From the Guidelines
The workup for new onset tremors should begin with a thorough clinical history and physical examination to characterize the tremor and identify potential causes, followed by initial laboratory tests and neuroimaging with MRI of the brain, as recommended by the American College of Radiology 1. The clinical history and physical examination are crucial in characterizing the tremor as rest, postural, intention, or mixed, and identifying potential causes such as Parkinson's disease, essential tremor, or cerebellar disorders. Initial laboratory tests should include complete blood count, comprehensive metabolic panel, thyroid function tests (TSH, free T4), and serum ceruloplasmin to rule out Wilson's disease, as well as liver function tests, blood glucose, calcium levels, and drug/toxicology screening if substance-induced tremor is suspected.
- Key laboratory tests:
- Complete blood count
- Comprehensive metabolic panel
- Thyroid function tests (TSH, free T4)
- Serum ceruloplasmin
- Liver function tests
- Blood glucose
- Calcium levels
- Drug/toxicology screening Neuroimaging with MRI of the brain is recommended to exclude structural lesions, particularly if there are accompanying neurological symptoms or signs, as it is an essential diagnostic tool in the evaluation of patients presenting with Parkinsonian symptoms 1. Electromyography (EMG) may help characterize the tremor pattern and frequency. If Parkinson's disease is suspected, a DaTscan (dopamine transporter scan) might be considered. For medication-induced tremors, a careful review of all medications including over-the-counter drugs is essential. In cases where the diagnosis remains unclear after initial evaluation, referral to a neurologist specializing in movement disorders is appropriate, as tremors can result from various conditions requiring different management strategies 1.
From the Research
Workup for New Onset Tremors
The workup for new onset tremors involves a thorough history and physical examination to categorize the tremor based on its activation condition, topographic distribution, and frequency 2, 3. The following steps are involved in the workup:
- Categorize the tremor as a resting tremor, postural tremor, or kinetic tremor 2, 4, 3
- Determine the frequency and amplitude of the tremor 4
- Identify any associated signs or symptoms, such as rigidity, bradykinesia, or cognitive impairment 2, 3
- Consider the patient's medical history, including any previous diagnoses or treatments 5, 6
- Perform a physical examination to assess the tremor and any other neurological signs 2, 3
Diagnostic Considerations
The diagnosis of tremor is based on clinical information obtained from the history and physical examination 2, 3. The following diagnostic considerations are important:
- Essential tremor: a postural and kinetic tremor with a frequency between 4 and 8 Hz, affecting mainly the upper extremities and head 2, 4, 3
- Parkinsonian tremor: a resting tremor with a frequency between 4 and 6 Hz, typically unilateral and asymmetric 2, 4, 3
- Psychogenic tremor: characterized by abrupt onset, spontaneous remission, changing tremor characteristics, and extinction with distraction 2, 3
- Other types of tremor: cerebellar, dystonic, drug- or metabolic-induced, and orthostatic 2, 4, 3
Diagnostic Tests
In some cases, diagnostic tests may be necessary to confirm the diagnosis or rule out other conditions 2, 3. The following tests may be considered: