title: Cortical plasticity predicts recovery from relapse in multiple sclerosis.
abstract: BACKGROUND
  Relapsing-remitting multiple sclerosis (RRMS) is characterized by the occurrence of clinical relapses, followed by remitting phases of a neurological deficit. Clinical remission after a relapse can be complete, with a return to baseline function that was present before, but is sometimes only partial or absent. Remyelination and repair of the neuronal damage do contribute to recovery, but they are usually incomplete.
  
  
  OBJECTIVE
  We tested the hypothesis that synaptic plasticity, namely long-term potentiation (LTP), may represent an additional substrate for compensating the clinical defect that results from the incomplete repair of neuronal damage.
  
  
  METHODS
  We evaluated the correlation between a measure of LTP, named paired associative stimulation (PAS), at the time of relapse and symptom recovery, in a cohort of 22 newly-diagnosed MS patients.
  
  
  RESULTS
  PAS-induced LTP was normal in patients with complete recovery, and reduced in patients showing incomplete or absent recovery, 12 weeks after the relapse onset. A multivariate regression model showed that PAS-induced LTP and age may contribute to predict null, partial or complete symptom recovery after a relapse.
  
  
  CONCLUSIONS
  Synaptic plasticity may contribute to symptom recovery after a relapse in MS; and PAS, measured during a relapse, may be used as a predictor of recovery.
authors.affiliation: Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mori
authors.forename: Hajime
authors.initials: H
authors.lastname: Kusayanagi
authors.forename: Carolina Gabri
authors.initials: CG
authors.lastname: Nicoletti
authors.forename: Sagit
authors.initials: S
authors.lastname: Weiss
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Marciani
authors.forename: Diego
authors.initials: D
authors.lastname: Centonze
mesh_terms: D000328:Adult; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D006801:Humans; D017774:Long-Term Potentiation / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000503:physiopathology*; D009473:Neuronal Plasticity / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology*; D012008:Recurrence; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
keywords: Evoked potentials; long term potentiation; paired associative stimulation; recovery; relapse; relapsing–remitting multiple sclerosis; remyelination; synaptic plasticity; transcranial magnetic stimulation