Focal Increase in Cerebral Blood Flow After Treatment with Near-Infrared Light to the Forehead in a Patient in a Persistent Vegetative State

Abstract

This study aimed to quantify the cerebral blood flow (CBF) after bilateral, transcranial near-infrared light-emitting diode (LED) irradiation to the forehead in a patient in a persistent vegetative state following severe head injury. Positive behavioral improvement has been observed following transcranial near-infrared light therapy in humans with chronic traumatic brain injury and acute stroke. Single-photon emission computed tomography with N-isopropyl-[123I]p-iodoamphetamine (IMP-SPECT) was performed following a series of LED treatments. IMP-SPECT showed unilateral, left anterior frontal lobe focal increase of 20%, compared to the pre-treatment value for regional CBF (rCBF) for this area, following 146 LED treatments over 73 days from an array of 23×850 nm LEDs, 13 mW each, held 5 mm from the skin, 30 min per session, the power density 11.4 mW/cm(2); the energy density 20.5 J/cm(2) at the skin. The patient showed some improvement in his neurological condition by moving his left arm/hand to reach the tracheostomy tube, post-LED therapy. Transcranial LED might increase rCBF with some improvement of neurological condition in severely head-injured patients. Further study is warranted.