Bruce A. Kaufman, Christopher J. Moran and James Schlesinger
Michael R. Chicoine, T. S. Park and Bruce A. Kaufman
✓ If the spasticity of cerebral palsy (CP) is reduced in children at a young age by selective dorsal rhizotomy, the incidence of lower-extremity deformities requiring orthopedic surgery may be reduced; however, this has never been investigated in detail. The authors examined the effects of selective dorsal rhizotomy on rates of lower-extremity orthopedic surgery in 178 children with CP. Age at selective dorsal rhizotomy ranged from 2 to 19.3 years (mean 5.5 years) with follow-up intervals ranging from 24 to 70 months (mean 44 months). Spastic CP was classified as quadriplegia (33%), diplegia (65%), and hemiplegia (2%). To assess the effects of early versus late rhizotomy on rates of orthopedic surgery, patients were grouped as follows: Group I underwent rhizotomy between 2 and 4 years of age (54 patients), and Group II underwent rhizotomy between 5 and 19 years of age (124 patients). Comparison of Kaplan—Meier plots of lifetime orthopedic surgery rates revealed that Group II underwent orthopedic surgery at a higher rate than Group I (p = 0.037). Analysis by procedure type revealed higher orthopedic surgery rates in Group II than Group I for heel cord releases (p = 0.0025), adductor releases (p = 0.018), and hamstring releases (p = 0.02). Orthopedic surgery rates were no higher for Group II compared to Group I for ankle/foot operations (p = 0.023), femoral osteotomy (p = 0.25), iliopsoas releases (p = 0.35), and “other” operations (p = 0.013). The data indicate that early rhizotomy reduces the need for orthopedic surgery for heel cord, hamstring, and adductor releases.
Bruce A. Kaufman, Lori Jones, Mary M. Zutter and T. S. Park
✓ The unusual presentation of acute megakaryoblastic leukemia as a temporal bone granulocytic sarcoma in an infant without systemic manifestations of leukemia is reviewed. Leukemia should be considered in the differential diagnosis of skull and skull-based lesions since the appearance on neuroradiological imaging is not unique in this diagnosis. Surgical treatment, as in this case, is limited to obtaining tissue for diagnosis and draining the infection.
Jeffrey G. Ojemann, T. S. Park, Robert Komanetsky, Richard A. A. Day and Bruce A. Kaufman
✓ The authors investigated the efficacy of anal sphincter electromyography (EMG) in identifying the lower sacral roots during selective dorsal rhizotomy. In nine children undergoing selective dorsal rhizotomy for cerebral palsy (CP) spasticity, direct electrical stimulation of the L1—S5 dorsal and ventral roots was performed while monitoring EMG responses from the anal sphincter and lower-extremity muscles. Anal sphincter activation was seen with stimulation of lumbosacral roots at many levels. Stimulation of dorsal and ventral roots gave anal sphincter EMG responses in 100% of the dorsal and ventral roots from L-4 and caudally. Only at the L-1 level did a minority of nerve roots have anal sphincter response to stimulation. Patterns of extremity muscle and sphincter activation specific to the S3–5 roots, namely anal sphincter activation without activation of other muscle groups, were found in only five (22%) of 23 roots stimulated. The pattern of stimulation responses in the majority of S3–5 roots indicated that the pathophysiology of lower-extremity spasticity in CP may involve the anal sphincter and does not spare the lower sacral roots. Thus, this study indicates that electrophysiological mapping alone, without anatomical identification, cannot be used to identify the lower sacral roots during selective dorsal rhizotomy for CP spasticity, and it proposes a model for investigation of associated bowel and bladder symptoms.
Paul C. Francel, T. S. Park, Jeffrey L. Marsh and Bruce A. Kaufman
✓ Frontal plagiocephaly may arise from either synostotic or deformational forces. Deformational causes of frontal plagiocephaly can be distinguished from synostotic causes by differences seen on physical examination, which can then be confirmed by skull x-ray films and if necessary three-dimensional computerized tomography (CT). Unilateral coronal synostosis is the main synostotic cause of frontal plagiocephaly, although it has also been seen with fusion of the frontozygomatic suture. In several syndromes presenting with bilateral coronal synostosis, fusion of the frontosphenoidal and frontoethmoidal sutures is also present.
The authors report, for perhaps the first time, a case showing synostotic frontal plagiocephaly secondary to fusion of the frontosphenoidal suture alone. Although the phenotypic appearance is superficially similar to that seen in unilateral coronal synostosis, analysis of the cranial base shows markedly different effects: angulation of the anterior cranial base with respect to the posterior cranial base away from the synostotic side and angulation of the posterior cranial base with respect to the midpalatal suture also away from the synostotic side. In unilateral coronal synostosis, both angulations are toward the synostotic side. These effects on the cranial base alter its relationship to the cranial vault and the facial skeleton. Most important, frontal plagiocephaly secondary to fusion of the frontosphenoidal suture should not be overlooked as being deformational. Because this fusion is difficult or impossible to visualize by skull x-ray films, three dimensional CT must be obtained in cases that are not clearly identified as deformational plagiocephaly by physical examination.
Jeffrey R. Leonard, Dan X. Cai, Dennis J. Rivet, Bruce A. Kaufman, T. S. Park, Beth K. Levy and Arie Perry
Object. Medulloblastoma is the most common malignant central nervous system neoplasm found in children. A distinct variant designated large cell/anaplastic (LC/A) medulloblastoma is characterized by frequent dissemination of cerebrospinal fluid (CSF) at presentation and a more aggressive clinical course. The authors report on their examination of the clinicopathological and genetic features of seven such cases encountered at their institution.
Methods. Eighty cases of medulloblastomas were reviewed and seven (8.8%) of these were believed to fit the histological and immunohistochemical criteria for LC/A medulloblastoma. In three cases (43%) either desmoplastic or classic medulloblastoma was the underlying subtype, and in two cases (28%) the LC/A tumor was found within the setting of medullomyoblastoma. Fluorescence in situ hybridization was used in six of the seven cases to characterize the presence of isochromosome 17q, deletion of chromosome 22q (a deletion characteristically found in atypical teratoid/rhabdoid tumors), and c-myc amplification. The patients' clinical histories revealed CSF dissemination in all cases and lymph node metastasis in one case. Isochromosome 17q was found in five (83%) of six cases. Evidence of chromosomal gains indicated aneuploidy in three tumors (50%), and amplification of c-myc was found in three tumors (50%). No 22q deletions were encountered.
Conclusions. A high percentage of LC/A medulloblastomas arise within a background of typical medulloblastomas or medullomyoblastomas. As is the case in conventional medulloblastomas, the presence of 17q is a common early tumorigenic event; however, in a significant percentage of specimens there is also evidence of aneuploidy and/or amplification of c-myc. These findings indicate that LC/A morphological characteristics reflect a more advanced tumor stage than that found in pure medulloblastomas or in typical medullomyoblastomas.
Robert C. Heim, T. S. Park, George P. Vogler, Bruce A. Kaufman, Michael J. Noetzel and Madeleine R. Ortman
✓ Selective dorsal rhizotomy is increasingly used for management of spastic quadriplegic cerebral palsy but rates of hip stability following the operation have not been reported. Determining hip stability by radiographic measurement of lateral migration of the femoral head beyond a lateral edge of the acetabulum after dorsal rhizotomy allows an objective assessment of the outcome of the operation. This prospective study examined the effect of selective dorsal rhizotomy on lateral migration of the femoral head in 45 children with spastic quadriplegic cerebral palsy. The children ranged in age from 2 to 9 years (average 5 years 1 month) and were grouped according to their ages with 23 children in the 2- to 4-year-old group and 22 children in the 5- to 9-year-old group. Postoperative follow up ranged from 7 to 50 months (average 20 months). The Reimers migration percentage (MP), a measure of the lateral migration of the femoral head, was calculated from anteroposterior hip radiographs taken prior to the operation and at the last follow-up examination. Of the 90 hips involved, 9% improved, 80% remained unchanged, and 11% worsened, yielding a radiographic stability rate of 89%. The hips with postrhizotomy worsening of the MP had an average preoperative MP of 14% (range 9% to 38%) and an average postoperative increase in MP of 18% (range 11% to 37%). Of the 45 children, four subsequently underwent unilateral derotational femoral osteotomies for persistent or worsening hip subluxation. There was a significant tendency for the MP to worsen in patients with lower prerhizotomy MP values (χ2 = 20.74, df = 4, p = 0.001), but the age of patients and their ambulatory status at the time of rhizotomy had no bearing on postoperative hip stability. The data indicate that selective dorsal rhizotomy prevents progressive lateral migration of the femoral head in the majority of children who undergo the operation for spastic quadriplegia.
Paul C. Francel, Myles Koby, T. S. Park, Benjamin C. P. Lee, Michael J. Noetzel, Susan E. Mackinnon, Martin M. Henegar and Bruce A. Kaufman
✓ Neurosurgical management of birth-related brachial plexus palsy involves observing the patient for a period of several months. Operative intervention is usually undertaken at 3 to 6 months of age or more in infants who have shown little or no improvement in affected muscle groups. Ancillary tests such as electromyography and nerve conduction studies are occasionally useful. No radiological study has been consistently helpful in operative planning, except for contrast computerized tomography (CT) myelography, which requires general anesthesia in infants. This is because the infant's small size exceeds the functional resolution of the imaging modalities.
This report describes the use of a special sequence of magnetic resonance (MR) imaging entitled “fast spin echo” (FSE-MR). Unlike CT myelography, this technique provides high-speed noninvasive imaging that allows clinicians to evaluate preganglionic nerve root injuries without the use of general anesthesia and lumbar puncture. The utility of this technique is illustrated in three cases, two involving either infraclavicular exploration or a combination of infraclavicular and supraclavicular exposure based on FSE-MR findings. The FSE-MR imaging offers an excellent alternative to contrast CT myelography in evaluation of infants with birth-related brachial plexus injuries.