Decompressive craniectomy for encephalitis with brain herniation: case report and review of the literature

Decompressive craniectomy (DC) has been sporadically used in cases of infectious encephalitis with brain herniation. Like for other indications of DC, evidence is lacking regarding the beneficial or detrimental effects for this pathology. We reviewed all the cases of viral and bacterial encephalitis treated with decompressive craniectomy reported in the literature. We also present one case from our institution. These data were analyzed to determine the relation between clinical and epidemiological variables and outcome in surgically treated patients. Of 48 patients, 39 (81.25 %) had a favorable functional recovery and 9 (18.75 %) had a negative course. Only two patients (4 %) died after surgical treatment. A statistically significant association was found between diagnosis (viral and bacterial encephalitis) and outcome (GOS) in surgically treated patients. Viral encephalitis, usually caused by herpes simplex virus (HSV), has a more favorable outcome (92.3 % with GOS 4 or 5) than bacterial encephalitis (56.2 % with GOS 4 or 5). Based on this literature review, we consider that, due to the specific characteristics of infectious encephalitis, especially in case of viral infection, decompressive craniectomy is probably an effective treatment when brain stem compression threatens the course of the disease. In patients with viral encephalitis, better prognosis can be expected when surgical decompression is used than when only medical treatment is provided.