An Evaluation of Low Level Laser Light Therapy for Autistic Disorder

Autism spectrum disorder (ASD) is a range of complex neurodevelopment disorders characterized by behavioral, developmental, cognitive and psychological deficits that include social impairment, communication and language difficulties, hyperactivity, irritability, obsessive interests and restricted, and repetitive behaviors. Autistic disorder, sometimes called autism or classical ASD, is the most severe form of ASD. ASD occurs in all ethnic and socioeconomic groups and affects every age group, with symptoms appearing before age 3. The Centers for Disease Control (CDC) estimates that 1 out of 88 children age 8 will have an ASD, with males four times more likely to have an ASD than females.

There is no cure for ASD and no single best treatment for all individuals with autistic disorder. The majority of diagnosed cases of autism are idiopathic with an enigmatic pathogenesis, and as a result, therapeutic approaches have focused on mitigating specific symptoms rather than treating disease etiologies. The current standard treatment approach is a team approach to customize an individual highly structured, specialized program or treatment plan including medications, therapies and behavioral interventions targeted toward improving the individual's specific symptoms.

The cause of ASD is not clearly understood, but it is believed that both genetics and environment likely play a role. Magnetic resonance imaging (MRI) studies have demonstrated increased brain volume and head circumference during early developmental childhood, suggesting that autistic brains experience a period a rapid overgrowth which hampers further development during later developmental stages. Morphological aberrations have been observed in the hippocampus, anterior cingulate cortex, prefrontal cortex, amygdala, and cerebellum. Another consistent observation has also been the reduction in cerebellar vermis volume, which helps to explain specific behavioral patterns in children.

Molecular analysis of postmortem brain tissue has revealed reduced Purkinje cell numbers, which helps to explain aberrant locomotive activity and level presser function. Another finding has been impaired neuronal connectivity within the cerebellum, amygdala, anterior cingulate cortex, and dorsolateral prefrontal cortex. As a consequence, synapse structure and function has demonstrated impairment in postmortem evaluations. Dendritic spines of glutamatergic neurons in autistic patients have shown morphological alterations and suppressed density, which, in turn, results in diminished synaptic transmissions. Nascent spines have been reported in frontal, temporal, and parietal cortices of autistic patients, and have a negative correlation with cognitive abilities in autism. Other neurological aberrations include signaling through metabotropic glutamate receptor (mGluR) and ƴ-aminobutyric acid (GABA)ergic system.

The elusive pathophysiology of autism provides a marked challenge for health care providers. One promising technology is low-level laser therapy (LLLT). LLLT uses photonic energy to modulate the behavior and function of cells by stimulating molecular entities capable of absorbing discrete wavelengths. or instance, cytochrome c oxidase (CCO), a terminal enzyme of the respiratory change, contains a tetrapyrrole prosthetic group that has been shown to absorb 635nm. Photon-induced activation of CCO increases cell bioenergetics, which, in turn, activates intra-cellular secondary signaling cascades that in turn affect growth factor synthesis, cell proliferation, cytokine production, and expression of specific transcription factors. Studies have reported increased adenosine triphosphate (ATP) synthesis along with activation of the intracellular redox state following the production of reactive oxygen species (ROS). As an essential bio-catalyst, ATP lowers the activation for pivotal biochemical reactions within cells. Concerning neurons, laser irradiation has been shown to promote the recovery of injured peripheral nerves and the spinal cord. Moreover, studies have revealed that excitable cells like neurons can be directly stimulated by light, enhancing the action potential of the cell increasing the release of neurotransmitters such as glutamate and acetylcholine.

Clinical outcomes with LLLT trials include nerve regeneration, increased neurotransmitter release, growth factor synthesis, and neovascularization to name a few. It follows that positioning of the laser along impaired regions of an autistic brain could elicit a positive therapeutic outcome in a safe and non-invasive manner.