title: Segmental somatosensory-evoked potentials as a diagnostic tool in chronic inflammatory demyelinating polyneuropathies, and other sensory neuropathies.
abstract: OBJECTIVE
  Somatosensory-evoked potentials with segmental recordings were performed with the aim of distinguishing chronic inflammatory demyelinating polyneuropathy from other sensory neuropathies.
  
  
  METHODS
  Four groups of 20 subjects each corresponded to patients with (1) possible sensory chronic inflammatory demyelinating polyneuropathy, (2) patients with sensory polyneuropathy of unknown origin, (3) patients with amyotrophic lateral sclerosis and (4) normal subjects. The patients selected for this study had preserved sensory potentials on electroneuromyogram and all waves were recordable in evoked potentials. Somatosensory-evoked potentials evaluations were carried out by stimulation of the posterior tibial nerve at the ankle, recording peripheral nerve potential in the popliteal fossa, radicular potential and spinal potential at the L4-L5 and T12 levels, and cortical at C'z, with determination of distal conduction time, proximal and radicular conduction time and central conduction time.
  
  
  RESULTS
  In the group of chronic inflammatory demyelinating polyneuropathy, 80% of patients had abnormal conduction in the N8-N22 segment and 95% had abnormal N18-N22 conduction time. In the group of neuropathies, distal conduction was abnormal in most cases, whereas 60% of patients had no proximal abnormality. None of the patients in the group of amyotrophic lateral sclerosis had an abnormal N18-N22 conduction time.
  
  
  CONCLUSIONS
  Somatosensory-evoked potentials with segmental recording can be used to distinguish between atypical sensory chronic inflammatory demyelinating polyneuropathy and other sensory neuropathies, at the early stage of the disease. Graphical representation of segmental conduction times provides a rapid and accurate visualization of the profile of each patient.
authors.affiliation: Département de neurophysiologie clinique, groupe hospitalier Pitié-Salpêtrière, AP-HP, 47, boulevard de l'Hôpital, 75013 Paris, France. Electronic address: regine.morizot-koutlidis@psl.aphp.fr.
authors.forename: R M
authors.initials: RM
authors.lastname: Koutlidis
authors.affiliation: Service de neurologie, hôpital Gui-de-Chauliac, CHU de Montpellier, Montpellier, France.
authors.forename: X
authors.initials: X
authors.lastname: Ayrignac
authors.affiliation: Département des maladies du système nerveux, groupe hospitalier Pitié-Salpêtrière, AP-HP, Paris, France; UMR-678, INSERM-UPMC, groupe hospitalier Pitié-Salpêtrière, Paris, France; Centre SLA, Ile-de-France, France.
authors.forename: P-F
authors.initials: PF
authors.lastname: Pradat
authors.affiliation: Département des maladies du système nerveux, groupe hospitalier Pitié-Salpêtrière, AP-HP, Paris, France; Centre SLA, Ile-de-France, France.
authors.forename: N
authors.initials: N
authors.lastname: Le Forestier
authors.affiliation: Centre de référence de pathologie neuro-musculaire Paris-Est, groupe Hospitalier Pitié-Salpêtrière, AP-HP, Paris, France.
authors.forename: J-M
authors.initials: JM
authors.lastname: Léger
authors.affiliation: Département des maladies du système nerveux, groupe hospitalier Pitié-Salpêtrière, AP-HP, Paris, France; Centre SLA, Ile-de-France, France.
authors.forename: F
authors.initials: F
authors.lastname: Salachas
authors.affiliation: Département de neurophysiologie clinique, groupe hospitalier Pitié-Salpêtrière, AP-HP, 47, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: T
authors.initials: T
authors.lastname: Maisonobe
authors.affiliation: Département de neurophysiologie clinique, groupe hospitalier Pitié-Salpêtrière, AP-HP, 47, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: E
authors.initials: E
authors.lastname: Fournier
authors.affiliation: Département de neurophysiologie clinique, groupe hospitalier Pitié-Salpêtrière, AP-HP, 47, boulevard de l'Hôpital, 75013 Paris, France; Département des maladies du système nerveux, groupe hospitalier Pitié-Salpêtrière, AP-HP, Paris, France.
authors.forename: K
authors.initials: K
authors.lastname: Viala
mesh_terms: D000328:Adult; D000368:Aged; D004558:Electric Stimulation / Q000379:methods; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000175:diagnosis* / Q000503:physiopathology*; D013979:Tibial Nerve / Q000503:physiopathology
keywords: Amyotrophic lateral sclerosis; Chronic inflammatory demyelinating polyneuropathy; Lumbar radiculopathy; Nerve conduction studies; Polyneuropathie inflammatoire démyélinisante chronique; Polyneuropathie sensitive conduction nerveuse; Potentiels évoqués somesthésiques; Radiculopathie lombaire; Sclérose latérale amyotrophique; Sensory polyneuropathy; Somatosensory-evoked potentials