Significance of O6-methyl guanine methyltransferase promoter methylation in high grade glioma patients: optimal cutoff point, CpG locus, and genetic assay.

PURPOSE: To evaluate O6-methyl guanine methyltransferase (MGMT) promoter methylation status in high grade glioma patients and to identify the best cutoff point as well as the most predictive CpG loci for patients survival. METHOD: Consecutive high grade glioma patients treated with surgical gross total resection followed by concomitant radiochemotherapy and adjuvant chemotherapy were included in this retrospective observational study. Methylation status of MGMT promoter CpG island of resected tumor tissue were evaluated using next generation sequencing assay. The outcomes were grouped as CpG 70-78, CpG 79-83, CpG 84-87, CpG 70-87, and whole promoter. Quantitative analyses were dichotomized as methylated or unmethylated based on the cutoff points set to %10, and methylation was further graded as <%10 unmethylated, %10-30 low-methylated, and %30-100 high-methylated. RESULTS: Total of 95 patients with the mean age of 51.50 ± 12.36 years were included in the study. Overall survival (OS) and progression free survival (PFS) were 14.53 ± 1.92 (95% CI 10.77-18.30) and 10.90 ± 2.05 (95% CI 6.89-14.92) months, respectively. MGMT promoter was methylated in 38.2% of cases and high-methylated in 10.5% of cases. Methylation status of MGMT promoter was recognized as a very powerful predictor of OS and PFS. In particular, high-methylation of CpG 79-83 and CpG 84-87 islands at promoter region were strongly associated with better survival outcomes (p < 0.05). CONCLUSION: Our outcomes support the prognostic value of MGMT promoter methylation in patients with high grade glioma. Sequencing of whole promoter CpG islands demonstrated that methylation of particular CpG sites might predict clinical outcomes more precisely.

Acute hydrocephalus caused by a gelatin-sponge material: a case report.

Third ventricle lesions, especially those located proximally to the foramen of Monro, generally present with obstructive hydrocephalus symptoms. In this report, we present a case with acute obstructive hydrocephalus secondary to a gel-foam material. The patient has previously underwent an endoscopic cystectomy. At postoperative third month, she admitted to our hospital with the complain of headache. Neuroradiological imaging revealed triventricular hydrocephalus. A second endoscopic operation was performed, and a piece of gelatin-sponge material was detected at the level of cerebral aqueduct, which obstructed the flow of cerebrospinal fluid (CSF). The CSF flow was immediately restored after removing this material, and an additional third ventriculostomy was performed.

Suturing of the Arachnoid Membrane for Reconstruction of the Cisterna Magna: Technical Considerations.

BACKGROUND: Postoperative cerebrospinal fluid (CSF) fistula following cranial or spinal surgery is associated with increased morbidity and mortality. To prevent CSF fistulas, various techniques have been described. Here, we describe the arachnoid membrane continuous-running suture technique in cisterna magna reconstruction for preventing postoperative CSF leakage. METHODS: After craniotomy and dural opening, the incision of the arachnoid of the cisterna magna was performed using a diamond blade. To prevent the arachnoid from drying out and shrinking during surgery, it was periodically irrigated with warm saline solution. Posterior fossa surgery was performed. When closing the membranes, the arachnoid membrane was closed with the running-suture technique. After the first surgical knot was made in the cranial end of the arachnoid opening, continuous suturing with a 2-mm distance between the stitches was performed without stretching them. After every 3 stitches, the free end of the thread was pulled gently along the suturing axis, and the edges of the arachnoid were closed. After the arachnoid edges were approximated, the surgical knot was tied. Watertight closure was checked by performing the Valsalva maneuver at the end of the surgery. RESULTS: No CSF leakages were observed after surgery. CONCLUSIONS: Arachnoid membrane suturing seems to be safe and effective in preventing postoperative CSF leakage and CSF-related complications. Using continuous running suturing alone, without any sealant, might be effective in cases with untraumatized arachnoid membrane.

Contralateral Subfrontal Supraorbital Approach for Microsurgical Resection of Optic Canal Meningioma.

ABSTRACT: Meningiomas are mostly benign tumors of the central nervous system. Recurrence can be seen in clinoidal meningiomas especially extending into optic canal. We present a patient with a history of left clinoidal meningioma excision via pterional approach and recurrence purely in left optic canal. Optic canal drilling is necessary for complete removal of these type of tumors. Contralateral subfrontal approach with an eyebrow incision and a keyhole supraorbital craniotomy was used for this patient. Contralateral viewing of the surgical area provided direct angles and created better workspace for the surgeon. Total excision was achieved with no additional neurological deficits in the postoperative period. This approach can be used with its wide exposure of surgical site, potential space usage without need of retraction and better postoperative scar healing.

Direct and transsynaptic retrograde degeneration and optic nerve head microvascular changes in patients with hemianopia.

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.