Stroke

Stroke, also known as a brain attack, occurs when blood supply to any part of the brain is blocked (ischemic stroke) or when a blood vessel in the brain bursts, thus depriving brain cells of oxygen and ultimately causing cell death (hemorrhagic stroke)1. Stroke is the third leading cause of death in the United States. It is also the leading cause of adult disability in the United States and Europe. It is the number two cause of death world-wide and may soon become the leading cause of death worldwide2. Risk factors for stroke include high blood pressure, cigarette smoking, heart disease, diabetes, and a history of transient ischemic attacks (TIAs)3. Full-body hypothermia is currently being studied to see if this treatment can improve outcome for stroke. While it is not exactly known how hypothermia might reduce brain damage from stroke, it is believed4 that hypothermia's protective benefits come from: Slowing the body's metabolism (use of energy), which in turn reduces the chemical reactions that lead to brain cell death. Reduction of inflammation (swelling and irritation), another cause of brain injury after a stroke. Possible protection against further damage to brain cells that can occur when clot-busting drugs, such as tissue plasminogen activator (tPA), are used to restore blood flow (called reperfusion). In animal models of ischemic stroke, moderate hypothermia decreased infarct size5 ; mild hypothermia also conferred modest protection6. In humans, several pilot studies of full-body cooling show promising results; however, complications of systemic hypothermia remain troublesome7,8. Selective brain cooling with the Neuro-Wrap avoids the complications seen with full body cooling and can be achieved rapidly and safely Preliminary studies show that brain temperature can be lowered 1.4o C per hour while maintaining normal body temperature Complications of systemic hypothermia do not occur as systemic normothermia is maintained

¹Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease. St. Louis, Mo: Elsevier Saunders.
²Feigin VL (2005). "Stroke epidemiology in the developing world". Lancet 365 (9478): 2160–1
³Stroke risk factors and symptoms.  The National Institute of Neurologic Disease and Stroke.  August 2008  http://www.ninds.nih.gov/disorders/stroke/stroke_bookmark.htm
⁴The Cleveland Clinic.  Hypothermia: Cooling the brain after acute stroke. http://my.clevelandclinic.org/disorders/stroke/hic_hypothermia_cooling_the_brain_and_acute_stroke.aspx
⁵Baker CJ, Onesti ST, Solomon RA. Reduction by delayed hypothermia of cerebral infarction following middle cerebral artery occlusion in the rat: a time-course study. J Neurosurg 1992; 77:438–444.
⁶Xue D, Huang ZG, Smith KE, Buchan AM.  Immediate or delayed mild hypothermia prevents focal cerebral infarction. Brain Res 1992; 587:66–72.
⁷Krieger DW, De Georgia MA, Abou-Chebl A, et al.  Cooling for Acute Ischemic Brain Damage (Cool Aid): An Open Pilot Study of Induced Hypothermia in Acute Ischemic Stroke. Stroke. 2001;32:1847-1854.
⁸Kurokawa Y, Kano H, Yonemasu Y, et al.  Brain Hypothermia Relieves Severe Brain Swelling Following Acute Major Cerebral Artery Occlusion.  Neurol Med Chir (Tokyo). 2001;41:53-61; discussion 61-62.