Gopalakrishnan M Sasidharan

Spinal aneurysms: clinicoradiological features and management paradigms

OBJECT Spinal aneurysms (SAs) are rare lesions. The clinicoradiological features and the exact degree of their association with comorbid conditions such as arteriovenous malformations (AVMs) and coarctation of the aorta have not been definitively described. The ideal management paradigm has not been established. The authors reviewed literature to determine the clinical patterns of presentation, management, and outcome of spinal aneurysms. METHODS A systematic review of literature was performed using 23 separate strings. A total of 10,190 papers were screened to identify 87 papers that met the inclusion criteria. A total of 123 SAs could be included for analysis. RESULTS The mean age of patients at presentation was 38 years; 10% of patients were aged less than 10 years and nearly 50% were greater than 38 years. Spinal aneurysms can be divided into 2 groups: those associated with AVMs (SA-AVMs, or Type 1 SAs) and those with isolated aneurysms (iSAs, or Type 2 SAs). Patients with Type 2 SAs were older and more likely to present with bleeding than those with Type 1 SAs. The acute syndromes can be divided into 3 groups of patients: those with spinal syndrome, those with cranial/craniospinal syndrome, and those with nonspecific presentation. Overall, 32.6% presented with angiography-negative cranial subarachnoid hemorrhage (SAH). Presentation with evidence of cord dysfunction (myelopathy/weakness/sensory loss/bladder involvement) correlated with poor outcome, as did presentation with hemorrhage and association with other comorbid conditions. Surgery and endovascular therapy both led to comparable rates of complete aneurysm obliteration for Type 2 SAs, whereas for the AVM-associated Type 1 SAs, surgery led to better rates of lesion obliteration. The authors propose a classification scheme for spinal aneurysms based on whether the lesion is solitary or is associated with a coexistent spinal AVM; this would also imply that the ideal therapy for the aneurysm would differ based on this association. CONCLUSIONS The clinical and radiological patterns that influence outcome are distinct for Type 1 and Type 2 SAs. The ideal treatment for Type 1 SAs appears to be excision, whereas surgery and endovascular therapy were equally effective for Type 2 SAs.

An analysis of the citation climate in neurosurgical literature and description of an interfield citation metric.

BACKGROUND The citation climate in neurosurgical literature is largely undefined. OBJECTIVE To study the patterns of citation of articles in neurosurgery as a scientific field and to evaluate the performance of neurosurgery journals vis-à-vis journals in other fields. METHODS References cited in articles published in neurosurgery journals during a specified time period were analyzed to determine the age of articles cited in neurosurgical literature. In the next analysis, articles published in neurosurgical journals were followed up for 13 years after publication. The postpublication citation patterns were analyzed to determine the time taken to reach the maximally cited state and the time when articles stopped being cited. The final part of the study dealt with the evolution of a new interfield citation metric, which was then compared with other standardized citation indexes. RESULTS The mean ± SD age of articles cited in neurosurgical literature was 11.6 ± 11.7 years (median, 8 years). Citations received by articles gradually increased to a peak (at 6.25 years after publication in neurosurgery) and then reached a steady state; articles were still cited well into the late postpublication period. Neurosurgical articles published in nonneurosurgical high-impact journals were cited more highly than those in neurosurgical journals, although they took approximately the same time to reach the maximally cited state (7.2 years). The most cited pure neurosurgery journal was Neurosurgery. CONCLUSION The citation climate for neurosurgery was adequately described. The interfield citation metric was able to ensure cross-field comparability of journal performance. ABBREVIATIONS G1, group 1G2, group 2G3, group 3G4, group 4IFCM, interfield citation metric.

Larsen syndrome with C3-C4 spondyloptosis and atlantoaxial dislocation in an adult.

Study Design. This is a clinical case report with a review of relevant literature. Objective. To describe a case of Larsen syndrome with C3–C4 spondyloptosis and atlantoaxial dislocation in a middle-aged female patient and to discuss management strategies. Summary of Background Data. Spondyloptosis of the cervical spine is relatively rare and is caused by trauma, destruction of the vertebral bodies by tumors, or tuberculosis. Such gross vertebral displacement is usually associated with significant neurological deficits. Larsen syndrome is characterized by multiple joint displacements and can, very rarely, be associated with nontraumatic spondyloptosis of the cervical vertebra. A single case report of C1–C2 joint laxity causing atlantoaxial dislocation in a patient with Larsen syndrome is available in literature. No reports of any patient (with Larsen syndrome or nonsyndromic) who had both cervical spondyloptosis and atlantoaxial dislocation are available in literature. Methods. A 36-year-old female presented with chronic neck pain, bilateral hand deformity, and mild spasticity involving all 4 limbs. Cervical radiograph, computed tomographic scan, and magnetic resonance image revealed C3–C4 spondyloptosis and atlantoaxial dislocation. Results. A combined ventral decompression of subaxial spine and instrumentation from C2 to C5, followed by posterior C1–C2 distraction arthroplasty and lateral mass stabilization of the subaxial spine up to C6, was done. The cervical deformity was corrected, and the patient remains symptom free. Conclusion. Patients with spondyloptosis of the cervical spine can rarely present with chronic neck pain and minimal neurological deficits. An additional pathology, such as atlantoaxial dislocation, can add to the complexity. Circumferential stabilization and fusion would be required in such cases to achieve a good outcome. Larsen syndrome is a rare cause of nontraumatic cervical displacements.

Measuring glioma volumes: A comparison of linear measurement based formulae with the manual image segmentation technique.

CONTEXT Gliomas are irregular in shape unlike benign brain tumors like meningiomas or schwannomas. Simplifying assumptions about glioma geometry are therefore more likely to lead to wrong calculations of glioma volumes than for other tumors. AIMS We compared simple linear measurement.based techniques of measuring glioma volume with manual region of interest.based image segmentation and to assess concordance. SETTINGS AND DESIGN This study was a retrospective radiology archive-based study. SUBJECTS AND METHODS The volumes of gliomas were measured by two assessors using five different techniques - manual image segmentation and four linear measurement-based formulae, which included the formulae for the volume of a sphere, cylinder, ellipsoid and its simplification v = abc/2. STATISTICAL ANALYSIS USED Intra-ssessor concordance was evaluated using mean vs. difference. (Bland-Altman) plots and raw agreement indices. Inter-rater agreement was assessed by calculating the intra-class correlation coefficient for each technique. RESULTS The best inter.rater concordance was for volume measured by manual segmentation. The tumor volumes measured using the formulae for volume of a sphere and cylinder had poor agreement with the planimetric volume and low inter.rater concordance. The formula for volume of an ellipsoid and its simplification had good agreement with the manual planimetric volume and had good inter.rater concordance. However, for larger tumors, the agreement with planimetric volume was poorer. CONCLUSIONS Manual region of interest-based image segmentation is the standard technique for measuring glioma volumes. For routine clinical use, the simple formula v = abc/2 (or the formula for volume of an ellipsoid) could be used as alternatives.

Idiopathic Intraventricular Aneurysm Presenting with Intraventricular Hemorrhage: Case Report and Review of the Literature

Intraventricular hemorrhage (IVH) is a relatively commonly encountered problem in neurosurgical practice. The underlying causes could include hypertension, arteriovenous malformations (AVM), angiomas, trauma, tumors, aneurysms and moyamoya disease. Truly idiopathic intraventricular aneurysms (IVA) are rare. A high index of suspicion needs to be maintained since, with the appropriate treatment, the outcome is generally good. We report the case of a 14-year-old boy who presented with sudden onset headache and vomiting. CT angiogram pointed to the possibility of an IVA. This was confirmed by MRI with three-dimensional constructive interference in steady state (CISS-3D) sequences and digital subtraction angiography. The patient underwent microsurgical excision of the aneurysm and is doing well on follow-up. Idiopathic IVA can present with IVH at any age. MRI with CISS-3D and MR angiography would be the imaging modality of choice since it can also rule out other causes of intraventricular bleeding such as tumors and AVM. These lesions could be managed effectively by microsurgical excision/clipping. The necessity of investigating every patient who presents with IVH is debatable.

Remote spinal epidural haematoma after spinal anaesthesia presenting with a 'spinal lucid interval'.

An obstetric patient who had no significant risk factors developed a spinal epidural haematoma remote from the site of needle puncture (for administration of spinal anaesthesia). The clinical deficits were manifest after recovery from the motor blockade had started a phenomenon that we have termed as a ‘spinal lucid interval’. The patient developed flaccid paraplegia with a sharp sensory level and urinary retention. The patient underwent emergency laminectomy and evacuation of the haematoma. She gradually recovered near normal power and was ambulant independently and had normal sphincter function at follow-up.

Giant cavernous carotid artery aneurysm mimicking a fungal granuloma and presenting with massive epistaxis

A 42-year-old man presented with frequent minor nasal bleeds since 1 month. He was undergoing chemotherapy for pulmonary tuberculosis. MRI brain revealed a space occupying lesion in the right cavernous sinus extending to sphenoid sinus, with T2 inversion. An initial diagnosis of fungal granuloma was made and endoscopic trans-nasal biopsy was attempted. During surgery, a pink pulsating mass was seen in the sphenoid sinus and the procedure was abandoned. A cerebral CT-angiography done subsequently revealed a giant right cavernous segment internal carotid artery (ICA) aneurysm. He was then referred to our centre and upon admission he collapsed secondary to a major bout of epistaxis. An emergency cervical carotid artery ligation resulted in transient control of epistaxis. Owing to recurrence of bleed, trapping of the aneurysm was done resulting in cure. The present case shows that a giant cavernous ICA aneurysm can occasionally be erroneously diagnosed as fungal granuloma.

Subclinical respiratory dysfunction in chronic cervical cord compression: a pulmonary function test correlation

OBJECTIVE Respiratory abnormalities are well documented in acute spinal cord injury; however, the literature available for respiratory dysfunction in chronic compressive myelopathy (CCM) is limited. Respiratory dysfunction in CCM is often subtle and subclinical. The authors studied the pattern of respiratory dysfunction in patients with chronic cord compression by using spirometry, and the clinical and surgical implications of this dysfunction. In this study they also attempted to address the postoperative respiratory function in these patients. METHODS A prospective study was done in 30 patients in whom cervical CCM due to either cervical spondylosis or ossification of the posterior longitudinal ligament (OPLL) was diagnosed. Thirty age-matched healthy volunteers were recruited as controls. None of the patients included in the study had any symptoms or signs of respiratory dysfunction. After clinical and radiological diagnosis, all patients underwent pulmonary function tests (PFTs) performed using a standardized Spirometry Kit Micro before and after surgery. The data were analyzed using Statistical Software SPSS version 13.0. Comparison between the 2 groups was done using the Student t-test. The Pearson correlation coefficient was used for PFT results and Nurick classification scores. A p value < 0.05 was considered significant. RESULTS Cervical spondylotic myelopathy (prolapsed intervertebral disc) was the predominant cause of compression (n = 21, 70%) followed by OPLL (n = 9, 30%). The average patient age was 45.06 years. Degenerative cervical spine disease has a relatively younger onset in the Indian population. The majority of the patients (n = 28, 93.3%) had compression at or above the C-5 level. Ten patients (33.3%) underwent an anterior approach and discectomy, 11 patients (36.7%) underwent decompressive laminectomy, and the remaining 9 underwent either corpectomy with fusion or laminoplasty. The mean preoperative forced vital capacity (FVC) (65%) of the patients was significantly lower than that of the controls (88%) (p < 0.001). The mean postoperative FVC (73.7%) in the patients showed significant improvement compared with the preoperative values (p = 0.003). The mean postoperative FVC was still significantly lower than the control value (p = 0.002). The mean preoperative forced expiratory volume in 1 second (FEV1) (72%) of the patients was significantly lower than that of the controls (96%) (p < 0.001). The mean postoperative FEV1 (75.3%) in the cases showed no significant improvement compared with the preoperative values (p = 0.212). The mean postoperative FEV1 was still significantly lower than the control value (p < 0.001). The mean postoperative FEV1/FVC was not significantly different from the control value (p = 0.204). The mean postoperative peak expiratory flow rate was significantly lower than the control value (p = 0.01). The mean postoperative maximal voluntary ventilation was still significantly lower than the control value (p < 0.001). On correlating the FVC and Nurick scores using the Pearson correlation coefficient, a negative correlation was found. CONCLUSIONS There is subclinical respiratory dysfunction and significant impairment of various lung capacities in patients with CCM. The FVC showed significant improvement postoperatively. Respiratory function needs to be evaluated and monitored to avoid potential respiratory complications.

Trigeminal schwannoma of the sphenoid sinus - report of a rare entity

Abstract Schwannomas are common slow growing benign tumors. About 25–45% of all schwannomas arise in the head and neck region. Less than 4% of these tumors are found in sinonasal regions and usually affect nasal ethmoid. There are very few case reports of a schwannoma arising from the sphenoid sinus. We report a case of sphenoid sinus schwannoma treated by microscopic decompression and review the relevant literature.

The Xomed Monopolar Cranial Nerve Stimulator Electrode: A Surprising Handy Tool for Deep Dissection of Epidermoid Tumors

Epidermoid cysts are notorious for their propensity to sneak into deep recesses between cranial nerves in the posterior fossa. Attempts to achieve complete excision using ordinary instruments when tempted by the seeming ease of dissection is known to cause unacceptable deficits. The Xomed monopolar stimulator electrode probe of the nerve integrity electromyography monitor has several advantages when used as the primary dissection tool for deep-seated epidermoid cysts. Cerebellopontine angle epidermoid is the classical prototype of a strategically placed deep-seated epidermoid tumor. The author describes the use of the monopolar stimulator electrode of the nerve integrity electromyography monitor as the primary dissection tool for excising epidermoid cysts of the cerebellopontine angle. Thin profile, rounded nontraumatic tip, and springiness of the body of the monopolar electrode aid the dissection. The monopolar electrode was used to tease and scoop out the flakes aided by a fine suction. An initial internal decompression allowed the capsule to be folded away and separated from neurovascular structures using the dissector. The thin profile of both the instruments allowed good visualization and delicate control over the dissection in depths of the resection cavity without undue traction or impacts on superficially dissected cranial nerves. This novel use of the monopolar electrode was employed in the surgical excision of epidermoid cysts of the cerebellopontine angle in nine patients. Total or near total excision was possible in eight of the nine patients who underwent excision using this technique. In three patients, mild deficits primarily of the fifth nerve sensory function were noted. The Xomed monopolar stimulating electrode of the nerve integrity electromyography monitor is an ideal instrument for deep dissection of epidermoid cysts in areas where neurovascular structures are at risk.