Post-operative seizure after first time endoscopic third ventriculostomy in pediatric patients.

PURPOSE: Post-operative seizure rates after endoscopic third ventriculostomy (ETV) are not definitively known. We analyzed our institution's experience for all causes of hydrocephalus in pediatric patients undergoing ETV to determine rates of post-ETV seizure. METHODS: A retrospective review of institutional pediatric patients undergoing ETV from May 2014 to December 2018. Included were < 21 years, with 1-year follow-up. Exclusion criteria included ventriculoperitoneal shunts (VPS) prior to ETV, VPS within 7 days post-ETV, and prior seizure disorder. Data included age, gender, diagnosis, early post-operative seizure (within 7 days post-ETV), late post-operative seizures (after first 7 days and within first year post-ETV), concomitant choroid plexus cauterization (CPC), VPS conversion within 1 year, and administration of prophylactic antiepileptics. RESULTS: Sixty of 81 ETV cases were included; 41% underwent concomitant CPC. Of these, 53% (n = 32) were male, 46% (n = 28) female, averaging 5.8 years, with the most common diagnosis neoplasm-related obstructive hydrocephalus (38.3%, n = 23). Early post-operative seizure occurred in 6.7% (n = 4); late post-operative seizure occurred in 8.3% (n = 5). Late post-operative seizures were higher in patients experiencing early post-operative seizure versus those without (75% vs 3.7%, p = 0.003). Late post-operative seizure occurred in 13.6% (n = 3 patients) requiring VPS versus 5.3% (n = 2 patients) with successful ETV (p = 0.36). Rates did not correlate with pathology. No patients received prophylactic antiepileptics prior to surgery or exhibiting a seizure. CONCLUSIONS: Patients with early post-operative seizures have an increased likelihood of developing late post-operative seizures. Pediatric ETV patients may have a lower rate of both early and late post-operative seizure; underlying pathology may influence these rates.

O6-Methylguanine-DNA methyltransferase in pediatric primary brain tumors: relation to patient and tumor characteristics.

The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) confers resistance to methylating and chloroethylating agents in pediatric medulloblastoma- and glioma-derived cell lines and xenografts. Here, we assayed MGMT activity in 110 pediatric brain tumors to establish correlates with patient and tumor characteristics. We also assayed MGMT in histologically normal brain adjacent to 22 tumors to characterize changes in activity accompanying neurocarcinogenesis. MGMT activity was detected in 94% of tumors, ranging ca. 1,500-fold from 0.34 to 498 fmol/10(6) cells (approximately 205-300,000 molecules/cell). Mean activity was 25 +/- 66 fmol/10(6) cells, including six specimens with undetectable activity (Mer- phenotype; <0.25 fmol/10(6) cells or 151 molecules/cell). MGMT content varied 10-fold among diagnostic groups and was associated with degree of malignancy, as evidenced by a 4-fold difference in activity between high- and low-grade tumors (P = 0.03). Tumor MGMT content was age dependent, being 5-fold higher in children 3-12 years old than in infants (P = 0.015) and adolescents (P = 0.015). Mean activity in tumors was 9-fold higher than in adjacent histologically normal brain (21 +/- 44 versus 2.4 +/- 4.0 fmol/10(6) cells; P = 0.05). By comparing tumor and adjacent normal tissue from the same patient, we found that 68% of cases exhibited an elevation of tumor activity that ranged from 2- to >590-fold. Moreover, 67% of Mer- normal tissue was accompanied by Mer+ tumor. These observations indicate that MGMT activity is frequently elevated during pediatric neurocarcinogenesis. Significantly, enhanced MGMT activity may heighten resistance to alkylating agents, suggesting a potential role for MGMT inhibitors in therapy.

Transfalcine approach to a callosomarginal artery aneurysm.

We describe a transfalcine approach to clipping and subsequently excising an expanding mycotic callosomarginal aneurysm. The patient had a devastating dominant (left) hemispheric spontaneous intracranial hemorrhage and was neurologically improving at the time of surgery nearly 2 months later. To avoid retracting the left hemisphere, we approached this left callosomarginal aneurysm from the nondominant side through the falx. The approach was straight-forward, and the result was satisfactory.

Tumors of the choroid plexus in children.

Primary neoplasms of the choroid plexus in children are surgically treatable, and the encouraging results of surgical removal, even for carcinoma, justify an aggressive surgical approach. Forty cases operated on over a span of 45 years have been reviewed in detail, including a rereading of all microscopic slides. The prognosis for children with papilloma has been excellent. The 5-year survival rate for children with carcinoma of the choroid plexus was 50%, and all deaths occurred within 7 months of operation. The patients whose carcinomas were totally removed had a better prognosis than did those with subtotal removal.

Quantitative cine-mode magnetic resonance imaging of Chiari I malformations: an analysis of cerebrospinal fluid dynamics.

Quantitative cine-mode magnetic resonance imaging of the craniocervical junction was performed in 17 patients with a Chiari I malformation to evaluate cerebrospinal fluid (CSF) dynamics, including 8 patients who underwent surgery. The cine-mode magnetic resonance images of these patients were compared with those of 12 normal pediatric and adult subjects. The craniocervical junction was imaged by 16 cardiac-gated velocity-encoded images arranged in a cine loop. These images allowed the measurement of both the magnitude and direction of CSF velocity. Velocity measurements were made in four regions of interest--the foramen Magendie, the foramen magnum, and ventral and dorsal to the spinal cord at C2--and were plotted in relation to the cardiac cycle to produce a CSF velocity profile. All patients who underwent surgery had the same procedure: a posterior fossa craniectomy with C1 laminectomy, lysis of arachnoid adhesions, and duraplasty. Normal subjects had unobstructed flow around the craniocervical junction: a short period of cranial CSF flow was followed by a sustained period of caudal CSF flow. Patients with tonsillar herniation of more than 5 mm had obstructed CSF flow, decreased CSF velocity, and shorter periods of caudal CSF flow. These patients also had preferential cranial CSF flow as compared with the controls. Postoperatively, there was a substantial increase in both the velocity of CSF flow and in the period of caudal CSF flow in the foramen magnum. The postoperative changes mirrored the velocity profiles of the normal subjects. These changes in CSF velocity and direction correlated with a more normal-appearing foramen magnum, a reduction in syrinx size, and an improvement in symptoms.

Cervical spondylotic myelopathy: treatment with posterior decompression and Luque rectangle bone fusion.

Cervical spondylotic myelopathy appears to result from a combination of factors. The two major components are 1) compressive forces resulting from narrowing of the spinal canal, and 2) dynamic forces owing to mobility of the cervical spine. There is substantial evidence to suggest that the repetitive trauma to the spinal cord that is sustained with movement in a spondylotic canal may be a major cause of progressive myelopathy. Utilization of extensive anterior procedures that remove the diseased ventral features as well as eliminate the dynamic forces owing to the accompanying fusion have grown in popularity. Cervical laminectomy enlarges the spinal canal, but does not reduce the dynamic forces affecting the spinal cord, and may actually increase cervical mobility, leading to a perpetuation of the myelopathy. The authors propose the combination of posterior decompression and Luque rectangle bone fusion to deal with both the compressive and the dynamic factors that lead to cervical spondylotic myelopathy. Ten patients who had advanced myelopathy underwent the combined procedures. Nine of the 10 experienced significant neurological improvement, and the 10th has had no progression. The combination of posterior decompression and Luque rectangle bone fusion may offer a simple, safe, and effective alternative treatment for cervical spondylotic myelopathy.

Precocious puberty following head injury. Case report.

A 6-year-old girl developed secondary sexual characteristics 5 months after severe closed head injury. Endocrinological tests confirmed a pubertal sexual condition; there was also diminution of serum melatonin and disruption of the diurnal pattern. Magnetic resonance imaging demonstrated focal hypothalamic injury; this is believed to be the first time such a posttraumatic lesion has been demonstrated by imaging techniques. The pathophysiology of this condition is discussed.

Atypical hemifacial microsomia associated with Chiari I malformation and syrinx: further evidence indicating that chiari I malformation is a disorder of the paraaxial mesoderm. Case report and review of the literature.

The authors present the first known reported case of hemifacial microsomia associated with a Chiari I malformation and syrinx. A 14-year-old girl presented with progressive torticollis of 3 years' duration and headaches exacerbated by exercise. Computerized tomography scanning and magnetic resonance imaging revealed extensive craniofacial and vertebral abnormalities, including aplasia of the floor of the left middle fossa and posterior fossa cranium, articulation of the left mandibular condyle with the left temporal lobe, and progressive development of a Chiari I malformation with associated syringomyelia. The patient first underwent posterior fossa decompression, duraplasty, and occipitocervical fusion. This procedure was later followed by reconstruction of the floor of the left middle fossa and temporomandibular joint. The patient's outcome was excellent. In this case report the authors review the complex embryological development of craniofacial and craniovertebral structures, and emphasize the use of a staged approach to treat pathophysiological consequences of this congenital anomaly.

Revision pedicle screws. Bigger, longer shims--what is best?

STUDY DESIGN: To evaluate the effect of change in screw dimensions and hole augmentation in pedicle screw revisions, the insertional torque was determined, and results were compared with those in control specimens in an in vitro study using cadaveric thoracolumbar spines. OBJECTIVES: To determine the best method of salvage for failed pedicle screws, by evaluating the insertional torque after placing a larger diameter or longer screw into a stripped hole. Use of a shim and use of larger and longer screws were also investigated. Finally, the effect on insertional torque of simply removing and replacing a pedicle screw in its original hole was investigated. SUMMARY OF BACKGROUND DATA: The effects of using bigger or longer screws and shims to salvage failed pedicles have been studied. The interaction between how much larger, how much longer, and inserting with or without shims, has not been well studied. Optimizing reinsertional torque through the use of bigger screws risks exceeding the pedicle capacity. Using longer screws risks violation of the anterior vertebral body, thereby placing the great vessels and viscera at risk. By knowing the relative contribution of increase in length and diameter, the surgeon can optimize the risk-benefit ratio. METHODS: Eight cadaveric spines from T10 to S1 were harvested. The specimens underwent radiographic screening and bone densitometry. A modified Latin square randomization was designed to evaluate the screw diameters and lengths. Each pedicle was its own control. A 35- x 6.5-mm screw was used as a control. Test screws were placed after pedicle screw hole failure was achieved and documented by stripping. For the test screws, the diameters were increased by 1 mm and 2 mm, the lengths were increased by 5 mm and 10 mm. Shims were added randomly. The peak insertional torque was measured for each control screw and test screw placement. In addition, during each screw placement, the screw was removed and replaced to determine the effect. RESULTS: Insertional torque, after the pedicle screw is removed and replaced in the same hole, was decreased by 34% (P < 0.000005). Increasing the diameter of the salvage screw by 2 mm caused the insertional torque to be increased by 8.4% of the original. Increasing the length of the screw did not improve the salvage screw insertional torque. There was an interaction effect for the 1-mm increase in diameter and the increase in length. At this diameter, increasing the length had a significant effect (P = 0.009) on the salvage torque. Using a shim created no improvement in salvage insertional torque (P = 0.77). There was a poor linear correlation between torque and bone mineral density (r = 0.18) in these osteoporotic specimens. CONCLUSIONS: Removing and replacing a pedicle screw in its original hole substantially decreases its mechanical fixation. For pedicle salvage, increasing the diameter causes the greatest restoration of strength. Shims had no effect in pedicle salvage in osteoporotic specimens.

Techniques for cerebral bypass: practical laboratory for microvascular anastomosis.

The techniques used for microvascular anastomosis are best mastered in the laboratory setting. A variety of techniques for end-to-end and end-to-side anastomoses are described and illustrated. An understanding of these different modalities allows the surgeon to choose the appropriate technique for each clinical setting.

Group B streptococcal infections of the central nervous system in infants with myelomeningocele.

Three cases of group B streptococcal infection of the central nervous system (CNS) occurred among 147 neonates treated for myelomeningocele at The Children's Hospital in Boston from 1970 to 1985. This pathogen was responsible for one third of the nine CNS infections noted in these patients over the 15-year study period. All three children with group B streptococcal CNS infections subsequently required multiple CNS shunting procedures and prolonged hospitalizations. Two children suffered major neurological sequelae. In neonates with myelomeningocele, group B streptococci have direct access to the CNS, perhaps explaining the high incidence of serious meningitis and ventriculitis in this population. Antibiotic prophylaxis for early myelomeningocele repair should be adjusted accordingly.

Detection of titanium in human tissues after craniofacial surgery.

Generally, titanium fixation plates are not removed after osteosynthesis, because they have high biocompatability and high corrosion resistance characteristics. Experiments with laboratory animals, and limited studies of analyses of human tissues, have reported evidence of titanium release into local and distant tissues. This study summarizes our results of the analysis of soft tissues for titanium in four patients with titanium microfixation plates. Energy dispersive x-ray analysis, scanning electron microscopy, and electrothermal atomic absorption spectrophotometry were used to detect trace amounts of titanium in surrounding soft tissues. A single metal inclusion was detected by scanning electron microscopy and energy dispersive x-ray analysis in one patient, whereas, electrothermal atomic absorption spectrophotometry analyses revealed titanium present in three of four specimens in levels ranging from 7.92 to 31.8 micrograms/gm of dry tissue. Results from this study revealed trace amounts of titanium in tissues surrounding craniofacial plates. At the atomic level, electrothermal atomic absorption spectrophotometry appears to be a sensitive tool to quantitatively detect ultra-trace amounts of metal in human tissue.

Inhibition of apoptosis: a potential mechanism for syndromic craniosynostosis.

The biologic pathogenesis of syndromic craniosynostosis remains unknown. The purpose of this investigation was to determine whether specific biologic differences exist between normal calvarial osteoblasts and osteoblasts derived from patients with syndromic craniosynostosis. This study (1) examined the apoptotic rate and cell cycle of osteoblasts derived from patients with syndromic craniosynostosis, and (2) investigated for the presence of soluble factors released from syndrome-derived osteoblasts. Osteoblast cell lines were established from calvarial specimens of patients with clinically diagnosed syndromic synostosis and from normal controls. A co-culture technique was used to investigate for the presence of elaborated soluble factors. Apoptotic rate and cell cycle analyses were performed by using flow cytometry after staining with annexin V-fluorescein isothiocyanate and propidiumiodide, respectively. The apoptotic rate was significantly reduced in syndrome-derived osteoblasts as compared with control osteoblasts. Control osteoblasts co-cultured with syndromic osteoblasts demonstrated a dramatic reduction in their apoptotic rate as compared with those co-cultured with control osteoblasts. These results indicate that osteoblasts derived from patients with syndromic craniosynostosis display a lower apoptotic rate, a normal DNA synthetic rate, and the capability to reduce the apoptotic rate in normal calvarial osteoblasts through the elaboration of soluble factors.

Transcortical surgery for lateral ventricular tumors.

OBJECT: Tumors of the lateral ventricle can be removed via two major approaches: the transcallosal or the transcortical route. The purpose of this study is to discuss the techniques and outcomes in transcortical surgery of tumors located in the lateral ventricle. METHODS: An experience with 29 consecutive lateral ventricular tumors resected via the transcortical route, over a 5-year period, is presented. The risks, complications, and outcomes of this surgical series, as well as those reported in the literature, are discussed. Surgical approaches to all five regions of the lateral ventricle are described. Neuropsychological, functional, and neurological outcomes are evaluated. CONCLUSIONS: The transcortical technique makes it possible to resect lesions in each of the five regions of the lateral ventricle. It provides superior microsurgical working space and flexibility for maneuvering within the lateral ventricle. The key to a successful transcortical approach is an understanding of the functional anatomy of eloquent cortex to be broached, the location of the lesion, and its vascular supply. A clear understanding of the advantages and limitations of the transcortical approach makes performing this procedure for resection of large lesions in the ventricle both safe and effective. The majority of the patients in this series (86%) had a good outcome, returning to baseline functional status and suffering minimal morbidity. In the microsurgical era, transcortical surgery-related postoperative morbidity and outcome are dependent more on tumor histological type and site of origin than on approach.

Toward a rational treatment of Chiari I malformation and syringomyelia.

In patients with Chiari I malformation with and without associated syringomyelia, aberrant cerebrospinal fluid (CSF) dynamics and a spectrum of posterior fossa pathological findings are demonstrated. In this study, the authors test the validity of using prospective cardiac-gated phase-contrast cine-mode magnetic resonance (MR) imaging to define the malformation, delineate its pathophysiology, and assist in implementing a rational treatment plan. Eighty-five cases were prospectively analyzed using cine MR imaging. Sixty-five patients, adults and children, with symptomatic Chiari malformation, with and without syringomyelia, were surgically treated from 1990 to 1999. All patients underwent pre- and postoperative cine MR evaluation. Ten patients were treated after a previous surgical procedure had failed. To establish CSF flow characteristics and normative CSF profiles, 20 healthy volunteers were examined. Compared with normal volunteers, in Chiari I malformation patients with and without syringomyelia, uniformly abnormal craniocervical junction CSF flow profiles were revealed. After intradural exploration, nearly all patients with Chiari I malformation experienced clinical improvement and CSF flow profiles, paralleling those of normal volunteers, were shown. In all patients in whom treatment had failed, abnormal preoperative CSF flow profiles, which correlated with suspected physiological abnormalities and the pathological findings noted at reoperation, were demonstrated. Symptomatic Chiari I malformation is a dynamic process characterized by the impaction of the hindbrain in an abnormal posterior fossa. This compression obstructs the normal venting of CSF in and out of the craniocervical subarachnoid space, throughout the cardiac cycle. Therefore, decompression or enlargement of the posterior fossa to establish normal CSF pathways should be the primary goal of surgical intervention. Aberrant CSF flow appears to be only one aspect of the pathological condition found in patients with Chiari I malformation. Arachnoid scarring in the posterior fossa and selective vulnerability of the spinal cord may also be factors in the pathogenesis and maintenance of associated syringomyelia. Phase-contrast cine MR imaging is a useful tool in defining physiological and anatomical problems in patients with Chiari I and syringomyelia, and it can help guide an appropriate primary or salvage surgical therapy.

19-year follow-up of fetal myelomeningocele brought to term.

We conducted a 19-year follow-up study of 223 infants with myelomeningocele born by cephalic presentation, 68 born by pre-rupture of amniotic membranes cesarean section (PRAM C/S) and 155 born vaginally to determine outcome. We recorded radiographic level as the last intact vertebral arch at the cephalad end of the spinal defect from standard AP films of the spine. Protrusions of the lesions dorsal to the back were obtained from medical records or parental recall. Subsequent spinal cord abnormalities (hydromyelia, tethered cord and hypoplasia) were determined by patient's symptoms and verified by MRI. Data were from our Patient Data Management System and analyzed using Microsoft Excel and Epi Info 6. Flat lesions protruding less than 1.0 cm beyond the plane of the back and those associated with breech position or kyphus were not benefited by PRAM CIS (Fisher's Exact, p = 0.58 between the two types of delivery for motor level). Flat lesions were more common in the vaginally delivered group (p = 0.01). Lesions protruding equal to 1.0 cm or beyond were associated with less paralysis after PRAM C/S (p = 0.01). Although tethered cord syndrome was more common in the PRAM C/S group (p = 0.02), there was no difference in the muscle strength loss between the PRAM C/S and the vaginally delivered groups. Symptomatic hydromyelia was equally distributed but spinal cord hypoplasia was more common in the PRAM C/S group (p = 0.03). Due to the limited numbers of patients in each group available for analysis, we recommend further study to ascertain the appropriate management of fetal myelomeningocele diagnosed in utero and brought to term.

Cerebral abscess after presumed superficial periorbital wound.

Penetrating wounds in the periorbital region may appear superficial and minor at first glance. The unique shape and thin bony roof of the orbit give these injuries a significant risk of associated intracranial penetration. This can initially be asymptomatic, and a high index of suspicion is essential to properly diagnose and treat these injuries. We report a case of an 8-year-old female who presented with delayed seizures from a frontal abscess resulting from such an injury. This article reviews the literature and discusses the appropriate management that should be used by emergency room and military physicians.

Lessons learnt from the management of 1500 complex facial fractures.

The lessons learnt from the management of 1500 consecutive patients with complex facial fractures have been analysed. This analysis and the major changes in treatment principles have resulted in dramatic improvement in results. The application of craniofacial surgical principles, extended exposure of the craniofacial skeleton, accurate fracture reduction with rigid internal bony fixation and primary bone graft reconstruction has revolutionised the care of these patients. The reattachment of the soft tissue to the reconstructed skeleton provides the final link in this comprehensive one stage reconstruction. Analysis of results has demonstrated the majority of complications and failures to be due to inadequate exposure and reduction of fractures with bone segments rigidly plated in their unreduced position. Inadequate bone grafting and failure to re-suspend the soft tissue and canthi results in post treatment deformity even if the bony reconstruction is adequate. Adherence to the principles of reconstruction will almost always result in a one-stage correction no matter how severe the initial injury.

Update on craniofacial surgery: the differential diagnosis of lambdoid synostosis/posterior plagiocephaly.

There has been an evolution of thought on the diagnosis and treatment of posterior plagiocephaly. Synostotic posterior plagiocephaly (lambdoid synostosis) can be diagnosed and differentiated from non-synostotic posterior plagiocephaly (positional molding) based on specific cosmetic and radiologic criteria. The advent of high-resolution three-dimensional CT analysis of cranial morphology combined with meticulous clinical studies of the two major causes of posterior plagiocephaly has added much to our understanding of this skull deformity. Children with lambdoid synostosis have a trapezoid-shaped skull with posterior displacement of their ipsilateral ear, ipsilateral mastoid bossing, contralateral occipital bossing, and a fused lambdoid suture that appears as a ridge. Children with posterior plagiocephaly without lambdoid synostosis have a characteristic parallelogram-shaped skull with anterior displacement of the ipsilateral ear and ipsilateral frontal bossing. This subject is surrounded in controversy because many of the children in the past thought to have lambdoid synostosis probably did not, based in part on the aforementioned specific criteria. This is an important point, as most patients with posterior plagiocephaly without synostosis will improve without surgery. One should thus be appropriately conservative in the selection of patients for surgery. The majority of infants evaluated at craniofacial clinics presumably have posterior plagiocephaly without synostosis and can be successfully treated with frequent head turning, helmet, or band therapy. Patients with clinically and radiologically proven synostotic posterior plagiocephaly and a severe deformity should undergo craniofacial surgery. The technique of biparieto-occipital craniotomy is safe, simple, and delivers a good cosmetic result. Our postoperative photographic evaluations have shown an immediate, aesthetically pleasing change in the contour of the occiput, which tends to improve with time.