Characterization of periodic upper limb movement disorder in a patient with restless arms syndrome.
Restless legs syndrome (RLS) and the frequently associated periodic limb movements (PLM) are common neurological disorders whose pathophysiology remains elusive. We report on the case of a 40-year-old patient presenting with severe restlessness in the upper limbs, a poorly known variant of RLS. Video-polysomnography was performed because of the associated poor sleep quality and daytime sleepiness evocative of PLM. An electromyogram of the extensor carpi radialis muscle was added. Remarkably, our patient had movements of repeated extension of the small finger that contrasted with the extension of the hallux, characteristic for PLM. Pramipexol was an effective treatment relieving the patient's upper limbs of discomfort and ameliorating her restless sleep. Involvement of the upper limbs in RLS is relatively common, but restlessness may be located on the upper limbs solely. One should be aware of the upper limb variant, and that treatment by dopaminergic agonists proves to be very efficient.