What history and physical examination should be performed for a patient presenting with a head tremor to identify the cause and guide management?

Head Tremor: History and Physical Examination

Perform a focused neurologic examination to distinguish essential tremor from dystonic head tremor, parkinsonian tremor, or cerebellar pathology, because isolated head tremor is more likely dystonic than essential tremor, and the activation pattern determines both diagnosis and treatment. 1

Critical History Elements

Tremor Characterization

• Document the exact activation condition: Does the head tremor occur at rest (suggests parkinsonism), with sustained posture (essential or dystonic), or during goal-directed movement (cerebellar)? 2, 3
• Determine the pattern of head movement: Horizontal "no-no" tremor is more common in essential tremor, while vertical "yes-yes" or complex patterns suggest dystonia. 1
• Ask about tremor suppressibility: Can the patient voluntarily suppress the tremor by touching their chin or turning their head? This "geste antagoniste" strongly suggests cervical dystonia rather than essential tremor. 1
• Assess for associated tremors: Essential tremor typically involves bilateral upper extremity action tremor in addition to head tremor, whereas isolated head tremor without limb involvement is more likely dystonic. 1, 4

Red Flags for Secondary Causes

• Screen for recent medication changes: Antipsychotics, metoclopramide, valproate, lithium, and selective serotonin reuptake inhibitors can induce tremor. 2, 3
• Document substance use: Caffeine intake, alcohol consumption patterns (essential tremor improves with alcohol), and withdrawal states can cause or unmask tremor. 2
• Identify metabolic triggers: Hyperthyroidism, hypoglycemia, and hepatic encephalopathy produce enhanced physiologic tremor. 2, 3
• Assess for psychogenic features: Abrupt onset, spontaneous remission, changing tremor characteristics, and extinction with distraction suggest functional tremor. 2

Associated Neurologic Symptoms

• Ask about bradykinesia and rigidity: Slowness of movement, reduced arm swing, or stiffness suggests Parkinson disease rather than isolated tremor. 2, 3
• Screen for dystonic features: Abnormal neck postures, pulling sensations, or pain accompanying the tremor point toward cervical dystonia. 1
• Evaluate for cerebellar signs: Ataxia, dysmetria, or intention tremor during reaching suggests cerebellar pathology requiring neuroimaging. 3, 4

Focused Physical Examination

Tremor Phenomenology Assessment

• Observe the head at rest: Have the patient sit quietly with hands in lap; resting tremor suggests parkinsonism and requires evaluation for other parkinsonian signs. 2, 3
• Test postural tremor: Ask the patient to hold their head in a neutral position without support; postural head tremor occurs in essential tremor and dystonia. 3, 4
• Assess kinetic tremor: Have the patient perform goal-directed movements (e.g., finger-to-nose testing) while observing whether head tremor worsens during limb movement, which suggests cerebellar dysfunction. 3
• Document tremor frequency and amplitude: Essential tremor is typically 4-12 Hz, parkinsonian tremor is 4-6 Hz, and cerebellar tremor is <4 Hz. 2, 3

Examination for Associated Signs

• Perform upper extremity tremor assessment: Have the patient extend arms with fingers spread (postural tremor), perform finger-to-nose testing (kinetic tremor), and rest hands in lap (resting tremor) to identify essential tremor or parkinsonism. 2, 3
• Test for bradykinesia: Assess finger tapping, hand opening/closing, and rapid alternating movements; slowness with decrement suggests Parkinson disease. 2, 3
• Examine for rigidity: Test passive range of motion at the neck, wrists, and elbows for cogwheel rigidity, which indicates parkinsonism. 2
• Assess for dystonia: Look for sustained abnormal neck postures (torticollis, laterocollis, retrocollis), shoulder elevation, or compensatory maneuvers that suggest cervical dystonia. 1, 4
• Perform cerebellar testing: Test finger-to-nose, heel-to-shin, and rapid alternating movements; dysmetria, dysdiadochokinesia, or intention tremor require brain MRI. 3, 4

Specific Maneuvers

• Test the "geste antagoniste": Ask the patient to lightly touch their chin or face; reduction of head tremor with this sensory trick is pathognomonic for cervical dystonia. 1
• Assess tremor with distraction: Engage the patient in conversation or have them perform serial-7 subtractions; functional tremor often disappears with distraction. 2
• Evaluate tremor entrainment: Have the patient tap their fingers at different frequencies while observing head tremor; psychogenic tremor may entrain to the voluntary movement frequency. 2
• Observe gait: Reduced arm swing, shuffling, or turning en bloc suggests parkinsonism; wide-based ataxic gait suggests cerebellar pathology. 3

Diagnostic Algorithm Based on Examination Findings

Isolated Head Tremor Without Limb Involvement

• Consider cervical dystonia first: Isolated head tremor is more likely dystonic than essential tremor, especially if there are abnormal postures, sensory tricks, or pain. 1
• Refer to neurology for botulinum toxin evaluation: Botulinum toxin injections are the treatment of choice for dystonic head tremor. 1

Head Tremor Plus Bilateral Upper Extremity Action Tremor

• Diagnose essential tremor: This combination is the classic presentation of essential tremor, which affects 0.4-6% of the population. 2, 5
• Initiate trial of propranolol or primidone: These are first-line medications for essential tremor, though propranolol is the only FDA-approved drug. 5

Head Tremor Plus Resting Tremor and Bradykinesia

• Diagnose Parkinson disease: More than 70% of Parkinson patients present with tremor, typically unilateral and at rest. 2
• Consider dopamine transporter imaging: If diagnostic uncertainty exists, single-photon emission computed tomography (SPECT) can visualize dopaminergic pathway integrity. 2

Head Tremor Plus Cerebellar Signs

• Order brain MRI immediately: Cerebellar tremor requires neuroimaging to exclude structural lesions, stroke, or multiple sclerosis. 3, 4

Common Pitfalls to Avoid

• Do not assume isolated head tremor is essential tremor: Isolated head tremor without limb involvement is more likely cervical dystonia, and misdiagnosis leads to ineffective treatment. 1
• Do not overlook drug-induced tremor: Always review medications before attributing tremor to a primary disorder, as drug-induced tremor is highly prevalent and reversible. 2, 3
• Do not miss psychogenic tremor: Abrupt onset, changing characteristics, and extinction with distraction are positive signs of functional tremor, not merely exclusion criteria. 2
• Do not order neuroimaging for typical essential tremor: Brain imaging is not indicated for bilateral action tremor without atypical features, focal deficits, or cerebellar signs. 3, 4