Clinical Assessment of the Tremor Patient
Elise Anderson, M.D., neurologist, Providence Neurological Specialties-East
Tremor is a common reason for referral to neurology. Tremor is an involuntary, rhythmic movement that can affect the head, arms and legs; rarely the trunk can be involved. Diagnosis of the cause of a tremor is almost always based on two types of information: the history provided by the patient and our exam in-clinic. Labs and imaging scans rarely lead us to the diagnosis, though this type of information can be crucial in some cases.
Prior to the in-clinic visit, there are a few clues about the patient from his or her chart. A younger patient will be more likely to have essential tremor (ET) or an enhanced physiologic tremor. Patients in their 60s are at greater risk of Parkinson’s disease (PD). A patient with an acute, severe tremor is more likely to have a brain insult, such as stroke or multiple sclerosis, and I might be seeing that patient in the emergency room rather than in a clinic.
In-clinic, I’ll want to know how long the tremor has been present and if one side is worse than the other. How bothersome is the tremor, and if it is a hand or arm tremor, is it worse with activity or at rest? Is it amplified by stress or fatigue? Does the tremor improve after alcohol? It turns out that most tremors get worse with stress, and in some cases stress management is the most effective treatment for tremor. Most tremors subside with alcohol – patients with ET can find it especially effective – but alcohol use is not a recommended treatment.
Medication history is significant. Antipsychotics and nausea medications that block dopamine receptors can cause a clinical picture that looks just like PD, while some pain meds and serotonergic antidepressants can produce myoclonus.
When I examine a tremor patient, I will use a distraction technique so that the tremor emerges more naturally, such as reciting the months of the year backwards. I’ll be looking at the amplitude and frequency of the tremor, and if it is more prominent with activity or at rest. A high-amplitude, symmetric tremor that emerges with activity, like eating or drinking, is usually ET – this can affect the head as well, and sometimes the legs. An asymmetric, lower-frequency tremor that is more prominent at rest and improves with activity suggests PD. A tremor that only affects the head, especially a jerky or “bobble head” tremor, is typical for cervical dystonia. A fine, fast, symmetric tremor is seen in enhanced physiologic tremor and with lithium therapy.
A few low-tech clinical tests can be helpful. A tremor that is at its worst when sipping from a cup favors essential tremor, while a tremor that is most prominent during a gait exam favors PD.
I’ll often ask patients for a writing sample. A tremor that is seen only with writing can be a more rare form of dystonic tremor.
In some cases additional testing is needed – possibly a TSH screen for hyperthyroidism, or ceruloplasmin testing in a younger patient with a Parkinsonian picture concerning for Wilson’s disease. We’ll want to rule out stroke in acute tremor cases, and if a patient with suspected PD does not respond to medication, we’ll often obtain an MRI to look for findings to suggest an alternative diagnosis, such as vascular Parkinsonism. A DaTscan is a type of SPECT scan that can be used to distinguish between ET and Parkinsonism.
Management of tremor is a topic for another day. However, I’ll note that a robust response to levodopa confirms the diagnosis of PD in a patient with typical symptoms, and this is an important part of the screening process when we consider deep brain stimulation (DBS) for our PD patients. We have a number of medication options for the different types of tremor reviewed above, as well as botulinum toxin injections, which can be very helpful in cervical dystonia. Finally, we can offer DBS, Gamma Knife and ultrasound thalamotomy to some patients with medication refractory tremors.
Sharma S, Paney S: Approach to a tremor patient. Ann Indian Acad Neurol. 2016 Oct-Dec; 19(4): 433–443.
Botzel K, Tronnier V, Gasser T: The Differential Diagnosis and Treatment of Tremor. Dtsch Arztebl Int. 2014 Mar; 111(13): 225-236.