title: Characteristics and outcome of ischemic stroke patients who are free of symptoms at 24 hours following thrombolysis.
abstract: BACKGROUND
  A part of ischemic stroke patients score 0 on the National Institutes of Health Stroke Scale (NIHSS) within 24 h following thrombolysis. Their clinical characteristics and long-term outcome are poorly studied. We report a single-center assessment of such patients.
  
  
  METHODS
  The cohort comprises 874 consecutive patients from the Helsinki Stroke Thrombolysis Registry, out of whom 113 scored 0 on 24-hour NIHSS. We analyzed their baseline demographic, clinical and radiological characteristics and 3-month outcome (modified Rankin Scale, mRS). Associations between the study parameters were tested by multivariate analysis.
  
  
  RESULTS
  Patients with a 24-hour NIHSS score = 0 (n = 113) were younger than the rest of the population (n = 761; median: 65.6 vs. 71.5 years; p < 0.001), their NIHSS score on admission was lower (median: 5 vs. 10; p < 0.001), as was their glucose level (median: 6.2 vs. 6.7 mmol/l; p = 0.02). The onset-to-treatment time was similar in both groups (median: 120 vs. 115 min; p = 0.89). Patients with a 24-hour NIHSS score = 0 more often achieved an excellent outcome (mRS scores: 0-1; 81 vs. 31%; p < 0.001) and had lower mortality (1.8 vs. 11.8%; p < 0.01). One third of these patients had a brain infarction visible on 24-hour imaging. Lower baseline NIHSS score and younger age were independently associated with 24-hour NIHSS score = 0, which, in turn, was independently associated with excellent 3-month outcome.
  
  
  CONCLUSIONS
  Patients with an NIHSS score = 0 at 24 h following thrombolysis are younger, have milder symptoms and have a lower glucose level on admission. They achieve more often excellent outcome and lower mortality. Still, 8% of them required help in daily activities or were dead at 3 months (mRS scores: 3-6).
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Strbian
authors.forename: Tiina
authors.initials: T
authors.lastname: Sairanen
authors.forename: Kirsi
authors.initials: K
authors.lastname: Rantanen
authors.forename: Katja
authors.initials: K
authors.lastname: Piironen
authors.forename: Sari
authors.initials: S
authors.lastname: Atula
authors.forename: Turgut
authors.initials: T
authors.lastname: Tatlisumak
authors.forename: Lauri
authors.initials: L
authors.lastname: Soinne
mesh_terms: D000367:Age Factors; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002545:Brain Ischemia / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D004185:Disability Evaluation; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D005387:Finland; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010343:Patient Admission; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D015912:Thrombolytic Therapy; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator