✓The authors present the case of a child with an untreated lipomyelomeningocele who developed an acquired Chiari malformation Type I (CM-I) with a large syrinx over the course of 3 years. To the best of the authors' knowledge, this is the first report to document a case in which an acquired CM-I evolved in a patient with an untreated tethered cord.
Ben Waldau, Gerald Grant and Herbert Fuchs
Report of four cases and review of the literature
Gerald A. Grant, Donald Farrell and Daniel L. Silbergeld
✓ The neurosurgical management of intrinsic brain tumors and brain metastases mandates maximum resection with preservation of functional cortex. There have been previous reports on the use of cortical somatosensory evoked potentials (SSEPs) for localization of functional cortex prior to resection. The identification of rolandic cortex with the use of intraoperative SSEP monitoring enables the neurosurgeon to tailor the surgery to achieve a greater extent of resection while minimizing the risk of morbidity. The use of continuous SSEP monitoring during resection to provide an ongoing functional assessment of somatosensory cortex has not been reported. This powerful technique is illustrated using four case examples.
Mohan R. Sharma, David W. Newell and Gerald A. Grant
Srinivasan Mukundan, Herbert Fuchs, Michael J. Alexander and Gerald A. Grant
✓The authors report the first clinical use of 3-tesla dynamic contrast-enhanced magnetic resonance (MR) angiography for the diagnosis of a vascular malformation in a pediatric patient. The supply and drainage of an arteriovenous malformation were accurately demonstrated on MR angiography, which was performed without sedating the patient. This lesion was confirmed on catheter angiography, and definitive treatment via embolization was undertaken in a single session. The patient's therapeutic response will be followed with surveillance dynamic MR imaging.
Terry C. Burns, Ahmed J. Awad, Matthew D. Li and Gerald A. Grant
Brain radiation is a fundamental tool in neurooncology to improve local tumor control, but it leads to profound and progressive impairments in cognitive function. Increased attention to quality of life in neurooncology has accelerated efforts to understand and ameliorate radiation-induced cognitive sequelae. Such progress has coincided with a new understanding of the role of CNS progenitor cell populations in normal cognition and in their potential utility for the treatment of neurological diseases. The irradiated brain exhibits a host of biochemical and cellular derangements, including loss of endogenous neurogenesis, demyelination, and ablation of endogenous oligodendrocyte progenitor cells. These changes, in combination with a state of chronic neuroinflammation, underlie impairments in memory, attention, executive function, and acquisition of motor and language skills. Animal models of radiation-induced brain injury have demonstrated a robust capacity of both neural stem cells and oligodendrocyte progenitor cells to restore cognitive function after brain irradiation, likely through a combination of cell replacement and trophic effects. Oligodendrocyte progenitor cells exhibit a remarkable capacity to migrate, integrate, and functionally remyelinate damaged white matter tracts in a variety of preclinical models. The authors here critically address the opportunities and challenges in translating regenerative cell therapies from rodents to humans. Although valiant attempts to translate neuroprotective therapies in recent decades have almost uniformly failed, the authors make the case that harnessing human radiation-induced brain injury as a scientific tool represents a unique opportunity to both successfully translate a neuroregenerative therapy and to acquire tools to facilitate future restorative therapies for human traumatic and degenerative diseases of the central nervous system.
James Pan, Ian D. Connolly, Sean Dangelmajer, James Kintzing, Allen L. Ho and Gerald Grant
Brain injuries are becoming increasingly common in athletes and represent an important diagnostic challenge. Early detection and management of brain injuries in sports are of utmost importance in preventing chronic neurological and psychiatric decline. These types of injuries incurred during sports are referred to as mild traumatic brain injuries, which represent a heterogeneous spectrum of disease. The most dramatic manifestation of chronic mild traumatic brain injuries is termed chronic traumatic encephalopathy, which is associated with profound neuropsychiatric deficits. Because chronic traumatic encephalopathy can only be diagnosed by postmortem examination, new diagnostic methodologies are needed for early detection and amelioration of disease burden. This review examines the pathology driving changes in athletes participating in high-impact sports and how this understanding can lead to innovations in neuroimaging and biomarker discovery.
Morgan Bliss, Gerald Grant, Ethan Tittler, Tina Loven, Kristen W. Yeom and Douglas Sidell
In contrast to more common nasal and cervical lesions, the frontotemporal pit is a rarely encountered lesion that is often associated with a dermoid and may track intracranially. Due to delays in diagnosis, the propensity to spread intracranially, and the risk of infection, awareness of these lesions and appropriate diagnosis and management are important. The authors present 2 cases of frontotemporal pits from a single institution. Epidemiology, presentation, and management recommendations are discussed.
Stephen R. Parker, Peggy Harris, Thomas J. Cummings, Timothy George, Herbert Fuchs and Gerald Grant
Posterior fossa decompression with duraplasty for Chiari malformation Type I (CM-I) is a common pediatric neurosurgery procedure. Published series report a complication rate ranging from 3% to 40% for this procedure. Historically, many dural substitutes have been used, including bovine grafts, human cadaveric pericardium, synthetic dura, and autologous pericranium. The authors hypothesized that a recently observed increase in complications was dependent on the graft used.
Between January 2004 and January 2008, 114 consecutive patients ≤ 18 years old underwent primary CM-I decompression using duraplasty. Records were retrospectively reviewed for short- and intermediate-term complications and operative technique, focusing on the choice of duraplasty graft with or without application of a tissue sealant.
The average age of the patients was 8.6 years. The dural graft used was variable: 15 were treated with cadaveric pericardium, 12 with Durepair, and 87 with EnDura. Tisseel was used in 75 patients, DuraSeal in 12, and no tissue sealant was used in 27 patients. The overall complication rate was 21.1%. The most common complications included aseptic meningitis, symptomatic pseudomeningocele, or a CSF leak requiring reoperation. The overall complication rates were as follows: cadaveric pericardium 26.7%, Durepair 41.7%, and EnDura 17.2%; reoperation rates were 13%, 25%, and 8.1%, respectively. Prior to adopting a different graft product, the overall complication rate was 18.1%; following the change the rate increased to 35%. Complication rates for tissue sealants were 14.8% for no sealant, 18.7% for Tisseel, and 50% for DuraSeal. Nine patients were treated with the combination of Durepair and DuraSeal and this subgroup had a 56% complication rate.
Complication rates after CM-I decompression may be dependent on the dural graft with or without the addition of tissue sealant. The complication rate at the authors' institution approximately doubled following the adoption of a different graft product. Tissue sealants used in combination with a dural substitute to augment a duraplasty may increase the risk of aseptic meningitis and/or CSF leak. The mechanism of the apparent increased inflammation with this combination remains under investigation.
Tej D. Azad, James Pan, Ian D. Connolly, Austin Remington, Christy M. Wilson and Gerald A. Grant
Resection of brain tumors is followed by chemotherapy and radiation to ablate remaining malignant cell populations. Targeting these populations stands to reduce tumor recurrence and offer the promise of more complete therapy. Thus, improving access to the tumor, while leaving normal brain tissue unscathed, is a critical pursuit. A central challenge in this endeavor lies in the limited delivery of therapeutics to the tumor itself. The blood-brain barrier (BBB) is responsible for much of this difficulty but also provides an essential separation from systemic circulation. Due to the BBB's physical and chemical constraints, many current therapies, from cytotoxic drugs to antibody-based proteins, cannot gain access to the tumor. This review describes the characteristics of the BBB and associated changes wrought by the presence of a tumor. Current strategies for enhancing the delivery of therapies across the BBB to the tumor will be discussed, with a distinction made between strategies that seek to disrupt the BBB and those that aim to circumvent it.
Shahid M. Nimjee, Ciaran J. Powers, Roger E. McLendon, Gerald A. Grant and Herbert E. Fuchs
Cerebrospinal fluid overproduction resulting in communicating hydrocephalus is observed in patients who have choroid plexus papilloma or choroid plexus carcinoma. Less often, patients with these conditions have diffuse villous hyperplasia. Prior studies report CSF production greater than 3 L per day in these patients. These patients are treated with CSF shunting or by either unilateral choroid plexectomy or staged bilateral choroid plexectomy. The authors present a patient who had a number of congenital anomalies and a karyotype that revealed balanced translocations, 5 to 7 and 9 to 11. She presented with hydrocephalus and had CSF production of 5 L per day, greater output than ever previously reported. She was treated with a single-stage bilateral choroid plexectomy. Histopathological analysis revealed a bilateral choroid plexus papilloma. Postoperatively, the patient responded well clinically and showed radiographic improvement of her hydrocephalus. Bilateral choroid plexus papilloma has been reported in the literature as a cause for neonatal and congenital hydrocephalus. It can result in high CSF output and can be successfully treated with a single-stage bilateral choroid plexectomy. Further studies are ongoing to identify genes involved in embryogenesis of the choroid plexus.