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Biomedical subjects

W M Chadduck

Publications and source records attributed to W M Chadduck.

At least 19 recordsLinked to original sources
PubMed1996

Synostectomy versus complex cranioplasty for the treatment of sagittal synostosis.

Although pediatric neurosurgeons traditionally have been trained to perform a sagittal synostectomy for the treatment of sagittal synostosis, numerous articles advocating modifications of this procedure or more complex cranial vault reconstructions point our the inadequacies of strip craniectomy in providing optimal short- and long-term cosmesis. This review addresses the major arguments for and against performing complex cranioplasties for sagittal synostosis, as well as issues regarding timing of surgery, mortality and morbidity, increased need for blood transfusion, and increased expense. The authors support the contention that for the majority of infants with sagittal synostosis, complex calvarial vault reconstruction provides a better outcome with little increase in operative risk.

Cephalometry↗
PubMed1996

Cervical kyphotic myelopathy in a child with Morquio syndrome.

A child with Morquio syndrome developed severe cervical kyphosis causing myelopathy. Decompression of the spinal cord was accomplished by an anterior approach using multilevel corpectomies and stabilization with calvarial bone grafts and halo immobilization. The case reported is unique in that cervical cord compression resulted from an uncommon degree of cervical kyphosis rather than the usual atlantoaxial instability seen in patients with Morquio syndrome. The operative procedure described shows another example of the usefulness of calvarial bone grafts for cervical spine fusions in children.

Cervical Vertebrae↗
PubMed1996

Telomeric associations in the progression of chromosome aberrations in pediatric solid tumors.

Telomeric association (tas) is a cytogenetic phenomenon in which chromosome ends fuse to form dicentric, multicentric, and ring chromosomes. We observed clonal tas in six pediatric solid tumors of various types and histological grades studied using short-term in situ culture and G-banding techniques. These tumors included a neurilemoma, an undifferentiated (embryonal) sarcoma of the liver (UESL), two anaplastic astrocytomas (AA), one case of glioblastoma multiforme (GBM), and a neuroblastoma (NB) of the kidney. Cytogenetic data from all six tumors demonstrated multiple numerical and structural aberrations including tas. The tas appeared to be a secondary aberration in these tumors, however, it was possible to follow the progression of the telomeric chromosome aberrations in several cases. In all but one case (UESL) the loss of chromosome segments occurred. Tas of 11p was observed in three of the six tumors, two of which showed the subsequent loss of 11p (AA and AB). In addition, tas of 4p was seen in three tumors, two of which showed clonal tas of 4p with 22q. Tas of 10p, 21p, and 22q were all observed in at least two different tumors. The clonal telomeric fusions of 4p with 22q, recurring tas of 11p, and the subsequent loss of the short arm of 11 demonstrated here, suggests that some chromosome regions are subject to nonrandom instability and sometimes loss.

Adolescent↗
PubMed1996

Outcome analysis of 85 patients undergoing the pi procedure for correction of sagittal synostosis.

The authors present a retrospective review of their experience with 85 cases using the pi procedure to correct sagittal synostosis. A male preponderance of four to one was recognized in this group. Sixty-five infants underwent computerized tomography scanning of the head prior to surgery; these scans revealed unexpected intracranial pathology in 5% of cases. Surgical complications included three intraoperative dural lacerations. All children received blood transfusions with no complications. Cosmetic outcomes were excellent in 53%, good in 43%, and poor in 4% of cases. One patient required reoperation. All poor outcomes were in infants who were younger than 8 weeks of age at the time of surgery and who underwent a "reverse pi" procedure. Most of the excellent outcomes occurred in infants who were between 3 and 6 months of age at the time of surgery. Although more extensive than strip craniectomy, the pi procedure can be accomplished with minimal morbidity. In the authors' opinion, the pi procedure provides better immediate and long-term cosmetic results than synostectomy alone.

Age Distribution↗
PubMed1995

Cranial burst fracture in infants: acute recognition and management.

In the past, the diagnosis of "growing skull fracture" or "diastatic fracture" has included a subset of injuries better referred to as "cranial burst fracture." Cranial burst fracture, typically associated with severe injury in infants less than 1 year of age, is a closed, widely diastatic skull fracture accompanied by acute cerebral extrusion outside the calvarium. We treated 11 such infants at the LeBonheur Children's Medical Center and 2 at the Children's National Medical Center from January 1986 through December 1994. Infants ranged in age from 1 to 17 months, with an average age of 5.7 months. All presented with marked scalp swelling and a Glasgow Coma Scale score of 10 or less. Twelve had a history consistent with severe injury (motor vehicle accident, 7, abuse 5). The cause of injury in one patient remains unproven. Surgery (reduction of herniated cerebral tissue, repair of large dural laceration, and cranioplasty) was usually performed within 10 days of injury, a time period long enough to assure hemodynamic stability and resolution of acute cerebral swelling, yet sufficiently brief to avoid the chronic changes (scarring, parasitization of scalp vessels by damaged cortex) associated with a "growing skull fracture." Prompt repair of cranial burst fracture may prevent ongoing brain injury such as has been neuropathologically demonstrated in patients with "growing skull fracture." Magnetic resonance imaging establishes the diagnosis of cranial burst fracture in equivocal cases, rendering unnecessary a "waiting period" to see if scalp swelling resolves. Our experience, together with information in the neuropathological and neurosurgical literature, suggests that cranial burst fracture is associated with severe trauma, requires expeditious treatment, and has been underdiagnosed in the past, leading to "growing skull fracture," a condition requiring more extensive surgery.

Fractures, Closed↗
PubMed1995

Pediatric cerebellar hemorrhages.

Cerebellar hemorrhage is a devastating condition with morbidity and mortality related not only to the etiology of the hemorrhage, but also to the timing of the intervention. Sixteen consecutive pediatric patients with acute cerebellar hemorrhages are presented: 6 had vascular abnormalities, 3 had tumors, and 2 had hemorrhages of unknown etiology. Thirteen of the 16 patients survived with only 1 of the 13 having persistent vegetative state as a neurologic outcome. Six of 8 patients presenting in a moribund condition had good outcomes, and 3 of 4 patients presenting with fixed and dilated pupils also had good outcomes. Thus, in contrast to adults, rapid evaluation by CT scanning, followed by the judicious use of ventricular drainage and prompt surgical treatment, have resulted in favorable outcomes in pediatric patients despite their poor clinical presentations. None of the neonates having cerebellar hemorrhages required surgical intervention; their courses could be followed clinically and with transfontanel ultrasound.

Adolescent↗
PubMed1995

Tumoral multiple sclerosis of the cerebellum in a child.

We present a case of cerebellar tumoral multiple sclerosis in an 11-year-old girl and emphasize these two features: (1) Tumoral multiple sclerosis can occur within the posterior fossa and should be strongly considered in the differential diagnosis of mass lesions of the posterior fossa when typical white matter lesions are seen on T2-weighted images. (2) Tumoral multiple sclerosis can demonstrate ring enhancement on MR.

Cerebellar Diseases↗
PubMed1994

Time-related patterns of ventricular shunt failure.

Proximal obstruction is reported to be the most common cause of ventriculoperitoneal (VP) shunt failure, suggesting that imperfect ventricular catheter placement and inadequate valve mechanisms are major causes. This study retrospectively examined patterns of shunt failure in 128 consecutive patients with symptoms of shunt malfunction over a 2-year period. Factors analyzed included site of failure, time from shunt placement or last revision to failure, age of patient at time of failure, infections, and primary etiology of the hydrocephalus. One hundred of these patients required revisions; 14 revisions were due to infections. In this series there was a higher incidence of distal (43%) than of proximal (35%) failure. The difference was not statistically significant when the overall series was considered; however, when factoring time to failure as a variable, marked differences were noted regardless of the underlying cause of hydrocephalus or the age of the patient. Of the 49 patients needing a shunt revision or replacement within 2 years of the previous operation, 50% had proximal malfunction, 14% distal, and 10% had malfunctions attributable directly to the valve itself. Also, 12 of the 14 infections occurred during this time interval. In sharp contrast, of the 51 patients having shunt failure from 2 to more than 12 years after the previous procedure, 72% had distal malfunction, 21% proximal, and only 6% had a faulty valve or infection. This difference between time to failure for proximal versus distal failures was statistically significant (P < 0.00001 for both Student's t-test and non-parametric Mann-Whitney U-test).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Chromosome aberrations in four ependymomas.

Cytogenetic analysis of short-term cultures from three untreated and one recurrent ependymoma revealed clonal aberrations in three of the four tumors. A posterior fossa ependymoma from a 3-year-old male patient showed trisomy 11 as the sole clonal chromosome aberration. A recurrent spinal ependymoma from a 35-year-old male showed hypertriploid clones with abnormalities involving chromosomes 1p11,7q21, and 10p13. A 62-year-old male patient with a cerebellar ependymoma showed a hypodiploid stem-cell line with clonal structural aberrations of both the long and short arms of chromosome 1, an interstitial deletion of 2q, trisomy 7, and monosomy for chromosomes 11, 13, and 16. A 3-year-old female patient with posterior fossa ependymoma showed a normal 46,XX karyotype. Chromosome 1 aberrations appear to be the most consistent finding in this small series of tumors, with the net loss or rearrangement of chromosome 1 pter-->p22 material from two of the four tumors. These findings, in addition to a previously published case [1], suggest a possible role for genes on the short arm of chromosome 1 in the cytogenetic evaluation of ependymomas.

Adult↗
PubMed1994

Reconstruction of the hypoplastic posterior arch of the atlas with calvarial bone grafts for posterior atlantoaxial fusion: technical report.

Posterior atlantoaxial fusion is a common procedure performed for instability at C1-C2. This operation requires intact posterior elements of both the atlas and the axis. When this is not the case, the incorporation of the occiput and the lower spinal segments is usually required for adequate posterior fusion, but such a procedure limits the mobility of the upper cervical spine. A technique for the reconstruction of the posterior arch of the atlas with calvarial bone is described in this report. This technique allowed the successful fusion of the C1 and C2 vertebrae in a patient with traumatic atlantoaxial subluxation who also had a congenital absence of the posterior arch of the atlas.

Atlanto-Axial Joint↗
PubMed1993

Cranial fasciitis of childhood.

We present a child with a rapidly growing mass and lytic skull lesion that on pathologic evaluation was diagnosed as cranial fasciitis. This disease entity is not widely known by radiologists, and should be included in the differential diagnosis of lytic skull lesions.

Fasciitis↗
PubMed1992

Premature fractures of platinum-cured Silastic shunts.

Experience with one unitized ventriculoperitoneal (VP) shunt system has disclosed an unacceptably high rate of premature distal shunt tube fracturing. From March, 1986, to February, 1989, 114 new or replacement unitized VP shunts were placed; the patients were followed through November, 1991. Twenty-two (19.3%) returned with peritoneal limb fractures, with a mean time from shunt implantation to fracture of 31.5 +/- 11.3 months (range 15-62 months). All shunts broke in the neck 1.1-11.2 cm below the valve. Of the 22 cases, there were no instances of infection, previous peritoneal limb revisions, or recognizable iatrogenic shunt injury at placement. These fractures also occurred earlier than the usual time expected for biodegradation of shunt tubing. The Silastic tubing in all of these shunts had been manufactured using a more recent platinum-curing process. This tubing has decreased elastance and is more brittle than tubing cured with the previously used dichlorobenzoyl peroxide (DCBP) catalyst. Our studies suggest that the premature shunt tube fractures were related to changes in physical characteristics of the platinum-cured Silastic tubing. Therefore, the DCBP-cured Silastic is to be considered preferable for shunting products. Neurosurgeons are asked to report recurring patterns of shunt system failure.

Benzoyl Peroxide↗
PubMed1992

Single cervical exostosis. Report of a case and review of the literature.

The authors present a rare case of solitary cervical osteochondroma. Because of its rarity and its predilection for the atlantoaxial area, the diagnosis may be overlooked in evaluating patients having cervical myelopathy. Surgical decompression usually improves the patient's neurologic status.

Adult↗
PubMed1992

Telomeric associations evolving to ring chromosomes in a recurrent pleomorphic xanthoastrocytoma.

Telomeric associations observed in a recurrent untreated pleomorphic xanthoastrocytoma were apparently the primary cytogenetic events that evolved by fusion and breakage events, resulting in subclones with ring chromosomes. The telomeric fusions between chromosomes 15pter and 20qter, and between an extra copy of the long arm of chromosome 1 and chromosome 22qter, evolved in a stepwise fashion to ring chromosomes 20 and 22. The findings in this tumor demonstrate that telomeric association is one mechanism that can initiate chromosome instability by generating subclones with unstable chromosome intermediates and result in ring chromosomes and subsequent chromosome loss.

Adolescent↗
PubMed1992

Cytogenetic findings in a case of pediatric glioblastoma.

We report a patient with glioblastoma multiforme (GBM) which showed stable and unstable telomeric associations involving the short arms of chromosomes 4 and 7. The karyotype was hyperdiploid, with chromosome numbers ranging from 84 to 87 in all cells, and showed a single stemline with variations in the number of marker chromosomes, teleomeric associations, and double minutes (dmin). The karyotype designation is 83-86,XX,-X,rea(X),-4,tas(4;7)(p16;?p22),der(6)t(6;?)(p21;?), -8, -9, der(9)t(9;?)(?p11;?), dup(9)(p12p23), -10 x 2, del(10)(p11), -11,del(11)(p11), -12, der(12)t(12;?) (p13;?),-13, -14 x 2,der(14)t(14;?) (p11;?), -16 x 2, -19, -21 x 2, -22 x 2, + 9-13mar, + dmin. Loss of the short arm of chromosome 10, structural aberrations of the short arm of chromosome 9, and dmin are consistent findings in GBM, whereas the high chromosome number is less common. Chromosome instability associated with the phenomenon of telomeric association/fusion has not been reported in GBM.

Adolescent↗
PubMed1992

Meningioma and sagittal craniosynostosis in an infant: case report.

The occurrence of a frontal base meningioma in a 3-month-old infant seen for the treatment of sagittal craniosynostosis is reported. The association of the two lesions is of interest both because it is unique and may lend support to theories of the cause of some forms of craniosynostosis.

Age Factors↗