Risk of Early Versus Later Rebleeding From Dural Arteriovenous Fistulas With Cortical Venous Drainage.

BACKGROUND: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. METHODS: Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. RESULTS: Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2-14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3-5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7-12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4-37.7; P, 0.026). CONCLUSIONS: The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.

Internal neurolysis: 'nerve combing' for trigeminal neuralgia without neurovascular conflict - early UK outcomes.

INTRODUCTION: Internal neurolysis (INL) is a surgical procedure where trigeminal nerve fibres are separated between the pons and porus trigeminus to relieve trigeminal neuralgia (TN). We report pain and functional outcomes to evaluate its safety and efficacy. MATERIALS AND METHODS: Prospective cohort of all patients undergoing retrosigmoid craniotomy and INL between 2015 and 2017 at University Hospital Southampton. Patients with type I (6) or type II (2) refractory TN and no clear neurovascular conflict were offered INL as an alternative to partial sensory rhizotomy. Barrow Pain Intensity Scale (BNI) and Brief Pain Inventory Facial scores (BPI-Facial) were assessed. Minimum follow-up was 2 years'. RESULTS: Eight patients (7F:1M) underwent INL. Two had MS. Pre-operatively, all had severe pain (BNI grade V) and the median BPI-Facial score was 115 (range 79-123).. There were no unexpected complications. On last follow-up, six (75%) had no pain (BNI grade I), while two (25%) had recurred (at 5 and 27 months). Median BPI-Facial score for all patients on the last follow-up was 20 (range 18-91) reflecting dramatically improved quality of life and activities. CONCLUSIONS: INL is a potentially safe and effective treatment for refractory TN. Long-term efficacy is unknown, but early results are promising.

Idiopathic Intracranial Hypertension: Shunt Failure and the Role of Obesity.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a chronic condition characterized by raised intracranial pressure in the absence of a known etiology. IIH typically presents in overweight women of childbearing age. Surgical intervention for IIH involves diversion of cerebrospinal fluid, often by the placement of a shunt. Experience suggests higher shunt failure rates in patients with IIH than shunts placed for other etiologies. Here we sought to both establish and compare failure rates for IIH and non-IIH shunts and to examine association with body mass index (BMI). METHODS: This study was a single-center retrospective consecutive cohort over a 13-year period. There were 1264 non-IIH patients and 116 patients with IIH included in the study. This was a retrospective analysis of time to shunt failure using Kaplan-Meier methods for IIH and non-IIH shunts. Secondary analysis of BMI, shunt type, and sex on IIH shunt failure was also conducted. RESULTS: The median time to failure of the initial IIH shunt was 22.9 months (interquartile range [IQR], 4-55) compared with 57 months (IQR, 12-87) in non-IIH shunts (P < 0.001; 95% confidence interval, 58.6-233.6). In the IIH group, the median shunt survival for BMI above the healthy range (18.5-25 kg/m2) was 18 months relative to 44 months for those with a healthy BMI. CONCLUSIONS: Our study suggests that in IIH, relative to hydrocephalus of other causes, shunts have higher failure rates and often require more frequent revisions. Higher shunt failure rates in patients with IIH may be associated with an unhealthy BMI.

An Evaluation of Commonly Used External Ventricular Drain Securement Methods in a Porcine Model: Recommendations to Improve Practice.

BACKGROUND: External ventricular drain (EVD) dislodgement is common and leads to significant morbidity and mortality. Many securement techniques to prevent this are described. There are, however, no objective studies comparing them. This study aimed to determine the most secure method of securing an EVD. METHODS: A survey was distributed through the British Neurosurgical Trainee Research Collaborative to determine common EVD securement methods and select techniques for testing. Securement methods were tested in a pig cadaver model. Peak pull force before EVD failure was measured. Failure was defined as catheter displacement 1 cm from the insertion site, catheter fracture, or suture fracture. RESULTS: Twenty-three neurosurgical units responded. Five basic EVD securement methods were in common use. These were tested in isolation and in combination so that in total 15 common methods were tested. The most secure method was a triple construct, consisting of an anchoring suture, sutures around a coil of the catheter, and either a soft plastic flange (25.85 N, 95% confidence interval 24.95 N-26.75 N) or a hard plastic flange (29.05 N, 95% confidence interval 25.69 N-32.41 N). Of the individual methods, single anchoring sutures, soft flanges, VentriFix, and staples were found to be the least secure, whereas multiple sutures and hard flanges were the most secure. CONCLUSIONS: An anchoring suture followed by a coil of the catheter and finally a flange is the most secure method for securing EVDs. This simple technique can withstand up to 8.2 times the force of a single anchoring suture, is easily used, and decreases the likelihood of EVD dislodgement and associated complications.

Degree and Duration of Functional Improvement on Long-Term Follow-Up of Spinal Dural Arteriovenous Fistulae Occluded by Endovascular and Surgical Treatment.

BACKGROUND: Long-term outcomes following occlusion of spinal dural arteriovenous fistula (SDAVF) are poorly understood and are based on small series reporting predominantly short-term outcomes. The degree and duration of improvement remain unclear. In this study, we analyzed long-term outcomes following occlusion in a cohort of patients with SDAVF. METHODS: This was a single-center cohort study of patients with SDAVF identified from a prospective database. Outcomes were assessed using a modified Aminoff and Logue Disability (ALD) Scale, the modified Rankin Scale (mRS), and patient-reported outcomes at presentation and long-term follow-up. Both angiographic recanalization and idiopathic functional recurrence rates were calculated. RESULTS: Of the total of 67 patients with SAVDF identified, 59 were eligible for inclusion in this study. Fifty-seven of these 59 (97%) underwent occlusion. Twenty-two patients underwent initial embolization; 12 were occluded. Two patients recanalized. Eleven patients underwent surgery after attempted embolization; 10 were occluded. Thirty-seven patients treated by surgery only were occluded. The median duration of follow-up was 63 months (range, 12-240 months). After occlusion, the ALD gait and urinary scores improved by a median of 1 point. Although the median mRS score was unchanged, 49% of the patients experienced improvement, most by 1 point. There was no difference between the patients occluded by embolization or surgery, but those requiring both approaches had worse gait and urinary scores (P = 0.005 and 0.03, respectively). The duration of symptoms by itself had no effect on outcomes (P = 0.61). Following occlusion, 5 patients experienced an idiopathic late functional deterioration. Of 16 patients presenting with paraplegia, 13 (81%) improved, with a median mRS improvement of 1 point. CONCLUSIONS: Following occlusion, patients with SDAVF experienced a modest improvement in symptoms, most commonly by 1 point on the ALD scale. Idiopathic late deterioration was seen in 9.1% of patients.

Heme-Hemopexin Scavenging Is Active in the Brain and Associates With Outcome After Subarachnoid Hemorrhage.

BACKGROUND AND PURPOSE: Long-term outcome after subarachnoid hemorrhage (SAH) is potentially linked to cytotoxic heme. Free heme is bound by hemopexin and rapidly scavenged by CD91. We hypothesized that heme scavenging in the brain would be associated with outcome after hemorrhage. METHODS: Using cerebrospinal fluid and tissue from patients with SAH and control individuals, the activity of the intracranial CD91-hemopexin system was examined using ELISA, ultrahigh performance liquid chromatography, and immunohistochemistry. RESULTS: In control individuals, cerebrospinal fluid hemopexin was mainly synthesized intrathecally. After SAH, cerebrospinal fluid hemopexin was high in one third of cases, and these patients had a higher probability of delayed cerebral ischemia and poorer neurological outcome. The intracranial CD91-hemopexin system was active after SAH because CD91 positively correlated with iron deposition in brain tissue. Heme-hemopexin uptake saturated rapidly after SAH because bound heme accumulated early in the cerebrospinal fluid. When the blood-brain barrier was compromised after SAH, serum hemopexin level was lower, suggesting heme transfer to the circulation for peripheral CD91 scavenging. CONCLUSIONS: The CD91-heme-hemopexin scavenging system is important after SAH and merits further study as a potential prognostic marker and therapeutic target.

Patient-reported nasal morbidity following endoscopic endonasal skull base surgery.

OBJECTIVE: To quantify the frequency and severity of nasal morbidity following endoscopic endonasal skull base surgery using patient-reported outcome measures. METHODS: Retrospective review and follow-up of all patients who underwent endoscopic endonasal skull base surgery at University Hospital Southampton between January 2007 and December 2011. Demographic data were collated from case notes and patients were asked a standardised questionnaire by telephone interview. Statistical sub-analysis of pituitary and other anterior skull base pathology groups was performed using SPSS 1.8. RESULTS: Out of 151 included patients, 85 had a pituitary pathology and the remaining had other anterior skull base pathologies. The mean age was 55.2 years, with 75 male and 76 female patients. Totally 124 patients were interviewed with a median follow-up of 15 months. Mild or no nasal crusting was reported by 77% of patients. In those experiencing crusting, more than 50% resolved within 4 weeks. The majority of patients reported no nasal blockage (52%), pain (83%) or nasal discharge (57%) post-operatively. Totally 71% reported no change in sense of smell post-operatively. The only statistically significant difference between the two pathology groups was that surgery on other anterior skull base pathology was associated with an increased rate of developing anosmia (p = 0.02). CONCLUSION: Endoscopic endonasal skull base surgery is associated with a low level of patient-reported post-operative nasal morbidity. There is no significant difference in frequency of crusting, blockage, pain or discharge between pituitary and other anterior skull base pathology groups. However, anterior skull base surgery would appear to be associated with an increased rate of anosmia post-operatively.

Spontaneous regression of a cystic hypoglossal schwannoma causing unilateral tongue atrophy.

A 60-year-old lady presented with intermittent headaches. Examination revealed striking marked unilateral tongue atrophy. Magnetic resonance imaging (MRI) revealed a cystic lesion in the hypoglossal canal and a provisional diagnosis of cystic hypoglossal schwannoma made. Annual surveillance scans showed stable appearances but surprisingly at 3 years they showed a significant reduction in the size of the lesion. Most patients with hypoglossal schwannomas present with ipsilateral hypoglossal nerve palsy; careful cranial nerve examination is vital in diagnosing such rare lesions. Little is known of their natural history, with most lesions undergoing surgery. This case highlights spontaneous regression following non-operative management.

Delayed extradural haemorrhage: a case for intracranial pressure monitoring in sedated children with traumatic brain injury within tertiary centres.

A 15-year-old girl sustained a mild isolated traumatic brain injury  following a pedestrian road traffic accident. She was ventilated for head computed tomography (CT) scan which revealed no intracranial abnormalities. Ventilation was not withdrawn until 15 h later when poor neurological recovery prompted urgent repeat CT, which demonstrated a delayed extradural haemorrhage (EDH). She underwent surgical evacuation, and intracranial pressure (ICP) monitoring was initiated postoperatively. She developed persistently raised ICP resistant to medical therapy, prompting further CT. This showed a recurrence of the delayed EDH requiring further surgical drainage. She made a good neurological recovery. There should be a low threshold for repeat CT to exclude delayed EDH when neurological status is poor despite normal CT soon after initial primary injury. ICP monitoring should be undertaken in children and adolescents who have normal initial CT, but in whom serial neurological assessment is not possible owing to sedation.

Lower thoracic spinal cord injury without radiographic abnormality in an amateur rugby player.

A 37-year-old man, amateur rugby player sustained a hyperextension injury to his lower thoracic spine during a scrum collapse. The patient developed extreme hyperpathia in the T10-12 dermatome, and parasthesia from T12 to S1 in the left lower limb. Medical Research Council grade 5 power was regained rapidly within minutes of the accident, and the hyperpathia resolved within a week. MRI showed contusion of the spinal cord at T10 level but no associated osseoligamentous injury. Six months later, parasthesia and subjective weakness remained in the left lower limb. To our knowledge, this is the first description of a lower thoracic spinal cord injury without radiographic abnormality following an isolated low-energy injury in a skeletally mature patient.

Interrater reliability of Engel, International League Against Epilepsy, and McHugh seizure outcome classifications following vagus nerve stimulator implantation.

OBJECT: Interrater reliability as measured by the kappa (κ) statistic is a widely used and valuable tool to measure the robustness of a scoring system. Seizure frequency reduction is a central outcome measure following vagus nerve stimulation (VNS). A specific VNS scoring system has been proposed by McHugh, but its interrater reliability has not been tested. The authors assessed its interrater reliability and compared it with that of the Engel and International League Against Epilepsy (ILAE) systems. METHODS: Using the Engel, ILAE, and McHugh scoring systems, 3 observers independently rated the medical records of children who had undergone vagus nerve stimulator implantation between January 2001 and April 2011 at the Southampton University Hospital. The interrater agreements were then calculated using the κ statistic. RESULTS: Interrater reliability for the McHugh scale (κ0.693) was very good and was superior to those of the Engel (κ0.464) and ILAE (κ0.491) systems for assessing outcome in patients undergoing VNS. CONCLUSIONS: The authors recommend considering the McHugh scoring system when assessing outcomes following VNS.

Endoscopic third ventriculostomy in the treatment of childhood hydrocephalus: validation of a success score that predicts long-term outcome.

OBJECT: The goal of this study was to externally validate the proposed Endoscopic Third Ventriculostomy Success Score (ETVSS), which predicts successful treatment for hydrocephalus on the basis of a child's individual characteristics. METHODS: The authors retrospectively identified 181 cases of consecutive endoscopic third ventriculostomy (ETV) performed in children at a single neurosurgery center in the United Kingdom. They compared actual success at both 6 and 36 months, with mean predicted probabilities for low, moderate, and high chance of success strata based on the ETVSS. Long-term success was calculated using Kaplan-Meier methods and comparisons were made by means of unpaired t-tests. RESULTS: Overall, 166 primary ETVs were performed; ETV success was 72.9% at 6 and 64.5% at 36 months. At long-term follow-up, the mean predicted probability of success was significantly higher in those with a successful ETV (99 patients) than in those with a failed ETV (67 patients) (p = 0.001). The ETVSS accurately predicted outcome at 36 months; the low, medium, and high chance of success strata had mean predicted probabilities of success of 82%, 63%, and 36%, and actual success of 76%, 66%, and 42%, respectively. The overall complication rate was 6%. CONCLUSIONS: The ETVSS closely predicted the overall long-term success rates in high-, moderate-, and low-risk groups. The results of this study suggest that the ETVSS will aid clinical decision making in predicting outcome of ETV.

Very good inter-rater reliability of Engel and ILAE epilepsy surgery outcome classifications in a series of 76 patients.

The inter-rater reliability, expressed as kappa score, k, of the Engel and International League Against Epilepsy (ILAE) classifications of epilepsy surgery seizure outcome has not previously been evaluated. In a consecutive series of 76 patients (40 male; 25 children), 75 undergoing resective and 1 disconnective surgery at a mean age of 27.5 years (13 months-62 years), one observer classified 88% (n=67) and a second observer classified 87% (n=66) of patients as either Engel I or II (free from or rare disabling seizures) after a median follow up of 36 months (range 12-92 months); comparably, both observers classified 84% (n=64) as ILAE 1-3. Correlation for Engel versus ILAE for observer 1 was 0.933 (p<.0005) and for observer 2 was 0.931 (p<.0005). Both ILAE (k 0.81, 95% confidence intervals 0.69, 0.91) and Engel (k 0.77, 95% CI 0.65, 0.87) classifications have very acceptable inter-rater reliability as well as significant correlation.

Spontaneous regression of a terminal myelocystocele and associated syringomyelia: a case report.

INTRODUCTION: Terminal myelocystocele is a rare form of spinal dysraphism characterised by cystic dilatation of the central canal of a low-lying terminal cord. Typical presentation is a skin-covered dorsal mass; early surgical repair has been recommended. CASE REPORT: We present the case of a 4-year-old girl with a terminal myelocystocele and syrinx, which were both observed to spontaneously regress on subsequent magnetic resonance imaging. CONCLUSION: Terminal myelocystocele and its associated syrinx may resolve spontaneously. Early surgical repair may not always be necessary.