Task Specific Tremor in Parkinson's Disease Responds to Apomorphine

Area of Science:

• Neurology
• Movement Disorders
• Neuropharmacology

Background:

• Task-specific tremor (TST) is a poorly understood neurological condition.
• TST may evolve into essential tremor or Parkinson's disease.
• Its pathophysiology, involving tremor, dystonia, and parkinsonism, remains unclear.

Purpose of the Study:

• To evaluate the efficacy of apomorphine in treating TST.
• To gain insights into the underlying pathophysiology of TST.

Main Methods:

• Sublingual apomorphine was administered to 8 patients with clinically diagnosed Parkinson's disease.
• These patients initially presented with TST and later developed other parkinsonian signs and dopamine imaging deficits.

Main Results:

• Apomorphine improved TST in 6 out of 8 subjects.
• The TST in these patients was refractory to oral levodopa and other tremor therapies.

Conclusions:

• Apomorphine provides a potential treatment for TST, especially in patients with co-existing parkinsonian features.
• The positive response suggests a dopaminergic pathophysiology for TST.