Method for providing phototherapy to the brain
Methods for providing and/or determining therapeutic treatment of at least a portion of a patient's brain are provided. The method includes applying light to at least a portion of a patient's brain and monitoring at least one physiological parameter of the patient. The method further includes receiving real-time feedback information regarding the at least one monitored physiological parameter and adjusting a treatment parameter of the applied light based on the real-time feedback information.
1. A method of treating an ischemic stroke in a subject, the method comprising:
fitting, onto a scalp of the subject, a light therapy apparatus comprising: (i) a light source, (ii) a temperature sensor, and (iii) an element interposed between the light source and the scalp such that a first side of the element faces the scalp and a second side of the element faces the light source,
wherein the first side of the element includes: (i) first portions that contact portions of the scalp and (ii) second portions that are spaced away from the scalp;
applying, via the first portions of the first side of the element, pressure to compress the portions of the scalp and force blood out therefrom;
irradiating, using the light source, a portion of a brain of the subject at a depth of 2 centimeters below a dura of the subject with a peak power density between 0.01 mW/cm 2 and 100 mW/cm 2 and a wavelength of light in the visible to near-infrared wavelength range;
detecting, using the temperature sensor, a scalp temperature of the subject during the irradiating; and
adjusting, during the irradiating, a parameter of the light source based on the detected scalp temperature to maintain the scalp temperature below a predetermined level,
wherein the treating occurs within 24 hours of the subject experiencing the ischemic stroke.
2. The method of claim 1 , wherein the light source comprises a low-energy laser.
3. The method of claim 1 , wherein the light has a wavelength between 630 nanometers and 1064 nanometers.
4. The method of claim 3 , wherein the light has a wavelength between 803 and 813 nanometers.
5. The method of claim 1 , wherein the peak power density is between 0.01 mW/cm 2 and 50 mW/cm 2 .
6. The method of claim 1 , wherein the peak power density is between 2 mW/cm 2 and 20 mW/cm 2 .
7. The method of claim 1 , wherein a cortical cerebral blood flow of the subject is increased by 10%, 15%, 20%, or 25% immediately post-irradiation, as compared to immediately prior to irradiation.
8. The method of claim 1 , wherein the element applies pressure to compress at least a portion of the scalp of the subject, thereby blanching the portion of the scalp and decreasing absorption of the light by blood in the scalp.
9. The method of claim 1 , wherein at least a portion of the element is within an optical path of light from the light source to the scalp of the subject.
10. The method of claim 9 , wherein the element is optically transmissive at the wavelength of light from the light source.
11. The method of claim 9 , wherein the element comprises a material having a refractive index which matches a refractive index of the scalp of the subject.
12. The method of claim 1 , wherein the element comprises a conduit containing a coolant which flows through the conduit toward the scalp of the subject, is heated by the scalp of the subject, and flows away from the scalp of the subject.
13. The method of claim 1 , wherein treating the subject with a light source results in a temperature increase at the scalp of the subject by up to 3° C.
14. A method of treating a source of neurodegeneration in a subject, the method comprising:
fitting, onto a scalp of the subject, a light therapy apparatus comprising: (i) a light source, (ii) a temperature sensor, and (iii) an element interposed between the light source and the scalp such that a first side of the element faces the scalp and a second side of the element faces the light source,
wherein the first side of the element includes: (i) first portions that contact portions of the scalp and (ii) second portions that are spaced away from the scalp;
applying, via the first portions of the first side of the element, pressure to compress the portions of the scalp to force blood out therefrom;
irradiating, using the light source, a portion of a brain of the subject at a depth of 2 centimeters below a dura of the subject with a peak power density between 0.01 mW/cm 2 and 100 mW/cm 2 and a wavelength of light in the visible to near-infrared wavelength range;
detecting, using a temperature sensor, a scalp temperature of the subject during the irradiating; and
adjusting, during the irradiating, a parameter of the light source based on the detected scalp temperature to maintain the scalp temperature below a predetermined level.
15. The method of claim 1 , wherein the light is applied continuously.
16. The method of claim 1 , wherein the light is pulsed.
17. The method of claim 16 , wherein the light has a pulsed frequency of up to 100 kHz.
18. The method of claim 14 , wherein the light has a wavelength between 630 nanometers and 1064 nanometers.
19. The method of claim 14 , wherein the light is applied continuously.
20. The method of claim 14 , wherein the light is pulsed.
21. The method of claim 20 , wherein the light has a pulsed frequency of up to 100 kHz.
22. The method of claim 14 , wherein the element applies pressure to compress at least a portion of the scalp of the subject, thereby blanching the portion of the scalp and decreasing absorption of the light by blood in the scalp.
23. The method of claim 14 , wherein the element comprises a conduit containing a coolant which flows through the conduit toward the scalp of the subject, is heated by the scalp of the subject, and flows away from the scalp of the subject.
24. The method of claim 1 , wherein the element reduces temperature increases at the scalp of the subject.
25. The method of claim 14 , wherein the element reduces temperature increases at the scalp of the subject.