Andrew J. Durnford

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 childs 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.

Patient-reported nasal morbidity following endoscopic endonasal skull base surgery

Abstract 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.

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.

Transsylvian selective amygdalohippocampectomy in children with hippocampal sclerosis: Seizure, intellectual and memory outcome

PURPOSE This study investigates the efficacy of transylvian selective amygdalohippocampectomy (TS SAH) in children with medically intractable epilepsy due to unilateral hippocampal sclerosis. Post-surgical seizure control, intellectual and memory outcomes are examined. METHOD This study reports on pre- and post-surgical clinical data from 10 patients who underwent TS SAH between 2002 and 2010 after 24 months follow-up. Pre- and post-operative change in seizure frequency, AED use, intellect and memory are compared. RESULTS At 12 months and 24 months post-surgery, 9/10 (90%) and 7/8 (87.5%) patients respectively, were seizure free (Engel I). No patients were classed as Engel III or IV. No significant improvement or decline at a group level was found on measures of intellect or verbal or visual memory. One hundred per cent improved or remained within 1 SD of their pre-operatives score on verbal and perceptual reasoning learning and reasoning measures. Significant improvement was found post-operatively for both immediate and delayed facial memory. CONCLUSION Our findings of good post-surgical seizure control and favourable cognitive outcome provides evidence against previous findings that SAH in children may not be effective.

Spontaneous regression of a cystic hypoglossal schwannoma causing unilateral tongue atrophy

Abstract 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.

Posterior reversible encephalopathy syndrome mimicking a cerebral tumour.

Posterior reversible encephalopathy syndrome (PRES) is a syndrome characterised clinically by headache, confusion, seizures, vomiting and visual disturbances with radiographic vasogenic oedema. CT imaging is typically normal, non-specific or suggestive of PRES or stroke. MRI usually shows symmetrical parietal and occipital lobe vasogenic oedema. The authors discuss a 58-year-old man presenting with right homonymous haemianopia, hypertension and ataxia. CT imaging suggested a left occipital lobe space occupying lesion (SOL). Surprisingly, subsequent contrast enhanced MRI showed characteristic bilateral vasogenic oedema in occipital and temporal lobes indicative of PRES. Hypertension, an associated predisposing factor, was present in this case and symptoms improved with antihypertensive therapy. This case highlights PRES may present with asymmetrical CT imaging findings mimicking a SOL. PRES is a potentially reversible condition with prompt treatment. MRI is essential in diagnosing both PRES and the cause of acute visual loss.

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.