Traumatic brain injury: classification, models, and markers.

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality worldwide. Due to its high incidence rate and often long-term sequelae, TBI contributes significantly to increasing costs of health care expenditures annually. Unfortunately, advances in the field have been stifled by patient and injury heterogeneity that pose a major challenge in TBI prevention, diagnosis, and treatment. In this review, we briefly discuss the causes of TBI, followed by its prevalence, classification, and pathophysiology. The current imaging detection methods and animal models used to study brain injury are examined. We discuss the potential use of molecular markers in detecting and monitoring the progression of TBI, with particular emphasis on microRNAs as a novel class of molecular modulators of injury and its repair in the neural tissue.

Chiari 1 malformation and holocord syringomyelia presenting as abrupt onset foot drop.

We present two patients with a Chiari 1 malformation and holocord syringomyelia who presented with abrupt onset unilateral foot drop. Neurophysiologic testing was consistent with a proximal nerve root lesion. This assisted with localization and directed magnetic resonance (MR) imaging to lumbosacral spine and nerve roots. Each child underwent a suboccipital craniectomy and laminectomy with duroplasty to decompress the foramen magnum. Each child also showed rapid and complete clinical recovery despite the significant electromyographic and MRI abnormalities on initial study.

Classification of symptomatic Chiari I malformation to guide surgical strategy.

BACKGROUND: Treatment options for Chiari I malformations include posterior fossa decompression (PFD) with additional techniques including laminectomy, intradural exploration, and duraplasty. Neuroimaging findings of cisterna magna volume, syringomyelia, and intraoperative ultrasonography may tailor surgical intervention. METHODS: We developed an algorithm classifying symptomatic Chiari I patients into three groups to define minimum operation. Without syringomyelia, the presence of cisterna magna defined Group A and the absence defined Group B. Patients with syrinx formed Group C. Mild structural pathology (Group A) or adequate space following PFD (Group B, normal intraoperative ultrasound (IOUS)) should be treated by PFD alone. Conversely, presence of syringomyelia (Group C) or inadequate space following PFD (Group B, abnormal IOUS) should additionally have duraplasty. We applied this algorithm to patients treated at a single institution over 16 years. RESULTS: Twenty-four symptomatic Chiari I malformation patients were divided into three groups that did not differ by age, gender, or extent of tonsillar ectopia. All patients treated by this algorithm experienced clinical and radiographic improvement. This included eight Group B patients who underwent PFD only (n=6) or additional duraplasty (n=2) decided by IOUS. CONCLUSION: Treatment of symptomatic Chiari I malformation may have inadequate outcome with conservative strategy or complications with aggressive strategy. This algorithm utilizes preoperative neuroimaging and intraoperative ultrasound to tailor intervention, with excellent clinical outcome and radiographic syrinx resolution on application to 24 patients. Further validation requires prospective multicenter evaluation with larger patient population.

Spinal intradural arteriovenous fistula with unusual presentation: case report and literature review.

OBJECT: The authors present their experience with a Cervical Spinal intradural arteriovenous fistula (AVF) with unusual clinical presentation in a pediatric patient and review of the international literature on this condition. METHODS: A 5-year-old girl was found by her parents in bed screaming and talking inappropriately. Later on, she calmed down and complained of occipital, back and neck pain. She was admitted to the CHEO-ICU for work up and observation. The admission head CT scan showed evidence of SAH. Brain MRI showed blood in the third and fourth ventricles. MRA showed a C2 vascular lesion consistent with spinal cord AVF. Conventional angiogram was done which confirmed the AVF fed by a posterior medullary artery originating from the left vertebral artery. An attempt to embolize the AVF with glue was made but proved to be unsuccessful. On December 4, 2002, direct surgery on the AVF was performed, through a midline posterior approach (C2-C3 laminectomies) and microsurgical technique a complete excision of the intradural extramedullary AVF was achieved. The postoperative course was uneventful and the patient remained neurologically intact. Post-operative angiography confirmed complete excision of the AVF. CONCLUSION: The rarity of a pediatric spinal AVF presenting with spontaneous Intracranial SAH, makes this case very peculiar. This is the first reported pediatric case of cervical cord AVF with this clinical presentation found in the literature.

Neuroregenerative strategies in the brain: emerging significance of bone morphogenetic protein 7 (BMP7).

Every year thousands of people suffer from brain injuries and stroke, and develop motor, sensory, and cognitive problems as a result of neuronal loss in the brain. Unfortunately, the damaged brain has a limited ability to enact repair and current modes of treatment are not sufficient to offset the damage. An extensive list of growth factors, neurotrophic factors, cytokines, and drugs has been explored as potential therapies. However, only a limited number of them may actually have the potential to effectively offset the brain injury or stroke-related problems. One of the treatments considered for future brain repair is bone morphogenetic protein 7 (BMP7), a factor currently used in patients to treat non-neurological diseases. The clinical application of BMP7 is based on its neuroprotective role in stroke animal models. This paper reviews the current approaches considered for brain repair and discusses the novel convergent strategies by which BMP7 potentially can induce neuroregeneration.