Evidence of peripheral axonal neuropathy in primary restless legs syndrome

Authors

  • Dr. Sandro Iannaccone,

    Corresponding author
    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    • Department of Neurology, S. Raffaele Hospital, via Prinetti 29, 20127 Milan, Italy
    Search for more papers by this author
  • Marco Zucconi,

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author
  • Paolo Marchettini,

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author
  • Luigi Ferini-Strambi,

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author
  • Raffaello Nemni,

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author
  • Angelo Quattrini,

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author
  • Stefano Palazzi,

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author
  • Marco Lacerenza,

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author
  • Fabio Formaglio,

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author
  • Salvatore Smirne

    1. Sleep Disorders Centre and Department of Neurology, State University and Istituto Scientifico H. San Raffaele, Milan, Italy
    Search for more papers by this author

Abstract

Restless legs syndrome (RLS) is a well-defined clinical entity characterized by an unpleasant creeping sensation arising in the legs with an irresistible need to move them. The trouble is more pronounced when the affected people lie in a prolonged rest position and try to fall asleep. It is known that RLS may be consequent to systemic disorders and to diseases affecting the central or peripheral nervous system. The International Classification of Sleep Disorders states that peripheral neuropathy should be ruled out by medical history and clinical grounds before diagnosing primary RLS (pRLS). The present study extended peripheral nerve investigation in eight consecutive pRLS patients with normal neurological examination results and showed that all patients exhibited two or more electrical, psychophysiological, and/or morphological features of peripheral axonal neuropathy. Morphometric analysis of sural nerve showed a significant reduction in myelinated fiber density and g ratio (axon diameter/fiber diameter) in the pRLS group compared with eight control biopsy specimens. These results suggest that axonal neuropathy is often present in patients with RLS. A comprehensive peripheral nerve investigation should be considered in RLS patients.

Ancillary