Anatomy of the occipital lobe using lateral and posterior approaches: a neuroanatomical study with a neurosurgical perspective on intraoperative brain mapping.

BACKGROUND

A major concern of occipital lobe surgery is the risk of visual field deficits. Extending anatomical occipital lobectomy to the functional requires awake conditions because the anterior resection border comprises language-, motor- and visuospatial function-related areas within the temporal and parietal lobes. This study investigated the lateral and posterior perspectives of the occipital lobe anatomy when approaching intraaxial occipital lobe lesions.

MATERIALS AND METHODS

Ten adult cadaveric cerebral hemispheres were dissected after being prepared following the concept described by Klingler for the first time.

RESULTS

The occipital lobe was located posteriorly to the parietotemporal line. Within the occipital lobe, the occipital horn of the lateral ventricle represented the only anatomical landmark. Laterally, optic radiation was identified as a part of the sagittal stratum. None of the intraoperatively identifiable tracts was found medial to the occipital horn. Language- and motor-related areas were identified anteriorly and should be actively identified when lobectomy based on function is planned. Subcortically, from a posterior perspective, the anterolateral border constituted the arcuate fascicle/superior longitudinal fascicle complex and was anteromedial to the thalamocortical tract. Remaining posterior to the line connecting the preoccipital notch with the superior Rolandic point avoided the cortical and white matter tracts related to language, motor and visuospatial function.

CONCLUSIONS

Knowledge of occipital lobe anatomy and surrounding structures is essential to preoperatively assess the risk of the procedure and proper consultation of a patient in terms of the extent of resection, primarily concerning visual field deficits.