Gamma Knife Radiosurgery in Partially Embolised Arteriovenous Malformations: Management Dilemmas and Outcomes.

Introduction: The role of Gamma Knife radiosurgery (GKRS) in partially embolized arteriovenous malformations (AVMs) has always remained a subject of debate. The aim of this study was to evaluate the efficacy of GKRS in partially embolized AVMs and to analyze factor that influence its obliteration. Methods: This was a retrospective study from a single institute performed over a period of 12 years (2005-2017). It included all patients who underwent GKRS for partially embolized AVMs. Demographic characteristics, treatment profiles, and clinical and radiological data were obtained during treatment and follow-up. Obliteration rates and factors affecting the same were sought and analyzed. Results: A total of 46 patients with a mean age of 30 years (range: 9-60 years) were included in the study. Follow-up imaging was available for 35 patients either by digital subtraction angiography (DSA) or magnetic resonance imaging (MRI). We found complete AVM obliteration in 21 patients (60%): one had near total obliteration (>90% obliteration), 12 had subtotal obliteration (<90%), and one had no change in the volume following GKRS. Following embolization alone, an average of 67% of the AVM volume was obliterated which resulted in an average 79% final obliteration rate after Gamma Knife radiosurgery. Mean duration to complete obliteration was found to be 3.45 years (range: 1-10 years). There was a significant difference (P = 0.04) in the mean interval between embolization and GKRS among cases with complete obliteration (12 months) and those with incomplete obliteration (36 months). There was no significant difference (P = 0.49) in the average obliteration rate between the ARUBA-eligible unruptured AVMs (79.22%) and ruptured AVMs (79.04%). Bleeding after GKRS during the latency period had a negative impact on obliteration (P = 0.05). Other factors like age, sex, Spetzler-Martin (SM)-grade, Pollock Flickinger score (PF-score), nidus volume, radiation dose, or presentation before embolization had no significant influence on obliteration. Three patients had permanent neurological deficits after embolization and none after radiosurgery. Six out of nine patients (66%) presenting with seizures were seizure-free after the treatment. Hemorrhage was noted in three patients following combined treatment and were managed non-surgically. Conclusion: Obliteration rates in partially embolized AVM after Gamma Knife are inferior when compared to Gamma Knife alone; moreover with volume staging and/or dose staging being increasingly plausible due to the new ICON machine, embolization may be completely replaced. However we have shown that in complicated and carefully chosen AVMs, embolization followed by GKRS is a valid modality of management. This study represents a real-world picture of individualized AVM treatment depending on patient choices and resources available.

Abusive head trauma in India: imaging raises the curtain.

The purpose of the study was to identify children at our institute who possibly suffered abusive head trauma (AHT). A retrospective study of CT imaging of children between one month to three years of age between January 2013 and May 2021 was carried out at a dedicated neurocentre in Southern India. We identified 48 cases of possible AHT. The demographics, clinical features at presentation, imaging and fundus findings were analyzed. Imaging revealed subdural hemorrhage (SDH) in 42 and sub dural effusion (SDE) in 5 cases, one case had only hypoxia. The location of SDH was studied as was hypoxia underlying SDH, global hypoxia and ischemia. Cases of subarachnoid hemorrhage (SAH), parenchymal hematoma & intraventricular hemorrhage (IVH) were also noted. Skeletal survey, chest X-ray and CT spine were reviewed. AHT needs to be paid attention to in the Indian scenario. An extensive work up is required to substantiate the claim and to work on prevention & management of these cases subsequently.

Transcranial approach for pituitary adenomas - An evaluation of surgical approaches over two decades and factors influencing peri-operative morbidity.

PURPOSE: Transcranial surgery(TCS) for pituitary adenoma(PA) is mostly reserved for lesions with widespread extensions. We sought to analyse the intraoperative challenges, morbidity and the factors associated with morbidity of transcranial approaches, in a large series from a tertiary neurosurgical institute. METHODS: We retrospectively evaluated 137 patients who underwent TCS for PA in our institute. The details of their clinical features, imaging, operative and peri-operative events and complications were collected and analysed. The factors associated with morbidity were evaluated. RESULTS: The mean age of the cohort was 40.86 ± 13.35 years. 21 (15.3%) patients developed significant post-operative hematoma, out of which 7 patients (5.1%) required re-exploration. Post-operative diabetes insipidus was noted in 45 patients (32.84%), while SIADH was noted in 10 patients (7.35%). Other complications were cranial nerve palsy in 14 patients (10.2%), visual deterioration in 7 patients (5.1%). Neither tumour characteristics nor the choice of approach was associated with occurrence of post op hematoma. SIADH was significantly associated with patients with tumours involving cavernous sinus (p = 0.019) and subfrontal extension (p = 0.031). Patients with post-operative hematoma had significantly higher incidence of post-op DI (57.1% vs 28.7%; p = 0.021), while similar correlation was not noticed with SIADH (4.7 vs 7.8%). CONCLUSION: TCS plays a distinct, albeit a small role in surgical management of pituitary adenoma. Tumour related or approach related factors are not significantly associated with the incidence of hematoma. Post-operative hematoma significantly influences the incidence of DI. A proper and judicious selection of approach and meticulous surgical technique should result in a reduction in associated morbidity and mortality.

Cerebrovascular pathology in cerebral amyloid angiopathy presenting as intracerebral haemorrhage.

Cerebral amyloid angiopathy (CAA) is the second most common cause of non-traumatic intracerebral haemorrhage (ICH) accounting for 12-15% of lobar haemorrhages in the elderly. Definitive diagnosis of CAA requires histological evaluation. We aimed to evaluate the spectrum of cerebrovascular changes in CAA-related ICH. Between 2011 and 2015, biopsy-confirmed cases of CAA were retrieved and clinical, radiological and pathological features were reviewed. The spectrum of vascular alterations was evaluated and amyloid deposition was graded in accordance with the Greenberg and Vonsattel scale. Seven cases of sporadic CAA [5 males and 2 females] were diagnosed, none of whom were suspected to have CAA pre-operatively. Six presented with large intracerebral haematoma (ICH) requiring neurosurgical intervention (age range: 56-70 years) and one had episodic headache and multiple microhaemorrhages requiring a diagnostic brain biopsy (45 years). In the presence of large ICH, vascular amyloid deposits were of moderate to severe grade (grade 4 in 4, grades 2 and 3 in 1 case each) with predominant involvement of medium (200-500 µm) to large (> 500 µm) leptomeningeal vessels. Fibrinoid necrosis was noted in four. Two were hypertensive and on antiplatelet agents. ß-Amyloid plaques were detected in two, one of whom had symptomatic dementia. MRI performed in 3 of 6 cases with ICH did not reveal any microhaemorrhages. Amyloid deposits in small (50-200 µm) to medium (200-500 µm) calibre intracortical vessels produced parenchymal microhemorrhages. Histopathological examination of ICH is essential for diagnosing CAA. The vascular calibre rather than grade of amyloid deposits dictates size of the bleed. Presence of co-morbidities such as antiplatelet agents may predispose to haemorrhage.

Intracranial Germ Cell Tumors: Spectrum of Disease in an Indian Cohort and Management Strategies.

BACKGROUND: Germ cell tumors (GCTs) represent approximately 3% of primary pediatric brain tumors in the West, whereas in Asia, they constitute between 8% and 15% of pediatric brain tumors. METHODS: We retrospectively studied all patients with intracranial GCT managed at our institute from January 1998 to December 2013. The clinical data and radiological data were analyzed. RESULTS: Forty-eight patients with intracranial GCT including 36 males and 16 females formed the cohort. The proportion of GCT in our study was 0.29%. The mean age was 16.5 ± 2.5 years. Germinomas constituted 56.3% and nongerminomatous GCTs constituted 43.7% of all the tumors. The most common location was posterior third ventricle (58.3%) followed by suprasellar (22.9%). Histopathological diagnosis was obtained in almost all patients (96%). Surgical procedures included tumor decompression (71.7%), stereotactic biopsy (13%), and endoscopic third ventriculostomy and biopsy (15%). Patient's age, location of the tumor, and histology did not influence the survival. Women with GCTs had poorer survival when compared to men. CONCLUSIONS: The present study documented a lower hospital-based incidence of GCT in Indian cohort. A multidisciplinary approach including surgical strategy based on location, appropriate radiation planning, and chemotherapy is needed for effective treatment and improved outcomes.

Supratentorial Pure Cortical Ependymoma: An Unusual Lesion Causing Focal Motor Aware Seizure.

Ependymomas usually arise from the ependymal lining cells of the ventricular system and central canal of the spinal cord. Supratentorial ependymoma is a rare entity with the variable clinical course. In a small number of cases, ependymoma arises from supratentorial parenchyma. Only a few cases are reported in the literature. We report a case of 3-year-old girl with left frontal mass. Total removal of the mass lesion was performed without any neurological deficit. Pathological examination of the excised tumor was consistent with anaplastic ependymoma. We have discussed management strategy of this rare entity.

Abscess within a Glioblastoma: Mimicking a Matryoshka Doll.

BACKGROUND: Abscess coexisting within a brain tumor is rare. Case reports in the literature primarily consist of sellar pathology and parenchymal lesions, including meningioma, glioma, and metastases. We report a case of glioblastoma with an intratumoral abscess in a middle-aged patient with no prior invasive procedure or systemic focus of infection. CASE DESCRIPTION: A 45-year-old woman presented with new-onset generalized seizures and rapidly progressive left hemiparesis. Imaging showed a right frontal necrotic lesion with a peripherally enhancing wall and solid component posteriorly. There was no diffusion restriction within the lesion. She was afebrile, and there was no systemic focus of infection. With provisional diagnosis of malignant glioma, she underwent surgical resection of the lesion. A differential diagnosis of abscess was considered preoperatively because of the rapid increase in size of the lesion. At surgery, there was a pus-filled cavity with a few areas of grayish, soft, flimsy wall and thrombosed veins. This raised a strong suspicion of a coexisting abscess within a malignant glioma, which was confirmed by histopathologic and microbiologic examination. CONCLUSIONS: It is important for neurosurgeons to be aware of this rare entity. The treatment protocol remains controversial and is primarily guided by expert opinion. It is important to aggressively treat the patient with antibiotics followed by adjuvant therapy for malignancy. The timing and administration of adjuvant therapy are unclear. We suggest a delay of chemotherapy until at least 4 weeks of therapy with sensitive antibiotics.

RNA interference mediated downregulation of human telomerase reverse transcriptase (hTERT) in LN18 cells.

Human telomerase reverse transcriptase (hTERT) gene is a biomarker for the targeted therapy in various cancers. Presence of increased telomerase activity is a common feature of all cancers including glioblastoma. Both RNA and catalytic subunits of hTERT are the target sites for blocking its activity. The current study focuses on the expression of hTERT in glioblastoma and its regulation using two different novel siRNAs (small interfering RNA). Our patient data demonstrated increased expression of hTERT, which could be correlated with carcinogenesis in glioma. In vitro studies in siRNA transfected LN18 cells confirmed significant cell death (p < 0.05) as evidenced by MTT and trypan blue exclusion assay. These results were further supported by flow cytometry data, which showed significant increase in early and late apoptosis. The hTERT mRNA expression was effectively downregulated by 45 and 39 % with siRNA1 and siRNA2, respectively. These results were further confirmed by immunoblotting analysis (p < 0.05). Our results suggest that both the siRNAs effectively down regulated the expression of hTERT at mRNA and protein levels, thereby decreasing cell viability and proliferation rate. Hence siRNA mediated downregulation of hTERT could be a potential therapeutic avenue in glioblastoma.