A 60-second hyperventilation event causes metabolic changes in the vestibular system and reveals a latent vestibular asymmetry. The presence of an excitatory pattern is the major criterion that suggests VS in patients with signs of unilateral vestibular deficit.

In our experience, the 3-D endoscope represents a critical development in visualization, thus enabling improved hand-eye coordination and depth perception, which are mandatory for the management of complex intradural neurovascular structures during tumor removal surgery.

Over the last years, fluorescence-based technology has begun an emergent intraoperative method for diagnostic confirmation of brain tumor tissue in stereotactic needle biopsy. However, the actual level of evidence is quite low, especially about fluorescein sodium (FL) application. This method needs to be further validated and better analyzed about its impact in clinical practice. Retrospective analysis of 11 cases with contrast-enhancing brain tumors, underwent awake stereotactic needle biopsy with intraoperative FL assistance (group 1), was verified under the operative microscope filter. This group was matched with a control group of 18 patients (group 2). In addition, a systematic literature review was performed in PubMed/Medline database according to PRISMA statement. All studies concerning FL or 5-ALA application in stereotactic biopsy as intraoperative confirmation of brain tumor tissue were included. The primary endpoint was the evaluation of diagnostic accuracy. In group 1, all fluorescent specimens were diagnostic. The number of samplings was the useful minimum and non-use of intraoperative neuropathological examination allowed to significantly reduce procedure time (42.09 vs 69.72 min of group 2). No complications occurred, and the average hospitalization time after procedure was 1.09 days (vs 2.33 of group 2). Literature analysis supports the usefulness of photodiagnosis and its high diagnostic yield especially at the core of high-grade/contrast-enhancing tumors. FL assistance during stereotactic biopsy of contrast-enhancing brain tumors may give a real-time confirmation of tumor tissue, maximizing the diagnostic yield, and reducing time of procedure, morbidity, and hospitalization.

No abstract