Transcranial Low-Level Laser Therapy May Improve Alertness and Awareness in Traumatic Brain Injured Subjects with Severe Disorders of Consciousness: a Case Series
Keywords:Brain stimulation, traumatic brain injury, minimal conscious state, near-infrared light, transcranial low-level laser therapy, revised coma recovery scale
Background: Transcranial low-level laser therapy (T-LLT) proved promising in acute stroke studies and in single traumatic brain injuredÂ subjects (TBI). It was assumed to increase cortical mitochondrial energyÂ production and/or vasodilatation.
Objective: Within this case series the potential of transcranial lowlevel laser therapy in improving the alertness and awareness in TBIÂ subjects with severe disorders of consciousness will be investigated.
Methods: Following a 21-day baseline, the forehead of fie patients,Â four chronic in a state of unresponsive wakefulness or minimal consciousness, one subacute in the state of akinetic mutism, was stimulated with the T-LLT (785 nm, 10 mW/cm2, CW mode, 21 emittingÂ diodes) for 10 min every workday for six weeks. Follow-up was fourÂ weeks after end of intervention. Primary variable was the revised version of the Coma Recovery Scale (r-CRS, 0-23), blindly assessed by anÂ external reviewer with the help of videos.
Results: The r-CRS, almost stable during baseline, improved in all patients during the intervention, from 3 to 12, 9 to 12, 8 to 12 and 5-12Â in the chronic, and from 6 to 21 in the subacute patient. Follow-upÂ revealed a sustained effect. The patient in the state of akinetic mutismÂ improved her competence in the activities of daily living and mobility status. Single epileptic fis occurred in two patients during the intervention.
Conclusion: T-LLT improved the patientsâ€™ alertness and awareness;Â epileptic fis were potential side effects. Sham-controlled studies including the quantitative assessment of awareness should follow theÂ case series.
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