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.

Figures

FIG. 1.

Location of right and left forehead placement areas for transcranial LED treatments performed by the patient at home, using a single, circular-shaped cluster head. The usual treatment time is 10 min per area (13.3 J/cm2). See text for further description of this second LED device.

FIG. 2.

Structural, T-1 weighted MRI scan for P2 (age 52), obtained in December 2008, 1 month after starting medical disability, for cognitive dysfunction. This MRI scan shows a left frontal horn that is slightly larger than the right one. Cortical atrophy is also present. Deep prominent sulci are present, especially in the high frontal and high parietal cortical areas. The images in the top row show the plane of section (white lines) for the coronal, mid-sagittal and axial views in the bottom row.

FIG. 3.

Second LED device (console model with three LED cluster heads) used by P2 during home treatments. These were used in three different areas at the same time. Here, two LED cluster heads are held in place, on left and right high-frontal areas on the scalp, with a loose-fitting elastic cap. The third LED cluster head has been placed on the sole of the foot (acupuncture point, Kidney 1); it is held in place with a soft, flexible, elastic band, secured with a Velcro strap. The usual treatment time is 10 min per area (13.3 J/cm2). See text for further description of this second LED device.

FIG. 4.

Neuropsychological test results for P2, pre- and post-transcranial LED Treatments. Post-testing was obtained after 9 months of nightly, transcranial LED treatments performed at home. After the LED treatments, significant improvement (+2 SD) in executive function, in terms of both inhibition and inhibition accuracy, was observed.

FIG. 5.

Diagram of structures present on coronal view at vertex of the skull, where one of the LED cluster heads was placed. When placed here, an acupuncture point located on the Governing Vessel (GV) meridian was treated (GV 20). See text for historical use of this point. Several other structures were also likely irradiated with the red/NIR LED cluster heads, including the valveless emissary veins that interconnect with veins in the superior sagittal sinus. Only 3% of NIR photons delivered at the surface of the skull are estimated to reach 1 cm deep (to cortex). Suture lines, and the superior sagittal sinus, may be areas where red/NIR photons have better potential for penetration.