An Observational Comparative Study to Evaluate the Use of Image-Guided Surgery in the Management and Outcome of Supratentorial Intracranial Space-Occupying Lesions.

Objectives: The objective of this article is to study the effect of neuronavigation on the outcome of surgery for supratentorial tumors, such as the extent of resection, size of craniotomy, and overall morbidity and mortality by comparing with conventional excision. Methods: A total of 50 patients undergoing intracranial surgery for supratentorial space-occupying lesions from 2020 to 2022 were included in the study. One intervention group consisted of patients undergoing surgical resection of supratentorial tumors utilizing image guidance versus the control group, which consisted of patients undergoing surgical excision of supratentorial tumor excision without image guidance. Parameters used to compare the outcome were the extent of resection of the lesions, craniotomy size, and overall morbidity and mortality. Results and Conclusion: There was no significant reduction in craniotomy size or prolongation of operative duration with the use of neuronavigation. There was no significant difference in postoperative hospital stay between the two groups. Neuronavigation-assisted cases did not show any significant reduction in the occurrence of postoperative neurological deficits or any reduction of overall morbidity and mortality.

Correlation Between Aneurysm Dome Direction and Patient Outcomes Following Surgery for Ruptured Anterior Communicating Artery Aneurysms.

Background Anterior communicating (Acom) artery aneurysms are the most common type of intracranial aneurysms. Despite the enormous advancements in the field of endovascular surgery for intracranial aneurysms, open surgical clipping of aneurysms remains the most durable management of Acom aneurysms. There have been various studies based on the clinical-radiological profile and outcome of open clipping for intracranial aneurysms, but the correlation of the direction of the aneurysm with the surgical outcome remains incompletely defined. Aim To analyze the correlation between the direction of the aneurysm dome and patient outcomes after surgery for ruptured Acom artery aneurysms. Materials and methods  CT angiography of the brain was done in all patients pre-operatively as part of the standard treatment protocol. Retrospective data was collected from an inter-departmental computerized database, which included the patient's details, history, investigations, a course in the hospital from admission to discharge, and an operative note by the surgeon. Prospective data was collected from patients with ruptured Acom artery aneurysms. We analyzed the relationship between the direction of the dome of the Acom aneurysm and preoperative, intraoperative, and postoperative variables. Results Of the 48 patients who underwent surgery for ruptured aneurysms, 34 (70.8%) were female and 14 (29.2%) were male. Among the 27 cases with anteriorly projecting aneurysms, 11 (40.7%) experienced postoperative complications. Of the five cases with posteriorly projecting aneurysms, two (40%) experienced postoperative complications. One-third of cases of the inferior dome direction and 10% of cases of the superior direction of the dome of aneurysm were also found to have postoperative complications. However, using the chi-square test, the association between postoperative complications and the direction of the aneurysm was determined to be statistically non-significant (p-value = 0.93). Conclusion The findings of our investigation indicate that aneurysms with superior projection exhibit the lowest likelihood of experiencing intraoperative rupture. However, it was seen that the outcome was influenced by dome projection throughout the three-month follow-up. The findings of our study indicate that aneurysms with a superior orientation exhibit the least likelihood of experiencing intraoperative rupture.

Validation of Freehand Cervical Pedicle Screw Placement in Subaxial Spine Using the "Burcev Technique": A Cadaveric Study.

The present study attempted to validate the "Burcev freehand method" based on anatomical observations in Indian cadavers. The study was conducted on 32 cervical pedicle screws (CPSs) that were placed in four cadavers by the authors according to the "freehand technique," described by Burcev et al, without the aid of fluoroscopy and the trajectory verified by computed tomography scans. The screws were designated as satisfactory, permissible, or unacceptable. Descriptive variables were represented in number and percentages, continuous variables were represented as mean ± standard deviation (SD). Of the 32 CPSs placed, 24 (75%) exhibited a satisfactory position, 1 (3%) exhibited a permissible position, and 7 (22%) exhibited an unacceptable position. Of the seven CPSs in the unacceptable group, four exhibited a lateral breach and three exhibited a medial breach, whereas the CPS in the permissible group exhibited a medial breach. The overall angle with contralateral lamina in the horizontal plane in terms of mean ± SD was 175.43 ± 2.82, 169.49, and 169.65 ± 6.46 degrees in the satisfactory, permissible, and unacceptable groups, respectively. In the sagittal plane, the screws exhibited an angle of 88.15 ± 3.56 degrees. No breach was observed superiorly or inferiorly. The "Burcev technique" is replicable with similar results in cadavers. Further studies must be conducted in a clinical setting to ensure its safety.

Evaluating Atlantoaxial Dislocation Based on Cartesian Coordinates: Proposing a New Definition and Its Impact on Assessment of Congenital Torticollis.

BACKGROUND: Conventional 2-dimensional (2-D) definition of atlantoaxial dislocation (AAD) is inadequate for coexisting 3-D displacements. OBJECTIVE: To prospectively classify AAD and its related abnormalities along 3 Cartesian coordinates and assess their association with torticollis. METHODS: One hundred and fifty-four patients with congenital AAD were prospectively classified according to their C1-2 displacement along 3 Cartesian coordinates utilizing 3-D multiplanar CT. The impact of this 3-D dislocation on occurrence of clinically manifest torticollis was also evaluated and surgical treatment was planned. RESULTS: Three dimensional CT assessment detected the following types of C1-2 dislocations: I:translational dislocation (along Z coordinate, n = 37 [24%]); II: central dislocation (along Y coordinate, n = 10 [6.5%]); III: translational+central dislocation (along Z+Y coordinates, n = 42 [27.3%]); IV: translational dislocation+ rotational dislocation+coronal tilt (along Z+X coordinates, (n = 6 [3.9%]); V: central dislocation (basilar invagination)+rotational dislocation+coronal tilt (along Y+X coordinates, n = 11 [7.1%]); VI: translational dislocation+ central dislocation+ rotational dislocation+ coronal tilt (along all 3 axes, n = 48 [31%]). Assessing degree of relative C1-2 rotation revealed that 27 (37%) of 85 patients with <50 rotation and 54 (78%) of 69 patients with >5° rotation had associated torticollis. Translational dislocation had negative association (odds ratio [OR] 0.1, 95% confidence interval [CI; 0.47-0.32], P = .00), while type VI (OR 5.0, 95% CI [2.2-11.19], P = .00), type V (OR 4.44, 95% CI [0.93-21.26], P = .04), and type IV (OR 1.84, 95% CI [0.32-10.38], P = .48) dislocations had strong positive association with torticollis. Sixty-two (40%) patients improved, 68 (44%) remained unchanged, and 24 (16%) patients worsened postoperatively. Twenty-eight patients required second-stage transoral decompression following posterior distraction-fusion due to neurological nonimprovement. CONCLUSION: Three-dimensional assessment of AAD including evaluation of culpable C1-2 facet joints addresses anomalous displacements in 3 Cartesian planes. This provides targets for adequate cervicomedullary decompression-stabilization, and helps in the management of accompanying torticollis.

Craniovertebral junction anomalies: When is resurgery required?

BACKGROUND: Craniovertebral junction (CVJ) abnormalities, such as atlantoaxial dislocation (AAD) with or without basilar invagination (BI), with or without associated Chiari malformation (CM), may cause a high cervical myelopathy. Occasionally, mechanical factors such as inadequate canal decompression, torticollis, and/or scoliosis may lead to lack of improvement following the primary surgery. Furthermore, implant-related factors, requiring implant revision/removal, or the presence of surgical site infections may cause the patient to undergo resurgery. AIMS: This study was aimed at highlighting the underlying etiopathogenesis of resurgery following the primary surgery undertaken in CVJ abnormalities. SETTING AND DESIGN: This was a retrospective study from a tertiary care referral institute focusing on 414 operated cases of CVJ anomalies. MATERIALS AND METHODS: The data of 55 patients who underwent resurgery included their clinicoradiological assessment and operative records. The inclusion criteria included failed primary procedure, repeat procedure for construct failure, infection at the surgical site, or wound dehiscence. Pure CM patients without bony anomalies were excluded from the study. RESULTS: A total of 137 procedures were performed in 55/414 (13%) patients. Causes of resurgery could be divided into ventral [redo or denovo transoral decompression (TOD) or wound-related complications, n = 33, 40.2%] and dorsal causes (implant-related factors/wound infections, n = 49, 59.8%). De novo TOD was done in persisting myelopathy following posterior fusion (PF) with C1-2 distraction (n = 15,18.3%,). Redo TOD was done for residual anterior bony compression [n = 8, 9.6%, OR 0.61; [CI = 0.20-1.86]. Causes for oral wound reexplorations (n = 10, 12.2%) included velopharyngeal insufficiency, wound resuturing, oral bleeding, and cerebrospinal fluid (CSF) leak. Dorsal causes included: (A) Implant factors (n = 27, 32.7%) and (B) neck wound reexplorations (n = 22, 26.8%). Presence of subaxial spine scoliosis, torticollis, and asymmetric joints increased the incidence of reexploration. Occipitocervical fusion rather than C1-2 fusion was more prone towards construct loosening. CONCLUSIONS: Patients undergoing distraction with PF may require transoral surgery due to persisting myelopathy, especially in the presence of torticollis, scoliosis, and symmetrical joints. Single stage TOD+PF increases the chances of implant infection due to tissue contamination, bacteremia, or transfacetal migration of microbes. Chronic/recurrent sinus is usually a harbinger of deeper infection and can be cured with implant removal.

Spinal intradural hydatid cyst causing arachnoiditis: A rare etiology of cauda equina syndrome.

This study aims to focus on a rare presentation of spinal hydatid cyst as cauda equine syndrome and misdiagnosed as intradural extramedullary (IDEM) benign lesion on magnetic resonance imaging. In this article, we report a case of spinal hydatid cyst masquerading as IDEM tumor, and intraoperatively, we accidently find clumped granuloma with severe arachnoiditis and hydatid cyst in lumber region, which was present as bilateral S1 radiculopathy with cauda equina syndrome. An 11-year-old boy who presented with symptoms and signs of cauda equina syndrome and planned for surgical excision. His radiological impression was IDEM possibly neurofibroma. To our surprise, we found multiple intradural cystic lesions with arachnoiditis. Dissecting in plane cyst was flushed out, and surgical cavity was irrigated with 3% saline. Postoperatively histopathology and serum tests confirmed the diagnosis of hydatid cyst. Hydatid disease is rare cause of cauda equine syndrome which can be miss diagnosed on radiological investigations. A high index of suspicion should be kept especially in a young patient from the Indian subcontinent.

Evaluation of modified Kumar and Kalra myelopathy scoring system in sub-axial spinal pathologies.

BACKGROUND: Various pathologies affect the spine, but these lesions present with more or less similar clinical profile. The present functional scoring systems are inadequate and insensitive to changes in neurological status of the patient. OBJECTIVE: Our study aims to assess the modified Kumar and Kalra (K and K) scoring system in patients with pathologies in the sub-axial spine. MATERIALS AND METHODS: A total of 78 consecutive patients from the period of January 2009 to June 2010 were prospectively included in the study. These patients were operated by the senior author at our institute. The mean Modified Japanese Orthopaedic Association (MJOA) score and the mean modified K and K score were calculated in the preoperative, at the time of discharge (post-surgery), and at 3 months and 6 months follow-up. RESULTS: There were 57 male (73.01%) patients and 21 female patients (26.92%), with the mean age of presentation of 39.20 years (±14.12 years) and a range of 9-75 years. Out of the total 78 patients, 60 patients had pathology in the cervical spine (sub-axial spine) and 18 patients had pathology in the dorsal spine. Majority of the patients had motor and sensory symptoms. The mean preoperative modified K and K score was 17.38 (±3.18) and the mean preoperative MJOA score was 11.21 (±2.12). The K and K score was able to predict the correct outcome in 70 patients (89.74%), whereas the MJOA score was able to predict correctly in 62 patients (79.49%). CONCLUSION: The modified K and K score has a better predictive value than the MJOA score.

Role of effective canal diameter in assessing the pre-operative and the post-operative status of patients with bony cranio-vertebral anomalies.

INTRODUCTION: The effective canal diameter (ECD) for the cranio-vertebral junction is measured from the posterior surface of the dens to the nearest posterior bony structure (foramen magnum or the posterior arch of the atlas). The ECD is the space which is occupied by the buffer space (which can be compromised without producing any signs or symptoms) and the cord itself. We intend to study the role of the ECD (especially in patients with markedly reduced ECD) in producing the symptoms and also the outcome of surgery in patients with bony cranio-vertebral junction (CVJ) anomalies. MATERIALS AND METHODS: A total of 67 consecutive patients from the period of January 2009 through June 2010 were prospectively included in the study. These patients were operated by a single experienced surgeon (the senior author) at the Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow. The ECD and the pre-operative Kumar and Kalra score (K and K score) (4) was calculated for all patients. The K and K score was also calculated at the time of discharge, at three months and six months follow-up. The patients were divided into three groups based on the ECD into 5 mm to 10 mm group, 10 mm to 15 mm group, and >15 mm group. RESULTS: There were 53 male (79.1%) patients and 14 female patients (20.9%) with mean age of presentation 27.10 years (±15.01 years) with range of 4-59 years. The duration of symptoms in our series varied from 1-120 months with mean of 23.79 months. The mean effective canal diameter was 9.027 mm (±2.23 mm) with range of 5-16 mm. The mean pre-operative K and K score was 19.27 (±4.19). There were 39 patients who had an ECD between 5 mm to 10 mm, 24 patients with ECD between 10 mm to 15 mm, and 4 patients with ECD more than 15 mm. The correlation coefficients between the effective canal diameter and the pre-operative and the post-operative Kumar and Kalra score at the time of discharge, 3 months and 6 months were 0.404 (P < 0.001), 0.320 (P < 0.008), 0.0302 (P < 0.013), and 0.284 (P < 0.020), respectively. The ECD and the pre-operative score were most significantly and strongly related to each other in patients with ECD between 5-10 mm. CONCLUSION: The ECD is significantly related to the pre-operative status (K and K score) of the patient. This correlation was strongest in the group with ECD of 5-10 mm. It was also observed that as the follow-up increased, the correlation between the ECD and the post-operative K and K score became less stronger though they remained significantly related to each other.

Cervicomedullary intramedullary peripheral primitive neuroectodermal tumor with intratumoral bleed: Report of one case and review of literature.

Primitive neuroectodermal tumors (PNET) are highly malignant, yet relatively uncommon neoplasms of the central nervous system. Although a host of different parts of the nervous system can be affected, intramedullary location of PNET is extremely rare. Most reports on intramedullary PNET have reported central PNET (cPNET); peripheral PNET (pPNET) affecting intramedullary spinal location is extremely rare. Till now, seven such cases of intramedullary pPNET have been described in medical literature in English. Here, we report an 11-year-old boy with cervicomedullary junction intramedullary pPNET who presented with intratumoral bleed, wherein the clinical presentation and radiological features gave us no clue preoperatively about the underlying diagnosis. In this report, we additionally review certain salient aspects of this dreaded disease in light of the existing evidence.

Transnasal endoscopic repair of pediatric meningoencephalocele.

INTRODUCTION: Encephaloceles in relation to the nose are rare lesions affecting the skull base. In the pediatric population, majority are congenital lesions manifesting as nasal masses requiring surgical intervention. MATERIALS AND METHODS: A retrospective study of 6 consecutive patients below 12 years of age with intranasal meningoencephalocele treated by endonasal endoscopic approach at our tertiary centre was done. The follow up period ranged from 6 months to 2 years. A detailed clinical and radiological evaluation of these cases was done. Endonasal endoscopic repair (gasket seal/fat plug) was carried out in all cases. RESULTS: Out of 6 patients, 4 patients had post-traumatic and rest 2 cases had congenital meningo-encephaloceles. All patients were asymptomatic in post-operative follow up period. One patient had minor complication of nasal alar collapse due to intra-operative adherence of encephalocele to cartilaginous framework. CONCLUSION: Transnasal endoscopic repair of anterior skull base meningoencephalocele is a minimally invasive single stage surgery, and has advantage in terms of lesser hospital stay, cost of treatment, and better cosmesis. The repair technique should be tailored to the size of defect to provide a water-tight seal for better outcome.

Multiple glioblastomas: Are they different from their solitary counterparts?

CONTEXT: Multiple glioblastomas (GBMs) have a reported incidence of 2-20%. AIMS: We intend to study these subsets of GBMs to know whether these are similar to their solitary counterparts. SETTING AND DESIGN: A retrospective study. MATERIALS AND METHODS: We analyzed 7 cases of biopsy-proven multiple GBMs. Multiple GBMs were described if there were >1 lesion which was at least 1 cm apart. The clinical data, radiological features, histopathological and immunohistochemical analysis and follow-up were recorded. RESULTS: The mean age was 45 years (range 17-69 years). All cases presented with features of raised intracranial pressure (ICP). Totally, 3 cases presented with hemiparesis and 2 cases with altered sensorium and generalized tonic clonic seizures each. The median Karnofsky performance status (KPS) was 50. Mean duration of symptoms was 40 days. All lesions were contrast enhancing (2 with homogenous enhancement and 5 had ring enhancement). Total excision of the lesion causing mass effect was done in all cases. Histopathologically, small cells were significantly present in 4 cases, and satellitosis was seen in 5 cases. Glial fibrillary acidic protein (GFAP) was absent in all cases in which small cells were significant. In these 4 cases, the proliferation index ranged from 40% to 95%. Totally, 3 patients died within 2 months of surgery, whereas remaining 4 patients underwent chemo-radiotherapy. CONCLUSIONS: We conclude that the cases usually present with features of raised ICP and poor KPS. Histopathologically these lesions show significant small cell population, satellitosis, and GFAP negativity.

Cerebral gliosarcoma: Analysis of 16 patients and review of literature.

BACKGROUND: Gliosarcoma (GS), a subtype of glioblastoma (GBM), is a rare primary neoplasm of the central nervous system. Certain features like temporal lobe affinity, tendency for extraneural metastasis and poorer outcome compared to GBM indicate that GS may indeed be a separate clinicopathologic entity. This led us to revisit this entity in our settings. MATERIALS AND METHODS: Between 2009 and 2014, 16 cases of histologically proven GSs (14 primary, two secondary) were treated. Patient data were retrieved retrospectively. Statistical analysis was performed with? Statistical Package for Social Sciences, version 17.0. (Chicago, Illinois, USA). Survival was analyzed by Kaplan-Meier method. RESULTS: GS predominantly affected males in their fifth decade of life. Raised intracranial pressure was the most common mode of clinical presentation. Temporal lobe was the most commonly affected part of the brain and majority of primary and all of secondary GBM were located peripherally. In 7 (43.8%) patients, tumor was radiologically well-demarcated and enhanced strongly and homogenously on contrast as compared to 9 (56.2%) patients where the tumor was ill-defined and showed heterogenous patchy or ring enhancement. Extent of excision was total in seven patients (43.8%), near total in 4 (25%) and subtotal in five patients (31.2%). Median survival was 6 months. Patients with well-demarcated, enhancing mass on imaging intraoperatively had firm tumors with a good plane of cleavage and had a better survival (8 months) compared to those in whom the tumor radiologically and intraoperatively mimicked GBM (2 months). CONCLUSION: GS is associated with poor survival (median survival 6 months). Radiological and intraoperative findings help categorize these tumors into GBM like GS and meningioma like GS. While the former histologically mimics GBM and has very poor survival (2 months), GS with meningioma like feature tends to have better survival (8 months).

Risk stratification of vertebral artery vulnerability during surgery for congenital atlanto-axial dislocation with or without an occipitalized atlas.

CONTEXT: Variability in dimensions and course of vertebral artery (VA) makes it vulnerable to injury during surgery for congenital atlanto-axial dislocation (AAD) with or without an occipitalized atlas. AIMS: This prospective study attempts to define anatomical variations that render VA at the craniovertebral junction (CVJ) vulnerable to injury during transoral decompression and posterior stabilization procedures; and, to propose a classification that helps in preoperative risk stratification. SETTINGS AND DESIGN: A prospective study. MATERIALS AND METHODS: 104 patients (65 with AAD; 39 controls) underwent a three-dimensional multiplanar computed tomographic angiogram to study anatomical variations in VA size, course, and anomalous medial deviation as well as in the type of axial isthmus and rotational deformity/tilt at the CVJ. The VA/foramen transversarium diameter; "stretched loop" sign of VA; and C1-2 facet joint angle were also assessed. STATISTICAL ANALYSIS USED: A medial VA deviation that brought it in close proximity to the trajectory of the surgical approach was evaluated (P ≤ 0.05 significant). RESULTS: An increased predisposition to VA injury was present in 23 (35.4%) patients (persistent first intersegmental artery [n = 20; 30%]; fenestrated VA [n = 1; 1.53%], and low-lying posterior inferior cerebellar artery [n = 2; 3.0%]) where VA crossed the C1-2 facet joint; 8 (12%) with an anomalous medial deviation; 12 (18%) with a high-riding VA at C2 and a narrow axial isthmus; and 13 (20%) with rotation/tilt at the CVJ. A normal score of 5 was obtained in 21 patients; and a score of 6-9 (that progressively indicated an increased vulnerability of VA to iatrogenic injury) in 44 patients. The "AAD with an occipitalized atlas" group was associated with a significant medial deviation of VA (right: P = 0.00 and left: P = 0.001). CONCLUSIONS: A preoperative detailed risk assessment of anatomical variations in the size and course of VA at the CVJ significantly reduces chances of its iatrogenic injury.

Pediatric anterior visual pathway gliomas: trends in fluid and electrolyte dynamics and their management nuances.

PURPOSE: Trends in pre- and postoperative fluid, electrolyte and osmolarity changes, and incidence of diabetes insipidus (DI) were assessed in pediatric patients with anterior visual pathway gliomas (AVPGs). METHODS: Thirty-three patients with AVPGs (age < 16 years) were divided into two groups: (1) no hypothalamic involvement [NHI; n = 17 (51.5 %) including optic (5, 15.2 %); chiasmal (5, 15.2 %); and optico-chiasmal (7, 21.2 %)] and (2) hypothalamic involvement [HI; n = 16 (48.5 %) including chiasmal-hypothalamic (12, 36.4 %) and optico-chiasmal-hypothalamic (4, 12.1 %)]. Frontotemporal transylvian decompression/biopsy was undertaken in 32 patients, while one patient (with severe diencephalic syndrome) was treated conservatively. Their endocrinal and fluid/electrolyte balance, serum osmolarity, and DI status were noted. Chi-square test compared clinical/endocrinological parameters, and unpaired T test evaluated mean daily water/electrolyte changes (p value < 0.05: significant). RESULTS: Significant visual deterioration (perception of light (PL) positive (left: n = 4; right: n = 4) and PL negative (left: n = 5; right: n = 5) was encountered due to optic atrophy. Larger lesions (>3 cm), hydrocephalus [(NHI: n = 7, 41.18 %; HI: n = 12, 75 %), endocrinopathies (p = 0.047), Na(+)/K(+) derangements, and preoperative DI (n = 8, p = 0.004)] were present in the group HI. Increased postoperative urine output (almost double in those with hypothalamic involvement) and hypernatremia/hyperkalemia were seen in group HI until the sixth postoperative day (p < 0.05). Two patients with progressive hypernatremia without increased urine output showed dehydration on central venous pressure monitoring and improved with vasopressin administration. Five patients [NHI: n = 4 (23.5 %); HI: n = 1 (6.3 %)] had neurofibromatosis types I and 3 (NHI: n = 1, 5.9 %; HI: n = 2, 12.5 %) had a diencephalic syndrome. CONCLUSIONS: Hypothalamic infiltration significantly increases the incidence of DI and fluid and electrolyte disturbances. Strict vigilance over postoperative fluid balance is mandatory during the first postoperative week. Rapidly rising serial serum sodium values without increased urine output mandates immediate central venous pressure measurement to detect DI associated with dehydration.

A I-segment aneurysms: management protocol based on a new classification.

BACKGROUND: Aneurysms of proximal (AI)-segment of anterior cerebral artery (ACA) constitute <1% of all intracranial aneurysms. AIM: Management dilemmas of A1-segment aneurysms were studied utilizing a new classification based upon their location on the longitudinal and circumferential axis of A1-segment. SETTING AND DESIGN: Tertiary care referral center. MATERIALS AND METHODS: This is a retrospective analysis of 14 patients (0.98%; mean age: 38.02 ± 15.74 years) with AI-segment aneurysms. The data collected included clinical features, computed tomography (CT) scan and CT-angiography (CTA)/digital subtraction angiography (DSA) findings, modified Hunt and Hess (H and H) grade, surgical steps and difficulties encountered. RESULTS: The modified Hunt and Hess (H and H) grades in the 14 patients were: grade I in two, grade II in two, grade III in four, grade IV in five and grade V in 1. The mean ictus-admission duration was 5.07 ± 2.30 days (range: 1-10 days). Multiple aneurysms were two. Thirteen patients underwent clipping and one, wrapping. Bilateral lateral ventricle hemorrhage occurred in 8 (66%) patients and frontal intracerebral hematoma in 2 (16.66%) patients. In one patient, the aneurysm could only be detected following the third angiogram. AI-aneurysms were classified as proximal (n = 6), distal (n = 7), and mid-segment (n = 1); and, anterior (n = 2), posterior-inferior (n = 7) and posterior-superior (n = 5). Follow-up (range: 6 months-10 years, mean: 2.9 years) recovery (assessed using Modified Rankin's score or mRS) correlated with preoperative status. The preoperative H and H grade and follow-up mRS status were as follows: H and H I (n = 2): mRS 0 (asymptomatic, n = 2); H and H II (n = 2): mRS 1 (minor symptoms without disability, n = 2); H and H III (n = 4):mRS 1 (n = 2) and mRS 2 (slight disability but performing unassisted activities of daily living, n = 1); H and H IV (n = 5): mRS 3 (moderate disability, requiring help for daily living but unassisted walking, n = 2) and mRS 4 (moderately severe disability, requiring help for daily living and walking, n = 2). One patient each from H and H grade III, IV and V died (mRS 6) during treatment due to severe vasospasm, pneumonitis and septicemia. CONCLUSIONS: AI-segment aneurysms have unique properties: rupturing of small-sized aneurysms; multiplicity; undetectable on initial imaging; frontal lobar/intraventricular bleeding; origin from main trunk and not bifurcating points; neck obscuration by AI-trunk; close proximity to perforators; and, associated AI-segment and ACA anomalies. A new classification identifies surgical difficulties inherent in different sites of origin of A1-aneurysms.