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Biomedical subjects

A H Menezes

Publications and source records attributed to A H Menezes.

At least 19 recordsLinked to original sources

Primary tumors of the spine in children. Natural history, management, and long-term follow-up.

STUDY DESIGN: Patients 16 years of age and younger with primary vertebral neoplasms diagnosed between 1951 and 1996 at The University of Iowa were reviewed retrospectively with specific consideration given to follow-up. OBJECTIVE: Follow-up extending beyond the growth of the axial skeleton was used to establish the natural history, management outcome, and current approach to treatment. SUMMARY OF BACKGROUND DATA: Primary tumors of the spine are uncommon. The treatment of such lesions generally has been based on small series of tumors, or extrapolated from the treatment of tumors in other regions and tumors in adults. Given the unique developing anatomy and dynamic nature of the growing spine in children, delineating appropriate modalities of treatment for these tumors beyond the growth of the axial skeleton is essential. METHODS: Clinical history, radiographs, radiographic reports, and interviews were used to establish this database. Outcome with respect to the various approaches to treatment was then compared in detail. RESULTS: Forty-five patients were identified in which follow-up greater than 10 years was available for 58% of patients. There were 29 histologically benign and 16 malignant tumors. Patients presented most frequently with pain (79%) and neurologic deficits (74%). The duration of symptoms was significantly shorter with malignant tumors (11 weeks) compared with benign tumors (26 weeks). Radiographic abnormalities were demonstrated on plain radiographs in 98% of cases. Tumor excision was achieved in 80%. Follow-up studies were available beyond the growth of the axial skeleton in these patients, with an average follow-up of 14 years. Recurrence was seen in 6 of 45 children, and the overall mortality rate was 6.7%, occurring only with malignant tumors. CONCLUSION: Our current approach to treatment of spinal neoplasms varies from that used in the earlier part of the series and reflects the need for single stage complete resection and stabilization.

Adolescent

Hemorrhagic complications in association with silastic dural substitute: pediatric and adult case reports with a review of the literature.

OBJECTIVE AND IMPORTANCE: Delayed intracranial hemorrhage is an unusual complication associated with the use of silastic dural substitute. CLINICAL PRESENTATION: We present three patients with this complication. Two adult patients developed subdural and epidural hemorrhages 9 months and 10 years after posterior fossa surgery for Chiari malformations. The remaining patient, a 13-month-old child, is the youngest reported patient to develop an epidural hematoma 8 months after a craniosynostosis repair. INTERVENTION: The hematomas were removed with the silastic dural substitute from all three patients, and the dural defect was repaired with autologous paracervical fascia. CONCLUSION: Silastic dural grafts have an increased incidence of hemorrhage associated with their use. A slight increase in the prevalence of hemorrhagic complications with silastic dural substitute was observed in women. We report our radiographic and surgical findings, including an extensive review of the literature.

Adult

Sudden attacks of head pain in a young child.

In the evaluation of headaches at any age, the clinical features of the episodes are the most important diagnostic information available. In the patient presented, the nature of the headaches suggests the need for further study as well as the most fruitful location in which to look.

Cerebellum

Management strategies for tumors of the axis vertebra.

Primary and metastatic tumors of the axis vertebra pose difficult surgical problems. The authors report 14 cases of patients with axis tumors who underwent surgery between 1970 and 1993. The eight male and six female patients ranged in age from 9 to 70 years (mean 46 years). Presenting symptoms and signs included pain in 12, myelopathy in nine, radiculopathy in four, and cranial nerve deficits in two patients. Preoperative instability of the cervical spine was present in eight patients. The goal of surgery was to achieve diagnosis, decompression, and stabilization; the choice of operative intervention was based on tumor location and patient prognosis. Six transoral-transpalatal resections, two lateral extrapharyngeal approaches, four posterolateral decompressions, and 11 dorsal decompressions were performed. Eleven fusion procedures were required to achieve spinal stability. Patients with aggressive tumors requiring concomitant radiotherapy underwent fusion using contoured loop instrumentation or methyl methacrylate, whereas those with benign lesions underwent fusion using traditional techniques. With maximum medical and surgical intervention, 10 patients are alive and their tumors are in remission. In eight of these 10 patients, gross-total resection was achieved. Four patients died from tumor progression, and in three of these cases gross-total resection was not possible. There were no operative deaths and morbidity was minimal. Development of new surgical approaches to the axis has allowed resection of previously inoperable tumors. The extent of resection correlated with the duration of survival. A classification system for axis tumors is proposed to facilitate selection of appropriate surgical approaches that will maximize the extent of resection while achieving or maintaining spinal stability.

Adolescent

Quantitative analysis of cerebrospinal fluid spaces in children with occipital plagiocephaly.

The etiology of occipital plagiocephaly (OP) is not fully understood. The authors have observed that many infants with this condition have external hydrocephalus. This study was undertaken to quantify cerebrospinal fluid (CSF) space caliber in children with OP and to compare these measurements to those derived from normal age-matched controls to further elucidate the pathogenesis of this condition. Thirty-one infants with isolated unilateral OP (mean age 6 months) were studied. Infants with multiple cranial suture abnormalities, impaired neurological function, developmental delay, and associated craniofacial anomalies were excluded. Twenty normal infants were evaluated as controls. The volumes of the sylvian fissures, frontal and occipital subarachnoid spaces, as well as the cross-sectional areas of the suprasellar and perimesencephalic cisterns, were calculated from computerized tomography (CT) studies. Ventricular size was also assessed. Generalized subarachnoid space dilation was observed in 29 (93.5%) of the 31 children with OP. Head circumference was significantly greater in the case group (71.4 vs. 50.8 percentile; p = 0.0002 by analysis of variance). The sylvian fissure volume was significantly larger in the case group (5.8 ml vs. 0.7 ml in controls, p < 0.0001). The volume of the contralateral sylvian fissure was greater than that ipsilateral to the side of OP (7.1 ml vs. 4.5 ml, p = 0.001). Frontal subarachnoid space volume was greater in infants with OP (27.5 ml vs. 0.6 ml in controls, p < 0.0001). Both the suprasellar and perimesencephalic cisterns were of greater caliber in the case group (p = 0.007 and p < 0.0001, respectively). No difference in ventricular size or occipital subarachnoid space volume was noted between groups. The extraventricular CSF spaces in neurologically unimpaired infants with OP are significantly larger than those in age- and sex-matched controls. Enlarged subarachnoid spaces may increase the compliance and malleability of the calvaria and sutures, predisposing to positional deformity. External hydrocephalus may be a fundamental etiological factor in OP.

Cerebrospinal Fluid

Periodontoid calcium pyrophosphate dihydrate deposition disease: "pseudogout" mass lesions of the craniocervical junction.

Between 1984 and 1996, seven patients with symptomatic masses located posterior to the odontoid process and containing calcium pyrophosphate dihydrate crystals were evaluated by the senior author (A.H.M). All patients presented with distal paresthesias and myelopathy and underwent transoral-transpharyngeal resection of the anterior arch of C-I, the odontoid process, and the compressing mass. Histological examination revealed the characteristic changes of calcium pyrophosphate dihydrate (CPPD) deposition disease, with nodular deposits of birefringent rhomboid crystals. On magnetic resonance imaging, the masses appeared predominantly isointense with neural tissue on T1-weighted images and iso-to hyperintense on T2-weighted images. On computerized tomography scans, small area of calcifications within the masses were apparent in all cases. All patients improved postoperatively, with six of seven patients requiring posterior fixation for instability as a second procedure. Calcium pyrophosphate dihydrate deposition causing periodontoid mass lesions is a distinct clinical disease entity that probably is underdiagnosed. In the authors' l opinion, the diagnosis can often be established preoperatively by the distinctive neuroradiological appearance of the masses. Therefore, CPPD deposition disease should be considered in the differential diagnosis of masses of the craniocervical junction, because it is amenable to early surgical intervention. The consulting neuropathologist should be made aware of this diagnostic possibility at the time of surgery.

Aged

Pathogenesis and treatment of growing skull fractures.

BACKGROUND: Growing skull fractures are poorly understood complications of pediatric skull fractures. METHODS: A retrospective review of skull fractures at our institution from 1980-1993 revealed 10 patients with growing skull fractures. The age at injury ranged from 1-144 months, with 9 of 10 patients being under one year of age. The etiology of these fractures included falls, motor vehicle accidents, and child abuse. On average, growth of the fracture was diagnosed 14 months after the initial injury. RESULTS: Six patients have had magnetic resonance imaging (MRI) with one demonstrating leptomeningeal cyst herniation, two having brain herniation, and three having both brain parenchyma and leptomeningeal cyst herniation. All patients had malacic cortex underlying the fracture, but there was no evidence of intracranial hypertension. Nine patients have undergone craniotomy with excision of granulation tissue and gliotic brain, dural repair, and cranioplasty using surrounding normal skull. There were no surgical complications or recurrences. CONCLUSIONS: Brain/leptomeningeal cyst herniation through a dural rent, without MRI evidence of increased intracranial pressure, implicates physiologic growth and brain cerebrospinal fluid (CSF) pulsations as the cause of fracture enlargement.

Child

Craniocervical intradural neurenteric cysts.

Neurenteric cysts are rare lesions of the central nervous system that are lined by epithelium of intestinal nature. They result from abnormal separation of germ cell layers in the 3rd week of embryonic life, leading to persistence of entodermal elements in the spinal canal. The common location is cervical and ventral to the spinal cord. The lesions have been recognized as being entodermal in origin by such markers as vertebral anomalies, gut cysts, bowel reduplication and the presence of keratin markers. Three unusual cases of childhood craniocervical intradural neurenteric cysts in patients aged 4-8 years are described. These cysts were located in the ventral aspect of the spinal canal ranging from the craniocervical junction to the C6 level and were associated with bony anomalies such as a bifid clivus, hemivertebrae and blocked vertebrae. Two patients presented with signs of cervical cord compression and 1 with recurrent meningitis. One child with an anterior cervicomedullary region mass had undergone unsuccessful transoral transpalatal exploration and subsequently required excision with a dorsolateral approach. The second patient, after two successful attempts at drainage via laminectomies, required myelotomy of the spinal cord to allow excision. Thus the patient with the lesion from C4 through C6 underwent vertebrectomy and anterior excision with a C4 through C7 strut graft fusion. There were bony and vascular anomalies which would have complicated a dorsal approach. Pathological diagnosis of neurenteric cysts was based on the findings of nonciliated mucin producing small cuboidal or columnar epithelium lining a cystic cavity. Neurenteric cysts are uncommon congenital anomalies which may become symptomatic in the pediatric population.(ABSTRACT TRUNCATED AT 250 WORDS)

Cervical Vertebrae

Primary craniovertebral anomalies and the hindbrain herniation syndrome (Chiari I): data base analysis.

This prospective study analyzes 100 patients with Chiari malformation and primary craniovertebral junction (CVJ) anomalies (3-66 years). Neurodiagnostic investigations employed tomography, gas myelography, CT and CT myelography, and MRI. Factors considered were reducibility, mode of encroachment, cerebrospinal fluid (CSF) dynamics and syringohydromyelia. Sixty-six patients with irreducible pathology underwent ventral or ventrolateral decompression and dorsal stabilization. Dorsal occipitocervical fixation was performed in reducible lesions that also required dorsal decompression (n = 34). Proatlas remnants were identified in 8 and atlas assimilation in 92 patients. Paramesial invagination was present in 20, syringohydromyelia in 46, and vertebral segmentation defects in 66 others. Completely reducible abnormalities were identified in 16 of 20 patients aged 2-14 years, and partially reducible abnormalities in 4 of 16 patients aged 14-20 years, 8 of 48 patients aged 20-40 years and 6 of 16 patients aged 40-60 years. The critical sagittal canal diameter at the foramen magnum was 19 mm. Twenty-two patients had previous posterior decompression and 27 had previous syrinx to subarachnoid shunt with delayed deterioration. Improvement occurred in all after ventral or ventrolateral decompression with resolution of the syringohydromyelia and normalization of CSF flow. We conclude that: (1) hindbrain herniation syndrome is frequently seen with fourth occipital sclerotome abnormalities; (2) Chiari malformation with craniovertebral abnormalities become symptomatic with a canal diameter of < 19 mm; (3) abnormal ventral bony pathology is reducible in children wit atlas assimilation and later becomes irreducible invagination, therefore early operation with fusion is recommended; (4) ventral decompression relieves brain stem, cerebellar symptoms and syringohydromyelia; (5) CSF studies with cine MRI shows reversal of craniospinal CSF dissociation after ventral CVJ decompression and; (6) craniovertebral anomalies associated with Chiari malformations must be addressed early and appropriately.

Adolescent

Cervical epidural hematoma secondary to an extradural vascular malformation in an infant: case report.

We present a report of a 22-month-old infant with a spontaneous spinal epidural hematoma arising from a purely epidural vascular malformation. Although often suspected as a cause of spontaneous epidural hemorrhage, vascular malformations have rarely been demonstrated. The important aspects of the presenting symptoms in this young age group are highlighted. We discuss the entity of spontaneous epidural hemorrhage and the characteristics that distinguish purely epidural from dural arteriovenous malformations.

Arteriovenous Malformations

Myelinoclastic diffuse sclerosis (Schilder's disease): report of a case and review of the literature.

The clinical, neuroimaging, and neuropathologic features of Schilder's disease in a 17-year-old girl are presented and compared to 11 well-documented cases reported since 1912. The evolution of knowledge about Schilder's disease and the confusion in nomenclature are reviewed. Signs and symptoms in this case and others reported in the literature are nonspecific and may mimic mass lesions. Neuroimaging studies also may mimic brain tumor or abscess; however, the absence of significant edema, the irregular and incomplete ring enhancement, the discrepancy between size of the lesions and the associated mass effect, and the absence of other lesions elsewhere in the brain may help differentiate Schilder's disease from neoplasm, infection, and other demyelinating lesions. Although frozen sections of these lesions are often interpreted as astrocytoma, the inflammatory, primarily histiocytic, nature of Schilder's disease is more easily recognized in paraffin-embedded material. Unique features of this case include multiple unilateral lesions and the cyst-like degeneration present in both lesions. Multiple lesions in Schilder's disease are characteristically bilateral. The examination of aspirated fluid is the first such report in Schilder's disease. The limitation of multiple lesions in our case to one hemisphere calls for reexamination of the restrictive 1985 criteria of Poser for the diagnosis of Schilder's disease.

Adolescent

Cervicomedullary compression in achondroplasia.

Six patients with achondroplasia and symptoms suggestive of cervicomedullary junction compression are reviewed; these included three females and three males, with an average age of 8 years (range 7 months to 30 years). The mean duration of symptoms prior to intervention was 1.9 years. Symptoms included occipitocervical pain, ataxia, incontinence, apnea, and respiratory arrest. Radiological investigations consisted of plain films with flexion and extension views, pluridirectional tomography, thin-section computerized tomography, and magnetic resonance imaging. Typical findings included marked foramen magnum stenosis, ventrolateral cervicomedullary junction compression secondary to central and paramesial basilar invagination, and dorsal cervicomedullary junction compression secondary to ligamentous hypertrophy and invagination of the posterior atlantal arch. All patients underwent posterior fossa decompression and atlantal laminectomy. Surgery consistently revealed marked dorsal and paramesial overgrowth of the rim of the rim of the foramen magnum, with thickening and invagination of the atlantal posterior arch and a dense fibrotic epidural band resulting in dorsal cervicomedullary compression. Intraoperative ultrasonography was used to determine the extent of decompression required. Three patients required duraplasty. Three patients had concurrent hydrocephalus, two of whom had undergone ventriculoperitoneal shunting prior to surgical decompression of the posterior fossa. One patient developed a pseudomeningocele postoperatively, requiring serial lumbar punctures before it resolved. No patient developed craniovertebral instability following decompression. Improvement or resolution of symptoms was noted in all patients, with an average follow-up period of 4.8 years. Thus, cervicomedullary compression in patients with achondroplasia can be successfully treated with dorsal decompression of the craniovertebral junction. Dense epidural fibrotic bands are frequently noted in these cases and must be aggressively released to ensure satisfactory decompression.

Achondroplasia

Nonrheumatoid cranial settling.

Cranial settling is a condition in which erosive changes of the atlantal lateral masses result in downward telescoping of the atlas onto the axis body, anterior displacement of the atlantal posterior arch, and subsequent ventral and dorsal cervicomedullary compression. Cranial settling is described in conjunction with rheumatoid basilar invagination and atlanto-axial instability, possibly representing the most life-threatening abnormality associated with rheumatoid arthritis. The authors describe a case of symptomatic cranial settling in a nonrheumatoid patient with chronic, severe, spasmodic torticollis resulting in erosive changes in the occipito-atlanto-axial complex.

Atlanto-Axial Joint

Craniovertebral abnormalities in Down's syndrome.

The ligamentous laxity associated with atlantoaxial subluxation has been assumed as a normal occurrence in 15-20% of Down's syndrome patients. The occipitoatlantoaxial instability that accompanies this entity has been poorly recognized. The medical records and radiographic findings of 18 symptomatic patients with Down's syndrome and cervicomedullary compromise were reviewed (1979-1991). All patients were evaluated prospectively under protocol for abnormalities of the cranial vertebral junction. There were 11 males and 7 females (age 3-42). 'Fixed' atlantoaxial luxation was seen in 8 (5 developed precipitous onset of cervical medullary compression). Occipitoatlantoaxial instability was present in 9 and associated rotary luxation in 9. The average predental space was 8 mm in the neutral position in 18 individuals. Two adolescents had previously undergone atlantoaxial dorsal fusion with subsequent progressive basilar invagination due to unrecognized occipitoatlantal instability. An os odontoideum was seen in 3 patients. Irreducible invagination in 2 was treated with anterior decompression followed by dorsal occipital cervical fixation. The occipital cervical fixation was utilized in 10 individuals. Atlantoaxial dorsal fusion was made in 7 and 2 patients with acute rotary luxation of C1 and C2 were treated with immobilization. Halo immobilization in two individuals following a dorsal occipital cervical fixation produced an anterior fusion at the cranial vertebral complex indicating active vertebral ligamentous pathology. The review focuses on increased incidence of occiput cervical instability in the spectrum of craniovertebral junction abnormalities associated with Down's syndrome. A large percentage has an odontoid ossicle probably as a result of repeated minor trauma. The results of surgical stabilization have been shown to be excellent.

Adolescent