Faculty Bibliography

We present our technique for extraoperative functional mapping in awake children with supratentorial tumors near eloquent cortex. This technique may help optimize tumor resection and/or the functional outcome, especially when an awake craniotomy is not possible or in the setting of coincident seizures. After subdural electrode implantation, extraoperative functional mapping and seizure focus mapping were performed, followed by staged tumor resection. Gross total resection was achieved in 6 patients and subtotal resection in 2. No complications due to electrode placement or invasive monitoring were observed. Staged resection of pediatric brain tumors near the eloquent cortex appears safe, allows functional mapping in awake patients, and may assist in decisions between maximal tumor resection and optimal functional outcome

PURPOSE: To determine whether pediatric patients treated with surgery only for low-grade tumors in the cerebral hemispheres, supratentorial midline, and exophytic brainstem evidence neurocognitive, academic, adaptive, or emotional/behavioral sequelae. PATIENTS AND METHODS: Ninety-three patients from a natural history study of low-grade astrocytomas were tested an average of 111 days after surgery. Rates of below average (< or = 25th percentile) scores in this sample were compared with test norms, and performances were compared across anatomic sites. Finally, the relationships of pre-, peri-, and postsurgical complications to outcome were investigated. RESULTS: For the entire sample, there was a significantly elevated rate of below average scores across intelligence quotient, achievement, and adaptive behavior, but not behavioral/emotional adjustment measures. Patients with hemispheric, midline, and brainstem tumors did not differ significantly. Patients with left hemisphere tumors generally performed worse than those with right hemisphere tumors. Finally, neurobehavioral outcome was unrelated to pre-, peri-, or postsurgery complications. CONCLUSION: After surgery for low-grade brain tumors, a significant number of patients was found to function below average, by as much as 55% compared with 25% in the normative population. Moreover, these results suggest greater risk for patients with lesions situated in the left cerebral hemisphere. Routine neuropsychological follow-up of children after treatment for low-grade tumors is recommended

OBJECTIVES: We evaluated and compared tumor antigen precursor protein (TAPP) profiles in adult and pediatric brain tumors of 31 genes related to tumor associated antigens (TAA) for possible use in immunotherapy. Antigens were selected based on their potential to stimulate T cell responses against tumors of neuroectodermal origin. METHODS: Thirty-seven brain tumor specimens from 11 adult and 26 pediatric patients were analyzed by quantitative real-time PCR for the relative expression of 31 TAPP mRNAs. The age range of adults (4F:7M) was 27-77 years (median 51.5 +/- 14.5 years) and for pediatrics (12F:14M) was 0.9-19 years (median 8.3 +/- 5.5 years). Histological diagnoses consisted of 16 glioblastomas, 4 low grade astrocytomas, 10 juvenile pilocytic astrocytomas, and 7 ependymomas. RESULTS: The adult gliomas expressed 94% (29 of 31) of the TAPP mRNAs evaluated compared with pediatric brain tumors that expressed 55-74% of the TAPP mRNAs, dependent on tumor histological subtype. Four types of TAPP expression patterns were observed: (1) equal expression among adult and pediatric cases, (2) greater expression in adult than pediatric cases, (3) expression restricted to adult GBM and (4) a random distribution. The pediatric brain tumors lacked expression of some genes associated with engendering tumor survival, such as hTert and Survivin. CONCLUSIONS: The potential TAA targets identified from the TAPP profiles of 31 genes associated with adult and pediatric brain tumors may help investigators select specific target antigens for developing dendritic cell- or peptide-based vaccines or T cell-based immunotherapeutic approaches against brain tumors

Tumors of the cerebellopontine angle (CPA) are common and represent up to 10% of all intracranial tumors. Rarely, intrinsic brainstem tumors can involve the CPA and present with auditory symptoms typical of CPA tumors such as hearing loss, vertigo and tinnitus. We report on a rare case of an intrinsic brainstem neoplasm presenting with steroid responsive fluctuating sensorineural hearing loss in a child. The patient initially presented with an acute worsening of an unilateral sensorineural hearing loss, without additional symptoms, that responded to oral steroids. Otoacoustic emission testing demonstrated normal outer hair cell function suggesting retrocochlear pathology. Magnetic resonance imaging with contrast enhancement revealed an intrinsic neoplasm of the middle cerebellar peduncle impinging on the 7th/8th neurovascular bundle within the CPA. The patient underwent gross total resection of the juvenile pilocytic astrocytoma via retrosigmoid craniotomy and remains disease free at 2 years postoperatively. This case highlights that suspicion of central nervous system pathology should be heightened in the presence of steroid responsive, fluctuating sensorineural hearing loss with normal outer hair cell function

OBJECTIVE: Transient paraplegia in the immediate postoperative period after lipomyelomeningocele repair is uncommon and is not discussed in the literature. We present the unique case of a patient who developed transient paraplegia 48 hours after lipomyelomeningocele repair attributable to the acute development of a thoracic syrinx. CLINICAL PRESENTATION: At birth, the patient was noted to have a large skin-covered mass in the lumbosacral region. On neurological examination, both iliopsoas and quadriceps exhibited 3/5 motor function, and the plantar flexors and dorsiflexors exhibited 1/5 motor function. Urodynamic studies were normal. Magnetic resonance imaging demonstrated the presence of a lipomyelomeningocele associated with tethering of the spinal cord in the lumbosacral region. INTERVENTION: At 5 months of age, the patient underwent repair of the lipomyelomeningocele. After surgery, the patient developed progressive paraplegia along with bowel and bladder dysfunction. Given the concern about a postoperative hematoma resulting in cauda equina syndrome, the patient returned to the operating room for a wound exploration. No compressive lesion such as a hematoma was found at surgery. A postoperative magnetic resonance imaging scan obtained afterward, however, demonstrated the presence of a large thoracic syrinx. CONCLUSION: Syrinx formation can occur as early as 48 hours after lipomyelomeningocele repair, leading to progressive lower extremity weakness and bowel and bladder incontinence. In the immediate postoperative period, an acute syrinx can mimic cauda equina syndrome, and a magnetic resonance imaging scan is necessary to distinguish between these two entities. In this patient, the syrinx was transient and resolved without a shunting procedure