Faculty Bibliography

PURPOSE: Intrathecal baclofen (ITB) therapy is an accepted treatment modality for spasticity and dystonia. Several complications related to ITB have been described, including mechanical malfunctions, infections, cerebrospinal fluid fistula, and baclofen withdrawal or overdose. In this study, we present our institutional experience with ITB therapy, emphasizing complication avoidance and lessons learned. METHODS: The charts of 87 patients treated with ITB therapy were retrospectively reviewed. The primary surgical technique, complication type and timing, method of treatment, and outcome were analyzed. RESULTS: Thirteen out of 76 (17.1%) patients primarily treated at our department had 25 complications. The first complication occurred 17.5-30.9 months (mean 24.2+/-6.7) after the pump implantation. Additional four patients with pumps placed elsewhere had six complications and were subsequently treated by our group. The main complications were: catheter fracture (11), subcutaneous fluid collection (5), lumbar wound/CSF infection (3), lumbar catheter or connector protrusion (3), pump malfunction (3), distal catheter migration outside the thecal sac (2), and baclofen withdrawal (1). Of the patients in the NYULMC group, six were treated by a single surgical procedure, six underwent multiple surgical procedures, and one was managed conservatively. In retrospect, changing the surgical technique, or adding an abdominal binder may have prevented 17 complications (54.8%). There were two deaths that were unrelated to the ITB therapy. CONCLUSION: ITB therapy is associated with complications, many of which require additional surgery. Some of these complications are avoidable by adhering to a strict surgical technique and a proper criterion for patient selection

Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, has shown promise in treating recurrent adult high-grade glioma (HGG). However, there is very little data on recurrent or progressive pediatric HGG treated with bevacizumab. We report the results of a single institution experience using bevacizumab and irinotecan in children who relapsed or progressed following standard therapy. Twelve pediatric patients with recurrent or progressive HGG received bevacizumab at 10 mg/kg every 2 weeks with irinotecan at 125 mg/m(2). Magnetic resonance imaging (MRI) was performed prior to therapy and every 8 weeks subsequently. Ten patients had supratentorial HGG; 2 had DIPG. Radiological responses were defined according to MacDonald's criteria. Progression-free survival (PFS), overall survival (OS), and toxicities were analyzed. Ten (83.3%) patients tolerated bevacizumab without serious toxicity. Therapy was discontinued in 1 patient because of anaphylaxis. Another patient developed grade III delayed wound healing and deep vein thrombosis. Two patients (16.7%) experienced a partial response after the first MRI. No complete radiographic responses were seen. Stable disease was noted in 4 (33.3%) patients. The median PFS and OS were 2.25 and 6.25 months, respectively. A diffuse invasive recurrence pattern was noted in 5 (45.5%) patients. Treatment tolerance, toxicity, and recurrence profiles were comparable to adult HGG patients treated with bevacizumab. However, the radiological response rate, response duration, and survival appeared inferior in pediatric patients. Genetic differences in pediatric gliomas might account for this difference

Metameric lesions of the spine are rare. The authors present a case of patient with a complex metameric vascular lesion of the thoracic spine and describe a management strategy for this entity

OBJECT: The object of this study was to assess a multiinstitutional experience with pediatric occipitocervical constructs to determine whether a difference exists between the fusion and complication rates of constructs with or without direct C-1 instrumentation. METHODS: Seventy-seven cases of occiput-C2 instrumentation and fusion, performed at 9 children's hospitals, were retrospectively analyzed. Entry criteria included atlantooccipital instability with or without atlantoaxial instability. Any case involving subaxial instability was excluded. Constructs were divided into 3 groups based on the characteristics of the anchoring spinal instrumentation: Group 1, C-2 instrumentation; Group 2, C-1 and C-2 instrumentation without transarticular screw (TAS) placement; and Group 3, any TAS placement. Groups were compared based on rates of fusion and perioperative complications. RESULTS: Group 1 consisted of 16 patients (20.8%) and had a 100% rate of radiographically demonstrated fusion. Group 2 included 22 patients (28.6%), and a 100% fusion rate was achieved, although 2 cases were lost to follow-up before documented fusion. Group 3 included 39 patients (50.6%) and demonstrated a 100% radiographic fusion rate. Complication rates were 12.5, 13.7, and 5.1%, respectively. There were 3 vertebral artery injuries, 1 (4.5%) in Group 2 and 2 (5.1%) in Group 3. CONCLUSIONS: High fusion rates and low complication rates were achieved with each configuration examined. There was no difference in fusion rates between the group without (Group 1) and those with (Groups 2 and 3) C-1 instrumentation. These findings indicated that in the pediatric population, excellent occipitocervical fusion rates can be accomplished without directly instrumenting C-1

Patients with symptomatic Chiari malformation Type I (CM-I) typically exhibit a chronic, slowly progressive disease course with evolution of symptoms. However, some authors have reported acute neurological deterioration in the setting of CM-I and acquired Chiari malformations. Although brainstem dysfunction has been documented in patients with CM-II and hydrocephalus or shunt malfunction, to the authors' knowledge only 1 report describing ventriculoperitoneal (VP) shunt malfunction causing neurological deterioration in a patient with CM-I exists. The authors report on their experience with the treatment of previously asymptomatic CM-I in 2 children who experienced quite different manifestations of acute neurological deterioration secondary to VP shunt malfunction. Presumably, VP shunt malfunction created a positive rostral pressure gradient across a stenotic foramen magnum, resulting in tetraparesis from foramen magnum syndrome in 1 patient and acute ataxia and cranial nerve deficits from syringobulbia in the other. Although urgent shunt revisions yielded partial recovery of neurological function in both patients, marked improvement occurred only after posterior fossa decompression

Rhombencephalosynapsis (RES) is a rare congenital malformation of the cerebellum characterized by hypogenesis or agenesis of the vermis and fusion of the cerebellar hemispheres with or without fusion of the dentate nuclei and superior cerebellar peduncles. No genetic or chromosomal abnormalities have been identified for RES. Although the occurrence of RES is presumed to be sporadic, no clear pattern of inheritance has been identified. The authors report on a 17-year-old girl with autosomal dominant polycystic kidney disease Type 1 as well as RES

BACKGROUND: Meningioangiomatosis (MA) is a rare benign disorder. It may occur sporadically or in association with neurofibromatosis (NF). The sporadic type typically presents with seizures, whereas that associated with NF is often asymptomatic. Of the 100 cases reported, only 14 are associated with NF. We now report 2 additional cases of MA associated with neurofibromatosis 2 (NF2) in a single family, with one occurring in the cerebellum. The etiology, pathology, and imaging features of MA are presented. CASE DESCRIPTION: A 38-year-old woman (patient 1) presented with a 4-month history of ataxia. She had been diagnosed previously with NF2. Magnetic resonance imaging (MRI) scans of the brain revealed bilateral acoustic neuromas and multiple calcified intracranial lesions. Her 13-year-old daughter (patient 2) presented with complex partial seizures. MRI scans of the brain revealed bilateral acoustic neuromas and a right parietal mass. Patient 1 underwent a suboccipital craniotomy to resect the right-sided acoustic neuroma. A small portion of normal-appearing cerebellar cortex was resected to avoid undue retraction. Histopathologic examination showed the presence of a lesion consistent with MA. Patient 2 underwent a right temporal-parietal craniotomy to remove the enhancing epileptogenic right posterior temporoparietal lesion. Histopathologic analysis showed a lesion consistent with meningioma and MA. CONCLUSIONS: MA has been reported infrequently in association with NF2. We now report 2 cases of MA associated with NF2 in one family, and we add the cerebellum to possible locations of occurrence. MA should be considered in the differential diagnosis of cortical lesions, particularly in patients with NF2

The roles of the mitogen-activated kinase protein (MAPK) pathway, nuclear factor-kappa B (NF-kappaB), and activator protein-1 (AP-1) in cellular responses to growth factors and mitogen are well established. However, the manner by which these proliferative pathways are affected by the tumor suppressor protein p53 is not fully understood. We report here the results of an investigation of the status of p53 on two human melanoma cell lines with wild-type p53 (SK-Mel-186) or mutant p53 (SK-Mel-110). The basal levels of the activated extracellular-signal regulated kinases 1 and 2 (ERK1/2) were high in cells with wild-type p53, but low in cells with mutant p53. The 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced activation of ERK1/2 through the phosphorylation of threonine and tyrosine at 202 and 204, respectively, was demonstrated in both cell lines, however, in a discrete manner. TPA-induced activation of ERK1/2 was sustained in wild-type p53 cells, while only a transient activation was seen in mutant p53 cells. Inhibition of MAPK kinase (MEK), an upstream kinase, by U0126, blocked TPA-induced activation of ERK1/2 in wild-type p53 cells and in mutant p53 cells. Treatment of wild-type p53 (SK-Mel 186) cells with small interfering RNA (siRNA) of p53 displayed a transient induction of activation of ERK1/2 following TPA treatment, indicating that p53 has a role in the regulation of the activation of ERK1/2. NF-kappaB activity decreased significantly in cells with wild-type p53, while enhanced NF-kappaB activity was evident in cells with mutant p53. The expression of either wild-type or mutant p53 had a similar effect on TPA-induced Jun N-terminal kinase (JNK) activation, indicating specificity for the ERK pathway. Similarly, AP-1 binding activity showed a transient variation in both cell lines after TPA treatment but with different kinetics. These observations suggest that both wild-type and mutant p53 can modulate the activation pathways for ERK1/2, and NF-kappaB distinctively, while modulating the pathways of JNK and AP-1 similarly. These differences may influence cellular processes such as proliferation, differentiation, and apoptosis

Tumors located in the region of the foramen of Monro often present with signs and symptoms of obstructive hydrocephalus. Various types of lesions occur in this location. We describe a case of a dysembryoplastic neuroepithelial tumor of the septum pellucidum presenting with obstructive hydrocephalus and its successful endoscopic excision. The surgical considerations and pathologic findings are discussed

BACKGROUND: An isolated or trapped fourth ventricle (TFV) is an occasional, serious sequela of hemorrhagic, infectious, or inflammatory conditions of the central nervous system. The TFV usually occurs after successful shunting of the lateral ventricles. It may be heralded by delayed clinical deterioration after an initial period of symptomatic improvement. The typical clinical findings suggest an expanding posterior fossa mass lesion. Surgical treatments include CSF diversionary procedures as well as open and endoscopic approaches. Complications related to the treatment of the TFV are common and relate to catheter obstruction and cranial nerve or brainstem dysfunction. METHODS: The author reviews the clinical features, pathophysiology, and available treatment options for the TFV, with special reference to complication avoidance and advances in ventriculoscopy and frameless stereotaxy. CONCLUSIONS: Treatment of the TFV remains a formidable challenge. However, prompt recognition and intervention may aid in the preservation of life and neurological function