title: EEG epileptiform abnormalities at admission to a rehabilitation department predict the risk of seizures in disorders of consciousness following a coma.
abstract: BACKGROUND
  Seizures affect about a quarter of patients with disorders of consciousness (DOC) after a coma.
  
  
  OBJECTIVE
  We investigated whether the presence of epileptiform abnormalities (EAs) in the electroencephalogram (EEG) of patients with DOC may predict the occurrence of seizures. Moreover, we evaluated whether EAs have a prognostic role in these patients.
  
  
  METHODS
  This was a retrospective single-center cohort study of patients hospitalized between January 2005 and December 2014 in a rehabilitation department (mean time from acute brain injury: 46.1 days). We analyzed 30-minute EEGs at admittance for 112 patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS), then compared occurrence of seizures over the following three months across patients with absent, unilateral, and bilateral EAs (generalized or bilateral independent). Outcomes at three months were assessed in the same groups using the Coma Recovery Scale Revised.
  
  
  RESULTS
  Epileptiform abnormalities were observed in 38 patients (33.9%). Of these, 25 were unilateral, and 13 were bilateral. Seizures occurred in 84.6% of patients with bilateral EAs, which was significantly higher than in patients without EAs (10.8%, p<0.001) or with unilateral EAs (24%, p=0.001). The presence of EAs was not related to etiology or different DOC and did not significantly affect outcomes at three months.
  
  
  CONCLUSIONS
  Patients with EAs at admission to a rehabilitation department have an increased risk of seizures. Specifically, most patients with bilateral EAs had seizures within the following 3 months. Evaluation of EAs in EEGs of patients with DOC may give valuable information in the management of antiepileptic drug treatment.
authors: Unit of Neurophysiology and Unit for Severe Acquired Brain Injuries, Rehabilitation Department, Fondazione Istituto San Raffaele G. Giglio, Cefalù (PA), Italy. Electronic address: sergiobagnato@gmail.com.
authors: Sergio
authors: S
authors: Bagnato
authors: Unit of Neurophysiology and Unit for Severe Acquired Brain Injuries, Rehabilitation Department, Fondazione Istituto San Raffaele G. Giglio, Cefalù (PA), Italy.
authors: Cristina
authors: C
authors: Boccagni
authors: Unit of Neurophysiology and Unit for Severe Acquired Brain Injuries, Rehabilitation Department, Fondazione Istituto San Raffaele G. Giglio, Cefalù (PA), Italy.
authors: Antonino
authors: A
authors: Sant'Angelo
authors: Unit of Neurophysiology and Unit for Severe Acquired Brain Injuries, Rehabilitation Department, Fondazione Istituto San Raffaele G. Giglio, Cefalù (PA), Italy.
authors: Caterina
authors: C
authors: Prestandrea
authors: Unit of Neurophysiology and Unit for Severe Acquired Brain Injuries, Rehabilitation Department, Fondazione Istituto San Raffaele G. Giglio, Cefalù (PA), Italy.
authors: Vittorio
authors: V
authors: Virgilio
authors: Unit of Neurophysiology and Unit for Severe Acquired Brain Injuries, Rehabilitation Department, Fondazione Istituto San Raffaele G. Giglio, Cefalù (PA), Italy.
authors: Giuseppe
authors: G
authors: Galardi
mesh_terms: D000293:Adolescent; D000328:Adult; D003128:Coma / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D003244:Consciousness Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D004569:Electroencephalography / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000639:trends; D011237:Predictive Value of Tests; D011379:Prognosis; D012047:Rehabilitation Centers / Q000639:trends; D012189:Retrospective Studies; D012307:Risk Factors; D012640:Seizures / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*
keywords: Disorders of consciousness; EEG; Epilepsy; Epileptic seizures; Minimally conscious state; Vegetative state