Brain damaged area reduced, physical ability improved, cholesterol reduced
In a study conducted in 2003, Dou et al randomly divided 60 patients who had suffered a stroke to the brain (cerebral infarction) and 36 patients with traumatic brain injury into 2 groups (total of 96 patients). 50 of these patients were treated with intranasal light therapy (low level laser) and 46 with intravenous low level laser blood irradiation. Both were treated once a day for 5 consecutive days, given a 2-day break and resumed for another 5 days, adding to a total of 12 days in the study.
They found that total cholesterol, LDL cholesterol, triglyceride levels, erythrocyte sedimentation rate and the hematocrit (red blood cell level) were significantly reduced. Fugi Meyer movement scale (assessment of motor recovery after a stroke) and Barthel index scores (measurement of a person’s daily functioning specifically the activities of daily living and mobility) were significantly increased. The damaged areas of the brain were reduced in both groups.
There was also no significant difference in whether the patients were being treated with Intranasal Light Therapy or intravenous blood irradiation therapy. 
Improved blood circulation to the affected area
Xiao et al treated 21 stroke patients with intranasal low level laser therapy and 18 with intravenous blood irradiation therapy. Through the use of single photon emission computed tomography (SPECT) they were able to observe the increase in regional cerebral blood flow. There was no change in the unaffected area. Again there was no significant difference in the outcome between the use of the intranasal and the intravenous devices. 
Drugs have better outcomes in combination with Intranasal Light Therapy
Several groups of scientists studied the combination of pharmaceutical drugs with intranasal light therapy for stroke patients. The results were consistent in demonstrating that the outcomes are superior than therapy with drugs alone.
Chen et al divided 100 stroke patients into two groups. 40 in a drugs only group and 60 in a group using drugs plus Intranasal Light Therapy (low level laser) daily. After 3 weeks, they found that for almost all rheological factors, the group with the added Intranasal Light Therapy method produced significantly better outcomes.
Jin et al conducted a trial with 93 randomly selected stroke patients over 10 days. They created a third group amongst these patients using drugs plus intravenous blood irradiation. Like the earlier mentioned study conducted by Dou et al, the groups that combined drugs with either the Intranasal Light Therapy or intravenous blood irradiation therapy showed better outcomes than the group that only used drugs. The outcomes were measured by way of reduced neurological disorder and improved red blood cell deformability.
A similar study conducted by Zhao et al (on 3 groups much like that by Jin et al) found that the markers for inflammation (soluble intercellular adhesion molecule-1) decreased twice as rapidly (in 5 days versus 10 days) when drugs were used in combination with either Intranasal Light Therapy or intravenous blood irradiation therapy.
Transcranial Laser Therapy method for stroke
An alternative method of irradiating the localised area of the brain uses “transcranial laser therapy” with near infra-red laser’ It is still in human trials but have shown promising safety and effectiveness when applied within 24 hours if a stroke event. See below.
Treatment with Photothera NeroThera Laser System
Because the laser light is applied above the skull to try to reach targeted areas of the brain, a infra-red laser source (longer wavelength for deeper penetration is required), although the energy dosage remains low.
Neurogenesis /neuroplasticity as explanations for outcomes with light irradiation therapy
Various studies and empirical evidence suggest that neurogenesis/neuroplasticity (formation/regeneration of nervous tissues and neural connections). Low-level laser applied transcranially to rats after induction of stroke significantly reduces long-term neurological deficits. The potential for neurogenesis with transcranial low level laser irradiation is further acknowledge by other scientists.
Theoretical advantage of Intranasal over Transcranial irradiation
The advantage of Intranasal Light Therapy over the transcranial method is that there is less tissue density between most f the brain and the source of light when applied intranasally. Whereas transcranial therapy would require light source of longer wavelengths such as infra-red, the visible red light of Intranasal Light Therapy may achieve equivalent outcomes, and in a much more convenient manner.
1. Dou Z, Hu X, Zhu H (2003). The effects of two kinds of laser irradiation on patients with brain lesion. Chin J Phys Med Rehabil. 25(2): 86-88 (in Chinese).
2. Xiao X, Guo Y, Chu X, Jia S, Zheng X, Zhou C (2005). Effects of low power laser irradiation in nasal cavity on cerebral blood flow perfusion of patients with brain infarction. Chinese Journal of Physical Medicine and Rehabilitation. 27(7): 418-450(in Chinese).
3. Chen L, Lin X, Liao L, Ging Y, Du A, Liu M (2004). Effects of intranasal SLT semiconductor laser therapy on blood blood viscosity. Chinese Journal of Clinical Rehabilitation. (13): 2463-2464 (in Chinese).
4. Jin L, Shi B (2001). Compared research of laser irradiation on blood to erythrocyte deformability and P3PL ingredient of patients with acute cerebral infarction. Chinese Journal of Rehabilitation Medicine. 16( 3) :152-153(in Chinese).
5. Zhao R, Wang C, Li S, Wang S, Li Q . Effects of low-dosage He-Ne laser irradiation through two different pathways on leukocyte adhesion function and intercellular adhesion molecule-1 in patients with cerebral infarction. Chinese Journal of Clinical Rehabilitation. 2(29): 73-75 (in Chinese).
6. Lampl Y, Zivin JA, Fisher M, Lew R, Welin L, Dahlof B, Borenstein P, Andersson B, Perez J, Caparo C, Ilic S, Oron U . Infrared laser therapy for ischemic stroke: a new treatment strategy: results of the NeuroThera Effectiveness and Safety Trial-1 (NEST-1). Stroke. 38(6):1843-9.
7. Oron A, Oron U, Chen J, Eilam A, Zhang C, Sadeh M, Lampl Y, Streeter J, DeTaboada, Chopp M (2006). Low-level laser applied transcranially to rats after induction of stroke significantly reduces long-term neurological deficits. Stroke. 37:2620-2624.
8. Naeser M, Hamblin MR (2011). Potential for Transcranial Laser or LED Therapy to Treat Stroke, Traumatic Brain Injury,
and Neurodegenerative Disease. Photomedicine and Laser Surgery. 29(7):443-446.
Image by Salvatore Vuono