Nonselective partial dorsal rhizotomy: a clinical experience with 1-year follow-Up.

The ability to perform a 'selective' dorsal rhizotomy has been challenged. EMG responses are inconsistent and often do not represent reflex responses. We perform nonselective partial dorsal rhizotomy (NSPDR) when reflex response is not evident. Ten children undergoing primarily NSPDR were evaluated preoperatively and postoperatively with the Modified Ashworth Scale, gait lab analyses gross motor function measure and the NSPDR was performed by nonselectively sectioning 50-75% of the dorsal roots not demonstrating a reflex response. Standard selective rhizotomy was performed in the remainder. Only 17 of 106 (16%) dorsal roots demonstrated reflex responses. The results reported in this study demonstrate a benefit to patients undergoing primarily NSPDR which is similar to that reported for patients in whom a selective procedure was intended.

The relative contributions of interpersonal and specific clinical skills to the perception of global clinical competence.

BACKGROUND: The objective structured clinical examination (OSCE), an established instrument for evaluating resident competence, was used to test the hypothesis that faculty assessment of clinical competence in residents at various levels of training may be influenced more by general skills as a physician and less by competency in the actual skills being specifically tested. In this study, advantage was taken of the anticipated observation that general surgery residents did not demonstrate improvement in their ability to perform a focused neurological assessment over time. METHODS: An OSCE, which was administered to 56 general surgery residents at all levels of training, included the assessment of a specific clinical neurosurgical problem (sciatica). Univariate and multivariate analyses were used to evaluate the relationship between the global faculty judgment of competent or noncompetent and the other performance measures that were applied. RESULTS: At different levels of training, there was no observed difference in the specific skills being tested; nevertheless, junior and senior residents were more likely than incoming interns to be judged "competent" and received better evaluations of how well they introduced themselves to the patient. The competence judgment correlated significantly with all of the other performance measures, including the skills being tested. CONCLUSIONS: The perception of competence is not solely dependent upon the particular skills under scrutiny. General competence does not guarantee competence in each specific skill set of a medical specialty.

Interpreting the judgment of surgical faculty regarding resident competence.

BACKGROUND: It is reasonable to propose that competence is a multifaceted characteristic defined in part by some minimum level of knowledge and skill. In this study we examined the relationship between surgical faculty's judgment of clinical competence, as measured by a surgical resident objective structured clinical examination (OSCE), and the residents' objective performance on the skills being tested. METHODS: Fifty-six general surgery residents at all levels of training participated in a 30-station OSCE. At the completion of each station, the faculty proctor made several overall judgments regarding each resident's performance, including a global judgment of competent or not competent. The competence judgment was applied to the objective percentage performance score in three different ways to construct methods for determining competence based solely upon this objective percentage score. RESULTS: The average mean competent score (MCS) across the stations was 61%, and the average mean noncompetent score (MNCS) was 38%. The difference between MCS and MNCS for each station was very consistent. Upper threshold scores above which a judgment of competent was always made, and lower threshold scores below which a judgment of noncompetent was always made were observed. Overall, the average mean and threshold scores for competent and noncompetent groups were remarkably similar. For performance scores in the range between the threshold competent and noncompetent scores at each station, measures other than objective performance on the skills being evaluated determined the judgment of competent or not competent. CONCLUSIONS: Empirically determined minimum acceptable standards for objective performance in clinical skills and knowledge appeared to have been subconsciously applied to the competence judgment by the faculty evaluators in this study. Other factors appeared to have become determinate when the objective performance score fell within a range of uncertainty.

Intracavernous teratoma in a school-aged child.

An eight-year-old boy presented with left eye pain, photophobia, proptosis, third nerve paresis and decreased visual acuity. Magnetic resonance imaging revealed a nonenhancing mass filling the cavernous sinus. Using an extradural fronto-orbitozygomatic approach, the cavernous sinus was approached laterally, and a teratoma was removed from within the cavernous sinus. This is the first case of a truly intracavernous teratoma in a child and the fourth case of a teratoma reported in the cavernous sinus region overall. This report outlines the diagnosis and treatment of this unusual cavernous sinus tumor.

Separation of complex pygopagus conjoined twins.

Pygopagus twins were born with a unique spectrum of anomalies including a conjoined distal spinal cord, single kidney (in twin A), single rectum (in twin A), single vagina (in twin B), and severe central nervous system anomalies in twin B that precluded her independent survival. Separation at 10 weeks of age was tailored toward Twin A's survival. This report discusses the surgical modifications necessary in view of the unique anatomy, including salvaging the distal spinal cord and vagina for twin A.

Cavernous sinus thrombophlebitis: case report.

OBJECTIVE AND IMPORTANCE: Cavernous sinus thrombophlebitis is a rare, dangerous, and historically difficult condition to diagnose and treat. Knowledge of the imaging findings and the importance of early diagnosis and treatment are emphasized. CLINICAL PRESENTATION: We present a case of cavernous sinus thrombo-phlebitis caused by sphenoid sinusitis. Previously undescribed magnetic resonance imaging findings of cavernous sinus thrombophlebitis include enlargement of the cavernous sinus, abnormal enhancement and increased T2 signal of the petrous apex and clivus, and marked narrowing of the cavernous portion of the internal carotid artery. Resolution of cavernous sinus thrombophlebitis is also documented by magnetic resonance imaging. INTERVENTION: The anatomy of the cavernous sinus dictates the natural history and diagnosis of cavernous sinus thrombophlebitis. We review the literature regarding the clinical diagnosis, differential diagnosis, and treatment of cavernous sinus thrombophlebitis. CONCLUSION: We emphasize the importance of a high index of suspicion, the potentially rapid and fatal course of the disease process, and the subsequent need for antibiotic therapy and selective surgery.

The electromyographic responses to dorsal rootlet stimulation during partial dorsal rhizotomy are inconsistent.

Concerns have arisen regarding the ability of physiologic techniques to select rootlets mediating spasticity in children undergoing partial dorsal rhizotomy (PDR) for the treatment of spastic gait from cerebral palsy. To determine whether these physiologic responses are reproducible, 60 rootlets in 6 patients were graded from 0 to 4+ according to the system first reported by Phillips and Park, and then retested and graded using a randomized, blinded paradigm. Two thirds of the rootlets had one or more grade difference between the two trials, and 25% had a grade change of 3 or more. Only 4 of 23 rootlets with a "normal' response (grade 0) on one test were also graded normal on the other test. Only 2 of 14 rootlets with a bilateral response (grade 4+) had a bilateral response on both trials. Statistical analysis demonstrated no correlation and poor agreement between trials. Regardless of whether responses are reflex in origin with technical or physiologic variability, or the consequence of stimulus spread to ventral roots, we found inconsistent responses with commonly used methods and the criteria most agreed upon. These findings suggest that currently used techniques are not reliable for rootlet "selection' and result only in a random partial rhizotomy.

Occult spinal dysraphism in the infant.

The progressive neurologic dysfunction caused by occult spinal dysraphism can be prevented with early clinical recognition, radiographic diagnosis, and neurosurgical treatment. However, detection of occult spinal dysraphism in the infant is difficult because neurologic symptoms often are not apparent until the child becomes ambulatory. Occult spinal dysraphism, however, can be suspected in the asymptomatic neonate when cutaneous stigmata, such as hemangiomas, hairy patches, deep and/or eccentric dimples, or subcutaneous masses are seen over the lumbosacral spine. Because of the serious, often irreversible, sequelae of a delayed diagnosis, spinal sonography of high-risk infants with midline, lumbosacral, cutaneous stigmata should be considered as an effective, noninvasive screening method.

Cervical paraspinous desmoid tumor in a child: case report.

Desmoid tumors are uncommon fibroblastic proliferative lesions usually occurring in the abdominal wall of adults. We report an unusual case of such a tumor presenting as a rapidly growing cervical paraspinous mass in a 19-month-old girl. After surgical resection without adjuvant therapy, the child is recurrence free after 17 months. The primary treatment of these lesions is surgical resection. We found magnetic resonance imaging to be the best imaging method for evaluation, because it was able to distinguish the tumor from the surrounding muscle. Careful postoperative surveillance is warranted, because these tumors have a high rate of recurrence. Although rare, desmoid tumor should be considered in the differential diagnosis of a paraspinous soft tissue tumor in a pediatric patient.

Tethered spinal cord in patients with anorectal and urogenital malformations.

We reviewed 26 patients with anorectal or urogenital malformations managed by the neurosurgical service at The Children's Hospital for tethered spinal cord as diagnosed by spinal MRI. There were 13 patients with cloacal exstrophy, 5 with the Vater association, 3 with imperforate anus, and 5 with other complex anomalies. Tethering spinal cord lesions included myelocystocele, lipomyelomeningocele, and filum lipoma. We review the clinical course, management, correlation of MRI and intraoperative findings, and outcome of the patients, as well as the embryology which underlies the association of these malformations.

Evidence for the ventral origin of oligodendrocyte precursors in the rat spinal cord.

The neuroepithelial cells of the mammalian neural tube are thought to give rise to all classes of differentiated neurons and macroglial cells in the adult CNS. In most cases, the regulation and timing of commitment of neuroepithelial cells to specific differentiative pathways are unknown. It has been proposed that in developing spinal cord, the macroglial cells--astrocytes and oligodendrocytes--arise either by the direct transformation of radial glial cells in the developing cord or, alternatively, by the differentiation of distinct precursor cells which migrate to presumptive white matter from the region of the central canal during development. In this study, the timing of oligodendrocyte differentiation in different levels of the spinal cord and the capacity of specific regions of the spinal cord to give rise to oligodendrocytes at various ages was tested in vitro. At embryonic day 14, all complete segments, as well as all ventral regions along the rostral-caudal axis of the spinal cord, have the capacity for oligodendrogenesis. By contrast, dorsal regions of the thoracic and lumbar spinal cord do not develop the capacity for oligodendrogenesis until later in development. The capacity of dorsal rat spinal cord to give rise to oligodendrocytes appears to be associated with the ventral-to-dorsal migration of oligodendrocyte precursors. These observations suggest that commitment to an oligodendrocyte differentiative pathway appears to occur in a distinct population of ventrally located glial precursors in the embryonic rat spinal cord.

Intracranial tumor in infants: characteristics, management, and outcome of a contemporary series.

Since 1980, 22 patients less than 2 years of age have been treated for intracranial tumors at our institution. The most common presentation was elevated intracranial pressure associated with ventriculomegaly (73%). The diagnosis was made by computed tomography or magnetic resonance imaging and confirmed surgically in every case. In 68% of cases, the tumor involved midline structures in the central nervous system. Tumors were infratentorial in 29% of patients less than 1 year of age and in 60% of those more than 1 year of age. Most tumors were either primitive neuroectodermal tumors (41%, 7 of 9 located in midline posterior fossa structures) or astrocytomas (27%, 5 of 6 located in the hypothalamus, chiasm, or optic nerve). Twenty patients had gross or subtotal tumor resection. Surgical mortality and neurological morbidity were 10% and 5%, respectively. Of 5 patients who underwent a second operation for tumor recurrence, 3 demonstrated a change in the pathological features of the tumor from those of the original diagnosis. Of 10 surgical survivors with malignant tumors, 8 received chemotherapy and 5 radiation therapy. Radiation was not administered before 1 year of age. The overall 1-year survival was 70%, and 2-year survival was 58%. Two-year survival for benign and malignant tumors was not significantly different. We think that the interdisciplinary efforts directed toward the treatment of these tumors has improved survival and that all children should be offered entry to a research protocol and aggressive treatment.

Ventral brain-stem compression from a subarachnoid ependymal cyst.

A case of ventral brain-stem compression by a congenital subarachnoid ependymal cyst in an infant is presented. Marsupialization of the cyst provided effective decompression and clinical improvement. Immunohistochemical staining demonstrated the glial nature of the epithelium. The fact that these cysts may be congenital, as demonstrated here, supports the hypothesis that they arise from glial elements that have been displaced during development.

Maternal intracranial hemorrhage complicating severe superimposed preeclampsia. A case report.

Subarachnoid hemorrhage as a result of superimposed preeclamptic toxemia is a well-known complication but fortunately not a common one. The maternal and fetal mortality rates are high. In one such patient the outcome for both mother and infant was excellent.

Neocarzinostatin chromophore binds to deoxyribonucleic acid by intercalation.

The nonprotein chromophore of neocarzinostatin was found to share many of the characteristics of classical intercalators in its interaction with DNA. Viscosity studies with PM2 DNA indicated that the DNA helix unwinding induced by the chromophore was 0.82 times that of ethidium or 21 degrees. Electric dichroism of the chromophore--DNA complex showed that each bound chromophore molecule lengthened DNA by 3.3 A and that absorbance transitions of the chromophore at 315--385 nm were oriented approximately parallel to DNA bases, as expected for an intercalated aromatic ring. Binding to DNA induced strong hypochromicity and a pronounced red shift in the absorbance spectrum of the chromophore. Spectrophotometric titrations suggested at least two types of chromophore binding sites on DNA; one type of site was saturated at rb = 0.125 chromophore molecule/nucleotide, but binding to additional sites continued to at least rb = 0.3. These physical--chemical studies were performed at pH 4--5 in order to keep the chromophore stable, but chromophore bound to an excess of DNA at pH 7 showed a stable absorbance spectrum identical with that seen at pH 4--5, suggesting that a similar type of binding occurs at neutral pH. Chromophore which had spontaneously degraded in pH 8 buffer did not bind to DNA at all, as judged by absorbance spectroscopy. The degree of protection afforded by DNA against spontaneous chromophore degradation implied a dissociation constant of approximately 5 microM for the DNA--chromophore complex at neutral pH and physiological ionic strength. Supercoiled DNA was nearly twice as effective as relaxed DNA in protecting chromophore from degradation, providing additional evidence for intercalation at neutral pH. Comparison of absorbance, fluorescence, and dichroism spectra suggests that the naphthalene ring system is the intercalating moiety.