests lithium toxicity and prompts an urgent level

›Establish the disposition trajectory early

›Isolated chronic action tremor with a normal neurologic examination is an outpatient neurology referral

›Any acute neurologic deficit, systemic instability, or suspected toxidrome is a resuscitation-area evaluation

Life-threatening tremor mimics and red flags

›Thyroid storm

›Fine high-frequency postural tremor with fever, atrial fibrillation, heart failure, and altered mental status

›TSH, free T4, and free T3, with empiric treatment if the clinical picture fits rather than waiting for results

›Alcohol withdrawal and delirium tremens

›Coarse tremor beginning 6 to 24 hours after the last drink, with tachycardia, hypertension, and tremulousness

›Progression to hallucinations, withdrawal seizures, and delirium tremens carries mortality if untreated

›Essential tremor patients commonly self-medicate with alcohol and are at risk of withdrawal when admitted for any reason

›Serotonin syndrome and neuroleptic malignant syndrome

›Serotonin syndrome: tremor, inducible clonus, hyperreflexia, hyperthermia, and a recent serotonergic drug change over hours

›Neuroleptic malignant syndrome: lead-pipe rigidity, coarse tremor, hyperthermia, and dysautonomia over days after a dopamine antagonist

02History/hx69

Tremor characterization

›Body parts involved

›Bilateral, roughly symmetric hands and forearms as the typical distribution

›Head tremor described as a yes-yes or no-no oscillation, often with underlying cervical dystonia

›Voice tremor causing a quavering quality to sustained phonation

›Jaw, tongue, or trunk involvement in advanced disease

›Isolated leg or chin tremor is atypical and should prompt reconsideration of the diagnosis

›Tremor phenomenology

›Action tremor present with sustained posture and with movement

›Absence of tremor at complete rest, unlike Parkinson disease

›Kinetic worsening as the hand approaches a target, for example at the finger-to-nose endpoint

›Task accentuation with writing, pouring, or holding a cup

›Tremor frequency and course as reported

›Frequency 4 to 12 Hz, slower with longer disease duration and older age

›Insidious onset with very slow progression over years to decades

›Long periods of stability rather than stepwise change

›Functional impact

›Difficulty eating, drinking from a full cup, writing, shaving, or applying make-up

›Occupational limitation for fine-motor tasks

›Social embarrassment and avoidance behaviour

›Falls are not expected from essential tremor alone and suggest an alternative or additional diagnosis

Activating, relieving, and temporal factors

›Alcohol responsiveness

›Marked transient reduction in tremor amplitude within 15 to 45 minutes of one to two alcoholic drinks in a majority of patients

›Rebound worsening several hours later

›History of escalating alcohol use as self-treatment, with dependence risk

›Aggravating factors

›Emotional stress, anxiety, fatigue, and sleep deprivation

›Caffeine and other stimulants

›Hunger and hypoglycaemia

›Extremes of temperature and physical exertion

›Diurnal and situational pattern

›Present throughout waking hours and absent during sleep

›Performance-anxiety worsening, for example signing a document while observed

›Reason for this visit

›Sudden subjective worsening, often driven by an intercurrent illness, a new medication, or a life stressor

›Fear of stroke or Parkinson disease prompting presentation

›An adverse effect from a tremor medication

›A new functional milestone lost, such as inability to self-feed

Medications, toxins, and comorbid exposures

›Tremorogenic prescription drugs

›Beta-2 agonists such as salbutamol and formoterol

›Valproate and lithium

›Amiodarone

›Selective serotonin reuptake inhibitors, serotonin-noradrenaline reuptake inhibitors, and tricyclics

›Metoclopramide, prochlorperazine, and antipsychotics causing drug-induced parkinsonism or tremor

›Corticosteroids, ciclosporin, tacrolimus, and thyroid hormone over-replacement

›Stimulants and toxins

›Caffeine, nicotine, pseudoephedrine, and energy drinks

›Cocaine, amphetamines, and 3,4-methylenedioxymethamphetamine

›Heavy metals including mercury, lead, arsenic, and manganese

›Solvent and toluene exposure

›Withdrawal states

›Alcohol, benzodiazepine, and opioid withdrawal

›Timing of the last use of each substance

›Relevant comorbidities

›Thyroid disease, diabetes, chronic kidney disease, and liver disease

›Anxiety and mood disorders

›Migraine, which is over-represented in essential tremor

Family history and prior evaluation

›Family history

›A first-degree relative with a similar action tremor in 50 to 70 percent of patients

›An autosomal dominant pattern with variable penetrance in many kindreds

›Apparently earlier onset in successive generations, usually recall bias rather than true anticipation

›Prior diagnostic workup

›Previous thyroid studies, brain imaging, or neurology assessment and their results

›Previous trials of propranolol or primidone, the dose reached, benefit, and side effects

›Prior dopamine transporter imaging if parkinsonism was considered

›Onset age

›A bimodal distribution with peaks in the second decade and after the fifth decade

›Onset before age 40 without a family history triggers Wilson disease screening

›Response to previous alcohol or medication

›Documented alcohol responsiveness supports the diagnosis but is not required to make it

03Physical Exam/exam59

Tremor examination

›Postural testing

›Arms outstretched, wrists extended, fingers spread, held against gravity for 20 seconds

›Immediate onset rather than the re-emergent delay of several seconds seen in Parkinson disease

›Loading the limb with a weight does not abolish essential tremor

›Kinetic and intention testing

›Finger-to-nose and finger-to-finger manoeuvres

›An amplitude increase near the target consistent with a cerebellar component in some patients

›Archimedes spiral and a written sentence for a permanent record, showing large-amplitude oscillation

›Water poured between two cups to grade functional severity

›Rest testing

›Hands fully supported in the lap while the patient is mentally distracted by serial subtraction

›True rest tremor absent in pure essential tremor

›A rest component in long-standing severe essential tremor can occur but remains a diagnosis of exclusion

›Distribution and symmetry

›Mild side-to-side asymmetry is acceptable

›Marked asymmetry, or onset in one limb, argues against essential tremor

›Head and voice tremor documented separately by having the patient sustain a vowel

Neurologic examination for mimics

›Parkinsonism screen

›Cogwheel rigidity at the wrist with contralateral activation

›Bradykinesia on finger tapping with a decrement in amplitude and speed

›Reduced arm swing, hypomimia, hypophonia, and a shuffling festinating gait

›Glabellar tap sign and micrographia

›Cerebellar screen

›Dysmetria, dysdiadochokinesia, and rebound

›Gait ataxia with a wide base and inability to tandem walk

›Nystagmus and scanning dysarthria

›Head titubation and truncal instability

›Dystonia screen

›An abnormal head or hand posture with a directional preponderance

›A sensory trick, or geste antagoniste, that reduces the tremor

›A position-specific or task-specific tremor such as primary writing tremor

›Signs of Wilson disease

›Kayser-Fleischer rings on slit-lamp examination

›A proximal wing-beating tremor

›Dysarthria, drooling, dystonia, and parkinsonism in a young patient

›Functional tremor features

›Distractibility, with the tremor attenuating during a contralateral rhythmic task

›Entrainment of the tremor frequency to an externally paced movement

›Variable frequency, amplitude, and direction, with abrupt onset and remission

›A tonic co-contraction pause when the limb is released suddenly

Systemic signs and vital signs

›Vital sign patterns

›Baseline heart rate and blood pressure documented before any beta blocker is started

›Resting sinus tachycardia above 100 beats per minute suggests thyrotoxicosis, withdrawal, or a sympathomimetic

›A temperature above 38 degrees Celsius with tremor is never explained by essential tremor

›Orthostatic vital signs, a fall of 20 mmHg systolic or 10 mmHg diastolic within 3 minutes of standing, before prescribing propranolol

›Larger asymptomatic drops can be chronic in autonomic failure or on antihypertensives, so compare with prior readings

›Thyroid examination

›Goitre, a thyroid bruit, lid lag, and warm moist skin

›Proximal myopathy and brisk reflexes

›Autonomic and hepatic signs

›Diaphoresis, mydriasis, and flushing in a toxidrome

›Jaundice, spider naevi, and asterixis, the last a flapping negative myoclonus of hepatic encephalopathy rather than a true tremor

›Cognitive and cranial nerve screen

›Brief cognitive assessment, since mild executive and memory impairment can accompany essential tremor

›Ocular movements for the ophthalmoplegia of Wernicke and for a supranuclear gaze palsy

›Standing test for orthostatic tremor

›Quadriceps palpation with the patient standing still

›A fine high-frequency 13 to 18 Hz tremor felt on standing and relieved by sitting or walking

›Thigh-muscle auscultation revealing a helicopter-like sound

04Differential Diagnosis/ddx54

Common action and rest tremor syndromes

›Enhanced physiologic tremor

›A low-amplitude 8 to 12 Hz postural tremor with an identifiable trigger such as caffeine, anxiety, fatigue, or hyperthyroidism

›Resolves when the trigger is removed and has no family history

›Parkinson disease

›An asymmetric 4 to 6 Hz pill-rolling rest tremor with bradykinesia and rigidity

›A re-emergent postural tremor after a latency of several seconds

›Anosmia, constipation, and rapid-eye-movement sleep behaviour disorder as prodromal clues

›Dystonic tremor

›An irregular, jerky, position-sensitive tremor in a body part affected by dystonia

›A null point where the tremor disappears at a specific joint angle

›Cerebellar tremor

›A low-frequency, high-amplitude intention tremor, often 3 to 5 Hz, with dysmetria

›Underlying multiple sclerosis, stroke, tumour, or spinocerebellar ataxia

›Functional tremor

›Abrupt onset, distractibility, entrainment, and variability

›Frequently follows a physical or psychological precipitant

Drug-induced and systemic tremor

›Drug-induced tremor

›A symmetric postural tremor temporally linked to a beta agonist, valproate, lithium, amiodarone, an antidepressant, or a calcineurin inhibitor

›Dose-dependent and reversible on withdrawal

›Drug-induced parkinsonism

›Symmetric bradykinesia and rest tremor after a dopamine-blocking antiemetic or antipsychotic

›Onset weeks to months after the offending drug, resolving over weeks to months after it is stopped

›Thyrotoxic tremor

›A fine fast postural tremor with weight loss, palpitations, heat intolerance, and hyperdefecation

›Metabolic tremor

›Hypoglycaemia, hyponatraemia, hypomagnesaemia, hypocalcaemia, and hepatic or uraemic encephalopathy

05Laboratory Tests/lt33

First-line screening bloodwork

›Thyroid function

›TSH as the primary screen, with free T4 and free T3 if TSH is abnormal or suppressed

›Expedited testing when thyroid storm is a consideration

›Metabolic panel

›Sodium, potassium, calcium, and magnesium for correctable metabolic tremor

›Magnesium below 0.7 mmol/l and corrected calcium below 2.1 mmol/l can each produce tremor

›Urea and creatinine for uraemia and to guide renally cleared drugs

›Glucose, with symptomatic hypoglycaemia treated at a blood glucose below 4.0 mmol/l

›The same threshold applies in diabetes, though long-standing poor control can produce adrenergic symptoms at higher values

›Liver panel

›Aminotransferases, bilirubin, albumin, and INR

›Abnormal results in a young patient raise Wilson disease and change the workup

›Full blood count

›Macrocytosis as a clue to alcohol use or B12 deficiency

Targeted and toxicology testing

›Drug levels

›Serum lithium level, sent urgently if any toxicity feature is present

›A single therapeutic lithium level drawn near a peak does not exclude toxicity; repeat 6 to 12 hours after the dose

›Valproate level if the tremor followed a dose increase

›Digoxin and other levels as directed by the medication list

›Toxicology

›Blood alcohol concentration and a timed withdrawal assessment

›Urine drug screen for sympathomimetics

›Carboxyhaemoglobin and a heavy-metal panel only if the history suggests exposure

›Young-onset tremor workup

›Serum caeruloplasmin, low in most symptomatic Wilson disease

›Caeruloplasmin is an acute-phase reactant and can read falsely normal during infection or inflammation, so a normal value does not exclude Wilson disease

06Diagnostic Tests/dt55

Scoring Systems

›Fahn-Tolosa-Marin Tremor Rating Scale

›A clinician-rated scale of tremor at rest, with posture, and with action across body regions

›Includes performance items for handwriting, drawing, and pouring

›Used to quantify baseline severity and track treatment response over time

›The Essential Tremor Rating Assessment Scale, TETRAS

›Performance and activities-of-daily-living subscales validated for essential tremor

›The preferred instrument in modern essential tremor trials

›Bain and Findley spiral rating

›A zero to ten visual scale applied to a drawn Archimedes spiral

›Clinical diagnostic criteria

›Consensus criteria require an isolated bilateral upper-limb action tremor for at least 3 years

›Absence of other neurologic signs such as dystonia, ataxia, or parkinsonism

›Soft signs such as impaired tandem gait define essential tremor plus rather than excluding the diagnosis

›Screening for a functional overlay

›No validated emergency-department score; diagnosis rests on positive functional signs

MRI

›Indications

›Not required for a typical bilateral action tremor with a normal examination and a supportive family history

›Indicated for unilateral tremor, abrupt onset, cerebellar signs, or onset before age 40

›Indicated before deep brain stimulation or focused ultrasound for procedural planning

›Expected findings

›A structurally normal brain in essential tremor

›Group-level cerebellar changes on quantitative studies, not diagnostic at the individual level

›Findings that redirect the diagnosis

›Midbrain atrophy with the hummingbird sign in progressive supranuclear palsy

›Middle cerebellar peduncle T2 hyperintensity and the hot cross bun sign in multiple system atrophy

›Symmetric T2 hyperintensity of the middle cerebellar peduncles and splenium in fragile X-associated tremor/ataxia syndrome

›Basal ganglia signal change in Wilson disease, including the face of the giant panda sign

›Demyelinating plaques, a posterior fossa tumour, or a prior infarct

›Emergency indications

›Non-contrast CT head for acute tremor with headache, trauma, a focal deficit, or reduced consciousness

›To exclude cerebellar haemorrhage, a posterior fossa mass, and hydrocephalus when MRI is not immediately available

›Limitations

›Poor sensitivity for acute posterior fossa ischaemia and for small structural lesions

›A normal CT does not exclude a brainstem or cerebellar stroke, and MRI should follow if suspicion persists

›Incidental findings

›Basal ganglia calcification suggesting a Fahr-type syndrome as a rare tremor cause

Ultrasound

›Transcranial parenchymal sonography

›Substantia nigra hyperechogenicity supports Parkinson disease and is typically absent in essential tremor

›Operator-dependent and limited by an inadequate temporal bone window in a minority of patients

›Thyroid ultrasound

›Assesses gland size, nodularity, and vascularity when thyrotoxic tremor is confirmed biochemically

›Point-of-care cardiac ultrasound

›Evaluates ventricular function before and during beta blockade when heart failure is suspected

›Surface electromyography with accelerometry

›Characterises tremor frequency and burst pattern at the bedside

›Confirms the 13 to 18 Hz pattern of orthostatic tremor, which is otherwise easily missed

Neurophysiology and nuclear imaging

›Tremor analysis with accelerometry and surface electromyography

›Quantifies frequency, amplitude, and the effect of limb loading and mental distraction

›Demonstrates entrainment and variability in functional tremor

›Dopamine transporter single-photon emission CT

›Normal striatal uptake in essential tremor

›Reduced putaminal uptake in Parkinson disease and other presynaptic parkinsonian syndromes

›Cannot separate Parkinson disease from atypical parkinsonism and does not change emergency management

›Metaiodobenzylguanidine cardiac scintigraphy

›Reduced uptake in Parkinson disease and normal in essential tremor, used only in specialist practice

07Disposition/dispo25

Discharge criteria and outpatient pathway

›Safe for discharge

›Chronic bilateral action tremor, neurologically intact, haemodynamically stable, with a normal glucose and no toxidrome

›No new focal deficit, no rest tremor, no ataxia, and no red flag feature

›Able to perform activities of daily living safely or with community support arranged

›Outpatient workup to arrange

›Outpatient TSH if not done, and neurology referral for diagnostic confirmation and treatment initiation

›Primary care follow-up within 1 to 2 weeks to review any medication started

›Shared decisions at discharge

›Many patients with mild tremor need reassurance and no drug therapy

›Driving is generally permitted unless the tremor or a comorbid condition impairs vehicle control

Admission, transfer, and referral criteria

›Admit

›Suspected stroke, haemorrhage, or a posterior fossa mass

›Thyroid storm, severe alcohol withdrawal, serotonin syndrome, neuroleptic malignant syndrome, or significant drug toxicity

›Symptomatic bradycardia or hypotension from a tremor medication

›Inability to maintain hydration or nutrition because of tremor severity, pending expedited therapy

›Transfer to a centre with neurology and neurosurgery

›Confirmed posterior fossa stroke or haemorrhage needing neurosurgical availability

›Suspected Wilson disease needing hepatology and specialist metabolic care

›Candidacy assessment for deep brain stimulation or MR-guided focused ultrasound

›Urgent versus routine neurology referral

›Urgent: subacute progression, cerebellar signs, young onset, or diagnostic uncertainty with functional impairment

›Routine: classic essential tremor for confirmation and long-term management

›Documentation for the receiving clinician

›A video of the tremor at rest, with posture, and with action if consent is given

›Baseline heart rate, blood pressure, glucose, and the full medication list

08Treatment/t128

General principles and cautions shared across agents

›Decide whether drug treatment is warranted

›Treat when the tremor causes functional or social disability, not merely because it is present

›Mild tremor is managed with reassurance, trigger avoidance, and reduction of caffeine and tremorogenic drugs

›Weighted utensils, wrist weights, and adaptive devices help selected patients

›Reversible contributors first

›Correct hyperthyroidism, hypoglycaemia, and electrolyte deficits

›Taper or substitute a culprit drug where feasible, for example switching a beta agonist device or reviewing an antidepressant

›Address anxiety and sleep deprivation

›Emergency-department role

›Initiation of a first-line agent is reasonable when follow-up is assured, with a clear written plan

›Avoid starting multiple agents at once, and give each drug an adequate trial before adding another

›Counsel on alcohol

›Acknowledge the transient benefit but advise against alcohol as therapy given dependence and rebound

›Class-wide monitoring

›Recheck heart rate and blood pressure after any beta blocker dose given in the department

›Warn about sedation and driving with primidone, topiramate, gabapentin, and benzodiazepines

›ECG before and during beta blocker or sotalol titration: watch for sinus bradycardia and PR prolongation, and for QT prolongation with sotalol

›With sotalol keep potassium above 4.0 mmol/l and magnesium above 0.8 mmol/l

First-line oral pharmacotherapy

›Propranolol

›Propranolol immediate-release 10 mg orally twice daily as a starting dose

›Increase by 20 to 40 mg per day every 3 to 7 days according to response and tolerance

›Slow to 10 to 20 mg per day increments once the daily dose reaches 120 mg or the resting heart rate approaches 55 beats per minute

›Usual effective dose 120 to 320 mg per day; maximum 320 mg per day for this indication

›Long-acting propranolol 60 to 80 mg once daily is an alternative, titrated to 160 to 320 mg once daily

›If blood pressure is borderline, start 10 mg once daily and omit any rapid escalation

›Non-selective beta blockade is the mechanism, acting largely at peripheral beta-2 receptors on muscle spindles

›Cardioselective agents are less effective; if a beta blocker must be used in mild reactive airways disease, atenolol 50 to 100 mg once daily or nadolol 40 to 120 mg once daily are partial options

›A cardioselective beta blocker does not remove bronchospasm risk and is not the first choice

›Contraindications and cautions

›Avoid in asthma and in decompensated heart failure

›Avoid with sinus bradycardia below 50 beats per minute, second- or third-degree heart block, and a systolic blood pressure below 100 mmHg

›Caution in diabetes because propranolol blunts adrenergic hypoglycaemia awareness; the blood glucose treatment threshold of 4.0 mmol/l still applies

›Caution in peripheral vascular disease and with concurrent verapamil or diltiazem because of additive bradycardia and hypotension

›Do not stop abruptly after chronic use; taper over 1 to 2 weeks to avoid rebound tachycardia

›Primidone

›Primidone 12.5 to 25 mg orally at bedtime as the starting dose

›Increase by 25 to 50 mg every 1 to 2 weeks, given at night first, then divided twice or three times daily

›Decelerate to 25 mg increments if daytime sedation or unsteadiness appears

›Usual effective dose 62.5 to 250 mg per day; some patients reach 500 to 750 mg per day divided; maximum 750 mg per day for tremor, occasionally up to 1000 mg per day under specialist care

›The low starting dose is essential because of an acute first-dose reaction of vertigo, nausea, ataxia, and sedation

›Mechanism and metabolism

›Primidone is metabolised to phenobarbital and phenylethylmalonamide, and the barbiturate action is thought to mediate the anti-tremor effect

›Hepatic enzyme induction lowers levels of other drugs, including direct oral anticoagulants and hormonal contraception

›Cautions

›Additive sedation with alcohol, opioids, and benzodiazepines

›Dependence and a withdrawal risk with abrupt cessation, including withdrawal seizures; taper slowly

›Reduce the increment and the target dose in older adults and in hepatic or renal impairment

›Choosing and combining

›Propranolol is preferred with prominent situational or stress-related tremor, in younger patients, and with comorbid migraine or hypertension

›Primidone is preferred with resting bradycardia, reactive airways disease, or when a single bedtime dose aids adherence

›Combining low-dose propranolol and primidone gives additive benefit when either alone is insufficient

Second-line and adjunctive pharmacotherapy

›Topiramate

›Topiramate 25 mg orally at night, increased by 25 mg per week

›Target 200 mg per day in two divided doses; maximum 400 mg per day

›Decelerate the titration if paraesthesia, word-finding difficulty, or cognitive slowing appears

›Cautions: renal stones, metabolic acidosis, weight loss, acute angle-closure glaucoma, and teratogenicity with an oral-cleft risk

›Gabapentin

›Gabapentin 300 mg orally at night, increased to 300 mg three times daily over 1 week

›Target 1200 to 3600 mg per day in three divided doses; maximum 3600 mg per day

›Reduce the dose in renal impairment according to creatinine clearance

›Cautions: sedation, dizziness, peripheral oedema, and misuse potential

›Benzodiazepines

›Clonazepam 0.25 to 0.5 mg orally at night, titrated slowly to a maximum of 2 mg per day, useful when anxiety coexists

›Alprazolam 0.125 to 0.25 mg orally up to three times daily, maximum about 2.75 mg per day in trial data

›Reserve for intermittent predictable situational tremor because of tolerance, falls in older adults, and dependence

›Other oral options with weaker evidence

›Atenolol, nadolol, and sotalol as alternative beta blockers, sotalol only where the QT can be monitored

›Zonisamide 100 to 200 mg per day as a specialist option

›Evidence does not support levetiracetam, pregabalin, or verapamil for routine use, though a monitored trial of one agent is reasonable in refractory cases

›Agents to avoid or use cautiously

›Avoid adding a second sedating anticonvulsant before optimising the first

›Avoid propranolol plus a non-dihydropyridine calcium channel blocker such as diltiazem or verapamil because of bradycardia and heart block

›A dihydropyridine such as amlodipine 5 to 10 mg once daily does not treat tremor and causes reflex tachycardia, so it is not a substitute for a beta blocker

Botulinum toxin for craniocervical and limb tremor

›Indications

›Head tremor and voice tremor that respond poorly to oral agents

›Selected disabling hand tremor when systemic drugs fail or are contraindicated

›Administration

›OnabotulinumtoxinA injected into target muscles under electromyographic or ultrasound guidance by a trained clinician

›A typical head-tremor regimen is 40 to 120 units total to the sternocleidomastoid and splenius capitis, individualised

›Hand tremor uses smaller per-muscle doses into wrist flexors and extensors

›Benefit lasts about 10 to 12 weeks and injections are repeated no more often than every 12 weeks

›Adverse effects

›Dose-dependent hand weakness with limb injection

›Dysphagia and neck weakness with cervical injection

›Breathy hypophonia with vocal-cord injection

›Not an emergency-department procedure

›Refer to a movement-disorders or otolaryngology service

Refractory tremor procedures

›Candidacy

›Severe disabling tremor despite adequate trials of propranolol and primidone and at least one second-line agent

›Referral to a movement-disorders centre for multidisciplinary assessment

›Deep brain stimulation of the ventral intermediate nucleus of the thalamus

›Reduces contralateral tremor by roughly 60 to 90 percent in appropriate candidates

›Adjustable and reversible; bilateral stimulation improves midline tremor but increases dysarthria and gait risk

›Risks include intracranial haemorrhage, infection, lead migration, paraesthesia, and stimulation-induced dysarthria or ataxia

›MR-guided focused ultrasound thalamotomy

›Incisionless unilateral lesioning of the ventral intermediate nucleus

›Sustained tremor reduction of roughly 40 to 55 percent on blinded scores at 1 year in trial data

›Risks include gait disturbance, paraesthesia, and dysgeusia, mostly transient; the lesion is not reversible

›Bilateral treatment is not standard

›Conventional radiofrequency thalamotomy

›Reserved for patients who cannot have an implanted device or focused ultrasound

›Emergency considerations in a patient with a deep brain stimulator

›Sudden tremor recurrence suggests battery depletion, lead fracture, or a programming change; arrange device interrogation

›Use bipolar rather than monopolar diathermy, keep it away from the system, and follow the manufacturer advisory

›MRI only under the device-specific conditional protocol

Managing treatment complications and the misidentified mimic

›Propranolol-induced bradycardia or hypotension

›Stop the drug and monitor; most cases resolve with time

›Atropine 0.5 mg IV every 3 to 5 minutes to a maximum of 3 mg for symptomatic bradycardia

›Intravenous crystalloid for hypotension; glucagon 3 to 5 mg IV over 1 to 2 minutes then an infusion of 3 to 5 mg per hour for refractory beta-blocker toxicity

›Monitor heart rate, blood pressure, and blood glucose every 15 minutes during the glucagon infusion and guard the airway against vomiting

›High-dose insulin euglycaemic therapy and vasopressors in consultation with toxicology for severe overdose

›Primidone or topiramate over-sedation and ataxia

›Withhold the next dose, protect the airway, assess for falls and aspiration, and taper rather than stop abruptly if on a chronic dose

›Iatrogenic-harms review for the essential tremor patient in the emergency department

›Intubation and rapid-sequence induction: chronic beta blockade blunts the reflex tachycardia to laryngoscopy and to induction agents, so anticipate hypotension and have vasopressors ready; tremor itself does not alter tube choice

›Sedation: benzodiazepines and propofol transiently suppress action tremor and can mask an evolving withdrawal state or toxidrome, so document a pre-sedation neurologic examination

›Fluid loading: no direct tremor harm, but give cautiously if beta blockade has produced a bradycardia-dependent low-output state

›Oxygen: no tremor-specific harm and no oxygen saturation target unique to essential tremor; usual targets apply, adjusted to 88 to 92 percent only in chronic hypercapnic lung disease

›Vasopressors: beta-blocked patients may need higher catecholamine doses or glucagon, so add a direct-acting agent early

›Mechanical circulatory support and intra-aortic balloon pump: relevant only for refractory beta-blocker or calcium channel blocker cardiotoxicity, as a bridge while drug effect wears off

›Anticoagulation: primidone induces hepatic enzymes and lowers direct oral anticoagulant levels and warfarin effect, so check the INR and reconsider agent choice

›Fibrinolysis: no interaction with tremor drugs, but it is contraindicated if the tremor is due to a cerebellar haemorrhage

›Analgesia: paracetamol 1 g orally or IV every 6 hours, maximum 4 g per day, or 3 g per day in low body weight, frailty, or hepatic impairment; avoid adding tramadol or pethidine in patients on serotonergic drugs because of serotonin syndrome risk

›Therapy-is-not-working troubleshooting

›Confirm adherence, the dose actually reached, and the duration of the trial before declaring failure

›Re-examine for a rest component, dystonia, or ataxia that reclassifies the tremor and changes the drug

›Reconsider functional tremor, Wilson disease in the young, and an unrecognised tremorogenic drug

›Escalate to the alternative first-line agent, then to combination therapy, then to specialist referral

09Special Populations/sp51

Pregnancy

›Course

›Essential tremor may worsen during pregnancy from physiologic and haemodynamic change

›Prefer non-drug measures, trigger reduction, and adaptive aids

›Pharmacotherapy if disabling

›Propranolol at the lowest effective dose, for example 10 to 20 mg twice daily, is the usual choice

›Associated with fetal growth restriction, neonatal bradycardia, and neonatal hypoglycaemia, so arrange fetal growth surveillance and monitor the newborn

›Consider tapering before delivery to reduce neonatal effects, and review the need each trimester

›Agents to avoid

›Avoid topiramate because of an oral-cleft and growth-restriction risk; if already established, discuss risks and high-dose folate

›Avoid primidone where possible because of neonatal sedation, withdrawal, and a bleeding-diathesis risk that warrants maternal vitamin K in the last month and vitamin K for the neonate

›Avoid benzodiazepines, especially near term, because of floppy-infant syndrome and neonatal withdrawal

›Breastfeeding

›Propranolol is compatible with breastfeeding at a low relative infant dose

›Primidone and benzodiazepines pass into milk and can sedate the infant, so monitor feeding and tone

Geriatric

›Diagnosis

›Prevalence rises steeply with age, reaching roughly 5 percent or more after age 65

›Distinguish from Parkinson disease, drug-induced tremor from polypharmacy, and enhanced physiologic tremor

›A late-life rapidly progressive tremor with cognitive change raises fragile X-associated tremor/ataxia syndrome and structural disease

›Treatment adjustments

›Start propranolol at 10 mg once or twice daily and titrate slowly, watching for bradycardia, fatigue, depression, and orthostatic hypotension defined as a fall of 20 mmHg systolic or 10 mmHg diastolic within 3 minutes of standing

›Start primidone at 12.5 mg at night; the first-dose reaction and cumulative sedation are worse in older adults and raise fall and fracture risk

›Avoid or minimise benzodiazepines under Beers-type prescribing guidance

›Topiramate can cause disproportionate cognitive impairment in older adults

›Falls and function

›Formal falls assessment when tremor coexists with gait impairment

›Occupational therapy for weighted devices, home safety, and medication organisers

Pediatrics

›Presentation

›Essential tremor can begin in childhood or adolescence, often with a strong family history

›It is usually mild; disabling tremor or additional neurologic signs warrant specialist referral

›Differential in children and young people

›Wilson disease is the critical not-to-miss diagnosis in any child or young adult with tremor, dystonia, or unexplained liver disease

›Enhanced physiologic tremor from salbutamol, valproate, methylphenidate, caffeine, and anxiety

›Dystonic tremor and functional tremor

›Treatment

›Non-drug management is first-line, reserving drugs for functional impairment

›Propranolol paediatric dosing about 0.5 to 1 mg per kg per day divided twice or three times daily, titrated to effect, with a usual ceiling near 2 to 4 mg per kg per day and not exceeding the adult maximum of 320 mg per day

›Primidone and topiramate are used off-label under paediatric neurology supervision

›Emergency hypoglycaemia in a child presenting with tremor

›Treat a blood glucose below 4.0 mmol/l with dextrose 10 percent 2 to 5 ml per kg IV, then recheck

›Verify against current pediatric guideline before use

Alcohol use disorder and hepatic impairment

›Alcohol use disorder

›Essential tremor patients are at elevated risk of hazardous drinking through self-medication

›Screen with a validated tool and offer treatment for alcohol use disorder

›On admission, anticipate withdrawal, give prophylactic thiamine, and use a symptom-triggered benzodiazepine protocol

›Propranolol can mask the tachycardia used to score withdrawal severity, so rely on a broader assessment

›Hepatic impairment

›Reduce or avoid primidone and topiramate, and watch for encephalopathy that itself causes asterixis

›Propranolol undergoes extensive first-pass hepatic metabolism, so levels rise in cirrhosis; start low and titrate slowly

›Renal impairment

›Dose-reduce gabapentin and topiramate by creatinine clearance

›Lithium-related tremor worsens as renal function falls, so involve the prescriber

10Background/b44

Epidemiology

›Frequency

›One of the most common movement disorders, with an estimated prevalence near 1 percent of the general population

›Prevalence rises to roughly 5 percent after age 65 and continues to climb into the ninth decade, exceeding 20 percent in the very old in some community studies

›Estimated incidence around 0.6 to 1 percent per year in older adults

›Demographics

›Roughly equal sex distribution, with a possible slight excess of head tremor in women

›A bimodal age of onset with peaks in the second decade and the sixth decade

›Reported across all ethnic groups studied

›Family history and genetics

›A positive family history in 50 to 70 percent of cases

›Autosomal dominant inheritance with incomplete penetrance in many families; several risk loci identified but no single causative gene for most patients

›Natural history and burden

›Slowly progressive amplitude increase and frequency decrease over decades

›Up to a quarter of referred patients change or stop employment because of tremor

›Associated with a modestly increased risk of later Parkinson disease, dementia, and hearing impairment in cohort studies

Pathophysiology

›Network model

›Tremor arises from abnormal oscillatory activity in the cerebello-thalamo-cortical circuit

›The inferior olive and the ventral intermediate nucleus of the thalamus are key nodes, which is why that nucleus is the surgical target

›Pathology

›Post-mortem studies show Purkinje cell loss, axonal torpedoes, and dendritic changes in a subset of cases

›A minority show brainstem Lewy pathology, supporting heterogeneity rather than a single disease

›Neurochemistry and provocation

›Peripheral beta-adrenergic mechanisms modulate tremor amplitude, explaining the effect of propranolol and of adrenergic stress

›The GABAergic system is implicated, consistent with the response to primidone, barbiturates, alcohol, and topiramate

›Ethanol suppresses tremor through a central cerebellar action rather than simple sedation

›Classification

11Patient Discharge Instructions/pdi33

Clinician handoff at discharge

›Communicate the working diagnosis

›State clearly whether this is probable essential tremor or undifferentiated tremor pending workup

›List the mimics considered and excluded and those still open

›Medication reconciliation

›Document any agent started, the dose, the titration plan, and monitoring parameters

›Flag interacting drugs, especially verapamil and diltiazem, insulin and sulfonylureas with propranolol, and anticoagulants with primidone

›Follow-up arranged

›Neurology referral with a priority level and the reason

›Primary care review timing and the specific checks required

›Pending results and who will action them

copy discharge instructions

›Your diagnosis

›You have been assessed for a tremor, which is a rhythmic shaking, most often of the hands

›The likely cause is essential tremor, a common condition that is not dangerous and is not a stroke

›A specialist will confirm the diagnosis and discuss long-term treatment

›What helps day to day

›Cut back on caffeine, including coffee, tea, cola, and energy drinks

›Aim for regular meals so your blood sugar does not drop, and keep a regular sleep schedule

›Try weighted cups, wide-grip cutlery, and using both hands for fine tasks

›Alcohol briefly reduces the shaking but it rebounds worse afterwards and regular use is harmful, so do not use alcohol as a treatment

›About any new medicine you were given

›If you were started on propranolol, take it exactly as written and do not stop it suddenly; report a slow pulse, dizziness on standing, wheezing, cold hands, or vivid dreams

›If you were started on primidone, take the first small dose at bedtime because it can cause several hours of unsteadiness, nausea, and drowsiness; do not drive until you know how it affects you

›If you have diabetes, check your blood sugar more often because propranolol can hide the warning signs of a low, and treat a reading below 4.0 mmol/l

›Come back to the emergency department now if

›The shaking starts suddenly on one side, or you develop weakness, numbness, slurred speech, double vision, or a severe headache

›You become unsteady on your feet or cannot walk heel to toe

12References/r18

Practice guidelines and consensus statements

›American Academy of Neurology practice parameter on the treatment of essential tremor

›Zesiewicz and colleagues, original practice parameter 2005 and evidence-based update 2011, Neurology

›Propranolol and primidone first-line; topiramate and gabapentin as options; deep brain stimulation and thalamotomy for refractory tremor

›Movement Disorder Society consensus statement on the classification of tremor

›Bhatia and colleagues, 2018, Movement Disorders

›Defines isolated essential tremor and essential tremor plus

›International Parkinson and Movement Disorder Society reviews of essential tremor management

›Contemporary summaries of pharmacologic and surgical options

Systematic reviews and evidence syntheses

›Cochrane reviews of propranolol, primidone, gabapentin, and topiramate for essential tremor

›Summarise roughly 50 percent amplitude reduction with first-line agents and frequent adverse effects

›Reviews of botulinum toxin for limb, head, and voice tremor

›Benefit for head and voice tremor, with dose-dependent limb weakness after hand injection

Landmark trials and device evidence

›Elias and colleagues, randomised trial of MR-guided focused ultrasound thalamotomy for essential tremor, New England Journal of Medicine 2016

›Improved tremor scores versus a sham procedure at 3 months with benefit maintained at 12 months, and gait and sensory adverse effects

›Controlled and long-term studies of ventral intermediate nucleus deep brain stimulation

›Sustained contralateral tremor suppression with stimulation-related dysarthria and disequilibrium, and partial habituation over years

›Cohort studies on essential tremor and later neurodegenerative disease

›Report a modestly increased incidence of Parkinson disease and dementia relative to controls

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed September 13, 2026

SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.