Tremor Diagnosis and Management

Clinical Classification and Diagnostic Approach

The American Academy of Neurology suggests that Parkinsonian tremor is a resting tremor (4-6 Hz) that improves with movement, essential tremor is a postural/action tremor that worsens with goal-directed activity, and functional tremor is highly variable and stops with distraction 1, 2
Cerebellar tremor becomes more pronounced during goal-directed movements and is associated with dysarthria and ataxic gait, and does not stop with distraction, distinguishing it from functional tremor 1
Functional tremor has specific diagnostic features, including distractibility as the hallmark feature—the tremor stops when attention is redirected, variability in frequency and amplitude, and extinction with distraction 1
If tremor occurs at rest and improves with movement, consider Parkinsonian tremor, and if tremor occurs with posture/action and worsens with goal-directed activity, consider essential tremor, and if tremor stops completely with distraction, consider functional tremor 1, 2
For Parkinsonian tremor, look for red flags suggesting atypical parkinsonism, such as early prominent falls and gait dysfunction, early autonomic dysfunction, vertical gaze palsy, and poor or absent levodopa response 2

For medically refractory essential tremor cases, MR-guided focused ultrasound (MRgFUS) thalamotomy is an effective and safe treatment option for unilateral tremor causing significant functional impairment 3, 4
Management of functional tremor focuses on rehabilitation rather than medication, including explaining that functional neurological disorder is a real neurological condition, avoiding reinforcing abnormal movement patterns, and implementing rehabilitation strategies focusing on redirecting attention away from symptoms 1
Avoid providing adaptive equipment in the acute phase of functional tremor, as this may prevent improvement 1

Do not assume all resting tremors are Parkinson's disease, as the combination of resting tremor with prominent early gait difficulties and falls is atypical for classic Parkinson's and should raise suspicion for PSP or MSA 2
Do not dismiss functional tremor as a diagnosis of exclusion, and demonstration of specific clinical signs (distractibility, variability, extinction with distraction) is needed to establish the diagnosis 1
Do not overlook secondary causes, such as enhanced physiologic tremor from medications, caffeine, or metabolic disturbances, and in younger patients with tremor and dystonia, check serum ceruloplasmin and 24-hour urinary copper for Wilson's disease 2
Do not confuse akathisia (severe restlessness from antipsychotics) with tremor, as akathisia manifests as pacing or physical agitation and is often misinterpreted as psychotic agitation, and lowering the antipsychotic dose is the primary intervention 5