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.

Comparison of first-time microvascular decompression with percutaneous surgery for trigeminal neuralgia: long-term outcomes and prognostic factors.

OBJECTIVE: Common surgical treatments for trigeminal neuralgia (TN) include microvascular decompression (MVD) and percutaneous procedures (glycerol rhizolysis; thermocoagulation; and balloon compression). Although the efficacy of each procedure has been documented, direct comparisons of their relative efficacies for TN are lacking. We aimed to directly compare long-term outcomes after first-time MVD with percutaneous surgery in primary (idiopathic and classical) TN and identify predictors of outcome. METHODS: We conducted a retrospective analysis of prospectively collected data on 185 patients undergoing MVD and 129 undergoing percutaneous surgery. Procedures were performed by one of two neurosurgeons in a single centre; an independent observer collected long-term follow-up data by interviews, using the same outcome measures for all procedures. RESULTS: MVD patients were younger than those undergoing percutaneous surgery (P <.001). MVD provided superior initial pain relief (P <.001): 87.0% had Barrow Neurological Institute class I or II pain scores after MVD compared with 67.2% after percutaneous surgery. The complication rate for percutaneous procedures was 35.7% and for MVDs was 24.9% (P =.04), including minor and transient complications. Kaplan-Meier analysis demonstrated that MVD provided longer pain relief than percutaneous procedures (P <.001); 25% of patients had recurrence at 96 months following MVD compared with 12 months after percutaneous surgery. Subgroup analysis showed that balloon compression provided more durable relief amongst percutaneous procedures. Multivariate analysis revealed that post-operative numbness and age were prognostic factors for percutaneous procedures (P =.03 and .01, respectively). CONCLUSIONS: MVD provides better initial pain relief and longer durability of relief than percutaneous surgery, although carrying a small risk of major complications. Amongst percutaneous procedures, balloon compression gave the most durable relief from pain. Older age and post-operative numbness were predictors of good outcome from percutaneous surgery. These results can help clinicians to counsel patients with primary TN on neurosurgical treatment selection for pain relief.

Ruptured intra-cranial arachnoid cysts: a case series from a single UK institution.

INTRODUCTION: Intracranial arachnoid cysts are a common incidental finding; however presentation with cyst rupture is a recognised complication. Patients are advised to avoid contact sports to reduce the risk of cyst rupture but the risk of rupture is not currently known. The aim of this study is to describe a single institution's experience of managing ruptured intra-cranial arachnoid cysts. METHOD: A retrospective case note review of all patients admitted to a single institution with a ruptured intra-cranial arachnoid cyst between 2005 and 2016 (inclusive). Medical records were reviewed for demographics, history of trauma, surgical treatment and radiological evidence of cyst rupture. RESULTS: Fourteen patients were identified for inclusion with an average age of 23.4 years (range 7-57) and 10 (71%) were male. Nine patients (64%) had a documented history of head trauma. Eleven patients (78.6%) required neurosurgical intervention which included hygroma/haematoma evacuation only (n = 5), haematoma evacuation with cyst fenestration (n = 4) and cyst fenestration/shunting only (n = 2). Twelve patients (85%) experienced full recovery and the remaining two had persisting headaches or neurological symptoms. DISCUSSION: Cyst rupture remains an uncommon cause for presentation with arachnoid cysts. However the majority are associated with head trauma and thus current advice to avoid contact sports seems justified.

Intracranial Masson Lesion Following Stereotactic Radiosurgery for Treatment of Intracranial Arteriovenous Malformations.

OBJECTIVES: Masson tumor or intravascular papillary endothelial cell proliferation was first described in 1923. Only a few cases of intracranial Masson tumor have been reported following stereotactic radiosurgery (SRS). We report a series of 6 cases, age range 28-56 years, with intracranial Masson tumor following SRS for treatment of an intracranial arteriovenous malformation (AVM). METHODS: We performed a retrospective case note review, reviewed the imaging, SRS records, and neuropathology specimens following surgical excision. RESULTS: In our series all patients received Leksell SRS with the periphery of the AVM receiving doses ranging from 22-25 Gy. The time lapse from SRS to a clear enhancing mass appearing on imaging ranged from 5-10 years. Four patients underwent craniotomy and excision of the enhancing lesion for persistent edema and an enlarging cyst resulting in a resolution of symptoms. CONCLUSIONS: SRS is an effective treatment for obliteration of intracranial AVMs.

Prenatal diagnosis of arachnoid cysts: a case series and systematic review.

INTRODUCTION: Primary cysts are believed to arise from the splitting of the arachnoid membrane during prenatal development and can be diagnosed in utero. Prenatal diagnosis is uncommon; therefore, the evidence base for counselling expectant mothers is limited. The purpose of this article is to present a case series and review the current literature on prenatally diagnosed arachnoid cysts. METHOD: A keyword search of hospital electronic records was performed for all patients with a prenatally diagnosed arachnoid cyst at a tertiary neurosurgical centre. Case notes were reviewed for all patients diagnosed between 2005 and 2017. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to structure a systematic review of all English language articles published up to May 2018. RESULTS: A total of eight eligible patients were identified from our own records and 123 from the literature. Sixty-eight per cent of patients had a normal outcome. Sixty-three per cent of patients underwent surgical intervention which was not associated with abnormal outcome. The diagnosis of syndromic/genetic diagnosis (p < 0.001) and the presence of other intra-cranial anatomical abnormalities (p = 0.05) were significant predictors of abnormal outcome. CONCLUSION: The pathogenesis and prognosis of a prenatal arachnoid cyst diagnosis remain unclear. These results suggest favourable outcomes from simple cysts without associated abnormalities and expectant mothers should be counselled accordingly. A wider prospective review is required to better established evidence-based practice.

Paediatric brain abscesses: a single centre experience.

Introduction: Brain parenchymal abscesses are relatively infrequent but potentially serious infections in the paediatric population. Surgical intervention in addition to a prolonged administration of antibiotics is generally appropriate management. This study presents our centre's experience of managing such patients in the context of relevant literature. Method: A single-centre retrospective case note review was conducted over a 15 year period (2003-2017). Patients were selected from electronic hospital records using ICD10 code G06.0. Patients < 18 years of age with a confirmed intra-parenchymal abscess were included. Patient records were reviewed for abscess location, microbiology results, surgical intervention, and outcome using the Glasgow Outcome Score at 3 months. Results: Twenty-four patients were identified (mean age: 7.4 ± 5.3 years, male n = 11). Twelve (50.0%) patients had an abscess in the frontal lobe and Streptococcus was the most common causative microorganism (n = 15). Nineteen patients (79.2%) had an identifiable source which included: ENT infections, congenital cardiac malformations, recent dental surgery and meningitis. All 24 patients underwent surgery with 20 patients having a total of 32 aspirations between them and the other 4 having craniotomy and excision. Twenty patients had 3 month follow-up data of which 18 patients scored GOS: 5, one was GOS: 4 and one was GOS: 3. Conclusions: Brain parenchymal abscess remains an uncommon pathology in the paediatric population. The majority of patients have a preceding infection with Streptococcus as the most common causative organism. Antimicrobial therapy should be selected accordingly. All of our patients underwent surgical intervention and received intravenous antibiotics with favourable outcome and no mortality.

The Effectiveness of Percutaneous Balloon Compression, Thermocoagulation, and Glycerol Rhizolysis for Trigeminal Neuralgia in Multiple Sclerosis.

BACKGROUND: Balloon compression (BC), thermocoagulation (TC), and glycerol rhizolysis (GR) are percutaneous surgical options for trigeminal neuralgia (TN). Whether the outcomes of these procedures in multiple sclerosis -related TN (MS-TN) are as effective as in idiopathic TN (ITN) is unknown. OBJECTIVE: To retrospectively compare pain relief, complications, and durability achieved by these 3 types of procedures in MS-TN and ITN. METHODS: Two hundred and four patients with typical TN were treated percutaneously: 33 had MS-TN (64 procedures) and 171 had ITN (329 procedures). All were performed by 1 of 2 neurosurgeons; interviews enabled long-term data to be gathered by an independent observer. RESULTS: MS-TN patients (53.1%) had Barrow Neurological Institute pain scores of I or II after a percutaneous procedure, compared with 59.3% in the ITN cohort; there was no difference in initial relief between the 2 groups overall (P = .52). There was a trend toward fewer complications in MS-TN compared with ITN (23.4% vs 33.7%, respectively; P = .058). Kaplan-Meier analysis demonstrated no difference in durability of relief in MS-TN (median 23.0 mo) compared with ITN overall (median 24.0 mo; P = .75). Subgroup analysis demonstrated longer relief from BC and TC compared with GR in MS-TN (P = .013). Multivariate analysis confirmed that although the presence of MS does not predict durability of outcome, postoperative numbness (P = .0046) and undergoing a repeat procedure (P = .037) were significant predictors. CONCLUSION: BC and TC are safe and effective in MS-TN. Postoperative numbness is the strongest prognostic factor in MS-TN.

Natural History of Intracranial Arachnoid Cysts.

BACKGROUND: Intracranial arachnoid cysts are a common incidental finding. Most of these remain asymptomatic with surgical intervention being reserved for those cysts causing symptoms from mass effect or hydrocephalus. It is not properly understood why cysts enlarge nor is it possible to predict in which cysts this will occur. The aim of this study is to review the natural history of incidental arachnoid cysts. METHODS: A retrospective case review was conducted of all patients diagnosed with an arachnoid cyst between 2007 and 2016. Case notes and radiology reports were reviewed for demographics, symptoms, and changes in cyst sizes. RESULTS: Four hundred and eighty-five patients were diagnosed with an arachnoid cyst during this time period; of these, 425 (87.6%) were asymptomatic. Patients with symptomatic cysts were significantly younger and more likely to have associated hydrocephalus. The most common indications for imaging which resulted in the diagnosis of the cyst were headaches (n = 106), stroke (n = 51), and seizures (n = 41). The cyst size remained stable or reduced in 147 patients (99.3%) with follow-up imaging (n = 148), and the enlarging cyst remained asymptomatic. CONCLUSIONS: Asymptomatic arachnoid cysts have a low rate of cyst enlargement on follow-up imaging, which supports not routinely imaging these patients. However, serial imaging and surgery may still be indicated in asymptomatic patients at risk of obstructive hydrocephalus which, in this series, was only seen in the pediatric population. A better understanding of the natural history of intracranial arachnoid cysts allows for more efficient follow-up planning.

Clinical and radiological outcomes following surgical treatment for intra-cranial arachnoid cysts.

OBJECTIVES: Intra-cranial arachnoid cysts are benign lesions which are usually incidental, however can produce neurological symptoms due to mass effect as they enlarge. Controversy still exists regarding the optimal option for the surgical management of these cysts. These options are neuroendoscopic fenestrations, microsurgical fenestrations +/- marsupialisation and insertion of a cysto-peritoneal shunt. PATIENTS AND METHODS: A retrospective case note review of all patients with intra-cranial arachnoid cysts treated surgically at a single UK neurosurgical centre over a 15 year period. Data on clinical presentations and outcomes was collected from the patient notes and the pre- and post-operative cyst volumes were calculated by creating 3-dimensional volumetric models. RESULTS: Eighty-two patients were identified of which 45 were treated endoscopically, 34 microscopically and 3 underwent cysto-peritoneal shunting. The most common cyst location was the middle fossa (n = 25). Amongst the symptomatic patients, improvement or resolution of symptoms was seen in 35 out of 40 cysts treated endoscopically (88%), 28 out of 32 treated microsurgically (88%) and 3 out of 3 treated by shunting (100%, p = 0.79). The reoperation rate was not significantly different between the endoscopic and microsurgical groups (24.4% vs 14.7%, p = 0.49). The endoscopic and shunted groups had a shorter length of stay than the microsurgical group (3.0 vs 3.0 vs 4.5 days, p = 0.04). All three treatment modalities had a similar percentage reduction in cyst volume after surgery (30.0 vs 41.7 vs 30.9%, p = 0.98). CONCLUSIONS: This cohort series shows that endoscopic and microsurgical approaches to treat intracranial arachnoid cysts produce comparable clinical and radiological outcomes. Endoscopic fenestration is associated with a shorter length of stay as would be expected from a minimally invasive procedure.

Outcomes of Microsurgical Clipping of Recurrent Aneurysms After Endovascular Coiling.

BACKGROUND: The outcomes of microsurgery of previously coiled aneurysms have been poorly described, and little is known about the factors predictive of poor outcome. Here we aimed to identify predictors of poor outcome following microsurgery for previously coiled recurrent aneurysms. METHODS: In this retrospective cohort study of a prospectively maintained vascular database, we reviewed presentations, recurrent aneurysm measurements, surgery, and outcomes of microsurgical clipping of recurrent previously coiled intracranial aneurysms. RESULTS: Our series comprised 39 patients (mean age, 49 years; range, 22-70 years) who underwent microsurgical clipping of 40 previously coiled intracranial aneurysms. One patient suffered seizures, 1 patient experienced transient neurologic worsening, and 1 patient developed hyponatraemia, none of whom had long-term sequelae. Two patients sustained postoperative infarcts, for an overall incidence of permanent morbidity of 5.1%. There were no deaths or rebleeds on follow-up. In 3 patients, including the 2 patients with infarct and 1 patient with a transient deficit, an attempt was made to remove the coil ball. These patients had larger aneurysms (1106 mm3 vs. 135 mm3; P = 0.005), with larger coil balls (257 mm3 vs. 52 mm3; P = 0.01) and wider necks (7.09 mm vs. 2.69 mm; P = 0.02) but smaller remnant heights (1.59 mm vs. 1.99 mm; P = 0.04). They were also more likely to have prolapsing coil loops (3/3 vs. 3/27; P = 0.016). CONCLUSIONS: Our study demonstrates good clinical outcomes from microsurgical clipping of recurrent aneurysms. In the vast majority of cases, clips can be applied primarily. Coil ball removal is associated with increased morbidity, and thus should be considered only as a second-line option, with the likely need identified before the initiation of surgery.

The Resolution of Oculomotor Nerve Palsy Caused by Unruptured Posterior Communicating Artery Aneurysms: A Cohort Study and Narrative Review.

OBJECTIVE: Recovery of oculomotor nerve palsy after microsurgical and endovascular treatment has been studied in numerous small series of predominantly ruptured aneurysms. Little consideration has been given to the distinction between ruptured and unruptured aneurysms. This study examines the influence of treatment modality on oculomotor palsy recovery as a result of unruptured posterior communicating artery aneurysms. METHODS: Patients who presented between 2003 and 2015 with an oculomotor palsy secondary to an unruptured posterior communicating artery aneurysm were identified from the hospital database. A keyword search for "posterior communicating artery aneurysm" and "oculomotor nerve palsy OR third nerve palsy" using the PubMed database was performed for the narrative review. RESULTS: The cohort study and narrative review identified 15 and 179 eligible patients, respectively. Surgically treated patients in the cohort study did not have a significantly better rate of complete palsy resolution than those who had been coiled (P = 0.08). In the review, clipping of the aneurysm resulted in a higher rate of complete palsy resolution (70.0%; 95% confidence interval [CI], 60.7%-79.3%) than did coiling (46.5%; 95% CI, 36.0%-57.0%). Patients who presented with an aneurysm <7 mm had a higher rate of complete palsy resolution compared with aneurysms >7 mm (68.6%; 95% CI, 57.7%-79.5% vs. 44.3%; 95% CI, 32.7%-55.9%). Patients presenting with a complete palsy (49.4%; 95% CI, 38.6%-60.2%) had a lower rate of recovery than did those with a partial palsy (71.4%; 95% CI, 60.2%-82.6%). CONCLUSIONS: In this narrative review, surgical clipping of unruptured posterior communicating artery aneurysms was associated with a higher rate of associated oculomotor palsy recovery than was endovascular treatment.

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.

Multimodality management and outcomes of brain arterio-venous malformations (AVMs) in children: personal experience and review of the literature, with specific emphasis on age at first AVM bleed.

PURPOSE: The purpose of this paper is to study the presentation and analyse the results of multimodality treatment of brain arterio-venous malformations (AVMs) in children at our centre and review age at first AVM rupture in the literature. METHODS: Of 52 patients aged <18 years, 47 with brain AVMs (27 males and 20 females) aged 4-17 years (mean 12.2) were retrospectively reviewed. PubMed search revealed five additional studies including 267 patients where the prevalence of age-related AVMs rupture was analysed. RESULTS: In our study, 37 patients had bled, 9 were symptomatic without haemorrhage and 1 was incidental. Spetzler-Martin score distribution was 5 cases grade I, 18 grade II, 21 grade III and 3 grade IV. Appropriate imaging was performed, either CT/MRI angiogram only (in emergency cases) or catheter angiogram, prior to definitive treatment. There were 40 supratentorial and 7 infratentorial AVMs. Twenty-nine patients had microsurgery alone and 9 patients were treated by radiosurgery only. Three patients were embolised, all followed by radiosurgery, with one requiring surgery too, while 4 patients had combined surgery and radiosurgery. One patient is awaiting radiosurgery while another was not treated. Good outcomes, classified as modified Rankin score (mRS) 0-2 improved significantly after intervention to 89.4% from 38.3% pre-treatment (p value <0.0001). Angiography confirmed 96.6% obliteration after first planned operation. Repeat cerebral angiogram around age 18 was negative in all previously cured patients. Reviewing the literature, 82.0% (95% CI = [77-87]; N = 267) of children diagnosed with brain AVMs (mean age 11.4 ± 0.4) presented with a bleed in the last 22 years. Males significantly outnumbered females (136 vs 84) (p < 0.001). Ninety-five patients underwent surgical intervention alone when compared to other treatment modalities (p < 0.001). CONCLUSIONS: Microsurgical excision of surgically accessible intracranial AVMs remains the primary treatment option with very good outcomes. A significant number of patients' AVMs ruptured around puberty; therefore, understanding the pathophysiology of AVM instability at this age may aid future therapy.

Comparing Percutaneous Treatments of Trigeminal Neuralgia: 19 Years of Experience in a Single Centre.

BACKGROUND: Glycerol rhizolysis, thermocoagulation, and balloon compression are well established in the treatment of trigeminal neuralgia. OBJECTIVE: To compare the outcome profile of these 3 percutaneous procedures in a single centre over a long follow-up period. METHODS: Over 19 years, 393 procedures were performed on 210 trigeminal neuralgia patients. Patient records and telephone follow-up were used to determine demographic and operative details and surgical outcomes. The length of follow-up extended to over 17 years. RESULTS: The initial rates of complete pain relief with or without medication were 72% for glycerol, 80% for thermocoagulation, and 86% for balloon compression. Kaplan-Meier analysis of recurrence times showed that balloon compression provides significantly longer relief than the other 2 procedures. Complication rates for glycerol, thermocoagulation, and balloon compression were 30.3, 27.1, and 43.5%, respectively. Analysis of repeat procedures showed no difference in recurrence times for balloon compression or thermocoagulation compared with primary procedures, but repeat glycerol procedures gave shorter recurrence times. CONCLUSION: Balloon compression provides longer pain relief than glycerol and thermocoagulation. Although balloon compression is more likely to give numbness and complications, the complications are largely minor and transitory. Moreover, balloon compression following previous percutaneous procedures remains highly effective.

Endoscopic biopsy and third ventriculostomy for the management of pineal region tumors.

OBJECTIVE: To assess the histologic accuracy of endoscopic biopsy samples of the pineal region. Pineal region tumors usually present with acute hydrocephalus. Histologic diagnosis is paramount, as it greatly influences treatment. Endoscopic techniques can combine histologic diagnosis with relief of the obstructive hydrocephalus in a single operation. Because pineal region tumors can be heterogeneous, initial biopsy samples may not represent the most aggressive portion of the tumor. METHODS: This retrospective study reviews our experience of endoscopic third ventriculostomy combined with biopsy of the lesion. The histologic diagnosis as a result of the initial biopsy was compared with the final histologic diagnosis to establish the accuracy of the endoscopic biopsy sample in aiding diagnosis. RESULTS: Forty-seven patients underwent an endoscopic third ventriculostomy. All but 1 patient underwent a concurrent biopsy of the space-occupying lesion and 39 of 46 patients (85%) had a histologic diagnoses. In the remaining 7 patients (15%), the histology was negative; in 6 cases, the second attempt to obtain a histologic diagnosis was successful (2 repeat endoscopic biopsy samples, 2 resections, 2 stereotactic biopsy samples). In 1 patient a presumed low-grade tectal tumor was followed up with sequential scanning. Twenty-eight patients underwent subsequent operations (24 resections, 4 stereotactic biopsies). In 6 of 28 patients (21%), the histologic report was amended after the second procedure. CONCLUSIONS: The endoscopic biopsy sample yields an accurate histologic diagnosis for most pineal region tumors, with a positive histologic sample in about 85% of patients. However, the results must be interpreted cautiously, as the heterogeneous nature of these tumors may lead to an approximately 21% error rate in the initial tumor diagnosis.

The SILVER (Silver Impregnated Line Versus EVD Randomized trial): a double-blind, prospective, randomized, controlled trial of an intervention to reduce the rate of external ventricular drain infection.

BACKGROUND: Cerebrospinal fluid (CSF) infections associated with external ventricular drain (EVD) placement attract major consequences. Silver impregnation of catheters attempts to reduce infection. OBJECTIVE: To assess the efficacy of silver catheters against CSF infection. METHODS: We performed a randomized, controlled trial involving 2 neurosurgical centers (June 2005 to September 2009). A total of 356 patients requiring an EVD were assessed for eligibility; 325 patients were enrolled and randomized (167 plain, 158 silver); 278 patients were analyzed (140 plain, 138 silver). The primary outcome measure was CSF infection as defined by organisms seen on Gram stain or isolated by culture. Secondary outcome measures included ventriculoperitoneal (VP) shunting. RESULTS: There was a significant difference in infection risk between the 2 study arms: 21.4% (30/140) for plain catheters vs 12.3% (17/138) for silver catheters (P = .0427; 95% confidence interval [CI]: 1.015-3.713). Patients who had an EVD infection had more than double the risk of requiring a VP shunt compared with patients without an EVD infection (45.7% [21/46] vs 19.7% [45/229], respectively, P = .0002; 95% CI: 1.766-6.682). There was also a significant difference in VP shunt risk with infection: plain (55.2%; 16/29) vs the silver arm (29.4%; 5/17); P = .0244 (95% CI: 1.144-11.695). A multivariate analysis demonstrated that infection risk was increased by duration of EVD placement (odds ratio: 1.160), spontaneous intracranial hemorrhage (odds ratio 4.958) and decreased by silver catheters (odds ratio: 0.423). CONCLUSION: The study provides Class I evidence that silver-impregnated catheters reduce CSF infection.

Posterior reversible encephalopathy syndrome: a case following reversible cerebral vasoconstriction syndrome masquerading as subarachnoid haemorrhage.

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic clinico-radiological diagnosis typically presenting with headache, encephalopathy and visual disturbance accompanied by a unique neuroradiological pattern of symmetrical parieto-occipital vasogenic oedema. Here we present the case of a 51-year-old woman who presented to hospital following a thunderclap headache, initially thought to be secondary to a subarachnoid haemorrhage (SAH). A tiny anterior choroidal artery aneurysm was demonstrated on cerebral angiogram. At surgical clipping, no evidence of haemorrhage was observed. Post-operatively, the patient developed delayed right-sided hemiparesis, managed with aggressive hypertensive treatment, and later, with onset of septicaemia, central visual loss. Computed tomography (CT) brain scans demonstrated oedematous changes within the parieto-occipital regions bilaterally and later areas of infarction. The initial diagnosis of SAH was revised to reversible cerebral vasoconstriction syndrome (RCVS), which gave rise to PRES. To our knowledge, this is the first reported case of RCVS with concomitant PRES and cerebral infarction.

The natural history of cranial dural arteriovenous fistulae with cortical venous reflux--the significance of venous ectasia.

BACKGROUND: The quoted risk of hemorrhage from dural arteriovenous fistulae with cortical venous reflux varies widely, and the influence of angiographic grade on clinical course has not previously been reported. OBJECTIVE: To assess the risk of hemorrhage and the influence of angiographic grade on this risk, compared with known predictors of hemorrhage such as presentation. METHODS: Seventy-five fistulae with cortical venous reflux identified in our arteriovenous malformations clinic between 1992 and 2007 were followed up clinically, and their angiograms were reviewed. RESULTS: There were 8 hemorrhages in 90 years of follow-up. The annual incidence of hemorrhage before any treatment was 13%, and 4.7% after partial treatment, giving an overall incidence of 8.9% before definitive treatment. Borden and Cognard grades were poor discriminators of risk for lesions with the exception of Cognard type IV lesions. These lesions, characterized by venous ectasia, had a 7-fold increase in the incidence of hemorrhage (3.5% no ectasia vs 27% with ectasia). Patients presenting with hemorrhage (20%) or nonhemorrhagic neurological deficit (22%) had a higher incidence of hemorrhage than those with a benign presentation (4.3%), but this may be directly linked to the presence of venous ectasia. CONCLUSION: In this series untreated dural arteriovenous fistulae with cortical venous reflux had a 13% annual incidence of hemorrhage after diagnosis. There was a significant difference between those with and without venous ectasia. This should be confirmed by further studies, but probably defines a high-risk subgroup of patients that requires rapid intervention.

Pathological laughter and crying in patients with pontine lesions.

Pathological laughter and crying (PLC) has been widely documented in the medical literature in association with various pathological processes in the brainstem, particularly infarction. However, it remains poorly understood. The authors present a case report and analyze all the cases in the literature to try to localize a putative faciorespiratory center. This 13-year-old girl developed a pontine abscess subsequent to sphenoid sinusitis. This increased in size despite antibiotic treatment, and she developed PLC. The abscess was then stereotactically aspirated, with resolution of the symptoms. A PubMed search of the term "pathological laughter and crying" was performed. From these papers all reported cases of PLC were identified. Cases without neuroimaging were excluded. The remaining cases were categorized as small lesions permitting accurate localization within the pons, or large nonlocalizing lesions. All images of localizing lesions were magnified to the same size and placed on a grid. From this an area of maximal overlap was identified. The authors identified 7 cases of small localizing lesions with adequate imaging. The area of maximal overlap was in the region of the anterior paramedian pons. All the lesions involved this region of the pons. There were 28 further reports of large lesions that either resulted in gross compressive distortion of the pons or diffusely infiltrated it, and thus, although implicating involvement of a pontine center, did not allow for localization of a specific region of the pons. The authors report a case of PLC caused by a pontine abscess. Symptoms were reversible with stereotactically assisted aspiration and antibiotic administration. Analysis of the lesions reported in the literature showed a pattern toward a regulatory center in the pons. The most consistently involved region was in the anterior paramedian pons, and this may be the site of a faciorespiratory center.

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.