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Vamseemohan Beeram, Sundaram Challa and Prasad Vannemreddy

✓ Craniocerebral maduromycetoma is extremely rare. The authors describe a case of maduromycetoma involving the left parietal cortex, bone, and subcutaneous tissue in a young male farm laborer who presented with left parietal scalp swelling that had progressed into a relentlessly discharging sinus. Computed tomography (CT) scanning of his brain revealed osteomyelitis of the parietal bone with an underlying homogeneously enhancing tumor. Intraoperatively, the mass was revealed to be a black lesion involving the bone, dura mater, and underlying cerebral cortex. It was friable and separated from the surrounding brain by a thick gliotic scar. Gross-total excision was performed, and the patient was placed on a 6-week regimen of itraconazole. To the authors' knowledge, this is the first instance of cerebral mycetoma with CT findings reported in the literature.

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Ali Nourbakhsh, Prashant Chittiboina, Prasad Vannemreddy, Anil Nanda and Bharat Guthikonda

Object

Transpedicular thoracic vertebrectomy (TTV) is a safe alternative to the more standard transthoracic approach. A TTV is most commonly used to address vertebral body fractures due to tumor or trauma.

Transpedicular reconstruction of the anterior column with cage/bone traditionally requires unilateral thoracic nerve root sacrifice. In a cadaveric model, the authors evaluated the feasibility of transpedicular anterior column reconstruction without nerve root sacrifice. If feasible, this may be a reasonable approach that could be extended to the lumbar spine where nerve root sacrifice is not an option.

Methods

A TTV was performed in 8 fixed cadaveric specimens. In each specimen, an alternate vertebra (either odd or even) was removed so that single-level reconstruction could be evaluated. The vertebrectomy included facetectomy, adjacent discectomies, and laminectomy; however, the nerve roots were preserved. The authors then evaluated the feasibility of inserting a titanium mesh cage (Medtronic Sofamor Danek) without neural sacrifice.

Results

Transpedicular anterior cage reconstruction could be safely performed at all levels of the thoracic spine without nerve root sacrifice. The internerve root space varied from 18 mm at T2–3 to 27 mm at T11–12; thus, the size of the cage that was used also varied with level.

Conclusions

Cage reconstruction of the anterior column could be safely performed via the transpedicular approach without nerve root sacrifice in this cadaveric study. Removal of the proximal part of the rib in addition to a standard laminectomy with transpedicular vertebrectomy provided an excellent corridor for anterior cage reconstruction at all levels of the thoracic spine without nerve root sacrifice.

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Prasad S. S. V. Vannemreddy and James L. Stone

Fifty years before a report on the complete bitemporal lobectomy syndrome in primates, known as the Klüver-Bucy syndrome, was published, 2 talented investigators working at the University College in London, England—neurologist Sanger Brown and physiologist Edward Schäfer—also made this discovery. The title of their work was “An investigation into the functions of the occipital and temporal lobes of the monkey’s brain,” and it involved excisional brain surgery in 12 monkeys. They were particularly interested in the then-disputed primary cortical locations relating to vision and hearing. However, following extensive bilateral temporal lobe excisions in 2 monkeys, they noted peculiar behavior including apparent loss of memory and intelligence resembling “idiocy.” These investigators recognized most of the behavioral findings that later came to be known as the Klüver-Bucy syndrome. However, they were working within the late-19th-century framework of cerebral cortical localizations of basic motor and sensory functions.

Details of the Brown and Schäfer study and a glimpse of the neurological thinking of that period is presented. In the decades following the pivotal work of Klüver and Bucy in the late 1930s, in which they used a more advanced neurosurgical technique, tools of behavioral observations, and analysis of brain sections after euthanasia, investigators have elaborated the full components of the clinical syndrome and the extent of their resections.

Other neuroscientists sought to isolate and determine the specific temporal neocortical, medial temporal, and deep limbic structures responsible for various visual and complex behavioral deficits. No doubt, Klüver and Bucy’s contribution led to a great expansion in attention given to the limbic system’s role in action, perception, emotion, and affect—a tide that continues to the present time.

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Prasad Vannemreddy, Gloria Caldito, Brian Willis and Anil Nanda

Object

The 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).

Methods

The 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.

Results

There 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.

Conclusions

Aneurysms 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.

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Ali Nourbakhsh, Runhua Shi, Prasad Vannemreddy and Anil Nanda

Object

The 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.

Methods

The 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.

Results

There 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).

Conclusions

Operative 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.

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James L. Stone, Aditi Gulabani, Gleb Gorelick, Siddharth N. K. Vannemreddy and Prasad S. S. V. Vannemreddy

Object

Halo orthosis placement is a common neurosurgical procedure for the treatment of cervical spine injuries. Frontal sinus puncture by the anterior pins may occur using standard techniques, and up to 30% are dissatisfied with forehead scarring, especially women and African Americans.

Methods

The authors describe a frontolateral (FL) anterior pin site placement supported by high-resolution CT scan skull thickness measurements. The standard supraorbital (SO) pin site is several centimeters above the lateral orbit, whereas the FL pin site is 2–3 cm posterolateral to the SO site. Frontolateral placement is just anterior to the temporalis muscle close to a triangular anterior projection of the temporal hairline. For quantitative information on skull thickness at the SO and FT pin sites, thin 0.625-mm CT scan measurements of the outer table, diploic space, and inner table were obtained in 40 adults (80 sites).

Results

The mean values for total skull thickness at the SO and FT sites were not significantly different. The inner table was significantly thicker at the FL site in both males and females, buttressed by the nearby greater sphenoid wing. The mean total skull thickness was significantly less in females than in males, but the values were not significantly different at the SO and FL sites.

Conclusions

The FL and SO anterior pin sites are comparable with respect to skull thickness CT measurements, with a significantly thicker inner table at the FL site. In the senior author's experience, the FL anterior pin site yielded secure fixation without skull perforation, neurovascular injury, or propensity to infection. The cosmetic result of the FL site is more acceptable, and the authors recommend its general usage be adopted.

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Anil Nanda, David A. Vincent, Prasad S. S. V. Vannemreddy, Mustafa K. Baskaya and Amitabha Chanda

Object. The goal of this study was to determine whether drilling out the occipital condyle facilitates surgery via the far-lateral approach by comparing data from 10 clinical cases with that from studies of eight cadaver heads.

Methods. During the last 6 years at Louisiana State University Health Sciences Center—Shreveport, 10 patients underwent surgery via the far-lateral approach to the foramen magnum. Six of these patients harbored anterior foramen magnum meningiomas, one patient a dermoid cyst, two patients vertebral artery (VA) aneurysms, and an additional patient suffered from rheumatoid disease of the craniocervical junction. The surgical approach consisted of retromastoid craniectomy and C-1 laminectomy.

The seven tumors and the pannus of rheumatoid disease were completely excised, and the two aneurysms were clipped without drilling the occipital condyle. In one patient a chronic subdural hematoma was found 3 months after surgery, but no patient displayed any complication associated with surgery. It is significant that in no patient was a cerebrospinal fluid leak present. All patients experienced improved neurological function postoperatively.

To compare surgical visibility, eight cadaveric specimens (16 sides) were studied, including delineation of the VA and its segments around the craniocervical junction. Increase in visibility as a function of fractional removal of the occipital condyle was quantified by measuring the degrees of visibility gained by removing one third and one half of the occipital condyle. Removal of one third of the occipital condyle produced a mean increase of 15.9° visibility, and removal of one half produced a mean increase of 19.9°.

Conclusions. On the basis of their findings the authors conclude that removal of the occipital condyle is not necessary for the safe and complete resection of anterior intradural foramen magnum tumors.

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Roy A. E. Bakay and Prasad S. S. V. Vannemreddy

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Ali Nourbakhsh, Jinping Yang, Sean Gallagher, Anil Nanda, Prasad Vannemreddy and Kim J. Garges

Object

The purpose of this study was to find a landmark according to which the surgeon can dissect the cervical spine safely, with the lowest possibility of damaging the vertebral artery (VA) during anterior approaches to the cervical spine or the VA.

Methods

The “safe zone” for each level of the cervical spine was described as an area where the surgeon can start from the midline in that zone and dissect the soft tissue laterally to end up on the transverse process and cross the VA while still on the transverse process. In other words, safe zone signifies the narrowest width of the transverse process at each level. In such an approach, the VA is protected from the inadvertent deep penetration of the instruments by the transverse process. The surgical safe zone for each level was the common area among at least 95% of the safe zones for that level. For the purpose of defining the upper and lower borders of the safe zone for each level, the line passing from the upper vertebral border perpendicular to the midline (upper vertebral border line) was used as a reference.

Cervical spines of 64 formalin-fixed cadavers were dissected. The soft tissue in front of the transverse process and intertransverse space was removed. Digital pictures of the specimens were taken before and after removal of the transverse processes, and the distance to the upper and lower border of the safe zone from the upper vertebral border line was measured on the digital pictures with Image J software. The VA diameter and distance from the midline at each level were also measured. To compare the means, the authors used t-test and ANOVA.

Results

The surgical safe zone lies between 1 mm above and 1 mm below the upper vertebral border at the fourth vertebra, 2 mm above and 1 mm below the upper vertebral border at the fifth vertebra, and 1 mm above and 2 mm below the upper vertebral border of the sixth vertebra. The VA was observed to be tortuous in 13% of the intertransverse spaces. There is a positive association between disc degeneration and tortuosity of the VA at each level (p < 0.001). The artery becomes closer to the midline (p < 0.001) and moves posteriorly during its ascent.

Conclusions

Dissection of the soft tissue off the bone along the surgical safe zone and removal of the transverse process afterward can be a practical and safe approach to avoid artery lacerations. The findings in the present study can be used in anterior approaches to the cervical spine, especially when the tortuosity of the artery mandates exposure of the VA prior to uncinate process resection, tumor excision, or VA repair.

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Prasad Vannemreddy, Christina Notarianni, Krishna Yanamandra, Dawn Napper and Joseph Bocchini Jr

Object

Studies have shown decreased levels of nitric oxide (NO), the product of endothelial NO synthase (eNOS) gene activity, in infants with respiratory conditions and intraventricular hemorrhage (IVH). The authors evaluated the association of the eNOS gene promoter polymorphism T-786C with the cause of these conditions (respiratory conditions and IVH) in premature infants.

Methods

Blood samples from 124 African American premature infants were studied. The DNA was isolated and microplate polymerase chain reaction–restriction fragment length polymorphism assay was performed. Genotypes were scored as: TT homozygotes with 140 bp and 40 bp; CC homozygotes with 90 bp, 50 bp, and 40 bp; and TC heterozygotes with 140 bp, 90 bp, 50 bp, and 40 bp. Genotypes were stratified according to ethnicity, preterm status, and prematurity conditions.

Results

The mutant allele -786C was present in 15.3% of premature infants with respiratory distress syndrome, bronchopulmonary dysplasia, and IVH, compared with 7.25% in those premature infants without these conditions. A significant 2-fold increase of the mutant allele in patients compared with controls (p = 0.04, OR 2.3) reveals that the eNOS -786C allele could be a significant risk factor in the origin of respiratory conditions and IVH in premature infants.

Conclusions

These results suggest that the mutant eNOS -786C allele is a significant risk factor in the origin of respiratory and IVH diseases, probably mediating an insufficient supply of endogenous NO in premature infants.