Purpose: To investigate optic nerve head (ONH) microvascular changes secondary to transsynaptic retrograde degeneration (TRD), comperatively with direct retrograde degeneration and healthy controls. Methods: Patients with hemianopia due to intracranial lesion included in the study. Intracranial lesion was categorized by location: postgeniculate (causing TRD), chiasmal (causing direct retrograde degeneration). For the postgeniculate lesions, the eye on the same side of the lesion was defined as the ipsilateral eye and the eye on the opposite side as the contralateral eye. Optic disc microvasculature was evaluated with the help of optic coherence tomography angiography. Results: Sixteen eyes of 16 patients with chiasmal lesion, 28 eyes of 14 patients with postgeniculate lesion, and 30 eyes of 30 healthy subjects were included in the study. Ipsilateral eyes of the patients with postgeniculate lesion had decreased vessel density at the temporal sectors compatible with the affected nasal side of the visual field. Contralateral eyes showed no reduction of the vessel density at the affected nasal sectors. The eyes with chiasmal lesions had decreased vessel density at the peripapillary region and nasal half of the ONH compatible with temporal hemianopia. Vascular changes in the chiasmal lesion were more prominent than those of the postgeniculate lesion. Retinal nerve fiber layer and ganglion cell complex thickness were reduced. Conclusion: Vessel density of ONH was reduced in patients with homonymous hemianopia, providing evidence for TRD secondary to acquired postgeniculate lesion. Direct retrograde degeneration was more prominent in affected sectors when compared to TRD.

In this case series, we aimed to report our clinical experience with hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI) navigation in the management of recurrent glial brain tumors. Consecutive recurrent neuroglial brain tumor patients who underwent PET/MRI at preoperative or intraoperative periods were included, whereas patients with non-glial intracranial tumors including metastasis, lymphoma and meningioma were excluded from the study. A total of eight patients (mean age 50.1 ± 11.0 years) with suspicion of recurrent glioma tumor were evaluated. Gross total tumor resection of the PET/MRI-positive area was achieved in seven patients, whereas one patient was diagnosed with radiation necrosis, and surgery was avoided. All patients survived at 1-year follow-up. Five (71.4%) of the recurrent patients remained free of recurrence for the entire follow-up period. Two patients with glioblastoma had tumor recurrence at the postoperative sixth and eighth months. According to our results, hybrid PET/MRI provides reliable and accurate information to distinguish recurrent glial tumor from radiation necrosis. With the help of this differential diagnosis, hybrid imaging may provide the gross total resection of recurrent tumors without harming eloquent brain areas.

BACKGROUND AND OBJECTIVES: Robotic surgery systems are commonly used in many surgical fields but currently have limited adoption in neurosurgery. The goal for this work was to share our experience with the da Vinci Xi surgical robot for neurosurgical practice. METHODS: Our senior surgeon (U. E.) underwent robotic surgery training followed by simulation training. Five patients then underwent robotic surgery performed by the surgeon; pathologies included clivus chordoma, odontoid metastatic mass, peroneal neuropathy, and arachnoid cyst. Clinical data, demographic details, and follow-up outcomes were analyzed. RESULTS: Of the 5 patients (2 female, 3 male; mean age, 43 years), 2 had a clivus chordoma, 1 had an odontoid metastatic mass, 1 had peroneal neuropathy, and 1 had an arachnoid cyst. No intraoperative or postoperative neurological deficits or complications were observed. All 5 of the patients had a favorable outcome. CONCLUSION: Robotic systems can offer clear advantages over traditional neurosurgery, particularly for transoral resection and intracranial cyst fenestration. However, practical training is essential for effectively integrating these systems into routine neurosurgical practice. The case series presented here reveals the feasibility of robotic neurosurgery and the need for further evaluation of this technology.