REFLEX STUDIES AND MRI IN THE RESTLESS LEGS SYNDROME

Brainstem and spinal pathways of untreated patients with idiopathic re stless legs syndrome (RLS) were examined using magnetic resonance imag ing (MRI), blink reflex, first and second exteroceptive suppression (E S1, ES2) of temporalis muscle, and H reflex. MRI of 25 patients elicit ed no structural lesions beyond age-related atrophy or white matter le sions on proton density- and T2-weighted coronal and axial images. All patients showed a normal latency of the soleus H reflex (mean +/- SD latency = 31.22 +/- 2.81 ms) and the H/M ratio was 48 +/- 17%. The dur ation and onset latency of the direct and indirect blink reflex respon ses were normal in all patients compared with those of controls (p>0.5 ). There was no significant difference in ES1 and ES2 latencies or dur ation between patients and controls (p>0.5). These results suggest tha t the etiology of RLS symptoms does not involve structural lesions.