Chandrasekaran Kaliaperumal

Vagal nerve stimulator: Evolving trends.

Over three decades ago, it was found that intermittent electrical stimulation from the vagus nerve produces inhibition of neural processes, which can alter brain activity and terminate seizures. This paved way for the concept of vagal nerve stimulator (VNS). We describe the evolution of the VNS and its use in different fields of medicine. We also review the literature focusing on the mechanism of action of VNS producing desired effects in different conditions. PUBMED and EMBASE search was performed for ‘VNS’ and its use in refractory seizure management, depression, obesity, memory, and neurogenesis. VNS has been in vogue over for the past three decades and has proven to reduce the intensity and frequency of seizure by 50% in the management of refractory seizures. Apart from this, VNS has been shown to promote neurogenesis in the dentate gyrus of rat hippocampus after 48 hours of stimulation of the vagus nerve. Improvement has also been observed in non-psychotic major depression from a randomized trial conducted 7 years ago. The same concept has been utilized to alter behavior and cognition in rodents, and good improvement has been observed. Recent studies have proven that VNS is effective in obesity management in patients with depression. Several hypotheses have been postulated for the mechanism of action of VNS contributing to its success. VNS has gained significant popularity with promising results in epilepsy surgery and treatment-resistant depression. The spectrum of its use has also extended to other fields of medicine including obesity, memory, and neurogenesis, and there is still a viable scope for its utility in the future.

Aneurysms unsuitable for endovascular intervention: Surgical outcome and management challenges over a 5-year period following International Subarachnoid Haemorrhage Trial (ISAT)

OBJECTIVE To analyse outcome of surgical management of aneurysms unsuitable for endovascular intervention in a tertiary referral neurosurgical unit over a 5-year post-ISAT period. To compare secondary parameters such as operating time, number of clips required, and training over last 5 years with similar number of patients in the pre-ISAT period. METHODS Consecutive 54 patients harbouring 62 uncoilable aneurysms admitted from May 2002 to April 2007 in a tertiary neurosurgical unit. Outcome analysed at 3 months using Glasgow Outcome Score and Modified Rankin Scale based on standard questionnaires. Comparison with outcome of surgical arm of ISAT study performed. RESULTS At 3 months 28 (90%) of Grades I-II and 9 (39%) of Grades III-V patients harbouring uncoilable aneurysms had good clinical outcome (MRS 0-2) comparing favourably with the surgical arm of the ISAT study at 2 months. (relative risk=0.28, 95% CI 0.08-0.45; P=0.01) Surgical time, number of clips required for aneurysmal obliteration had however increased significantly compared to pre-ISAT period. The training potential was severely restricted with uncoilable aneurysms. CONCLUSIONS Ruptured cerebral aneurysms deemed unsuitable for endovascular intervention are also difficult cases to treat surgically. However, with neurovascular sub-specialisation, it is possible to achieve favourable surgical outcome in a higher percentage of cases than reported in the ISAT study and the National Study of Subarachnoid Haemorrhage. These cases, due to their technical complexities, unfortunately offer limited training potential for pre-certification Neurosurgical trainees.

Outcome of nucleoplasty in patients with radicular pain due to lumbar intervertebral disc herniation

Background: Nucleoplasty (percutaneous lumbar disc decompression) is a minimally invasive procedure that utilizes radiofrequency energy as a treatment for symptomatic lumbar disc herniation, against open microdiscectomy, which would be the mainstay treatment modality. The literature reports a favorable outcome in up to 77% of patients at 6 months. Aim: To evaluate the effectiveness of nucleoplasty in the management of discogenic radicular pain. Materials and Methods: The medical notes of 33 patients, admitted for nucleoplasty between June 2006 and September 2007, were reviewed retrospectively. All had radicular pain, and contained herniated disc as seen on magnetic resonance imaging (MRI) of lumbosacral spine. Patients were followed up at 1 and 3 months post-procedure. The outcome measures employed in this study were satisfaction with symptoms and self-reported improvement. Results: Thirty-three cases were examined (18 males and 15 females). Twenty-seven procedures were performed with no complications and six were abandoned due to anatomical reasons. There were 18 and 15 cases of disc herniation at L5/S1 and L4/5 levels, respectively. Four weeks following the procedure, 13 patients reported improvement in symptoms, and 14 remained symptomatically the same and subsequently had open microdiscectomy. Conclusion: Nucleoplasty has been shown to be a safe and minimal-access procedure. Less than half of our selected cohort of patients reported symptomatic improvement at 1-month follow-up. We no longer offer this procedure to our patients. Possible reasons are discussed.

Recurrent intramedullary epidermoid cyst of conus medullaris.

Spinal intramedullary epidermoid cyst is a rare condition. Recurrent epidermoid cyst in the spine cord is known to occur. The authors describe a case of recurrent conus medullaris epidermoid cyst in a 24-year-old female. She initially presented at 7 years of age with bladder disturbance in the form of diurnal enuresis and recurrent urinary tract infection. MRI lumbar spine revealed a 4 cm conus medullaris epidermoid cyst. Since the initial presentation, the cyst had recurred seven times in the same location and she underwent surgical intervention in the form of exploration and debulking. This benign condition, owing to its anatomical location, has posed a surgical and overall management challenge. This occurrence is better managed in a tertiary-care centre requiring multi-disciplinary treatment approach.

Aneurysmal subarachnoid haemorrhage in Parry-Rhomberg syndrome

Parry–Romberg syndrome (PRS) or progressive hemi facial atrophy syndrome is a rare condition of unknown aetiology that is characterised by progressive unilateral facial and cranial atrophic changes of skin, subcutaneous tissues and bone. The authors describe a 37-year-old female with a history of PRS, who presented with a subarachnoid haemorrhage secondary to rupture of a 9 mm fusiform aneurysm of the posterior cerebral artery. There was an associated external carotid arterio-venous fistula noted with this aneurysm. The aneurysm was treated by endovascular route and was successfully coiled. Follow-up angiogram revealed spontaneous resolution of the fistula with good occlusion of the aneurysm. The aetio-pathogenesis of this rare occurrence, literature review and its management is discussed.

'Teeth in the brain' - a case of giant intracranial mature cystic teratoma.

The authors describe a case of a giant intracranial mature cystic teratoma in a 16-year-old girl presenting acutely with a severe headache, vomiting and a complex generalised seizure with a background history of intermittent headaches for 3 years. CT and MRI brain demonstrated a ruptured large cystic teratoma encapsulating two large teeth within the diffusely dense fatty heterogeneous lesion. Surgical debulking of the cyst was performed and the calcific remnants were left behind owing to dense adhesion to the brain. The procedure was complicated by postoperative hydrocephalus and needed a ventricloperitoneal shunt. She is currently asymptomatic and undergoing rehabilitation.

Recurrence of a paediatric arteriovenous malformation 9 years postcomplete excision: case report and review of literature

Cerebral arteriovenous malformations (AVMs) are a common congenital vascular anomaly, which often present in both children and adults. Surgery is considered curative once postoperative angiography confirms the absence of vessels. We describe a 6-year-old girl, who had a Spetzler-Martin Grade II AVM resected successfully, in which a recurrent AVM was detected on routine follow-up over 9 years post excision. The aetiopathogenesis of this rare occurrence with a review of literature is discussed. Long-term postoperative follow-up in the form of MRI/MR angiogram is recommended for all fully resected AVMs in the paediatric age group, anticipating the possibility of future recurrence.

Spontaneous haemorrhage and rupture of third ventricular colloid cyst.

Acute bleeding within a colloid cyst of the third ventricle represents a rare event causing sudden increase in the cyst volume that may lead to acute hydrocephalus and rapid neurological deterioration. We report a case of spontaneous rupture of haemorrhagic third ventricular colloid cyst and its management. A 77-year-old ex-smoker presented with unsteady gait, incontinence and gradually worsening confusion over a 3-week period. Brain CT scan findings were highly suggestive of a third ventricular colloid cyst with intraventricular rupture. He underwent cyst excision and histopathology, which confirmed the radiological diagnosis with evidence of haemorrhage within the cyst. A ventriculo peritoneal shunt was performed for delayed hydrocephalus. Surgical management of these patients must include emergency ventriculostomy followed by prompt surgical removal of the haemorrhagic cyst.

Carotid "Trifurcation" aneurysm: Surgical anatomy and management

The authors describe a rare case of internal carotid artery (ICA) trifurcation aneurysm and its surgical management. Carotid trifurcation is a unique anatomical variant where three arterial branches arise from the carotid termination than the usual two. Aneurysm arising from the trifurcation, due to its rarity, is difficult to treat. The anatomy, embryological basis and significance of such an anomaly during surgical management are discussed.

Suprasellar pilocytic astrocytoma: one national centre's experience.

IntroductionPilocytic astrocytomas in the supratentorial compartment make up 20 % of all brain tumours in children with only 5 % of these arising in the suprasellar region. Optic pathway gliomas or suprasellar gliomas are often seen in neurofibromatosis type 1 (NF1) patients. Given their location, suprasellar pilocytic astrocytomas are challenging to manage surgically with high morbidity rates from surgical resection. We assess our cohort of patients with suprasellar pilocytic astrocytoma and document our experience.MethodA retrospective review of patients diagnosed with suprasellar glioma between 2000–October 2012. We included patients diagnosed with optic pathway glioma based on radiological features (with or without biopsy) and those who had a biopsy confirming pilocytic astrocytoma.ResultsFifty-three patients included (sporadic tumours 24 and NF1 related 29). Fifteen sporadic and four NF1 patients were biopsied. Twelve sporadic and 13 NF1 patients were initially treated with chemotherapy while only 1 patient had radiotherapy initially. Progression was noted in 58 % of the sporadic group and 24 % of the NF1 group. The only significant factor for progression was NF1 status (p = 0.026).ConclusionManagement should be guided by individual patient circumstance. In our cohort, chemotherapy did not significantly improve progression free survival; however, NF1 status significantly correlated with the decreased progression.