Frameless navigation-guided percutaneous rhizotomy of the trigeminal nerve: an appraisal of the literature.

Percutaneous rhizotomy is a cornerstone of trigeminal neuralgia treatment. The procedure is classically performed under intermittent fluoroscopic guidance. While frameless navigation has been advanced to overcome potential difficulties and risks of the technique, literature on the subject is limited, and a gap between actual use and published series is likely. We have assessed all available studies of percutaneous rhizotomy of the trigeminal nerve performed under frameless navigation. Technical and clinical data that has been reviewed included clinical outcome, type of navigation employed, type of rhizotomy performed, types and rate of complications, operative time, cannulation time, and cannulation rate. Reports are heterogeneous, and most of these aspects have been inconsistently described. Comparisons with non-guided procedures are mostly indirect. While no obvious disadvantages are apparent when employing navigation, the ability to draw conclusions is nonetheless limited. Navigation appears as an inviting adjunct to trigeminal rhizotomy, but publication of longer, rigorously evaluated series would be welcomed.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.