title: Lateral inhibition in the somatosensory cortex during and between migraine without aura attacks: Correlations with thalamocortical activity and clinical features.
abstract: BACKGROUND
  We studied lateral inhibition in the somatosensory cortex of migraineurs during and between attacks, and searched for correlations with thalamocortical activity and clinical features.
  
  
  METHODS
  Somatosensory evoked potentials (SSEP) were obtained by electrical stimulation of the right median (M) or ulnar (U) nerves at the wrist or by simultaneous stimulation of both nerves (MU) in 41 migraine without aura patients, 24 between (MO), 17 during attacks, and in 17 healthy volunteers (HVs). We determined the percentage of lateral inhibition of the N20-P25 component by using the formula [(100)-MU/(M + U)*100]. We also studied high-frequency oscillations (HFOs) reflecting thalamocortical activation.
  
  
  RESULTS
  In migraine, both lateral inhibition (MO 27.9% vs HVs 40.2%; p = 0.009) and thalamocortical activity (MO 0.5 vs HVs 0.7; p = 0.02) were reduced between attacks, but not during. In MO patients, the percentage of lateral inhibition negatively correlated with days elapsed since the last migraine attack (r = -0.510, p = 0.01), monthly attack duration (r = -0.469, p = 0.02) and severity (r = -0.443, p = 0.03), but positively with thalamocortical activity (r = -0.463, p = 0.02).
  
  
  CONCLUSIONS
  We hypothesize that abnormal migraine cycle-dependent dynamics of connectivity between subcortical and cortical excitation/inhibition networks may contribute to clinical features of MO and recurrence of attacks.
authors.affiliation: G.B. Bietti Foundation-IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Rome, Italy gianluca.coppola@gmail.com.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Coppola
authors.affiliation: "Sapienza" University of Rome Polo Pontino Department of Medical and Surgical Sciences and Biotechnologies, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Bracaglia
authors.affiliation: "Sapienza" University of Rome Polo Pontino Department of Medical and Surgical Sciences and Biotechnologies, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Di Lenola
authors.affiliation: "Sapienza" University of Rome Polo Pontino Department of Medical and Surgical Sciences and Biotechnologies, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Iacovelli
authors.affiliation: Fondazione Don Gnocchi, Italy.
authors.forename: Cherubino
authors.initials: C
authors.lastname: Di Lorenzo
authors.affiliation: "Sapienza" University of Rome Polo Pontino Department of Medical and Surgical Sciences and Biotechnologies, Italy.
authors.forename: Mariano
authors.initials: M
authors.lastname: Serrao
authors.affiliation: Istituto di Anestesiologia, Rianimazione e Terapia del Dolore, Università Cattolica del Sacro Cuore/CIC, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Evangelista
authors.affiliation: G.B. Bietti Foundation-IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Parisi
authors.affiliation: Headache Research Unit, Department of Neurology-CHR Citadelle, University of Liège, Belgium.
authors.forename: Jean
authors.initials: J
authors.lastname: Schoenen
authors.affiliation: "Sapienza" University of Rome Polo Pontino Department of Medical and Surgical Sciences and Biotechnologies, Italy INM Neuromed IRCCS, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Pierelli
mesh_terms: D000328:Adult; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D020326:Migraine without Aura / Q000503:physiopathology*; D013003:Somatosensory Cortex / Q000503:physiopathology*
keywords: Migraine; clinical features; evoked potentials; lateral inhibition; thalamocortical activity