Prasad Vannemreddy

Intracranial aneurysms and cocaine abuse: analysis of prognostic indicators.

OBJECTIVEnThe outcome of subarachnoid hemorrhage associated with cocaine abuse is reportedly poor. However, no study in the literature has reported the use of a statistical model to analyze the variables that influence outcome.nnnMETHODSnA review of admissions during a 6-year period revealed 14 patients with cocaine-related aneurysms. This group was compared with a control group of 135 patients with ruptured aneurysms and no history of cocaine abuse. Age at presentation, time of ictus after intoxication, Hunt and Hess grade of subarachnoid hemorrhage, size of the aneurysm, location of the aneurysm, and the Glasgow Outcome Scale score were assessed and compared.nnnRESULTSnThe patients in the study group were significantly younger than the patients in the control group (P < 0.002). In patients in the study group, all aneurysms were located in the anterior circulation. The majority of these aneurysms were smaller than those of the control group (8 +/- 6.08 mm versus 11 +/- 5.4 mm; P = 0.05). The differences in mortality and morbidity between the two groups were not significant. Hunt and Hess grade (P < 0.005) and age (P < 0.007) were significant predictors of outcome for the patients with cocaine-related aneurysms.nnnCONCLUSIONnCocaine use predisposed aneurysmal rupture at a significantly earlier age and in much smaller aneurysms. Contrary to the published literature, this group did reasonably well with aggressive management.

Congenital hydrocephalus and ventriculoperitoneal shunts: influence of etiology and programmable shunts on revisions

OBJECTnHydrocephalus is a notorious neurosurgical disease that carries the adage once a shunt always a shunt. This study was conducted to review the treatment results of pediatric hydrocephalus.nnnMETHODSnPediatric patients who underwent ventriculoperitoneal shunt surgery over the past 14 years were reviewed for shunt revisions. Variables studied included age at shunt placement, revision, or replacement; programmable shunts; infection; obstruction; and diagnosis (congenital, posthemorrhagic, craniospinal dysraphism, and others including trauma, tumors, and infection). Multiple regression analysis methods were used to determine independent risk factors for shunt failure and the number of shunt revisions. The Kaplan-Meier method of survival analysis was used to compare etiologies on the 5-year survival (revision-free) rate and the median 5-year survival time.nnnRESULTSnA total of 253 patients were studied with an almost equal sex distribution. There were 92 patients with congenital hydrocephalus, 69 with posthemorrhagic hydrocephalus, 48 with craniospinal dysraphism, and 44 with other causes. Programmable shunts were used in 73 patients (other types of shunts were used in 180 patients). A total of 197 patients (78%) underwent revision surgeries due to shunt failures. The mortality rate was 1.6%. Age at first revision, the 5-year survival rate, and the median 5-year survival time were significantly less for both posthemorrhagic and craniospinal dysraphism than for either the congenital or other group (p < 0.05). The failure rate and number of revisions were not significantly reduced with programmable shunts compared with either pressure-controlled or no-valve shunts (p > 0.5).nnnCONCLUSIONSnPosthemorrhagic hydrocephalus and craniospinal dysraphism hydrocephalus had significantly earlier revisions than congenital and other etiologies. Programmable systems did not reduce the failure rate or the average number of shunts revisions.

Operative versus nonoperative management of acute odontoid Type II fractures: a meta-analysis

OBJECTnThe purpose of this study was to evaluate the feasibility of the criteria described in the literature as the indications for surgery for acute Type II odontoid fractures.nnnMETHODSnThe authors searched the PubMed database for studies in which the fusion rate of acute Type II odontoid fractures following external immobilization (halo vest or collar) or surgery (posterior C1-2 fusion or anterior screw fixation) was reported. The only studies included reported the fusion rate for either 1) groups of patients whose age was either more or less than a certain age range (45-55 years); or 2) groups of patients with a fracture displacement of either more or less than a certain odontoid fracture displacement (4-6 mm) or the direction of displacement (see Methods section of text for more details). A meta-analysis in which the random effect model was used was conducted to analyze the data.nnnRESULTSnThere was a statistically significantly higher fusion rate for operative management compared with external immobilization (85 vs 60%, p = 0.01) for the patients > 45-55 years. However, the overall fusion rate was > 80% for the patients whose age was < 45-55 years, regardless of treatment modality, and no significant differences were observed between surgically and nonsurgically treated patients (89 and 81%, respectively; p = 0.29). The result of operation (overall fusion rate 89%) was superior to external immobilization (44%) when the fracture was posteriorly displaced (p < 0.001), but for anteriorly displaced fractures, the results of operative and nonoperative management were identical (p = 0.15). The overall fusion rate of operative management of both anteriorly and posteriorly displaced fractures proved to be > 85%, and no statistically significant difference was observed (p = 0.50). For all degrees of displacement (either > or < 4-6 mm) the operation proved to provide significantly better results than conservative treatment. The fusion rate of conservatively treated fractures with < 4-6 mm displacement was significantly better than in fractures with > 4-6 mm displacement (76 vs 41%, p = 0.002).nnnCONCLUSIONSnOperative treatment (posterior C1-2 fixation or anterior screw fixation) provides a better fusion rate than external immobilization for acute odontoid Type II fractures, although in certain situations, such as anterior displacement of the fracture and for younger (< 45-55 years of age) patients, conservative management (halo vest or collar immobilization) can be as effective as surgery. Operative management is recommended in older patients, in cases of posterior displacement of the fracture, and when there is displacement of > 4-6 mm.

Ventricular reservoirs and ventriculoperitoneal shunts for premature infants with posthemorrhagic hydrocephalus : an institutional experience

OBJECTnThe aim of the study was to analyze the outcome of surgical treatment for posthemorrhagic hydrocephalus in premature infants.nnnMETHODSnFrom 1990 to 2006, 32 premature infants underwent surgical treatment for posthemorrhagic hydrocephalus, and their charts were retrospectively reviewed to analyze the complications and outcome with respect to shunt revisions. Multivariate analysis and time series were used to identify factors that influence the outcome in terms of shunt revisions.nnnRESULTSnThe mean gestational age was 27+/-3.3 weeks, and mean birth weight was 1192+/-660 g. Temporary reservoir placement was performed in 15 patients, while 17 underwent permanent CSF diversion with a ventriculoperitoneal (VP) shunt. In 2 patients, reservoir tapping alone was sufficient to halt the progression of hydrocephalus; 29 patients received VP shunts. The mean follow-up period was 37.3 months. The neonates who received VP shunts first were significantly older (p=0.02) and heavier (p=0.04) than those who initially underwent reservoir placement. Shunts were revised in 14 patients; 42% of patients in the reservoir group had their shunts revised, while 53% of infants who had initially received a VP shunt required a revision. The revision rate per patient in the reservoir group was half that in the direct VP shunt group (p=0.027). No patient in the reservoir group had >2 revisions. Shunt infections developed in 3 patients (10.3%), and 2 patients in the reservoir group died of nonneurological issues related to prematurity.nnnCONCLUSIONSnBirth weight and age are useful parameters in decision making. Preterm neonates with low birth weights benefit from initial CSF drainage procedures followed by permanent CSF diversion with respect to the number of shunt revisions.

Congenital Chiari malformations.

Chiari malformation is the commonest anomaly of the craniovertebral junction involving both the skeletal as well as the neural structures. This entity has rapidly evolved over the past decade with newer visualization techniques, thus posing new challenges to diagnosis and management. This review includes the developmental theories, the latest nomenclature and existing treatment modalities of this interesting anomaly. Five theories tried to explain the malformation of the hindbrain and the neuraxis but no single theory completes the development of embryonic defects. Several atypical presentations have been reported with either incidental/asymptomatic features resulting in further classifications. The new magnetic resonance imaging flow techniques attempt to substantiate the clinical presentations and correlate with the abnormality which can be subtle in correlation. Surgical correction to improve the cranial volume, decrease the hydrocephalus and improve flow across the foramen magnum is the mainstay but needs to be tailored to a given type of malformation. Further clinical and imageological studies, especially longitudinal natural history, might improve our understanding of the atypical/asymptomatic presentations and the management that is currently available.

Traumatic spondylolisthesis of the axis: a biomechanical comparison of clinically relevant anterior and posterior fusion techniques

OBJECTnSurgical management of unstable traumatic spondylolisthesis of the axis includes both posterior and anterior fusion methods. The authors performed a biomechanical study to evaluate the relative stability of anterior fixation at C2-3 and posterior fixation of C-1 through C-3 in hangmans fractures.nnnMETHODSnFresh-frozen cadaveric spine specimens (occipital level to T-2) were subjected to stepwise destabilization of the C1-2 complex, replicating a Type II hangmans fracture. Intact specimens, fractured specimens, and fractured specimens with either anterior screw and plate or posterior screw and rod fixation were each tested for stability. Each spine was subjected to separate right and left rotation, bending, flexion, and extension testing.nnnRESULTSnAnterior fixation restored stiffness in flexion and extension movements to values greater than those for intact specimens. For other movement parameters, the values approximated those for intact specimens. Posterior fixation increased the stiffness to above those values seen for anterior fixation specimens.nnnCONCLUSIONSnIn cadaveric spine specimens subjected to a Type II hangmans fracture, both anterior fixation at C2-3 and posterior fixation with C-1 lateral mass screws and C-2 and C-3 pedicle screws resulted in a consistent increase in stiffness, and hence in stability, over intact specimens.

Hydatid disease of the central nervous system: a review of literature with an emphasis on Latin American countries.

Abstract Objective: To provide an up to date review of the epidemiology, etiology, treatment and prevention of hydatid cyst of the central nervous system, with an emphasis in South American countries. Methods: We searched the PubMed databases for articles containing the terms hydatid cyst and nervous system. Results: We found and reviewed 303 articles and their related references. We provide the available information on the pathology, life cycle and diagnostic modalities (laboratory tests and imaging) along with possible complications of the disease. Current treatment methods of hydatid cyst in the brain and spine are also being discussed. Discussion: Echinococcosis is a rare parasitic disease, endemic in some parts of South America. The epidemiology of echinococcosis is influenced by agricultural, educational, economic, medical and cultural factors. Human infestation occurs through the fecal–oral route. Infection of the central nervous system is rare, and the mainstay of treatment is surgical excision of the intracranial or spinal cyst, when present. Preventive programs should break the parasite life cycle and also educate the farmers in endemic areas.

Influence of cocaine on ruptured intracranial aneurysms: a case control study of poor prognostic indicators

OBJECTnThe purpose of this study was to determine whether cocaine use is a significant prognostic factor for outcome measures such as Hunt and Hess grade and Glasgow Outcome Scale (GOS) score among patients presenting with ruptured intracranial aneurysms (IAs).nnnMETHODSnThe authors performed a MEDLINE/PubMed search for cases of ruptured IAs associated with cocaine use. Fourteen cases from the authors experience were combined with 50 from a literature review, for a total of 64 cases associated with cocaine use. These 64 cases were compared with 65 cases without cocaine use (controls), which had been obtained from an aneurysm database. Logistic regression analysis was performed to determine significant prognostic factors for a poor Hunt and Hess grade and a poor GOS score, and a general linear model was applied to identify significant factors for these measures among cocaine users.nnnRESULTSnThere were 40 women in each group. The mean age was 32.3 +/- 8.1 years in the cocaine group and 49.7 +/- 10.6 years in the control group; thus, patients in the cocaine group were significantly younger (p < 0.01). Cocaine was snorted in 21% of cases, smoked in 55%, and intravenously injected or taken in through a combination of routes in 24%. Fifty-one percent of cocaine users and 7.7% of nonusers presented with a poor GOS score (p < 0.01). Fifty-six percent had ictus during cocaine abuse. At the end of a 30-day follow-up, 51% of the patients in the cocaine group had a good GOS score compared with 92% in the control group (p < 0.01). Controlling for the effects of other significant factors, cocaine use had a significant effect on Hunt and Hess grade (p < 0.03) and GOS score (p < 0.01). The odds of having a poor Hunt and Hess grade among cocaine users were 4.2 times greater than those in nonusers, and the odds of having a poor GOS score among cocaine users were 38.8 times greater.nnnCONCLUSIONSnAneurysms were significantly smaller and ruptured at a younger age among cocaine users compared with nonusers. Although the poor clinical grade was not significantly different between the 2 groups, outcome was significantly worse in cocaine users.

Microsurgical excision of colloid cyst with favorable cognitive outcomes and short operative time and hospital stay: operative techniques and analyses of outcomes with review of previous studies.

OBJECTIVEMicrosurgical and endoscopic colloid cyst excision differ with regard to operative time, length of hospital stay, and extent of resection. METHODSA retrospective review of a single surgeons microsurgical colloid cyst resection in 10 consecutive patients was performed. Cyst size, hydrocephalus, symptoms, operative time, postoperative stay, complications, and objective testing of memory, concentration, calculation, and attention (cognition), along with performance at job, were noted. RESULTSAll 10 patients had complete excision. Mean cyst size, mean operative time, and median postoperative stay were 1.6 cm, 124 minutes, and 3.5 days respectively. The mean operative time from cyst visualization to complete excision was 18 minutes. Follow-up ranged from 6 to 111 months (mean, 49.5 months). There were no recurrences; symptoms (headache, visual and balance problems) improved significantly in 70%. Postoperative cognitive performance, including memory, was the same in 8 patients (5 of whom had preoperative memory problems) and worse in 2 patients who had no preoperative memory problems. The bone flap was removed in 1 patient for wound dehiscence. Hemiparesis in another patient, seen immediately after surgery, completely resolved before discharge. One patient with loculated ventricles and multiple previous shunt revisions had unresolved hydrocephalus after cyst excision. CONCLUSIONWe report the very short operative times and postoperative stay for microsurgery, which are comparable to some endoscopic series. We also report results of objective tests of cognitive performance. With adoption of a callosal incision of 1 cm or less, meticulous dissection around the fornix, and complete excision, acceptable long-term cognitive function and functional performance were achieved. Our results support the microsurgical approach. A larger sample size can more conclusively establish whether it should be chosen over the endoscopic technique.

Recurrence and Outcome in Skull Base Meningiomas: Do They Differ from Other Intracranial Meningiomas?

BACKGROUND AND OBJECTIVESnMeningiomas have diverse presentations and the skull base harbors the most difficult of them to operate upon. The objective of this study was to learn whether the recurrence and outcome of these tumors may differ based on their location.nnnDESIGNnConsecutive admissions with intracranial meningiomas between 1999 and 2004 were considered according to their location, WHO grade, recurrence, and outcome following treatment.nnnRESULTSnThere were 83 skull base meningiomas and 86 at other locations. In 22 cases of skull base tumors there was recurrence (26.5%), while 15% (13) of the other group showed recurrence. There was no statistically significant difference in the outcome between the two groups; though skull base lesions had a better outcome based upon a raw count. Only 5.1% of skull base meningiomas in comparison to 10.6% of non-skull base meningiomas had death or significant morbidity. Increasing age was associated with poor outcome (p < 0.001) while recurrence was a function of skull base location (p < 0.03) on logistic regression analysis.nnnCONCLUSIONnSkull base meningiomas can be operated upon with good outcome, which is comparable to the convexity meningiomas. Except for the increasing age, skull base location does not contribute to increased mortality or morbidity.