Murad Bavbek

Monoclonal Antibodies Against ICAM-1 and CD18 Attenuate Cerebral Vasospasm After Experimental Subarachnoid Hemorrhage in Rabbits

BACKGROUND AND PURPOSE Inflammatory responses have been implicated in the elaboration of several forms of central nervous system injury, including cerebral vasospasm after subarachnoid hemorrhage (SAH). A critical event participating in such responses is the recruitment of circulating leukocytes into the inflammatory site. Two of the key adhesion molecules responsible for the attachment of leukocytes to endothelial cells are intercellular adhesion molecule-1 (ICAM-1) and the common beta chain of the integrin superfamily (CD18). This study examined the effects of monoclonal antibodies on ICAM-1 and the effects of CD18 on cerebral vasospasm after SAH. METHODS A rabbit model of SAH was utilized to test the influence of intracisternally administered antibodies to ICAM-1 and CD18 on cerebral vasospasm. Antibodies were administered alone or in combination, and the cross-sectional area of basilar arteries was assessed histologically on day 2 post-SAH. RESULTS Treatment with antibodies to ICAM-1 or CD18 inhibited vasospasm by 22% and 27%, respectively. When administered together, the attenuation of vasospasm increased to 56%. All of these effects achieved statistical significance. CONCLUSIONS These findings provide the first evidence that the severity of cerebral vasospasm can be attenuated using monoclonal antibodies against ICAM-1 and CD18. The results reinforce the concept that cell-mediated inflammation plays an important role in cerebral vasospasm after SAH and suggest that therapeutic targeting of cellular adhesion molecules can be of benefit in treating cerebral vasospasm.

Intima-media thickness of the carotid arteries is related to serum osteoprotegerin levels in healthy postmenopausal women

Abstract Osteoprotegerin (OPG) regulates bone mass by inhibiting osteoclast differentiation and activation, and also plays a role in vascular calcification. The objective of this study was to evaluate the relationship between serum OPG levels, and carotid artery intima-media thickness (IMT) and carotid plaque formation in healthy postmenopausal women. We recruited 68 healthy postmenopausal women for the study. Carotid plaque presence and IMT were evaluated by high resolution B-mode ultrasound. IMT was positively correlated with presence of plaque, age, menopause age and OPG, and inversely correlated with Apolipoprotein A1 (Apo A1). Serum OPG level was positively correlated with IMT (r = 0.366; p < 0.003) and age (r = 0.324; p < 0.008), and negatively correlated with Apo A1 (r = –0.481; p < 0.0001). We did not observe any significant relation between plaque occurrence and levels of serum OPG. In regression analysis OPG (p < 0.02) and menopause age (p < 0.05) were independent risk factors for IMT, and age (p < 0.05) and IMT (p < 0.05) were independent risk factors for plaque formation. Although the role of OPG in the vascular biology is poorly understood, our results suggest that elevated levels of serum OPG is associated with IMT and may play a role in the pathogenesis of atherosclerotic disease.

Functional and clinical evaluation for the surgical treatment of degenerative stenosis of the lumbar spinal canal: Clinical article

OBJECT This study was designed to evaluate the efficacy of decompressive surgery for degenerative lumbar spinal stenosis (LSS) on a functional and clinical basis. METHODS A prospective analysis and follow-up of 125 consecutive patients with degenerative LSS between 2000 and 2006 were performed. All patients underwent surgery for lumbar stenosis. Functional evaluations of the patients were performed using a treadmill, the visual analog scale, and the Oswestry Disability Questionnaire (ODQ). These parameters were recorded before surgery and the 3rd month and 1st and 2nd years after treatment. The first symptom time (FST), maximal walking duration (MWD), and thecal sac cross-sectional area (CSA) before and after surgery were also recorded. Statistical relations between variables were calculated. RESULTS As patient ages increased, the CSA of the thecal sac decreased. Decompressive surgery reached the target according to the difference between the preoperative and postoperative thecal sac CSA. A correlation between the CSA of the thecal sac and FST, and between the CSA of the thecal sac and MWD could not be established. There was a significant correlation between the FST and MWD, and a negative correlation could be established between the MWD and the ODQ score. Surgery led to significant decreases in the ODQ score. Maximal improvement was observed in the 3rd month after decompressive surgery. CONCLUSIONS The treatment for LSS should be decided using functional criteria; radiological criteria may not correlate with the severity of the disease. Improvements following lumbar decompression surgery continued within 1 year of treatment according to the ODQ and did not change significantly thereafter.

Internal Reduction Established by Occiput-C2 Pedicle Polyaxial Screw Stabilization in Pediatric Atlantoaxial Rotatory Fixation

Atlantoaxial rotatory fixation is an uncommon disorder of childhood, which can be treated conservatively whendiagnosed early. Although spontaneous correction occasionally occurs, most of the patients usually benefit from collar or traction therapies. If there is no intervention or if all external therapeutic modalities fail, the deformity may become chronic and irreducible. In such rare cases, surgical correction and stabilization are needed to prevent future head and neck deformity or facial asymmetry. In this report we describe a novel surgical technique used in a pediatric case presenting with delayed type 2 atlantoaxial rotatory fixation, in whom all external reduction methods had failed. The patient’s deformity was treated by occiput-C2 pedicle polyaxial screw stabilization. This technique is effective for reducing the atlantoaxial fixation in children.

Freehand C1 lateral mass screw fixation technique: our experience.

BACKGROUND Although C1 lateral mass fixation technique is frequently performed in upper cervical instabilities, it requires the guidance of fluoroscopic imaging. The fluoroscopy guidance is time-consuming and has the risks of accumulative radiation. Biplane fluoroscopy is also difficult in upper cervical pathologic conditions because of the use of cranial fixations. This study aimed to demonstrate that unicortical C1 lateral mass screws could be placed safely and rapidly without fluoroscopy guidance. METHODS Between 2002 and 2008, 32 C1 lateral mass screws were inserted in 17 consecutive patients with various pathologic conditions involving either atlantoaxial or occipitocervical instability. RESULTS C1 screw lengths ranged from 18 to 32 mm. The atlantoaxial fixation was performed in 13 patients, and C1 lateral mass screws were added to the occipitocervical construct in 3 patients, to the posterior cervical construct in 2 patients, and to the cervicothoracic construct in 1 patient. In 2 patients, because C1 lateral mass screws could not be inserted unilaterally, C1 pedicle screw analogs were inserted. There were no screw malpositions or neurovascular complications related to screw insertion. Operation time and intraoperative bleeding of the isolated atlantoaxial fixations were retrospectively evaluated. The mean follow-up was 32.3 months (range, 7-59 months). No screw loosening or construct failure was observed within this period. Postoperatively, 4 patients complained of hypoesthesia, whereas one patient had superficial wound infection. CONCLUSION C1 lateral mass screws may be used safely and rapidly in upper cervical instabilities without intraoperative fluoroscopy guidance and the use of the spinal navigation systems. Preoperative planning and determining the ideal screw insertion point, the ideal trajections, and the lengths of the screws are the most important points.

Unusual Presentation of Cervical Spinal Intramedullary Arachnoid Cyst in Childhood: Case Report and Review of the Literature

The authors report a 7-year-old girl who presented with progressive quadriparesis which had started a month before admission. Magnetic resonance imaging of the spine revealed an intramedullary cystic lesion extending from C2 to C4. After performing a C2–5 laminectomy, the cyst was drained and anatomically fenestrated with the subarachnoid space by a 1-cm vertical median myelotomy without using a stent. The histopathological findings revealed arachnoid cyst. In the first month after operation, the neurological deficits disappeared gradually, except for a slight left upper paresis. Cervical spinal intramedullary arachnoid cyst is extremely rare and should be considered in the differential diagnosis of intramedullary cystic lesions in childhood. Recovery is possible after subtotal excision and fenestration of the cyst to allow communication with the subarachnoid space even if neurological deficits are present for a long time.

Lamotrigine attenuates cerebral vasospasm after experimental subarachnoid hemorrhage in rabbits.

BACKGROUND Increasing evidence implicates voltage-dependent sodium and potassium channels, in addition to calcium channels of various types, in the pathophysiological development of cerebral vasospasm. This study investigated the ability of LTG, an antiepileptic drug with multi-ion channel inhibition properties, to prevent cerebral vasospasm and subsequent neural ischemia in a rabbit model of SAH. METHODS Thirty-five New Zealand white rabbits were assigned to 1 of 3 groups: (1) control (no SAH, saline injection); (2) SAH alone; (3) SAH + LTG, 20 mg/kg daily. Animals were killed 72 hours after SAH, then basilar artery lumen areas and arterial wall thickness were measured in all groups. The histological sections of the CA1 and CA3 regions and dentate gyri of the hippocampi were evaluated semiquantitatively for neural tissue degeneration. RESULTS In the SAH group, the mean luminal cross-sectional area of the basilar artery was reduced by 62% after SAH as compared with the non-SAH controls (P < .0001). After SAH, the vasospastic response was attenuated by 36% in animals treated with 20 mg/kg of LTG compared with the SAH group (P < .005). The mean luminal cross-sectional areas of the basilar artery were 279000 +/- 27000 microm(2) in the control group, 173000 +/- 17600 microm(2) in the SAH group, and 236000 +/- 10000 microm(2) in the SAH + LTG group. The differences between the SAH group and the LTG-treated group were statistically significant (P < .0001). Histological examination was done in 12 control, 12 SAH, and 9 SAH + LTG-treated animals. The mean degeneration score for the control group and SAH + LTG group was statistically significant (P = .012). The difference between the SAH group and SAH+ LTG group was also statistically significant (P = .006). CONCLUSIONS These findings demonstrate that oral administration of LTG has marked neuroprotective effect and significantly attenuates cerebral vasospasm after SAH, thus providing additional support for the role of non-L-type calcium channels and voltage-dependent sodium channels in vasospasm.

Spinal subdural abscess: A rare cause of low back pain

Spinal subdural abscess (SSA) is a rare but well-described entity. It may occur secondary to a systemic infectious focus or following a surgical procedure. There are only two SSA cases in the literature that are unrelated to such conditions and without any well-documented etiology. SSA is a neurosurgical emergency and diagnosis may be difficult. Progressive neurological deficits and severe pain with fever suggest the diagnosis. Surgical drainage and subsequent prompt antimicrobial therapy should be performed without delay. We report a patient with SSA unrelated to any predisposing condition and discuss underlying mechanisms of this disease.

Ogilvie's syndrome as a rare complication of lumbar disc surgery.

BACKGROUND In this study we report a rare complication after lumbar surgery, Ogilvies syndrome, that presents as acute colonic dilatation in the absence of mechanical obstruction. CASE A 43-year-old obese woman underwent lumbar surgery for L4-L5 lumbar disc herniation. The patient complained of persistent abdominal distention and lack of bowel sounds. Plain radiography and ultrasonography revealed massive dilatation of the colon. Nasogastric aspiration was initiated and all analgesic drugs were withdrawn. Abdominal distention gradually disappeared within three days. CONCLUSIONS Only three cases of Ogilvies syndrome following lumbar spinal surgery have been reported in the literature. In our case obesity, chronic constipation, and narcotic drugs were the most likely precipitating causes. Ogilvies syndrome may resolve with conservative treatment, but if the cecal diameter continues to increase, colonoscopy or laparotomy may be needed to prevent perforation of colon.

Atretic Parietal Cephalocele

A 3-month-old girl was admitted to the hospital with a 2.5 ! 3 ! 2 cm, posterior parietal vertex midline cystic lesion. The smooth lesion was a round pulsating swelling. Neurological examination was within normal limits according to the patient’s age. Her delivery had been via the spontaneous vaginal route with no accompanying anomalies. There was no family history of congenital central nervous system lesions. Magnetic resonance imaging (MRI) was performed, which demonstrated a posterior parietal extra-axial lesion on sagittal T 1 -weighted images. The lesion was isointense similar to cerebrospinal fluid (CSF) on T 1 -weighted sequences ( fig. 1 ). At surgery, a smooth mass was found filled with CSF, which contained no neural or glial tissue within the lesion. No associated venous structure or any other visible venous abnormality was detected. The lesion was excised totally at the dural junction, dura and overlying skin were repaired. A postoperative MRI showed no abnormality except normal postoperative changes ( fig. 2 ). The patient had an uneventful recovery and was discharged without any complication.