title: Cutaneous silent period recordings in demyelinating and axonal polyneuropathies.
abstract: OBJECTIVE
  To investigate the cutaneous silent period (CSP), a spinal inhibitory reflex mainly mediated by A-delta fibres, in demyelinating and axonal polyneuropathy (PNP) and evaluate whether CSP parameters differ between patients with and without neuropathic pain.
  
  
  METHODS
  Eighty-four patients with demyelinating PNP, 178 patients with axonal PNP and 265 controls underwent clinical examination, DN4 questionnaire, standard nerve conduction study, motor-root stimulation and CSP recordings from abductor digiti minimi. We calculated the afferent conduction time of CSP (a-CSP time) with the formula: CSP latency-root motor evoked potential latency.
  
  
  RESULTS
  In the demyelinating PNP group the a-CSP time was significantly longer; in the axonal PNP group, CSP duration was shorter than the demyelinating group (p=0.010) and controls (p=0.001). CSP parameters were not different between patients with and without neuropathic pain.
  
  
  CONCLUSIONS
  The abnormality of a-CSP time in the demyelinating PNP group suggests the crucial role of A-delta fibres in the mechanism of CSP; the shorter CSP duration in the axonal PNP group supports the strong influence of the number of axons on this parameter. Our study suggests that neuropathic pain could be related to pathophysiological mechanisms differing from mere A-delta fibre loss.
  
  
  CONCLUSIONS
  CSP evaluation is effective in detecting A-delta fibre dysfunction in axonal as well as demyelinating PNP.
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Lopergolo
authors.affiliation: Marmara University Hospital School of Medicine, Department of Neurology, Fevzi Cakmak Mah. Mimar Sinan Cad. No: 41, 34899 Ust Kaynarca/Pendik, Istanbul, Turkey; Department of Clinical Neurophysiology, Aarhus Universitets hospital, Nørrebrogade 44, 8000 Aarhus C, Denmark.
authors.forename: Baris
authors.initials: B
authors.lastname: Isak
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Gabriele
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Onesti
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ceccanti
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Gelsomina
authors.initials: G
authors.lastname: Capua
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Fionda
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Biasiotta
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Di Stefano
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: La Cesa
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Frasca
authors.affiliation: Department of Neurology and Psychiatry, University "Sapienza", Viale dell'Università 30, 00185 Rome, Italy. Electronic address: maurizio.inghilleri@uniroma1.it.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Inghilleri
mesh_terms: D000368:Aged; D001369:Axons / Q000502:physiology; D015331:Cohort Studies; D003711:Demyelinating Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D004576:Electromyography / Q000379:methods*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D011115:Polyneuropathies / Q000175:diagnosis* / Q000503:physiopathology*
keywords: A-delta fibres; Axonal polyneuropathy; Cutaneous silent period; Demyelinating polyneuropathy; Neuropathic pain