Intraoperative spinal cord monitoring for intramedullary surgery: an essential adjunct?
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to A L Albright.
Explore the source record for details and available documents.
The authors reviewed the records of 94 patients who underwent initial repair of a lipomyelomeningocele between 1982 and July 1996 at the Children's Hospital of Pittsburgh to determine the incidence and time course of symptomatic retethering. In each of these patients, the initial operative goals were to microsurgically debulk as much of the lipoma as possible to allow the conus to move freely within the spinal canal, to divide any tethering arachnoidal adhesions, to close the pia if possible and to reconstitute a capacious thecal sac, using a dural graft if necessary. With a median follow-up of 58 months, 19 of these patients (20.2%) required 28 subsequent operations for symptomatic retethering. Median time between the initial procedure and reoperation for retethering was 52 months. The primary complaint of 12 patients was intractable low-back or leg pain. Other common symptoms were progressive bowel and/or bladder dysfunction, deterioration of motor function and foot deformities. The decision to reoperate was based predominantly on the clinical situation of the patient; magnetic resonance imaging was used to confirm the location and extent of tethering. Patients with transitional lipomas had a significantly higher frequency of symptomatic retethering than those with caudal or dorsal lesions (p < 0.05). No other clinical or technical feature correlated with an increased frequency of retethering. In particular, none of a variety of types of dural graft materials appeared to entirely prevent symptomatic retethering. Following reoperation, pain complaints resolved and many of the other symptoms improved partially or resolved completely. Although the long-term results were also favorable in the majority of patients, a small subgroup (n = 6) exhibited repetitive symptomatic tethering that proved increasingly difficult to treat. We concluded that symptomatic retethering is a common problem in children with lipomyelomeningoceles, even after an adequate initial operation. To date, no type of graft material has been shown to entirely prevent this problem. Close long-term surveillance of such patients is required to allow detection and treatment of symptomatic retethering.
UNLABELLED: Generalized dystonia occurs in 15 to 25% of persons with cerebral palsy (CP) and responds poorly to medical and surgical treatments. OBJECT: After the authors observed a woman whose dystonic CP was dramatically improved by continuous infusion of intrathecal baclofen, they designed this pilot study to evaluate the effect of this treatment on a group of patients with dystonic CP. METHODS: The authors assessed the short-term response to intrathecal baclofen infusion in 12 patients with dystonic CP. An intrathecal catheter was inserted percutaneously and connected to an external microinfusion pump. The infusion began at a rate of 100 microg/day and was increased by 50 microg every 12 hours until the dystonia abated, adverse effects occurred, or the dose reached 900 microg/day with no improvement. Two observers, one blinded and one not blinded to the patient's treatment status, viewed videotapes made before and after the infusions and graded the dystonia in eight body regions, using a 5-point scale. Overall and regional scores were compared by using Wilcoxon signed-rank tests. CONCLUSIONS: Dystonia diminished in 10 of 12 patients whose average daily dose of intrathecal baclofen was 575 microg. Overall dystonia scores and scores for the extremities, trunk, and cervical regions were significantly better after infusion (p = 0.003). The two observers' scores were not significantly different. Programmable infusion pumps were subsequently implanted in eight patients for long-term therapy and improvement was sustained in six (p < 0.05). Intrathecal baclofen infusion is a promising treatment option for generalized dystonia associated with CP. The effects of intrathecal baclofen infusion on dystonia can be evaluated by using short-term continuous infusions.
OBJECT: Ependymomas in children continue to generate controversy regarding their histological diagnosis and grading. optimal management, and possible prognostic factors. To increase our knowledge of these tumors the authors addressed these issues in a cohort of children with prospectively staged ependymomas treated with radiotherapy and chemotherapy. METHODS: Children between the ages of 2 and 17.3 years harboring an intracranial ependymoma confirmed by a central review of the tumor's pathological characteristics were treated according to Children's Cancer Group Protocol 921 from 1986 to 1992. Treatment following surgery and postoperative tumor staging (including brain computerized tomography or magnetic resonance [MR] imaging, spinal MR imaging or myelography, and cerebrospinal fluid cytological investigation) included craniospinal irradiation with a local boost to the primary tumor and patient randomization to receive adjuvant chemotherapy with either 1) CCNU, vincristine, and prednisone, or 2) the eight-drugs-in-1-day regimen. Centralized review of the tumor pathological characteristics revealed 20 ependymomas and 12 anaplastic ependymomas in the 32 children included in the study. Diagnoses made at the individual institutions included anaplastic (malignant) ependymoma (15 patients), ependymoma (four patients), ependymoblastoma (nine patients), ependymoastrocytoma (one patient), and primitive neuroectodermal tumor (three patients), which were discordant with the centralized review diagnosis in 22 of 32 cases. Only three of the 32 patients had metastatic disease (two with M and one with M3 stages). At surgery, 47% of tumors were estimated to be totally resected. Among the 14 of 17 patients who suffered a relapse and were evaluated for site of relapse, 10 (71%) had an isolated local relapse, three (21%) had concurrent local and metastatic relapse, and only one (7%) had an isolated metastatic relapse. Kaplan-Meier estimates of 5-year progression-free survival (PFS) and overall survival rates were 50 +/- 10% and 64 +/- 9%, respectively. CONCLUSIONS: Predictors of PFS duration included an estimate of the extent of resection made at surgery (total compared with less than total, p = 0.0001) and the amount of residual tumor on postoperative imaging as verified by centralized radiological review (< or = 1.5 cm2 compared with > 1.5 cm2, p < 0.0001). No other factors, including centrally reviewed tumor histopathological type, location, metastasis and tumor (M and T) stages, patient age, race, gender, or chemotherapy treatment regimen significantly correlated with PFS duration. The pattern of predominantly local relapse and the important influence of residual tumor or the extent of resection on PFS duration confirms a prevailing impression that local disease control is the major factor in the prediction of outcome of ependymoma. Survival rates were comparable with those reported by other investigators who have treated patients with similar doses of radiation and no chemotherapy.
UNLABELLED: Intrathecal baclofen infusion (IBI) is an effective treatment for spasticity secondary to cerebral palsy (CP). OBJECT: To assess the need for orthopedic surgery of the lower extremities in such cases, the authors retrospectively reviewed the outcome in 48 patients with spastic CP who were treated with IBI. METHODS: Pumps were placed in 40 patients (84%) suffering from spastic quadriplegia and eight patients (16%) with spastic diplegia. The patients' ages ranged from 5 to 43 years (mean 15 years). The mean follow-up period was 53 months (range 24-94 months). The mean baclofen dosage was 306 microg/day (range 25-1350 microg/day). At the time of pump placement, subsequent orthopedic surgery was planned in 28 patients (58%); however, only 10 (21%) underwent surgery after IBI therapy. In all 10 cases, the surgical procedure was planned at the time of initial evaluation for IBI therapy. In the remaining 18 patients, who did not subsequently undergo their planned orthopedic operation, it was believed that their lower-extremity spasticity had improved to the degree that intervention was no longer indicated. In addition, although six patients had undergone multiple orthopedic operations before their spasticity was treated, no patient required more than one operation after IBI treatment for spasticity. CONCLUSIONS: The authors conclude that IBI for treatment of spastic CP reduces the need for subsequent orthopedic surgery for the effects of lower-extremity spasticity. In patients with spastic CP and lower-extremity contractures, spasticity should be treated before orthopedic procedures are performed.
Explore the source record for details and available documents.
Technology enabling radical resection has expanded treatment options for children with spinal cord astrocytomas. Comparison of long-term survival and neurological function after complete tumor removal with more conservative treatment may determine whether radical surgery can improve outcome in well-differentiated and anaplastic spinal cord astrocytomas. In all, 18 children with spinal cord astrocytomas were initially treated between 1976 and 1992 with biopsy in 6, subtotal removal in 7, and complete resection in 5. Seven had anaplastic tumors. Nine children treated before 1988 received radiotherapy. Survival after a median follow-up of 11 years was 82% (9/11). Five patients with anaplastic tumors are alive between 12 and 18 years after treatment. No patient relapsed after total resection, whereas more than two-thirds treated with other than complete resection relapsed within 3 years (P = 0.029). All but 1 patient with symptomatic relapse received radiotherapy (P = 0.059). Magnetic resonance imaging more than 3 years postoperatively showed no recurrences in 13 of the 15 survivors and asymptomatic progression in the other 2. Although excellent long-term survival was seen, frequent relapse was associated with either incomplete resection or radiotherapy. Prolonged relapse-free survival was observed in all patients treated with complete resection, including 3 with anaplastic tumors.
OBJECTIVE AND IMPORTANCE: This case illustrates that although endoscopic third ventriculostomy for patients with aqueductal stenosis is successful and minimally invasive, it can have severe, life-threatening complications. CLINICAL PRESENTATION: A 3-year-old girl presented with hydrocephalus and aqueductal stenosis. She underwent endoscopic third ventriculostomy with laser fenestration of the third ventricular floor. During the procedure, she developed a severe intraventricular hemorrhage that required prolonged external ventricular drainage and ultimately ventriculoperitoneal shunting. Despite having a negative angiogram after the procedure, she presented 1 month later with a subarachnoid hemorrhage and a traumatic basilar tip aneurysm. INTERVENTION: The patient underwent a right subtemporal approach with clip ligation of the aneurysm and subsequently had a good recovery. CONCLUSION: Hemorrhagic complications after endoscopic third ventriculostomy are rare. The formation of a traumatic basilar tip aneurysm after this procedure has not been reported in the literature. Laser fenestration of the third ventricular floor may increase the risk of this event.
Intrathecal baclofen (ITB) infusion has been shown to be an effective treatment for spasticity secondary to both cerebral palsy and spinal cord injury. Its effect on the ambulatory status of individuals with cerebral spasticity, however, has not previously been addressed. We reviewed the effect of ITB on functional ambulation in 24 patients who were ambulatory to some extent, either with or without assistive devices. Twenty-one pumps were placed in patients with spastic cerebral palsy and 3 in patients with spasticity secondary to traumatic brain injury (13 boys and 11 girls, mean age 18 years). The mean ITB dose was 200 microg/day (range 22-550 microg/day) and the mean length of follow-up was 52 months. Ambulation was retrospectively graded on four functional levels: community, household, non-functional, and non-ambulatory. The level of ambulation improved by one functional level in 9 patients, did not change for 12 patients, and was worse in 3 patients. Gait was considered to be improved in 20 of 24 patients by the patients or their families. The overall functional improvement not directly related to ambulation was found to be improved in 20 patients, unchanged in 2 patients, and worse in 2 patients. ITB allows for improved ambulation in a certain subset of patients with lower extremity spasticity. It is not contraindicated in patients who rely upon their spasticity for support during ambulation. ITB infusion allows for baclofen dosage titration to balance between extensor tone for support and suppression of hyperactive reflexes which may impede normal locomotion.
In order to determine if routine yearly evaluations of children with shunted hydrocephalus were likely to diagnose shunt malfunction, we reviewed the medical records of the last 100 children who had such routine evaluations. Only 4 children had symptoms that were potentially referable to malfunction; none were subsequently found to have malfunction and no child had signs of malfunction. We also reviewed the medical records of the last 100 children who had shunt revisions to determine if any of them were diagnosed during routine follow-up examinations. Four were: 2 with clinical signs of malfunction and 2 with evidence of malfunction on routine scans. Only 1 child in either group had signs or symptoms of malfunction if they had a functioning shunt in place for longer than 1 year. Although yearly follow-up visits are common practice, we conclude that such examinations are unlikely to detect shunt malfunction. Follow-up at intervals of 2 years is probably appropriate after 2 years of age if the child has had a functional shunt for 1 year and has had a scan that indicates a functioning shunt.
The authors reviewed the results of continuous intraoperative electromyographic (EMG) monitoring of muscles innervated by cranial nerves in 17 children whose preoperative imaging studies showed compression or infiltration of the fourth ventricular floor by tumor to determine how intraoperative EMG activity correlated with postoperative cranial nerve morbidity. Bilateral lateral rectus (sixth) and facial (seventh) nerve musculatures were monitored in all children. Cranial nerve function was documented immediately postoperatively and at 1 year. Of the 68 nerves monitored, nine new neuropathies occurred in six children (sixth nerve in four children and seventh nerve in five). In five new neuropathies, intraoperative EMG activity could be correlated in one of four sixth nerve injuries and four of five seventh nerve injuries. Electromyographic activity could not be correlated in four children with new neuropathies. Of 59 cranial nerves monitored that remained unchanged, 47 had no EMG activity. Twelve cranial nerves (three sixth nerves and nine seventh nerves) had EMG activity but no deficit. Of four children with lateral rectus EMG activity, three had new seventh nerve injuries. Lateral rectus EMG activity did not predict postoperative abducens injury. The absence of lateral rectus EMG activity did not assure preserved abducens function postoperatively. Likely because of the close apposition of the intrapontine facial nerve to the abducens nucleus, lateral rectus EMG activity was highly predictive of seventh nerve injury. Although facial muscle EMG activity was not an absolute predictor of postoperative facial nerve dysfunction, the presence of facial muscle EMG activity was associated statistically with postoperative facial paresis. The absence of facial muscle EMG activity was rarely associated with facial nerve injury. The authors speculate that EMG activity in the facial muscles may have provided important intraoperative information to the surgeon so as to avoid facial nerve injury.
Endodermal sinus tumor is an uncommon malignant germ-cell neoplasm. These tumors usually present in childhood or young adulthood as testicular or ovarian masses; however, mediastinal and intracranial tumors have been described. The authors report the occurrence of a primary paraspinal endodermal sinus tumor in a 21-month-old boy who presented with thoracic spinal cord compression. A review of the literature failed to reveal a similar case. The clinical presentation, radiographic characteristics, operative findings, and patient outcome are discussed.
The outcomes of 25 pediatric patients who underwent upper cervical or occipitocervical fusion at the authors' institution since 1983 were reviewed. At a mean age of 9 years, the patients presented with spinal instability that was associated with os odontoideum in 11 cases, rotatory subluxation in five cases, odontoid fracture in two cases, atlantooccipital dislocation in two cases, and congenital atlantoaxial instability in five patients, four of whom had Down's syndrome (trisomy 21). Ten children had abnormal findings on neurological examination preoperatively; however, nine experienced improvement or resolution of deficits as of their latest follow-up evaluation (mean 17 months). Fusion was achieved with the first operation in 21 of 25 patients; eventually it was attained in all but one. Four patients exhibited persistent spinal instability after an initial procedure. This was caused by erosion of a multistranded cable through the intact arch of C-2 in two cases, by pin site infection necessitating early halo removal in one case, and by slippage in a halo following a Gallie procedure, which was revised with a Brooks fusion in one case. This series, the largest yet published, shows that with appropriate surgical management, posterior upper cervical fusion in the pediatric population is highly successful. Careful attention to halo pin site care and caution in using multistranded cable in young patients may improve results.
The authors reviewed the results of continuous intraoperative electromyographic (EMG) monitoring of muscles innervated by cranial nerves in 17 children whose preoperative imaging studies showed compression or infiltration of the fourth ventricular floor by tumor to determine how intraoperative EMG activity correlated with postoperative cranial nerve morbidity. Bilateral lateral rectus (sixth) and facial (seventh) nerve musculature were monitored in all children. Cranial nerve function was documented immediately postoperatively and at 1 year. Of the 68 nerves monitored, nine new neuropathies occurred in six children (sixth nerve in four children and seventh nerve in five). In five new neuropathies, intraoperative EMG activity could be correlated in one of four sixth nerve injuries and four of five seventh nerve injuries. Electromyographic activity could not be correlated in four children with new neuropathies. Of 59 cranial nerves monitored that remained unchanged, 47 had no EMG activity. Twelve cranial nerves (three sixth nerves and nine seventh nerves) had EMG activity but no deficit. Of four children with lateral rectus EMG activity, three had new seventh nerve injuries. Lateral rectus EMG activity did not predict postoperative abducens injury. The absence of lateral rectus EMG activity did not assure preserved abducens function postoperatively. Likely because of the close apposition of the intrapontine facial nerve to the abducens nucleus, lateral rectus EMG activity was highly predictive of seventh nerve injury. Although facial muscle EMG activity was not an absolute predictor of postoperative facial nerve dysfunction, the presence of facial muscle EMG activity was associated statistically with postoperative facial paresis. The absence of facial muscle EMG activity was rarely associated with facial nerve injury. The authors speculate that EMG activity in the facial muscles may have provided important intraoperative information to the surgeon so as to avoid facial nerve injury.
Castleman syndrome (giant lymph node hyperplasia) is a rare, heterogeneous lymphoproliferative disorder of unknown etiology and pathogenesis. Most cases occur as mediastinal masses, although extrathoracic involvement including nodal and extranodal locations have been reported. The localized variants (solitary lesions) respond well to surgical excision. We report a 10-year-old boy who presented with headache, intermittent fever, and progressive weakness of his legs. MRI imaging showed an enhancing epidural mass with impingement on the spinal cord at the C6-T2 level. Other laboratory abnormalities included anemia, hypergammaglobulinemia, increased erythrocyte sedimentation rate, and cerebrospinal fluid pleocytosis with slightly increased cerebrospinal protein. The mass was partially resected and the histopathology showed lymphoplasmocytic infiltration compatible with Castleman syndrome. There was no evidence of malignancy. Castleman syndrome is the most likely diagnosis in the presence of the associated systemic findings, although the epidural site for lymphoplasmocytic inflammation is atypical.
The histopathology of 66 children with the diagnosis of ependymoma who were operated on at our institution between 1954 and 1994 were reviewed. We performed an initial analysis using the entire study cohort to determine which histopathological features associated with each other in a statistically significant fashion in an attempt to identify combinations of features that together might be useful in predicting outcome. A detailed outcome analysis was then performed on the 37 most recent cases who survived the postoperative period, in whom pre- and post-imaging studies as well as long term follow-up were obtained, in order to identify the histopathological features and combinations of features that were predictive of overall and progression-free survival. Five- and ten-year progression-free survivals were 45.1% and 36.1%, respectively. Overall survivals were 57.1% and 45.0%, respectively. Of the eight individual histopathological features, only the presence of necrosis was found to correlate with a less favorable overall and progression-free survival (PFS) (p = 0.06 and 0.03, respectively). In addition, the combination of necrosis with vascular proliferation or nuclear pleomorphism was associated with a worse PFS (p = 0.01 and 0.02, respectively). However, when other clinical predictive factors were included in a multivariate regression analysis, none of the histological features or combinations of features were independently associated with outcome. In addition, no relationship was found between the pattern of rosettes (true rosette, pseudorosette, or perivascular pseudorosette) and clinical outcome. In conclusion, although this study found an association between certain histopathological features and clinical outcome in children with ependymomas, these relationships did not reach statistical significance on multivariate analysis and, thus, do not provide sufficient evidence for modifying therapy based on histopathology alone.
We reviewed the data of children with high-stage primitive neuroectodermal tumors (medulloblastomas) who were treated on Children's Cancer Group-921 protocol to evaluate the correlation between tumor resection and prognosis. Patients enrolled in the study had either tumors that were operatively categorized to be Chang tumor stage 3b or 4, postoperative residual tumors > 1.5 cm2, or evidence of tumor dissemination (Chang metastasis Stages [M Stages] 1-4) at diagnosis. Resections were analyzed in two ways, as follows: 1) by the extent of resection (percent of the tumor that was removed), as estimated by the treating neurosurgeon; and 2) by the extent of residual tumor (how much of the tumor was left), as estimated from postoperative scans. Two hundred and three children were enrolled in the study with institutional diagnoses of primitive neuroectodermal tumors-medulloblastomas; diagnoses were confirmed by central neuropathological review in 188 patients. Progression-free survival (PFS) at 5 years was 54% (standard error, 5%). As in previous Children's Cancer Group studies, age and M stage correlated with survival; PFS was significantly lower in children 1.5 to 3.0 years old at diagnosis and in those with any evidence of tumor dissemination (M Stage 1-4). On univariate analysis, neither extent of resection nor extent of residual tumor correlated with PFS. However, adjusting for other factors, extent of residual tumor was important; PFS was 20% (standard error, 14%) better at 5 years in children with no dissemination (M Stage 0) who had < 1.5 cm2 of residual tumor (P = 0.065) and was 24% (standard error, 14%) better at 5 years in children > 3 years old with no tumor dissemination (M Stage 0) and with < 1.5 cm2 residual tumor (P = 0.033). On the basis of our observations, we conclude that extent of tumor resection, as estimated by the neurosurgeon, does not correlate with outcome but that extent of residual tumor does correlate with prognosis in certain children (those who are > 3 years old, with no tumor dissemination). In contrast to age and M stage, the major factors associated with outcome, residual tumor is an important variable in outcome, one that neurosurgeons can control.
Five patients with generalized dystonia who were refractory to oral medications were treated by continuous intrathecal baclofen infusion. Dystonia was related to cerebral palsy in three patients and to Hallervorden-Spatz disease in two. Responsiveness to intrathecally administered baclofen was evaluated after bolus injections in one patient and during continuous infusions via an external micropump in four. Patients who responded to trial injections were subsequently implanted with a programmable pump for continuous infusion of baclofen. Dystonia in the three patients were cerebral palsy was substantially improved by continuous intrathecal baclofen infusion in doses of 500 to 800 micrograms/d. Benefit has persisted for > 19 months of continuous infusion. Dystonia in the two patients with Hallervorden-Spatz disease was not improved, although the screening trial was limited by side effects in one patient and by meningitis in the other. We conclude that continuous intrathecal baclofen infusion is beneficial therapy for some patients with generalized dystonia and that additional investigations are indicated.