Yi Yuen Wang

Tolerability, safety, and side effects of levetiracetam versus phenytoin in intravenous and total prophylactic regimen among craniotomy patients: A prospective randomized study

Purpose:u2002 Practical choice in parenteral antiepileptic drugs (AEDs) remains limited despite formulation of newer intravenous agents and requirements of special patient groups. This study aims to compare the tolerability, safety, and side effect profiles of levetiracetam (LEV) against the standard agent phenytoin (PHT) when given intravenously and in total regimen for seizure prophylaxis in a neurosurgical setting.

Global Expression Profiling in Epileptogenesis: Does It Add to the Confusion?

Since the inception of global gene expression profiling platforms in the mid‐1990s, there has been a significant increase in publications of differentially expressed genes in the process of epileptogenesis. In particular for mesial temporal lobe epilepsy, the presence of a latency period between the first manifestation of seizures to chronic epilepsy provides the opportunity for therapeutic interventions at the molecular biology level. Using global expression profiling techniques, approximately 2000 genes have been published demonstrating differential expression in mesial temporal epilepsy. The majority of these changes, however, are specific to laboratory or experimental conditions with only 53 genes demonstrating changes in more than two publications. To this end, we review the current status of gene expression profiling in epileptogenesis and suggest standard guidelines to be followed for greater accuracy and reproducibility of results.

Trauma as a precipitant of haemorrhage in synovial cysts.

Synovial cysts have been well reported as a cause of sciatica, with a sudden acute exacerbation being attributed to haemorrhage and subsequent enlargement of the cyst. Cyst formation is attributed to facet joint degeneration associated with a defect or rupture of the joint capsule. The mechanisms of haemorrhage have not been well described previously. Two cases of haemorrhagic synovial cysts causing acute exacerbation of sciatica are described. Both cases were directly attributable to manipulation of degenerate spines. The MRI and histopathological findings are discussed and we propose a mechanism whereby excessive stress on a degenerate revascularized synovium leads to haemorrhage within synovial cysts.

Optic nerve penetration by a carotico–ophthalmic artery aneurysm

Fenestration of a cranial nerve by an internal carotid artery aneurysm is rarely identified at surgical repair of intracranial aneurysms. Classically this condition is associated with visual disturbance in either acuity, fields or diplopia. We describe a patient with optic nerve fenestration by a carotico-ophthalmic artery aneurysm and discuss its likely pathophysiology. It is important to consider this anatomical variation during microsurgical approaches to the pericarotid and perioptic cisterns to prevent inadvertent damage to the optic apparatus.

Cystic lesion of the ventriculus terminalis in an adult

We present a 40-year-old man with conus medullaris syndrome secondary to a cystic lesion of the ventriculus terminalis (CLVT) and review the relevant literature. The patient presented with 4 years of worsening right leg weakness, and examination showed bilateral fasciculations and hyporeflexia. MRI showed a cystic lesion at T11-12. He was managed with a T11-12 laminectomy and fenestration of an intramedullary cyst. A total of 32 patients, including ours, have been described since 1968: 24 were female with a mean age of 46.6 years. All patients presented symptomatically: five were managed conservatively, four using percutaneous aspiration under MRI guidance, and 22 with open surgery. We conclude that symptomatic patients are best managed surgically, although percutaneous aspiration is an emerging technique.

Progression of choroid plexus papilloma.

Choroid plexus papillomas are rare neoplasms that arise from choroid plexus epithelium. The World Health Organization classification describes three histological grades. Grade I is choroid plexus papilloma, grade II is atypical choroid plexus papilloma and grade III is choroid plexus carcinoma. Progression between grades is rare but documented. We present two adult cases, a 53-year-old female and a 70-year-old male, who demonstrated clear interval histological progression from grade I choroid plexus papilloma to higher grades.

Anaplastic pilocytic astrocytoma

This clinical series examines the presentation of three adult patients who were found to have de novo anaplastic pilocytic astrocytoma. Initial imaging demonstrated an intracranial mass with histological analysis diagnostic of pilocytic astrocytoma with anaplastic features including necrosis, marked nuclear pleomorphism and a very high mitotic rate leading to the diagnosis of anaplastic pilocytic astrocytoma. We discuss the clinical pitfalls, treatment and implications when managing this condition.

Anterior visual pathway cavernous malformations

Anterior visual pathway cavernous malformations (CM) are rare diagnoses with poorly-defined natural history and management. A systematic review of all reports of anterior visual pathway CM was performed to identify all English-language articles with histopathologically-proven anterior visual pathway CM published from 1950 to December 2013. Patient demographics, presenting symptoms, CM location, treatment modality and clinical outcome were recorded and analyzed. The case of a 60-year-old woman from our institution with acute-on-chronic visual disturbance secondary to visual pathway CM is presented. Including the current patient, 70 cases of anterior visual pathway CM have been published to our knowledge. The average patient age is 34.8 ± standard deviation of 14.2 years, with a female preponderance (n = 37, 52.9%). The majority of patients had an acute (n = 44; 62.9%; 95% confidence interval [CI] 0.51-0.73) onset of symptoms. In at least 55.6% (n = 40) of patients, the cause of visual disturbance was initially misdiagnosed. The majority (91.4%; n = 64) of patients underwent craniotomy, with complete resection and subtotal resection achieved in 53.1% (n = 34; 95%CI 0.41-0.65) and 17.2% (n = 11; 95%CI 0.10-0.28) of all surgical patients, respectively. Comparing surgically managed patients, complete resection improved visual deficits in 59.0% (n = 20; 95%CI 0.42-0.75), while subtotal resection improved visual deficits in 50.0% (n = 5; 95%CI 0.24-0.76; p = 0.62). CM is an important differential diagnosis for suprasellar lesions presenting with visual disturbance. A high index of suspicion is required in its diagnosis. Expeditious operative management is recommended to improve clinical outcomes.

Brainstem distortion from postoperative cerebellar herniation through a dural and bony defect

We report a patient with a cerebellar encephalocele following excision of a cerebellar metastasis. This is a life-threatening condition that may be prevented with adequate dural and bony closure.

Glimpse into Pathophysiology of Sellar Arachnoid Cysts

BACKGROUNDnSellar arachnoid cysts are a rare occurrence but may impinge on vital parasellar anatomy and thus are often symptomatic. The etiology of sellar arachnoid cysts is contentious, fueled by heterogeneity in cyst wall structure and contents between cases. The ball-valve mechanism is 1 of 2 predominant theories describing their formation, which contends that an aperture in the diaphragm allows cerebrospinal fluid to enter the cyst, propelled by pulsatile flow, but its egress is obscured by the pituitary during the ebb of the pressure wave.nnnCASE DESCRIPTIONnHere we present a case of a 51-year-old female with a symptomatic sellar arachnoid cyst. She underwent an endoscopic transsphenoidal fenestration which alleviated her symptoms.nnnCONCLUSIONSnIntraoperative video evidence during arachnoid cyst fenestration supports the ball-valve theory of sellar arachnoid cyst development.