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Frameless Pinless Stereotaxy

Francesco T. Mangano and Matthew D. Smyth

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Hydrogel-induced cervicomedullary compression after posterior fossa decompression for Chiari malformation

Case report

Spiros l. Blackburn and Matthew D. Smyth

✓The use of an absorbable hydrogel dural sealant has been approved for neurosurgical applications with no published reports of complications to date. The authors present the case of a 13-year-old girl with syringomyelia and quadriparesis who underwent posterior fossa decompression and dural augmentation for Chiari malformation Type I. Dural closure was performed with a dural substitute patch, hydrogel dural sealant, and gelatin sponge. Magnetic resonance imaging, performed after initial postoperative improvement in the patient's quadriparesis deteriorated, demonstrated an expanding epidural mass collection causing cervicomedullary compression. Exploration on postoperative Day 15 revealed an expanded layer of hydrogel underlying a layer of gelatin sponge. The authors conclude that hydrogel dural sealants should be used cautiously in spaces that cannot tolerate significant mass effect.

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Iatrogenic intradural epidermoid cyst after lumbar puncture

Case illustration

Daniel Refai, Richard J. Perrin, and Matthew D. Smyth

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Radiosurgical posterior corpus callosotomy in a child with Lennox–Gastaut syndrome

Case report

Matthew D. Smyth, Eric E. Klein, W. Edwin Dodson, and David B. Mansur

✓The authors report the successful use of radiosurgery in a child for posterior corpus callosotomy; the early results are good and the patient has not suffered any morbid conditions. The relevant literature pertaining to the use of radio-surgery for treating epilepsy is reviewed. Details of the radiosurgical techniques and prescription dose used are presented, along with 1-year serial neuroimaging results.

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Giant intracranial teratoma with epignathus in a neonate

Case report and review of the literature

James M. Johnston, Nilesh A. Vyas, Alex A. Kane, David W. Molter, and Matthew D. Smyth

✓Epignathus, a congenital oropharyngeal teratoma, is a rare clinical entity with variable clinical outcomes described in the literature. Even fewer cases of epignathus with intracranial extension have been reported, all with poor outcomes. In this manuscript, the authors present a case of epignathus with intracranial extension, emphasizing clinical presentation, imaging findings, a staged surgical approach, multidisciplinary management, and outcome.

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Outcome following surgery for temporal lobe epilepsy with hippocampal involvement in preadolescent children: emphasis on mesial temporal sclerosis

Matthew D. Smyth, David D. Limbrick Jr., Jeffrey G. Ojemann, John Zempel, Shenandoah Robinson, Donncha F. O'Brien, Russell P. Saneto, Monisha Goyal, Richard E. Appleton, Francesco T. Mangano, and Tae Sung Park

Object

The authors conducted a multiinstitutional, retrospective analysis to better define outcome and prognostic indicators for temporal lobe epilepsy surgery for suspected mesial temporal sclerosis (MTS) in young children.

Methods

Data were collected for all children undergoing temporal resections at four epilepsy centers over approximately 10 years. Children with a histopathological diagnosis of neoplasm were excluded.

Forty-nine patients (28 boys and 21 girls) were included in the study. Their mean age at surgery was 9.1 years (range 1.25–13.9 years). The mean age at seizure onset was 3.2 years (range birth–10 years). Histopathological examination demonstrated MTS in 26 cases, gliosis in nine, dysplasia in five, gliosis with dysplasia in four, and nonspecific or normal findings in five. Forty-one anterior temporal lobectomies (nine tailored) and eight selective amygdalohippocampectomies were performed (28 left side, 21 right side). Twenty-nine children (59.2%) underwent invasive monitoring. Operative complications included extraaxial hematomas (two cases), cerebrospinal fluid leaks (two cases), and hydrocephalus (one case), each in children undergoing invasive monitoring. The mean duration of follow up was 26.4 months (range 5–74 months) overall and 23.9 months (range 6–74 months) for the Engel Class I subgroup. Outcomes at the most recent follow-up examination were categorized as Engel Class I–II in 31 (63.3%) of 49 children overall, 20 (76.9%) of 26 children with confirmed MTS, four (36.4%) of 11 children with gliosis, and four (57.1%) of seven children with dysplasia. All patients who underwent selective amygdalohippocampectomies had confirmed MTS and Engel Class I outcomes. Patients with more than one seizure type (p = 0.048) or moderate to severe developmental delay (p = 0.03) had significantly worse outcomes (Engel Class III or IV). Age at seizure onset, age at surgery, and duration of seizure disorder were not significantly related to outcome. There was a trend for bilateral or extratemporal findings on electroencephalography (EEG) (p = 0.157), high preoperative seizure frequency (p = 0.097), and magnetic resonance (MR) imaging findings inconsistent with MTS (p = 0.142) to be associated with worse outcome, although it did not reach statistical significance. In only 12 (46.1%) of the 26 patients with confirmed MTS was the condition prospectively diagnosed on preoperative MR imaging.

Conclusions

Younger children with temporal lobe epilepsy have satisfying surgical outcomes, particularly when MTS is present. Magnetic resonance imaging may not be as sensitive in detecting MTS in children as in older patients. Negative predictors identified include multiple seizure types and preoperative developmental delay. Multifocal or bilateral EEG findings, high preoperative seizure frequency, and MR imaging findings inconsistent with MTS also independently suggested worse outcome.

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Complications of invasive subdural electrode monitoring at St. Louis Children’s Hospital, 1994–2005

James M. Johnston Jr., Francesco T. Mangano, Jeffrey G. Ojemann, Tae Sung Park, Edwin Trevathan, and Matthew D. Smyth

Object

The purpose of this study was to better define the incidence of complications associated with placement of subdural electrodes for localization of seizure foci and functional mapping in children.

Methods

The authors retrospectively reviewed the records of 112 consecutive patients (53 boys, 59 girls; mean age 10.9 years, range 10 months–21.7 years) with medically intractable epilepsy who underwent invasive monitoring at the Pediatric Epilepsy Center at St. Louis Children’s Hospital between January 1994 and July 2005. There were 122 implantation procedures (85 grids and strips, 32 strips only, five grids only, four with additional depth electrodes), with a mean monitoring period of 7.1 days (range 2–21 days). Operative complications included the need for repeated surgery for additional electrode placement (5.7%); wound infection (2.4%); cerebrospinal fluid leak (1.6%); and subdural hematoma, symptomatic pneumocephalus, bone flap osteomyelitis, and strip electrode fracture requiring operative retrieval (one patient [0.8%] each). There were four cases of transient neurological deficit (3.3%) and no permanent deficit or death associated with invasive monitoring.

Conclusions

Placement of subdural grid and strip electrodes for invasive video electroencephalographic monitoring is generally well tolerated in the pediatric population. The authors found that aggressive initial electrode coverage was not associated with higher rates of blood transfusion or perioperative complications, and reduced the frequency of repeated operations for placement of supplemental electrodes.

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The “clamshell” craniotomy technique in treating sagittal craniosynostosis in older children

Matthew D. Smyth, Marissa J. Tenenbaum, Christian B. Kaufman, and Alex A. Kane

Object

Although most patients with sagittal craniosynostosis are recognized and treated in infancy, some children are not referred to craniofacial centers until later in childhood. In this paper the authors describe a novel operative technique for calvarial reconstruction in older children with previously untreated sagittal craniosynostosis.

Methods

The authors report a clinical series of eight patients who were treated using novel single-stage calvarial reconstruction, and they assess the complications and outcomes. The patient is placed supine for the procedure, which consists of a coronal incision, bifrontal craniotomy without orbital osteotomy, and multiple interlocking midline parietooccipital osteotomies and recontouring. Fixation is achieved using a bioabsorbable plate system. Cranial indices were calculated from measurements obtained before and after the reconstructive procedures. Preoperative, intraoperative, and postoperative photographs and three-dimensional computed tomography scans are presented for review.

Between November 2003 and April 2005, the authors treated seven boys (age range ~ 1–10 years, mean age 4.2 years) with uncorrected sagittal craniosynostosis and one with bicoronal and sagittal synostosis. The mean operating time was 5.13 hours (range 4.3–8 hours), with a mean blood loss of 425 ml (range 200–800 ml). As a percentage of the estimated circulating blood volume, the mean operative blood loss was 33.5% (range 17–57%). The mean hospital stay was 4.9 days. The cranial index significantly improved from a mean of 65.6 to 71.3% (p = 0.001). No acute or delayed complications have been noted. Follow-up examinations performed at an average of 12 months (range 1–17 months) have confirmed early patient and family satisfaction.

Conclusions

An approach of aggressive calvarial reconstruction with multiple interleaving osteotomies crossing the midline achieves improvements in biparietal narrowing. Combined with a bifrontal reconstruction, early outcomes are excellent, with an acceptable amount of intraoperative blood loss and no significant complications.

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Pediatric neurosurgical injuries associated with all-terrain vehicle accidents: a 10-year experience at St. Louis Children’s Hospital

Francesco T. Mangano, Jose A. Menendez, Matthew D. Smyth, Jeffrey R. Leonard, Prithvi Narayan, and Tae Sung Park

Object

All-terrain vehicles (ATVs) have been characterized as inherently unstable and are associated with significant pediatric injuries in the US. The authors performed a study to analyze data obtained in pediatric patients who had sustained neurological injuries in ATV-related accidents, identify potential risk factors, and propose preventive measures. The study is based on a 10-year experience at the St. Louis Children’s Hospital.

Methods

The authors retrospectively analyzed data obtained in all patients admitted to the St. Louis Children’s Hospital between 1993 and 2003, limiting their focus to pediatric cases involving ATV-related accidents. A total of 185 patients were admitted with these criteria. Sixty-two patients (33.5%) suffered neurological injuries; there were 42 male and 20 female patients whose age ranged from 2 to 17 years. The most common injuries included skull fracture (37 cases) and closed head injury (30 cases). There were 39 cases of intracranial hemorrhage and 11 of spinal fracture. A total of 15 types of neurosurgical procedure were performed: six craniotomies for hematoma drainage, five craniotomies for elevation of depressed fractures, two procedures to allow placement of an intracranial pressure monitor, one to allow placement of an external ventricular drain, and one to allow the insertion of a ventriculoperitoneal shunt. Two patients had sustained spinal cord injury, and three procedures were performed for spinal decompression or stabilization. The duration of hospital stay ranged from 1 to 143 days (mean 6.6 days). Fifty-seven patients (30.8%) were eventually discharged from the hospital, three (1.6%) were transferred to another hospital, two (1.1%) died, and 123 (66.4%) required in-patient rehabilitation.

Conclusions

Children suffered significant injuries due to ATV accidents. In passengers there was a statistically significant increased risk of neurological injury. The relative risk of neurological injury in patients not wearing helmets was higher than that in those who wore helmets, but the difference did not reach statistical significance. Further efforts must be made to improve the proper operation and safety of ATVs, both through the education of parents and children and through the creation of legislation requiring stricter laws concerning ATV use.

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Early programmable valve malfunctions in pediatric hydrocephalus

Francesco T. Mangano, Jose A. Menendez, Tracy Habrock, Prithvi Narayan, Jeffrey R. Leonard, Tae Sung Park, and Matthew D. Smyth

Object

The use of adjustable differential pressure valves has been recommended to improve ventriculoperitoneal (VP) shunt performance in selected patients; however, published data are scarce regarding their clinical reliability. Recently, the identification of a number of malfunctioning programmable valves during shunt revision surgery in children prompted a retrospective review of valve performance in this patient cohort.

Methods

The authors performed a retrospective chart analysis of 100 patients with programmable valve shunts and 89 patients with nonprogrammable valve shunts implanted at the St. Louis Children's Hospital between April 2002 and June 2004. They noted the cause of hydrocephalus, the type of shunt malfunction, and cerebrospinal fluid (CSF) protein levels. Regular clinical follow up ranged from 1 to 26 months, with a mean follow-up time of 9.75 months for patients with programmable valves and 10.4 months for patients with nonprogrammable valves.

Patient ages ranged from 2 weeks to 18 years. One hundred patients had 117 programmable valves implanted, and 35 of these patients (35%) underwent shunt revision because of malfunction. The programmable valve itself malfunctioned in nine patients who had undergone shunt revision (11.1%/year of follow up). The nonprogrammable valve group had no valve malfunctions. The overall VP shunt revision rate in the nonprogrammable valve group was 20.2%. No significant differences were identified when CSF protein levels and specific malfunction types were compared within the programmable valve and nonprogrammable valve groups.

Conclusions

In this study the authors demonstrated an annualized intrinsic programmable valve malfunction rate of 11.1%, whereas during the same period no intrinsic valve malfunctions were noted with nonprogrammable valve systems for similar causes of hydrocephalus. The CSF protein levels did not correlate with observed valve malfunction rates. Further evaluation in a prospective, randomized fashion will elucidate specific indications for programmable valve systems and better determine the reliability of these valves in the pediatric population.