Phantosmia as the first presentation of a cavernous sinus - clinoidal meningioma.

Cavernous sinus meningiomas (CSM) are complex skull base lesions that, due to their particular anatomical location, render surgical management difficult. Their symptomatology is versatile, and the clinical outcome is difficult to predict. We present the case of a 57-year old female patient who experienced phantosmia - an abnormal, persistent, olfactory sensation of cigarette smell for 18 months. MRI was performed and revealed a left cavernous sinus meningioma, extending into the left temporal fossa, with olfactory and optic nerve distortion. To our knowledge, this is the first reported case of phantosmia as the initial presentation of a lesion in the cavernous sinus.

Are Fetal-Type Posterior Cerebral Arteries Associated With an Increased Risk of Posterior Communicating Artery Aneurysms?

BACKGROUND: Fetal-type posterior cerebral arteries (F-PCAs) might result in alterations in hemodynamic flow patterns and may predispose an individual to an increased risk of posterior communicating artery aneurysms (PCoAAs). OBJECTIVE: To determine the association between PCoAAs and the presence of ipsilateral F-PCAs. METHODS: We retrospectively reviewed the radiographic findings from 185 patients harboring 199 PCoAAs that were treated at our institution between 2005 and 2015. Our study population consisted of 4 cohorts: (A) patients with 171 internal carotid arteries (ICAs) harboring unilateral PCoAAs; (B) 171 unaffected ICAs in the same patients from the first group; (C) 28 ICAs of 14 patients with bilateral PCoAAs; and (D) 180 ICAs of 90 patients with aneurysms in other locations. We then determined the presence of ipsilateral F-PCAs and recorded all aneurysm characteristics. RESULTS: Group A had the highest prevalence of F-PCAs (42%) compared to 19% in group B, 3% in group C, and 14% in group D (odds ratio A : B = 3.041; A : C = 19.626; and A : D = 4.308; P < .001). PCoAAs were associated with larger diameters of the posterior communicating arteries (median value 1.05 vs 0.86 mm; P = .001). The presence of F-PCAs was associated with larger sizes of the aneurysm necks (median value 3.3 vs 3.0 mm; P = .02). CONCLUSION: PCoAAs were associated with a higher prevalence of ipsilateral F-PCAs. This variant was associated with larger sizes of the aneurysm necks but was not associated with the sizes of the aneurysm domes or with their rupture statuses.

Multimodal management of arteriovenous malformations of the basal ganglia and thalamus: factors affecting obliteration and outcome.

OBJECTIVE: Arteriovenous malformations (AVMs) of the basal ganglia and thalamus are particularly difficult lesions to treat, accounting for 3%-13% of all AVMs in surgical series and 23%-44% of malformations in radiosurgery series. The goal of this study was to report the results of multimodal management of basal ganglia and thalamic AVMs and investigate the factors that influence radiographic cure and good clinical outcomes. METHODS: This study was a retrospective analysis of a prospectively maintained database of all patients treated at the authors' institution. Clinical, radiological, follow-up, and outcome data were analyzed. Univariate and multivariate analyses were conducted to explore the influence of various factors on outcome. RESULTS: The results and data analysis pertaining to 123 patients treated over 32 years are presented. In this cohort, radiographic cure was achieved in 50.9% of the patients. Seventy-five percent of patients had good clinical outcomes (stable or improved performance scores), whereas 25% worsened after treatment. Inclusion of surgery and radiosurgery independently predicted obliteration, whereas nidus diameter and volume predicted clinical outcomes. Nidus volume/diameter and inclusion of surgery predicted the optimal outcome, i.e., good clinical outcomes with lesion obliteration. CONCLUSIONS: Good outcomes are possible with multimodal treatment in these complex patients. Increasing size and, by extension, higher Spetzler-Martin grade are associated with worse outcomes. Inclusion of multiple modalities of treatment as indicated could improve the chances of radiographic cure and good outcomes.

Brainstem arteriovenous malformations: lesion characteristics and treatment outcomes.

OBJECTIVE Brainstem arteriovenous malformations (AVMs) are rare lesions that are difficult to diagnose and treat. They are often more aggressive in their behavior when compared with their supratentorial counterparts. The consequence of a brainstem hemorrhage is often devastating, and many patients are in poor neurological status at presentation. The authors examine the factors associated with angiographically confirmed cure and those affecting management outcomes for these complex lesions. METHODS This was a retrospective analysis of data gathered from the prospectively maintained Stanford AVM database. Lesions were grouped based on their location in the brainstem (medulla, pons, or midbrain) and the quadrant they occupied. Angiographic cure was dichotomized as completely obliterated or not, and functional outcome was dichotomized as either independent or not independent at last follow-up. RESULTS Over a 23-year period, 39 lesions were treated. Of these, 3 were located in the medulla, 14 in the pons, and 22 in the midbrain. At presentation, 92% of the patients had hemorrhage, and only 43.6% were functionally independent. Surgery resulted in the best radiographic cure rates, with a morbidity rate of 12.5%. In all, 53% of patients either improved or remained stable after surgery. Absence of residual nidus and female sex correlated with better outcomes. CONCLUSIONS Brainstem AVMs usually present with hemorrhage. Surgery offers the best chance of cure, either in isolation or in combination with other modalities as appropriate.

The Prevalence of Cerebrovascular Abnormalities Detected in Various Diagnostic Subgroups of Spontaneous Subarachnoid Hemorrhage in the Modern Era.

OBJECTIVE: To determine prevalence of cerebrovascular abnormalities in diagnostic subgroups of spontaneous subarachnoid hemorrhage (SAH) in a regional neurosurgical center in the modern era. METHODS: Data of 609 consecutive patients with spontaneous SAH in a 3-year period (August 2010 to August 2013) were prospectively collected. Patients were divided into 3 diagnostic subgroups: computed tomography (CT) positive for SAH; CT negative but positive cerebrospinal fluid examination by spectrophotometry for SAH; CT negative for SAH and inconclusive cerebrospinal fluid examination. All patients fit for intervention underwent CT angiography with or without digital subtraction angiography to identify vascular abnormalities for subsequent treatment. RESULTS: Of 609 patients, 554 were fit for further investigation and consideration of further intervention; 514 patients had confirmed SAH. Mean patient age was 54.0 years; 61.5% of patients were women. Of patients, 390 (75.9%) showed vascular abnormalities on angiography. There were 438 patients (85.2%) with confirmed SAH diagnosed on CT scan (group 1). Vascular abnormalities were detected in 81.1% of patients; 18.9% of patients with positive CT scan had no identifiable cause of SAH. Of patients with confirmed SAH, 76 (14.8%) had negative CT scan but positive lumbar puncture (group 2); 46.1% of patients in this group had vascular abnormalities. Three patients with inconclusive cerebrospinal fluid examination had lesions requiring treatment. Median length of hospital stay in group 1 patients was longer than median length of hospital stay in group 2 patients. CONCLUSIONS: Frequency of vascular abnormalities in spontaneous SAH is lower than the traditionally quoted figure, which has diagnostic and prognostic implications for patient management.

Adenosine-induced cardiac arrest as an alternative to temporary clipping during intracranial aneurysm surgery.

OBJECTIVE The purpose of this study was to analyze the impact of adenosine-induced cardiac arrest (AiCA) on temporary clipping (TC) and the postoperative cerebral infarction rate among patients undergoing intracranial aneurysm surgery. METHODS In this retrospective matched-cohort study, 65 patients who received adenosine for decompression of aneurysms during microsurgical clipping were identified (Group A) and randomly matched with 65 selected patients who underwent clipping but did not receive adenosine during surgery (Group B). The matching criteria included age, Fisher grade, aneurysm size, rupture status, and location of aneurysms. The primary outcomes were TC time and the postoperative infarction rate. The secondary outcome was the incidence of intraoperative aneurysm rupture (IAR). RESULTS In Group A, 40 patients underwent clipping with AiCA alone and 25 patients (38%) received AiCA combined with TC, and in Group B, 60 patients (92%) underwent aneurysm clipping under the protection of TC (OR 0.052; 95% CI 0.018-0.147; p < 0.001). Group A required less TC time (2.04 minutes vs 4.46 minutes; p < 0.001). The incidence of postoperative lacunar infarction was equal in both groups (6.2%). There was an insignificant between-group difference in the incidence of IAR (1.5% in Group A vs 6.1% in Group B; OR 0.238; 95% CI 0.026-2.192; p = 0.171). CONCLUSIONS AiCA is a useful technique for microneurosurgical treatment of cerebral aneurysms. AiCA can minimize the use of TC and does not increase the risk of IAR and postoperative infarction.

Management of Arteriovenous Malformations Associated with Developmental Venous Anomalies: A Literature Review and Report of 2 Cases.

BACKGROUND: Classification of cerebrovascular malformations has revealed intermediary lesions that warrant further review owing to their unusual presentation and management. We present 2 cases of arteriovenous malformation (AVM) associated with a developmental venous anomaly (DVA), and discuss the efficacy of previously published management strategies. METHODS: Two cases of AVMs associated with DVA were identified, and a literature search for published cases between 1980 and 2016 was conducted. Patient demographic data and clinical features were documented. RESULTS: In case 1, a 29-year-old female presenting with parenchymal hemorrhage and left homonymous hemianopia was found to have a right parieto-occipital AVM fed from the anterior cerebral, middle cerebral, and posterior cerebral arteries, with major venous drainage to the superior sagittal sinus. In case 2, imaging in a 34-year-old female evaluated for night tremors and incontinence revealed a left parietal AVM with venous drainage to the superior sagittal sinus. Including our 2 cases, 22 cases of coexisting AVMs and DVAs have been reported in the literature. At presentation, 68% had radiographic evidence of hemorrhage. Stereotactic radiosurgery was performed in 7 cases, embolization in 6 cases, surgical resection in 4 cases, and multimodal therapy in 5 cases. Radiography at follow-up demonstrated successful AVM obliteration in 67% of cases (12 of 18). CONCLUSIONS: Patients with coexisting AVMs and DVAs tend to have a hemorrhagic presentation. Contrary to traditional AVM management, in these cases it is important to preserve the draining vein via the DVA to ensure a safe, sustained circulatory outflow of the associated brain parenchyma while achieving safe AVM obliteration.

"Dirty coagulation" technique as an alternative to microclips for control of bleeding from deep feeders during brain arteriovenous malformation surgery.

BACKGROUND: Meticulous haemostasis is one of the most important factors during microneurosurgical resection of brain arteriovenous malformation (AVM). Controlling major arterial feeders and draining veins with clips and bipolar coagulation are well-established techniques, while managing with bleeding from deep tiny vessels still proves to be challenging. This technical note describes a technique used by the senior author in AVM surgery for last 20 years in dealing with the issue highlighted. METHOD: "Dirty coagulation" is a technique of bipolar coagulation of small feeders carried out together with a thin layer of brain tissue that surrounds these fragile vessels. The senior author uses this technique for achieving permanent haemostasis predominantly in large and/or deep-seated AVMs. To illustrate the efficacy of this technique, we retrospectively reviewed the outcome of Spetzler-Martin (SM) grade III-V AVMs resected by the senior author over the last 5 years (2010-2015). RESULTS: Thirty-five cases of AVM surgeries (14 SM grade III, 15 SM grade IV and 6 SM grade V) in this 5-year period were analysed. No postoperative intracranial haemorrhage was encountered as a result of bleeding from the deep feeders. Postoperative angiograms showed complete resection of all AVMs, except in two cases (SM grade V and grade III). CONCLUSIONS: "Dirty coagulation" provides an effective way to secure haemostasis from deep tiny feeders. This cost-effective method could be successfully used for achieving permanent haemostasis and thereby decreasing postoperative haemorrhage in AVM surgery.

Microneurosurgical Management of Posterior Communicating Artery Aneurysm: A Contemporary Series from Helsinki.

OBJECTIVE: The objectives of this study were to analyze microsurgical techniques and to determine correlations between microsurgical techniques and the radiographic findings in the microneurosurgical treatment of posterior communicating artery aneurysms (PCoAAs). METHODS: We retrospectively analyzed radiographic findings and videos of surgeries in 64 patients with PCoAAs who underwent microsurgical clipping by the senior author from August 2010 to 2014. RESULTS: From 64 aneurysms, 30 (47%) had acute subarachnoid hemorrhage (SAH) that necessitated lamina terminalis fenestration (odds ratio [OR], 67.67; P < 0.001) and Liliequist membrane fenestration (OR, 19.62; P < 0.001). The low-lying aneurysms significantly necessitated the coagulation of the dura covering the anterior clinoid process (ACP) (OR, 7.43; P = 0.003) or anterior clinoidectomy (OR, 91.0; P < 0.001). We preferred straight clips in 45 (83%) of 54 posterolateral projecting aneurysms (OR, 45.0; P < 0.001), but preferred curved clips for posteromedial projecting aneurysms (OR, 6.39; P = 0.008). The mean operative time from the brain retraction to the final clipping was 17 minutes and 43 seconds. Postoperative computed tomography angiography revealed complete occlusion of 60 (94%) aneurysms. Three (4.6%) patients with acute SAH suffered postoperative lacunar infarction. CONCLUSIONS: For ruptured aneurysms, lamina terminalis and Liliequist membrane fenestration are useful for additional cerebrospinal fluid drainage. For low-lying aneurysms, coagulation of the dura covering the ACP or tailored anterior clinoidectomy might be necessary for exposing the proximal aneurysm neck. Type of clips depends on the direction of projection. The microsurgical clipping of the PCoAAs can achieve good immediate complete occlusion rate with low postoperative stroke rate.

Comparative surgical outcome associated with the management of brain arteriovenous malformation in a regional neurosurgical centre.

OBJECTIVES: Microsurgical resection of brain arteriovenous malformation (AVMs) is challenging, however, expert surgical series from large volume centres, have reported over 95% occlusion rates with 2 to 8% risk of morbidity & mortality. Data from a regional neurosurgical unit was analysed and compared with published series for the purposes of quality control. We also compared our surgical result with other treatment modalities from the whole AVM cohort managed over the same study period. DESIGN: Retrospective analysis of a locally held AVM database. SUBJECTS: Of the 141 AVM patients, 54 (35M, 19F, age range 9-68 years) underwent microsurgical removal of AVM by the senior author, from 2006 to 2012. 27 (19%), 18 (13%), 20 (14%), 22 (16%) had endovascular therapy only, radiosurgery only, combination therapy (endovascular and radiosurgery) and conservative management, respectively. METHODS: Case notes were reviewed to determine clinical and radiological outcomes. Statistical analysis performed using SPSS with p < 0.05 defined as statistical significance. RESULTS: In the surgical series, the Spetzler-Martin (SM) grade distribution was as follows: 17 grade I (32%), 31 grade II (57%), and 6 grade III (11%). 31 patients (57%) presented with intracranial haemorrhage, 12 patients (22%) with seizures. Of the 54 patients, 51 (94%) had angiographically confirmed obliteration of their AVM. Median follow-up for the entire cohort was 7 years. 83% of surgical patients have mRS 0-1, compared to 78%, 67%, 45%, 18% of patients managed by endovascular therapy, radiosurgery, combination therapy, conservative surveillance, respectively (p < 0.0001). However, the groups were not comparable in terms of SM grade or clinical presentation and the numbers in each group were relatively small. Seizure presentations were encountered in 23% (32/141) of the overall patients, and all the surviving patients were on anticonvulsants, except in the surgical arm, 7/12 (58%) patients were off their antiepileptic medications at last follow-up. CONCLUSIONS: The results demonstrate a 94% surgical obliteration rate and 11% long-term neurological deficits for brain AVM patients managed surgically and were comparable to expert series. Achieving acceptable results is possible in lower volume settings, however, patient selection is important and the role of an experienced neurovascular team cannot be overstated.

Defending a traditional practice in the modern era: The use of lumbar puncture in the investigation of subarachnoid haemorrhage.

INTRODUCTION: Acute severe headache is a common medical presentation, and a common area of diagnostic uncertainty. Subarachnoid haemorrhage (SAH) is the cause in a minority of patients and has a high rate of morbidity and mortality. Therefore, its conclusive diagnosis with computed tomography (CT) or lumbar puncture (LP) is paramount. With advancement in imaging technology, emerging evidence now suggests that LP is no longer required for a subset of patients as CT has 100% sensitivity in detecting SAH, when performed under specific conditions. OBJECTIVES: To assess the proportion of patients with conclusive CSF xanthochromia results following a negative CT scan in suspected SAH to determine the diagnostic efficacy of LP. METHODS: CSF bilirubin and oxyhaemoglobin spectrophotometric absorbance data from all centres in a regional health board were identified for consecutive patients over a 6-month period. Results were stratified as conclusive (positive or negative), or inconclusive according to national guidelines. RESULTS: 239 of 255 (93.7%) results were conclusive: 89.0% were negative (227 of 255). 4.7% of results were positive (12 of 255), revealing 4 cerebral aneurysms requiring treatment. 16 out of 255 (6.3%) samples were inconclusive, yielding 1 aneurysm requiring treatment. In the same period, there were 27 CT-positive cases of SAH. CONCLUSIONS: LP has a high diagnostic yield, eliminating the need for neurosurgical opinion or investigation in almost 90% of cases. The test is both cost and time efficient and subjects only a small number of patients to the radiation and contrast risks of angiography.

Effective management of lower divisional pain in trigeminal neuralgia using balloon traction.

Percutaneous balloon compression (PBC) of the trigeminal ganglion uses a differential injury of axons to interfere with the nerve's ability to transmit signals. In our experience, patients with lower divisional pain (V3) are often more difficult to control using PBC. We describe a modification to the PBC technique for patients with lower division (V3) pain, and present our experience to date.

Cauda equina lymphoma--a rare presentation of primary central nervous system lymphoma: case report and literature review.

The spinal cord is an extremely rare site for primary central nervous system (CNS) lymphoma (< 1%). Very few cases of primary cauda equina (including conus) lymphoma were previously reported. We report such a case, and with literature review, discuss their clinical features, operative and histopathological findings. Although rare, with an increasing incidence of CNS lymphoma, they should be considered in the differential diagnosis of intradural lesions. Furthermore, with intraoperative smear to establish diagnosis, extensive surgery can be avoided. The controversial role of glucocorticoids in the management of these patients is also discussed.

Role of craniotomy repair in reducing postoperative headaches after a retrosigmoid approach.

BACKGROUND: The retrosigmoid (RS) approach provides an excellent access corridor to the cerebellopontine angle. However, 80% of patients experience headaches after RS approaches. OBJECTIVE: We reviewed our prospective database to determine the risk factors influencing headaches after RS procedures. METHODS: From 2003, craniotomy, instead of craniectomy, became our standard approach for RS procedures. Patients' demographic, management, and outcome data were collected prospectively. We also retrospectively analyzed similar data collected between 2000 and 2003 to compare headache outcomes after RS approaches. Subgroup analysis of data was performed to identify other risk factors contributing to postoperative headaches. RESULTS: Of 105 patients (mean age, 56 years; 43 men; 62 women) who underwent RS surgery, 30 underwent craniectomy and 75 underwent craniotomy. There were 57 vestibular schwannomas, 40 microvascular decompressions, and 8 other procedures. The patients' age, sex, pathological diagnosis, and length of hospital stay were not statistically different in the 2 subgroups. At discharge, postoperative headache was observed in 43% of patients (13/30) after craniectomy and 19% of patients (14/75) after craniotomy (P = .01). The incidence of headache decreased with further follow-up; 10% of patients (3/30) who underwent craniectomy and 1% of patients (1/75) who underwent craniotomy still had headache at 12 months of follow-up. CONCLUSION: Patients who underwent the RS approach with craniotomy had a significantly lower rate of headache at discharge than did those who underwent craniectomy. These patients continued to have a lower incidence of headache in the long term.