Joseph Frantzias’s research while affiliated with Stanford Medicine and other places

Idiopathic spinal cord herniation presenting with low-pressure headache is extremely rare. We present a case of thoracic ventral spinal cord herniation in a 35-year-old lady who presented with low-pressure headaches. To our knowledge, this is only the fourth case described in the literature of spontaneous ventral cord herniation presenting in this way. The patient was managed conservatively with no manifestation of focal neurological symptoms at 12-month follow-up. The proposed aetiology of spontaneous ventral cord herniation is an initial CSF leak via a dural defect, through which the cord subsequently also enters blocking the CSF leak. We endorse a conservative approach for patients who present similarly, secondary to the above pathophysiology.

Hemangiopericytoma (HPC) of the trigeminal nerve is extremely rare. We present a case of a large cystic HPC of the mandibular division of the trigeminal nerve, only the third case described in the literature, with both intradural and extradural components. We describe the surgical approach, assisted by neurophysiological techniques of mapping and monitoring including blink ref lex and triggered electromyography. Additionally, we report a method of monitoring of the sensory branches of the trigeminal nerve, poorly described in the literature, through peripheral and direct nerve stimulation and recording of transcranial somatosensory evoked potentials.

Objective We describe the chronological trends in cerebral revascularization surgery through a single-surgeon experience; and we review whether in the context of giant and fusiform cerebral aneurysms, flow-diverting stents have impacted on the use of cerebral revascularization surgery. Methods We review our single institution prospectively collected database of cerebral revascularization procedures between 2006 and 2018. Comparing this to our database of flow-diverting endovascular stent procedures, we compare the treatment of fusiform and giant aneurysms. We describe patient demographics, procedural incidence, complications, and outcomes. Results Between 2006 and 2018, 50 cerebral revascularization procedures were performed. The incidence of cerebral revascularization surgery is declining. In the context of giant/fusiform aneurysm treatment, the decline in cerebral revascularization is accompanied by a rise in the use of flow-diverting endovascular stents. Thirty cerebral revascularizations were performed for moyamoya disease and 11 for giant/fusiform aneurysm. Four (14%) direct bypass grafts occluded without neurological sequela. Other morbidity included hydrocephalus (2%), transient ischemic attacks (2%), and ischemic stroke (2%). There was one procedure-related mortality (2%). Flow-diverting stents were inserted for seven fusiform and seven giant aneurysms. Comparing the treatment of giant/fusiform aneurysms, there was no significant difference in morbidity and mortality between cerebral revascularization and flow-diverting endovascular stents. Conclusion We conclude that with the decline in the incidence of cerebral revascularization surgery, there is a need for centralization of services to allow high standards and outcomes to be maintained.

Background There is limited evidence to direct the management of unruptured intracranial aneurysms. Models extrapolated from existing data have been proposed to guide treatment recommendations. The aim of this study is to assess whether a consensus-based treatment score (UIATS) or rupture rate estimation model (PHASES) can be used to benchmark UK multi-disciplinary team (MDT) practice. Methods Prospective data was collected on a consecutive series of all patients with unruptured intracranial aneurysms (UIAs) presenting to a major UK neurovascular centre between 2012 and 2015. The agreement between the UIATS and PHASES scores, and their sensitivity and specificity in predicting the real-world MDT outcome were calculated and compared. Results A total of 366 patients (456 aneurysms) were included in the analysis. The agreement between UIATS and MDT recommendation was low (weighted kappa 0.26 [95% CI 0.19, 0.32]); sensitivity and specificity were also low at 36% and 52% respectively. Groups that the MDT allocated to treatment, equipoise or no treatment had significantly different PHASES scores (p = 0.004). There was no significant difference between the two scores when predicting patients for whom MDT outcome was to recommend aneurysm treatment, but the UIATS score was superior in predicting patients who received an MDT recommendation of ‘treatment-equipoise’, or ‘not-for-treatment’ (AUC of 0.73 compared to 0.59 for PHASES). Conclusions The models studied failed to agree with the consensus view of multi-disciplinary team in a major neurovascular centre. We conclude that decision support tools such as the UIATS and PHASES scores should not be blindly introduced in respective institutions without prior internal validation, as they may not represent the local reality.

Introduction Isolated acute bilateral foot drop due to degenerative spine disease is an extremely rare neurosurgical presentation, whilst the literature is rich with accounts of chronic bilateral foot drop occurring as a sequela of systemic illnesses. We present, to our knowledge, the largest case series of acute bilateral foot drop, with trauma and relevant systemic illness excluded. Methods Data from three different centres had been collected at the time of historic treatment, and records were subsequently reviewed retrospectively, documenting the clinical presentation, radiological level of compression, timing of surgery, and degree of neurological recovery. Results Seven patients are presented. The mean age at presentation was 52.1 years (range 41–66). All patients but one were male. All had a painful radiculopathic presentation. Relevant discopathy was observed from L2/3 to L5/S1, the commonest level being L3/4. Five were treated within 24 h of presentation, and two within 48 h. Three had concomitant cauda equina syndrome; of these, the first two made a full motor recovery, one by 6 weeks follow-up and the second on the same-day post-op evaluation. Overall, five out of seven cases had full resolution of their ankle dorsiflexion pareses. One patient with 1/5 power has not improved. Another with 1/5 weakness improved to normal on the one side and to 3/5 on the other. Conclusion When bilateral foot drop occurs acutely, we encourage the consideration of degenerative spinal disease. Relevant discopathy was observed from L2/3 to L5/S1; aberrant innervation may be at play. Cauda equina syndrome is not necessarily associated with acute bilateral foot drop. The prognosis seems to be pretty good with respect to recovery of the foot drop, especially if partial at presentation and if treated within 48 h.

Objectives Haemangiopericytoma of the trigemimal nerve is extremely rare, with only two previous cases described to our knowledge. We present the surgical approach to this tumour, and describe a previously poorly reported method of monitoring the function of the branches of the trigeminal nerve: mapping of the sensory roots through transcranial somatosensory cortex sensory evoked potentials (SSEPs), motor evoked potentials (MEP) for the motor root and blink reflex. Design Case and technical reports Subjects 32 year-old male patient presenting with headaches and vomiting, found to have a mixed cystic-solid tumour of the left middle skull base region, in close relation with the foramen ovale and Meckel’s cave. Methods The radiological features of the tumour, technical aspects of the technical approach and neurophysiologic monitoring will be described. Results A pterional craniotomy with fronto-temporal extradural-interdural-intradural approach, and the tumour was debulked with MEP, SSEP and blink reflex monitoring of the branches of the trigeminal nerve. Complete tumour removal was achieved with no post-operative cranial nerve deficits. The histopathology revealed a cystic haemangiopericytoma. Conclusions Haemangiopericytoma is a rare entity. MEP and SSEP monitoring of the trigeminal nerve can be used to achieve complete and safe removal of the tumour.

Background Supratentorial Metastatic Melanomas are common and increasingly treated with immunotherapy. While improving the outcome, the immunotherapy potentially increases the risks of the intracranial surgical procedures, particularly bleeding. However, scarce reports address this complications. Case Description A 52-year old male with a history of right upper limb excised skin lesion resected with wide local excision 6 months prior to admission, who presented with a three weeks history of progressive headaches, vomiting, odd behaviours, forgetfulness, and left lower sided weakness. Brain imaging showed a right frontal lesion with evidence of haemorrhage within it with midline shift and mass effect. He underwent craniotomy and resection of the lesion with no post-operative complication, resolution of left sided hemiparesis and post-operative imaging documenting complete resection and no post-operative complications. The histopathology confirmed metastatic melanoma and he received adjuvant immunotherapy (Nivolumab), however he represented 4 weeks post operatively with sudden onset headache with vomiting with no neurological deficit, brain imaging showed a delayed hematoma in the surgical site. Conclusions This case report highlights the risk of post-operative bleeding with the immunotherapy and paves the way for further studies with regards to the safety of immunotherapy after intracranial procedures

We present the surgical approach to this tumour, the commonly used blink reflex test and the identification of the motor branch of the trigeminal nerve and describe a previously poorly reported method of monitoring the function of the branches of the trigeminal nerve: mapping of the sensory roots through transcranial somatosensory cortex sensory evoked potentials (tcSSEPs).

Introduction Arachnoid cysts (ACs) account for a small proportion of all intracranial lesions. They are often incidental but can become symptomatic and even cause a threat to life. Symptoms are usually due to direct compression of neural elements and/or raised intracranial pressure. Case report We report the case of an infant with an enlarging posterior fossa arachnoid cyst (PFAC) causing torticollis and gastro-oesophageal reflux (GOR), the combination of which had been previously unreported in this context. Endoscopic fenestration and cyst decompression were followed by complete resolution of the symptoms. We discuss the possible mechanisms of torticollis and GOR in this context.