Tremor Diagnosis and Characteristics

Tremor Types and Clinical Features

Parkinsonian tremor is primarily a resting tremor that occurs when the affected body part is relaxed and supported against gravity, typically asymmetric at onset, affecting one side more than the other, with a frequency range of 4-6 Hz, often described as a "pill-rolling" tremor of the hands, and is associated with other cardinal features of Parkinson's disease, including bradykinesia, rigidity, and postural instability, according to the American College of Radiology 1, 2
Cerebellar tremor is primarily an intention or action tremor that worsens as the limb approaches a target, characterized by a coarse, irregular tremor with a "wing-beating" appearance, particularly evident during finger-to-nose testing, and is often accompanied by dysarthria and ataxic gait, as noted by Praxis Medical Insights 3
The American College of Radiology recommends that the timing of tremor, associated features, and response to treatment be considered when diagnosing tremor types, with Parkinsonian tremor occurring predominantly at rest, essential tremor during posture/action, and cerebellar tremor during intentional movement 1, 3

Advanced imaging techniques such as MRI and functional neuroimaging can help differentiate between tremor types when clinical diagnosis is unclear, according to the Journal of the American College of Radiology 2
Ioflupane SPECT/CT (DaTscan) can help differentiate Parkinsonian tremor from essential tremor by demonstrating dopaminergic deficiency, as recommended by the American College of Radiology 2
Hepatic encephalopathy can cause asterixis or "flapping tremor," which is technically a negative myoclonus rather than a true tremor, as noted in the Journal of Hepatology 4