Tremor

A tremor is an involuntary, rhythmic shaking of a body part, most often the hands, but also the head, voice, legs or trunk.

Tremors are classified by when they occur: a resting tremor appears when the limb is relaxed and is characteristic of Parkinson's disease, while an action tremor appears during movement or when holding a position and is typical of essential tremor, the most common type. Other causes include anxiety, caffeine, thyroid overactivity, medication side effects, alcohol withdrawal and cerebellar disease. In dogs and cats, tremors can stem from toxins, metabolic disease, inherited conditions or, in some breeds, an idiopathic tremor syndrome.

Assessment involves recording the tremor's frequency, amplitude and timing, a neurological examination and, where useful, blood tests or imaging; veterinarians follow a similar path in animals. Cannabinoids have been studied for tremor mostly in Parkinson's disease and multiple sclerosis, and the evidence is preliminary.