Objective: To better characterize the clinical features, electrophysiologic features, and treatment outcomes of painful legs and moving toes (PLMT) syndrome.
Design: Large case series.
Setting: Neurology outpatient clinic at a tertiary referral center, 1983-2011.
Patients: All cases of PLMT seen at our institution during an 18-year period were identified using our medical record linkage system.
Main outcome measures: Key demographic, clinical, imaging, and electrophysiologic features of PLMT. Treatment outcomes and long-term follow-up are also reported.
Results: Of 76 cases identified (including 50 women [66%]), the mean age at onset was 58 years (range, 24-86 years) and at neurologic evaluation was 63 years (range, 26-88 years). Pure lower limb involvement was most common (69 patients [91%]), and 44 cases (58%) were bilateral. The most frequently diagnosed causes were peripheral neuropathy (21 cases [28%]), previous trauma (8 [11%]), and radiculopathy (7 [9%]); 32 cases (42%) were cryptogenic. Electromyography consistently showed irregular 50-millisecond to 1-second bursts of normal motor unit potential firing at 2 to 200 Hz accompanying the movements. Pain occurred first in nearly all cases and was more distressing to patients than the movements. Both components were difficult to treat, with no consistent benefit from a variety of drugs and therapeutic modalities. The syndrome persisted in most patients (83%) during the mean follow-up of 4.6 years, suggesting low likelihood of spontaneous resolution.
Conclusions: Painful legs and moving toes syndrome is a debilitating clinical syndrome, not because of the movements but rather because of the pain, which often is refractory to treatment. Segmental lower limb involvement is most common, and neurophysiologic findings support a pathophysiologic process localizing to a central generator at the spinal cord or brainstem level.