title: Improved cognitive function after transcranial, light-emitting diode treatments in chronic, traumatic brain injury: two case reports.
abstract: OBJECTIVE
  Two chronic, traumatic brain injury (TBI) cases, where cognition improved following treatment with red and near-infrared light-emitting diodes (LEDs), applied transcranially to forehead and scalp areas, are presented.
  
  
  BACKGROUND
  Significant benefits have been reported following application of transcranial, low-level laser therapy (LLLT) to humans with acute stroke and mice with acute TBI. These are the first case reports documenting improved cognitive function in chronic, TBI patients treated with transcranial LED.
  
  
  METHODS
  Treatments were applied bilaterally and to midline sagittal areas using LED cluster heads [2.1″ diameter, 61 diodes (9 × 633 nm, 52 × 870 nm); 12-15 mW per diode; total power: 500 mW; 22.2 mW/cm(2); 13.3 J/cm(2) at scalp (estimated 0.4 J/cm(2) to cortex)].
  
  
  RESULTS
  Seven years after closed-head TBI from a motor vehicle accident, Patient 1 began transcranial LED treatments. Pre-LED, her ability for sustained attention (computer work) lasted 20 min. After eight weekly LED treatments, her sustained attention time increased to 3 h. The patient performs nightly home treatments (5 years); if she stops treating for more than 2 weeks, she regresses. Patient 2 had a history of closed-head trauma (sports/military, and recent fall), and magnetic resonance imaging showed frontoparietal atrophy. Pre-LED, she was on medical disability for 5 months. After 4 months of nightly LED treatments at home, medical disability discontinued; she returned to working full-time as an executive consultant with an international technology consulting firm. Neuropsychological testing after 9 months of transcranial LED indicated significant improvement (+1, +2SD) in executive function (inhibition, inhibition accuracy) and memory, as well as reduction in post-traumatic stress disorder. If she stops treating for more than 1 week, she regresses. At the time of this report, both patients are continuing treatment.
  
  
  CONCLUSIONS
  Transcranial LED may improve cognition, reduce costs in TBI treatment, and be applied at home. Controlled studies are warranted.
authors.affiliation: VA Boston Healthcare System , Boston, Massachusetts. mnaeser@bu.edu
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Naeser
authors.forename: Anita
authors.initials: A
authors.lastname: Saltmarche
authors.forename: Maxine H
authors.initials: MH
authors.lastname: Krengel
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hamblin
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Knight
mesh_terms: D001930:Brain Injuries / Q000523:psychology* / Q000532:radiotherapy*; D020208:Brain Injury, Chronic / Q000523:psychology* / Q000532:radiotherapy*; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology / Q000628:therapy*; D005260:Female; D006801:Humans; D028022:Low-Level Light Therapy; D008875:Middle Aged