Treatment options for large hemispheric stroke

Some stroke patients suffering acute middle cerebral artery (MCA) infarctio n develop massive brain edema and herniation, a condition known as malignan t MCA infarction. Severe swelling increases intracranial pressure (ICP) and leads to progressive brainstem dysfunction. Once ICP reaches critical valu es (> 30 mm Hg) herniation occurs, usually within 2 to 5 days. Patients rar ely survive (80% mortality) with standard treatment, and those who do are o ften severely disabled. Malignant MCA infarction is often missed by neurolo gists, despite well-defined clinical and neuroimaging (CT scan) diagnostic criteria. After diagnosis, conventional treatments such as osmotherapy, bar biturates, buffers, and hyperventilation center on reducing ICP. The goal o f hyperosmolar therapy is to increase the serum osmolarity to approximately 315-320 mOsm/L. Enteric glycerol is used routinely to reduce ICP. In more severe cases and when glycerol fails, mannitol may be administered. Other t herapies are also available, including hypertonic saline solution, THAM (Tr is-hydroxy-methyl-aminomethane) buffer, and high-dose barbiturates. Hyperve ntilation also helps reduce ICP. All measures work effectively for a short time only. Other approaches to control elevated ICP, including decompressio n surgery and hypothermia, have shown promising results. In the Heidelberg decompression surgery trial, mortality in surgically treated patients was s ignificantly lower (32%) than in non-treated patients (76%) despite convent ional treatment. Importantly, of the surviving treated patients, 66% were r ated independent with only mild to moderate disability. Moderate hypothermi a (33-36 degreesC) has recently been shown to be effective in severe MCA in farction. Hypothermia induction within 14 hours of ischemic injury and main tained for 72 hours significantly reduced ICP and mortality (44%).