An apparatus and method to characterize causes of positional plagiocephaly.

Positional plagiocephaly (misshapen head in infants) has increased dramatically in the United States since the beginning of the Back to Sleep program in 1992. In order to understand the increase due to repositioning from prone to supine position for sleep, we developed a home-based monitoring system to discern state of sleep and re-positioning frequency in infants. The portable system allows real-time logging of sleep position and patterns by a simplified sleep algorithm and association of sleep head position and movement which are time-stamped for correlation. Preliminary correlatory results suggest that plagiocephalic infants experience greater periods of rapid-eye-movement (REM) sleep than controls and show more narrow range of motion during sleep.

A provocative test to determine brain compliance in the management of patients with hydrocephalus.

Non-invasive techniques to explore intracranial compliance and pressure have been extensively explored in recent years. Previous techniques have used expensive technologies to make these measurements, often with difficulty. We present a novel, inexpensive method and algorithm to observe trends in intracranial compliance measurement targeted towards the treatment and management of hydrocephalus. The technique uses two photo-plethysmographic sensors to record arterial pulse perfusion, a common tilt table apparatus to methodically and artificially increase intracranial pressure, and a digital signal processing algorithm to determine phase difference between the waveforms. A secondary phase-difference disease signature approach is also hypothesized.

A signal analysis algorithm for determining brain compliance non-invasively.

Patients with increased intracranial pressure (ICP) caused by hydrocephalus or brain injury have poor brain compliance or increased brain stiffness. The condition is commonly treated by a surgical diversion of cerebrospinal fluid (CSF) through placement of a ventriculoperitoneal (VP) shunt. These inserted devices frequently fail and require replacement. Assessment of failed devices typically requires an invasive surgical procedure to implant an ICP sensor. Brain compliance can be determined non-invasively by comparing the intracranial pressure (ICP) waveform to the digital artery waveform. The ICP waveform is derived from a piezo sensor snugged into the external ear canal and worn as a headset. The digital artery waveform is derived from a stand pulse oximeter. Digital signal processing performed on sampled data from these two sensors shows a time-lag or phase relationship between the two waves which widens with worsening brain stiffness or compliance. An algorithm is presented that shows how these signals can be used to compute brain compliance. An instrument designed to calculate real-time brain compliance to aid healthcare professionals is described.

Treatment of posterior third ventricular central neurocytoma with endoscopic biopsy, endoscopic third ventriculostomy and stereotactic radiosurgery.

Central neurocytomas of the posterior third ventricle are rare. These typically benign lesions have recently been shown to respond well to Gamma knife stereotactic radiosurgery (SRS). We present the case of a posterior third ventricle central neurocytoma presenting with aqueduct obstruction. The patient was treated with endoscopic biopsy and endoscopic third ventriculostomy, followed by Gamma knife radiosurgery. At 2 years the tumor has diminished in size and the patient is neurologically intact. This treatment strategy may avoid the risk of open ventricular surgery and the need for shunts in patients with central neurocytomas of appropriate size and location.

Functional brain mapping using positron emission tomography scanning in preoperative neurosurgical planning for pediatric brain tumors.

OBJECT: The purpose of this report is to demonstrate the value of functional brain mapping using the positron emission tomography (PET) method for preoperative neurosurgical planning in children with brain tumors. Brain maps were used to characterize the relationship between potentially resectable tumors and functionally eloquent brain areas. METHODS: Five children, ranging in age from 3 to 13 years, with hemispheric brain tumors adjacent to eloquent cortex were studied. Magnetic resonance (MR) imaging was used to identify the brain tumors; PET imaging after injection of [18F] fluorodeoxyglucose (FDG), [11C]L-methionine (CMET), or a combination of the two was performed to grade the tumors; and a [15O] H2O uptake study was used to characterize the anatomical relationships of the tumors to functional cortex. The cortical activation maps were obtained during control periods and during behavioral tasks and were used to document motor, visual, and speech and language organizational areas. Wada tests were performed in two patients. Language and speech activation was concordant with the results of Wada testing. CONCLUSIONS: Functional brain mapping using PET scans and coregistered MR images provided the neurosurgeon with precise definitions of structural and functional cortical areas; this altered surgical management in some cases and/or was used to predict outcome. The combination of PET imaging with FDG and/or CMET and measurements of [15O] water uptake was useful in characterizing and grading tumors and instrumental in achieving effective neurosurgical planning. Postoperative results in the five cases suggest that preoperative functional brain mapping has the potential to improve outcome by defining a surgical plan to maximize resection and minimize the risk of neurological sequelae.

Positron emission tomography using [18F] fluorodeoxyglucose and [11C] l-methionine to metabolically characterize dysembryoplastic neuroepithelial tumors.

Dysembryoplastic neuroepithelial tumors are unique and benign congenital tumors occurring frequently in children and adolescents. Differentiation from other low-grade tumors is important for management. Five patients with confirmed dysembryoplastic neuroepithelial tumors were studied with positron emission tomography using glucose and protein metabolic uptake in an attempt to categorize these tumors metabolically. Functional brain mapping also was obtained to aid in operative management. Results of the study conclude that dysembryoplastic neuroepithelial tumors, although having similar neuroimgaing characteristics to other low-grade tumors, are distinguished by a unique metabolic profile. They are inactive tumors with no significant glucose or protein metabolic activity. The combination of preoperative positron emission tomographic metabolic studies with functional brain mapping allowed for prediction of tumor type, defined eloquent areas of cortical function, and improved approach and resection of the tumors with minimal risk of neurologic impairment.

Cranial growth unrestricted during treatment of deformational plagiocephaly.

OBJECTIVES: The Dynamic Orthotic Cranioplasty (DOC) Band(TM) is a cranial orthosis used to treat deformational plagiocephaly. The ability of this device to redirect growth and thus, improve craniofacial asymmetry has raised concerns regarding the potential restriction of cranial growth. The purpose of this study was to evaluate the growth of the head during correction of plagiocephaly. METHODS: The study sample consisted of 190 children: 81 females (42. 6%) and 109 males (57.4%) All patients had been diagnosed with nonsynostotic plagiocephaly, did not have other significant medical conditions, were compliant with DOC protocol, and had complete anthropometric measurements at entrance and exit from treatment. Growth of the head was evaluated using head circumference, maximum cranial width and maximum cranial length. Correction of plagiocephaly was evaluated by documenting the reduction of craniofacial asymmetry of the cranial vault, skull base and face. Paired t tests were used to assess the significance of changes in these anthropometric measurements. Differences were considered significant if p < 0.05. RESULTS: Average entrance age was 6.5 months with a mean treatment time of 4.1 months. Statistical analysis demonstrated highly significant reductions in asymmetry in all three regions (p < 0.001). More importantly, these corrections were achieved with synchronous growth of the skull as demonstrated by highly significant increases (p < 0.001) in head circumference, maximum cranial width and maximum cranial length. CONCLUSIONS: These findings document statistically significant increases in cranial growth in association with concomitant reductions of the cranial asymmetries associated with deformational plagiocephaly.

Incidence and management of subdural hematoma/hygroma with variable- and fixed-pressure differential valves: a randomized, controlled study of programmable compared with conventional valves.

Shunt systems with differential pressure valves are prone to the complications of overdrainage. A programmable valve permits adjustment of the opening pressure of the valve. In this paper the authors report the incidence of subdural fluid collections in a randomized trial of programmable compared with conventional valves, and they describe methodologies used in management of this complication. A multiinstitutional, prospective, randomized trial of the Codman Hakim programmable valve and conventional fixed-pressure valves was undertaken. Two classes were defined: "new" and "replacement" valves. Randomization of the type of valve in each group was performed at each study site. Clinical and radiological studies were required at fixed intervals over a 104-week period. All complications were reported. The experimental valves were required to be reprogrammed after magnetic resonance imaging studies, but all other decisions regarding pressure setting were left to each investigator. Three hundred seventy-seven patients were randomized; 194 were treated with a programmable valve and 183 with a fixed-pressure valve. The two groups were statistically similar in demographic composition, as were the "new" and "replacement" categories. The investigators made 540 valve pressure changes (five per patient; range one-41 changes). More than half of the reprogramming adjustments were made in the first 3 months postplacement; 70% were made within 6 months. More than half of all reprogramming adjustments were required in a group of 30 patients. Four treatment modalities were observed: 1) 30% of the fluid collections resolved spontaneously (25% in the patients with programmable valves and 36.3% in those with conventional valves) and were largely found to be hygromas in infants and children; 2) four subdural fluid collections were unresolved and under observation; 3) the subdural hematoma was drained and the shunt removed (in 8.3% of patients with the programmable valve and 36.3% of those with the control valve); 4) the pressure of programmable valve was raised in 58% of patients (seven of 12), and this increase in opening pressure was a feature used by investigators to affect treatment. There was no significant difference in the incidence of subdural fluid collections between the programmable and fixed-pressure valve treatment groups. The programmable feature provided a considerable advantage in treatment when subdural collections occurred.

Treatment of craniofacial asymmetry with dynamic orthotic cranioplasty.

Dynamic Orthotic Cranioplasty (DOC) was developed to treat craniofacial deformities associated with positional plagiocephaly. This investigation describes the treatment of more than 750 patients with the DOC Band since 1988. All patients undergoing DOC treatment were fit with a custom fabricated orthosis made from a plaster impression taken from the infant's head. When the orthosis was applied, the corrective pressure was directed to hold growth at the calvarial prominences and redirect symmetrical growth. A detailed medical history was obtained and anthropometric measurements were taken at start, exit, 12, 18, and 24 months follow-up. This information was recorded in a database created in Microsoft Excel. Mean length of treatment was 4.3 months with an average entrance age of 6.9 months. Analysis of anthropometric data showed significant reduction in mean cranial vault, skull base, and facial asymmetries. Correction of the more difficult skull base was documented with computed tomography. Our anthropometric and clinical observations document complete or near complete correction of asymmetry for a wide variety of head shapes. Based on the results of this investigation, we are able to support the earlier claims of our pilot study, which concluded that DOC is effective in the treatment of positional plagiocephaly.

Ventricular shunt removal: the ultimate treatment of the slit ventricle syndrome.

OBJECT: The aim of this study was to assess the effectiveness of an algorithm used to evaluate and prescribe treatment for patients having slit ventricle syndrome (SVS). METHODS: All patients included in this protocol underwent fiberoptic intracranial pressure monitoring after removal or externalization of their ventricular shunt systems. A significant number of patients did not need extracranial cerebrospinal fluid (CSF) diversion and tolerated removal of their shunt systems without requiring further intervention. Patients who demonstrated a need for CSF drainage underwent an endoscopic third ventriculostomy, regardless of the putative cause of their hydrocephalus. Sixteen (72.7%) of 22 patients experienced resolution of or significant improvement in their SVS complaints after their inclusion in the protocol. Concomitantly, 14 (64%) of 22 patients were no longer shunt dependent after a mean follow-up period of 21.4 months. CONCLUSIONS: A significant number of patients debilitated by SVS may experience improvement in their symptoms and undergo shunt removal according to this protocol, improving their quality of life and simplifying their medical follow up.

Endoscopic treatment of brain abscess in children.

Three children with intracerebral abscesses were treated endoscopically. Two of the treated abscesses were located in the left temporal lobe and one in the right parietal lobe. The presenting symptoms included headaches, seizures, hemiparesis and signs of infection. Burr hole craniotomy, insertion of a peelaway sheath, obtaining of a specimen, introduction of endoscope, and complete irrigation under view was performed. After this a draining catheter was positioned in the abscess. All three abscesses grew multiple organisms. The patients received longstanding intravenous treatment with antibiotics. The follow-up period in this group ranges between 5 and 32 months. The initial neurological deficits were relieved in all three patients. The follow-up MRI studies revealed minor residual changes without evidence of significant sequelae. Neuroendoscopic treatment of brain abscesses has additional advantages compared to stereotactic aspiration or more complete drainage and lavage.

Use of positron emission tomography for presurgical localization of eloquent brain areas in children with seizures.

Successful surgical management of a neoplastic or nonneoplastic seizure focus in close proximity to or within eloquent brain areas relies on precise delineation of the relationship between the lesion and functional brain areas. The aim of this series was to validate the usefulness and test the efficacy of noninvasive presurgical PET mapping of eloquent brain areas to predict surgical morbidity and outcome in children with seizures. To identify eloquent brain areas in 15 children (6 female and 9 male; mean age 11 years) with epileptogenic lesions PET images of regional cerebral blood flow were performed following the administration of [(15)O]water during motor, visual, articulation, and receptive language tasks. These images with coregistered magnetic resonance (MR) images were then used to delineate the anatomic relationship of a seizure focus to eloquent brain areas. Additional PET images using [18F]fluoro-2-deoxy-D-glucose (FDG) and [11C]methionine (CMET) were acquired to help localize the seizure focus, as well as characterize the lesion. Patient surgical management decisions were based on PET mapping in combination with coregistered MR images, PET-FDG findings, and the anatomic characteristics of the lesion. At follow-up 1-26 months after surgery, all patients that underwent temporal lobectomy (9 patients) and extratemporal resection (4 patients) for a neoplastic or nonneoplastic seizure focus are seizure-free with minimal postoperative morbidity. Of prime importance, no child sustained a postoperative speech or language deficit. PET imaging was also well tolerated without procedural complications. Based on PET mapping, a nonoperative approach was used for 2 children and a biopsy only was used in one child. When cortical injury involved prenatally determined eloquent cortex, PET demonstrated reorganization of language areas to new adjacent areas or even to the contralateral hemisphere. Integration of anatomical and functional data enhanced the surgical safety, defined optimal surgical approach, delineated the seizure focus from eloquent brain areas, facilitated maximum resection and optimized the timing of surgery, thereby minimizing surgical morbidity while maximizing surgical goals. PET measurements of FDG and CMET uptake were also helpful in localizing the seizure focus and grading the tumors. PET used for brain mapping in children provides the surgeon with strategic preoperative information not readily attainable with traditional invasive Wada testing or intraoperative cortical stimulation. PET mapping may also improve the outcome of extratemporal resections by allowing aggressive seizure focus resection. In addition, serial brain maps may optimize timing for surgical intervention by demonstrating reorganization of eloquent cortex often seen in younger children after cortical injury. Our results suggest that noninvasive presurgical brain mapping has the potential to reduce risk and improve neurologic outcome.

Etiology of positional plagiocephaly in triplets and treatment using a dynamic orthotic cranioplasty device. Report of three cases.

In 1994 a set of triplets presented to the authors for treatment of their positional plagiocephaly with Dynamic Orthotic Cranioplasty (DOC). The three 8-month-old infants were diagnosed with severe, moderate, and mild plagiocephaly. Only the severe and moderate cases were treated with the DOC band. The mild case was not treated with the DOC band because it was thought that the condition could be addressed through alteration in the child's sleeping position. The child with severe deformation required 8.5 months of treatment with two DOC bands and had significant residual asymmetries at the end of the treatment course. The child with moderate deformity required 2.5 months of treatment with only one DOC band and had excellent correction of the initial asymmetries. The results of their treatment provide a unique forum for discussing the etiology of positional plagiocephaly, as well as those factors that can influence the efficacy of DOC treatment.

Controlled external lumbar drain as treatment for therapy resistant intracranial hypertension--case report.

We report the case of an eleven year old male with a history of severe head injury who had manifested high intracranial pressure refractory to aggressive medical therapy, including ventriculostomy, controlled hyperventilation, mannitol and barbiturate application. The insertion of an external lumbar drain in this patient resulted in rapid permanent control of the intracranial hypertension. No transtentorial or tonsillar herniation occurred.

Controlled lumbar drainage in pediatric head injury.

A retrospective study of external lumbar subarachnoid drainage in 16 pediatric patients with severe head injuries is presented. All patients had Glasgow Coma Scale scores of 8 or lower at 6 hours postinjury and were initially treated with ventriculostomy. Five patients required surgical evacuation of focal mass lesions. All patients manifested high intracranial pressures (ICPs) refractory to aggressive therapy, including hyperventilation, furosemide, mannitol, and in some cases, artificially induced barbiturate coma. After lumbar drainage was instituted, 14 patients had an abrupt and lasting decrease in ICP, obviating the need for continued medical management of ICP. In no patient did transtentorial or cerebellar herniation occur as a result of lumbar drainage. It was also noted retrospectively that the patients in this study had discernible basilar cisterns on computerized tomography scans. Fourteen patients survived; eight made good recoveries, three are functional with disability, and three have severe disabilities. Two patients died, most likely from uncontrolled ICP before the lumbar drain was placed. It is concluded that controlled external lumbar subarachnoid drainage is a useful treatment for pediatric patients with severe head injury when aggressive medical therapy and ventricular cerebrospinal fluid evacuation have failed to control high ICP. Selected patients with elevated ICP, which may be a function of posttraumatic cerebrospinal fluid circulation disruption and/or white matter cerebral edema, can be treated with this modality, which accesses the cisternal spaces untapped by ventriculostomy.

Transplanted demineralized bone graft in cranial reconstructive surgery.

Surgical reconstruction of cranial deformities and synostosis is occasionally accompanied by incomplete bone growth to cover all areas of cranial vault that have been exposed in the correction. The restrictive nature of some forms of synostosis require more bone in the repair than is available using the child's natural skull for autogenous bone cranioplasty. Rib and iliac crest autografts have been used with success. These grafts must be harvested form a remote site with increased morbidity. A split-thickness skull autograft is the cranioplasty material of choice but children under the age of 6 years may lack the skull thickness needed to use this technique. Perforated demineralized bone matrix has been transplanted in 46 operations in 42 patients from 1990 to 1995 for repair of residual skull defects in children having previously undergone craniofacial repairs, for primary reconstruction of the cranial vault for patients with synostosis and for repair of skull defects resulting from trauma and skull tumor excisions. The vast majority of grafts have resulted in complete closure of the defect, providing a matrix for new bone formation. These patients are presented. Surgical techniques of cranial defect repair with perforated demineralized bone matrix are discussed.

Treatment of positional plagiocephaly with dynamic orthotic cranioplasty.

Dynamic orthotic cranioplasty (DOC) was developed to treat asymmetrical head shape of a nonsynostotic origin, which is defined by the term positional plagiocephaly. These positional deformations have been found to correlate with a number of environmental factors. Infants with positional plagiocephaly may exhibit complex multistructural asymmetry affecting the cranial vault, face, and skull base, or expression may be local in nature. Between 1988 and 1993, we performed DOC on 124 infants with positional plagiocephaly. Through clinical, anthropometric, radiographic, and statistical evaluation, we found that DOC corrects positional deformation of the cranial vault, skull base, and upper face, with no evident relapse following treatment. The design and the global approach to deformation address a wide spectrum of abnormal head shapes. The procedure is dynamic and customized, and it does not rely on passive growth alone for improvement.

Magnetic field guided endoscopic dissection through a burr hole may avoid more invasive craniotomies. A preliminary report.

The neuroendoscope, coupled with radiofrequency or laser dissecting tools, can effectively resect obstructing membranes, biopsy and debulk tumor, and evacuate hematomas when the pathology is within the ventricular system. This less invasive approach through a burr hole usually avoids craniotomies. When the abnormal condition is within parenchyma or in the presence of opacifying bloody fluid, landmarks are not recognizable and the neurosurgeon quickly becomes disoriented. A more extensive craniotomy or a stereotaxic-guided procedure is then necessary. We describe our preliminary experience with a geographic intracranial navigation system using realtime measurement of electromagnetic field strength in multiple planes to precisely indicate the position of the tip of the endoscope. A transmitting antenna is positioned beneath the patient's head. A 1.5 centimeter cubic antenna receiver is mounted upon a lenscope with instrument channel. The scope is guided into the surgical field after insertion through a burr hole. A square wave pulsed electromagnetic field measurement is made 140 times per second with correction for the earth's magnetic field once per second. Intracranial position data for the dissecting tip in regard to X, Y, Z, pitch, roll and yaw are output to a digitized computer map of the patient's MRI or CT scan. Also displayed on the computer screen is the video image from the endoscope. The neurosurgeon thus has simultaneous realtime geographic and near-field localization as he dissects. Electromagnetic field guided accuracy is within 2.0 mm inside the allowable 24 inch working sphere about the patient's head. Coupled with near-field video precision, accuracy is within 1 mm of recognizable dissection planes.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of skin necrosis in rats by using a new microneedle electrocautery, standard-size needle electrocautery, and the Shaw hemostatic scalpel.

"Microneedle" electrocautery was compared against the standard-size needle electrocautery and the Shaw hemostatic scalpel to determine the differences in tissue necrosis when used as a cutting instrument. Incisions were made on the dorsal skin of anesthetized white rats using each of the three devices with the no. 15 scalpel as control. The specimens were submitted for histological evaluation. The microneedle caused less necrosis than the standard-size needle electrocautery (0.18 vs 0.27 mm, p < 0.01) and less necrosis than the Shaw hemostatic scalpel set at 220 degrees F (0.18 vs 0.25 mm, p < 0.05). The microneedle electrocautery was also found to be an instrument that causes very little tissue distortion during fine dissection and helps to minimize blood loss in craniofacial and neurosurgical operations.

Chronic tonsillar herniation and Crouzon's syndrome.

Patients born with craniofacial syndromes such as Crouzon's syndrome will often develop hydrocephalus after their initial craniofacial reconstructive procedures. We have treated 10 patients with Crouzon's syndrome; 5 patients required a shunting procedure after cranial remodeling. Each of these 5 shunted patients later demonstrated chronic tonsillar herniation on magnetic resonance imaging studies. One of these patients exhibited signs of pseudotumor cerebri and 1 had a spastic quadriparesis. Of the 5 patients who did not require a shunt, none displayed chronic tonsillar herniation. Our evidence suggests that jugular foramen stenosis produces an increased cerebral venous turgor that leads to a cerebrospinal fluid absorption defect and hydrocephalus. After the hydrocephalus is treated the increased venous turgor remains and provides the driving force for the development of chronic tonsillar herniation.