Near-infrared Diffuse Optical Imaging for Noninvasive Monitoring of Cortical Spreading Depression

Cortical spreading depression (CSD) is a region of transient electrical and metabolic failure that propagates through peri-lesional brain tissue. Although characteristics of CSD have been shown to be relevant to injury outcome, subdural electrode measurements currently in use restrict monitoring only to patients requiring craniotomy. A portable, noninvasive monitoring device applicable to all patients experiencing CSD would therefore be of great clinical utility from the standpoint of furthering our basic understanding as well as guiding treatment strategies. Ultimately, the device will have broad utility across military and civilian populations for real-time monitoring of a wide variety of events ranging from penetrating brain injury to stroke and migraine. Physical Sciences, Inc. and Massachusetts General Hospital propose to develop a near-infrared spectroscopic device to monitor CSD noninvasively and with minimal interference with routine patient care. The device will produce real-time, 2-dimensional images of cerebral blood flow changes by spatial localization of the absorption coefficients of oxy- and deoxyhemoglobin. Phase I studies will determine the feasibility of the technique for monitoring CSD in a piglet model. In Phase II, a prototype device will be developed that is compact, robust, and suitable for field deployment.