Ruhezustremor

Ruhezustremor, or resting tremor, is a rhythmic, often low-frequency shaking that occurs when the muscles are at rest and is reduced during voluntary movement. It is a classic feature of Parkinsonian syndromes, most notably Parkinson's disease, where the tremor is frequently described as pill-rolling of the fingers and thumb.

It commonly affects one side initially (unilateral onset) and may involve the hands, forearms, jaw, lips, or legs. The tremor tends to be most prominent at rest, may decrease with purposeful action, and can reappear during stress or fatigue. It can be accompanied by bradykinesia, rigidity, and postural instability.

Pathophysiology involves degeneration of dopaminergic neurons in the substantia nigra pars compacta and dysfunction of basal ganglia-thalamocortical circuits, leading to abnormal rhythmic activity in motor networks.

Differential diagnosis includes essential tremor (usually action or postural rather than resting), dystonic tremor, and other parkinsonian syndromes such as multiple system atrophy or progressive supranuclear palsy. Drug-induced parkinsonism can also present with resting tremor.

Diagnosis is clinical, supported by the presence of rest tremor and other parkinsonian signs. A dopaminergic response to levodopa and imaging such as a DaT scan can help differentiate conditions. Management focuses on symptom relief and function.

Treatment options include levodopa as the most effective therapy for rest tremor in Parkinson's disease, supported by dopamine agonists, MAO-B inhibitors, and amantadine. For refractory tremor, deep brain stimulation of the subthalamic nucleus or globus pallidus interna can be considered, in combination with physical therapy and lifestyle adjustments. Prognosis varies with the underlying disease and treatment response.