title: Cauda equina conduction time in Guillain-Barré syndrome.
abstract: The proximal segment of peripheral nerves is assumed to be involved in both demyelinating and axonal types of Guillain-Barré syndrome (GBS). However, electrophysiological examinations have not yet clarified if this segment is involved. We measured cauda equina conduction time (CECT) in nine demyelinating GBS and seven axonal GBS patients. Compound muscle action potentials (CMAPs) were recorded from the abductor hallucis muscle. Electrical stimulation was given at the ankle and the knee, and magnetic stimulation was given over the first sacral (S1) and first lumbar (L1) spinous processes using a magnetic augmented translumbosacral stimulation (MATS) coil. CECT was obtained by subtracting S1-level latency from L1-level latency. CECT was prolonged in all the patients with demyelinating GBS who had leg symptoms, whereas motor conduction velocity (MCV) at the peripheral nerve trunk was normal in all the patients. In all the patients with axonal GBS having leg symptoms, CECT and MCV were normal and no conduction blocks were detected between the ankle and the neuro-foramina. The cauda equina is much more frequently involved than the peripheral nerve trunk in demyelinating GBS. In axonal GBS, usually, CECT is normal and segmental lesions are absent between the ankle and the neuro-foramina. Therefore, the CECT measurement should be very useful for directly detecting demyelinating lesions in GBS.
authors.affiliation: Department of Neurology, Japanese Red Cross Medical Center, Tokyo, Japan; Department of Neurology, The University of Tokyo, Tokyo, Japan. Electronic address: hideyukimatsumoto.jp@gmail.com.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsumoto
authors.affiliation: Department of Neurology, The University of Tokyo, Tokyo, Japan; Department of Neurology, Kitasato University School of Medicine, Kanagawa, Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Hanajima
authors.affiliation: Department of Neurology, The University of Tokyo, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terao
authors.affiliation: Department of Neurology, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Hideji
authors.initials: H
authors.lastname: Hashida
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ugawa
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000368:Aged; D002420:Cauda Equina / Q000503:physiopathology*; D004558:Electric Stimulation; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D005528:Foot / Q000503:physiopathology*; D020275:Guillain-Barre Syndrome / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009431:Neural Conduction / Q000502:physiology*
keywords: Acute inflammatory demyelinating neuropathy (AIDP); Acute motor axonal neuropathy (AMAN); Cauda equina; Magnetic stimulation; Motor-evoked potential; Spinal nerve