Andrew J. Grossbach

Flexion-distraction injuries of the thoracolumbar spine: open fusion versus percutaneous pedicle screw fixation

OBJECT Flexion-distraction injuries occur due to distractive forces causing disruption of the posterior and middle spinal columns. These fractures classically consist of a fracture line through the posterior bony elements; involvement of the posterior ligamentous complex is, however, common. Surgical treatment is often required for these unstable injuries to avoid neurological deterioration and posttraumatic kyphosis, and the surgery traditionally consists of an open posterior approach with instrumented fusion. Percutaneous pedicle screw fixation for these injuries, with the goal of minimal tissue disruption and preservation of normal anatomy while achieving adequate stabilization, has recently been reported in the literature, but to date, a direct comparative study comparing open and percutaneous fixation has not been reported. The authors report their experience treating these fractures with both techniques and review the available literature. METHODS Patients with flexion-distraction injury who were treated between May 2003 and March 2013 were prospectively followed. American Spinal Injury Association scores and degree of kyphotic angulation were recorded at admission, discharge, and follow-up. Data regarding intraoperative blood loss and operative time were obtained from a chart review. Patients treated with open versus minimally invasive procedures were compared. RESULTS The authors identified 39 patients who suffered flexion-distraction injuries and were treated at their institution during the specified period; one of these patients declined surgery. All had injury to the posterior ligamentous complex. Open surgical procedures with pedicle screw fixation and posterolateral fusion were performed in 27 patients, while 11 patients underwent minimally invasive pedicle screw placement. Overall, there was improvement in kyphotic angulation at the time of discharge as well as most recent follow-up in both the open surgery and minimally invasive surgery (MIS) groups. The authors found no significant difference in American Spinal Injury Association score or the degree of kyphotic angulation between the MIS and open surgery groups. There was a trend toward shorter operative time for the MIS group, and patients who underwent minimally invasive procedures had significantly less blood loss. CONCLUSIONS Minimally invasive percutaneous pedicle screw fixation appears to have similar efficacy in the treatment of flexion-distraction injuries and it allows for reduced blood loss and tissue damage compared with open surgical techniques. Therefore it should be considered as an option for the treatment of this type of injury.

Traumatic intracranial hemorrhage in patients taking dabigatran: report of 3 cases and review of the literature.

BACKGROUND AND IMPORTANCE Dabigatran is a direct thrombin inhibitor gaining popularity as a stroke prevention agent in patients with atrial fibrillation. In comparison with warfarin, dabigatran showed superiority in stroke prevention, but lower rates of major hemorrhage and intracerebral hemorrhage. Although warfarin has a well-established reversal strategy, there is far less experience reversing dabigatran. CLINICAL PRESENTATION We present our experience with 3 patients who experienced an intracranial hemorrhage either spontaneously or after low-energy cranial trauma and review the available literature describing dabigatran use in patients with traumatic brain injury. CONCLUSION Intracranial hemorrhage in patients taking anticoagulants and/or antiplatelets can have either a benign or malignant clinical course. At this time, there is little experience with dabigatran reversal; however, several strategies for rapid reversal have been proposed. All patients with intracranial hemorrhage taking dabigatran should be admitted for close neurological monitoring and serial imaging.

Hypertensive posterior reversible encephalopathy syndrome causing posterior fossa edema and hydrocephalus

Posterior reversible encephalopathy syndrome (PRES) is a well characterized entity resulting from the inability of cerebral autoregulation to adequately protect the brain from uncontrolled hypertension. It primarily affects the occipital lobes, but can also involve the structures in the posterior fossa including the brainstem and cerebellum. Treatment usually consists of strict blood pressure control, but more aggressive management may be indicated with acutely worsening neurological status. We present a patient with hypertensive encephalopathy that resulted in hydrocephalus and brainstem compression necessitating surgical decompression requiring ventriculostomy and suboccipital craniectomy. In rare cases, PRES can present with severe brainstem compression requiring emergent posterior fossa decompression. When brainstem signs are present on exam, emergent posterior fossa decompression may be safer than ventriculostomy alone.

Surgical options in the treatment of subaxial cervical fractures: A retrospective cohort study

OBJECTIVE To compare clinical and radiographic parameters and outcomes in patients undergoing anterior vs. posterior surgery in unstable cervical subaxial spine fractures. METHODS We analyzed a group of 33 patients with reducible cervical subaxial fractures. Patients underwent anterior or posterior cervical instrumentation. Inpatient and outpatient records were retrospectively reviewed, and the multiple pre-operative and post-operative clinical and radiographic factors were recorded and analyzed. RESULTS Posterior cervical fixation was performed in 15 patients, and anterior cervical fixation in 18 patients. Operative time, blood loss, and number of levels instrumented were all significantly less in the anterior than the posterior cervical group. There was no difference in patient age, surgical complications, follow-up ASIA score, Rand SF-36 evaluation, or cost analysis between the two groups. Mean follow-up time was 11.8±7 months. All patients achieved bony fusion and good alignment at follow-up. CONCLUSIONS In patients with reducible cervical subaxial dislocations, posterior cervical fixation entails a larger number of fused segments. Anterior surgery is associated with shorter operative times and less blood loss. Anterior instrumentation with interbody grafting can be the initial choice of treatment for stabilization for this subgroup of patients. Posterior surgery is indicated if radiographs after anterior instrumentation show failure.

Lateralized effect of pallidal stimulation on self-mutilation in Lesch-Nyhan disease

Lesch-Nyhan disease (LND) is an X-linked hereditary disorder caused by a deficiency of hypoxanthine-guanine phosphoribosyltransferase. This syndrome is characterized by hyperuricemia, self-mutilation, cognitive impairment, and movement disorders such as spasticity and dystonia. The authors describe the case of a 15-year-old boy who underwent bilateral placement of globus pallidus internus (GPi) deep brain stimulation (DBS) electrodes for the treatment of generalized dystonia. His self-mutilating behavior gradually disappeared several weeks after the start of GPi stimulation. The dystonia and self-mutilating behavior returned on the left side only after a right lead fracture. This case is the first reported instance of LND treated with DBS in which the stimulation was interrupted and the self-mutilation returned in a lateralized fashion. The findings indicate that the neurobehavioral aspect of LND is lateralized and that contralateral GPi stimulation is responsible for lateralized improvement in self-injurious behavior.

Effects of brain derived neurotrophic factor Val66Met polymorphism in patients with cervical spondylotic myelopathy.

Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord related disability in the elderly. It results from degenerative narrowing of the spinal canal, which causes spinal cord compression. This leads to gait instability, loss of dexterity, weakness, numbness and urinary dysfunction. There has been indirect data that implicates a genetic component to CSM. Such a finding may contribute to the variety in presentation and outcome in this patient population. The Val66Met polymorphism, a mutation in the brain derived neurotrophic factor (BDNF) gene, has been implicated in a number of brain and psychological conditions, and here we investigate its role in CSM. Ten subjects diagnosed with CSM were enrolled in this prospective study. Baseline clinical evaluation using the modified Japanese Orthopaedic Association (mJOA) scale, Nurick and 36-Item Short Form Health Survey (SF-36) were collected. Each subject underwent objective testing with gait kinematics, as well as hand functioning using the Purdue Peg Board. Blood samples were analyzed for the BDNF Val66Met mutation. The prevalence of the Val66Met mutation in this study was 60% amongst CSM patients compared to 32% in the general population. Individuals with abnormal Met allele had worse baseline mJOA and Nurick scores. Moreover, baseline gait kinematics and hand functioning testing were worse compared to their wild type counterpart. BDNF Val66Met mutation has a higher prevalence in CSM compared to the general population. Those with BDNF mutation have a worse clinical presentation compared to the wild type counterpart. These findings suggest implication of the BDNF mutation in the development and severity of CSM.

Risk factors and outcomes in thoracic stenosis with myelopathy: A single center experience

OBJECTIVE Identify risk factors predisposing to thoracic spinal stenosis and myelopathy (TS) and address treatment options and outcomes. METHODS A retrospective review of our centers experience with TS over 10 years. Clinical and magnetic resonance imaging (MRI) data, surgical intervention and outcomes using Frankel and Japanese Orthopedic Association (JOA) scales were collected. RESULTS A total of 44 patients with TS were identified. There were 30 men and 14 women with a mean age±SD of 66±15years. Neurological performance was evaluated using the Frankel scale (A-E or 1-5), and JOA scale for myelopathy (0-11). Frankel scores (1-5) and JOA scores (0-11) on admission were 3.5±0.9 and 6.8±2.6 respectively. At follow-up, Frankel scores had improved to 4.1±0.8 (p=0.041) and JOA scores had improved to 8.3±2.4 (p=0.021). The presence on admission of increased signal from the cord on T2-weighted MRI was associated with lower Frankel and JOA scores (3.3±0.9, and 6.2±2.5 respectively) than in those with absent increased signal (4.0±0.4 and 8.6±2.1, p=0.02 and p=0.008 respectively). There were 4 complications, requiring exploration and debridement for dehiscence in 3 and an epidural hematoma in the fourth that necessitated evacuation, with a good outcome. A fifth patient underwent reoperation at the same level 18 months later for persistent stenosis. CONCLUSION Thoracic stenosis with myelopathy should be entertained in patients with myelopathy. Over half of our patients with TS were over the age of 70, and men outnumbered women by a ratio of 2:1. Nearly half the patients with TS had concomitant cervical and/or lumbar degenerative disease warranting surgery also. Increased signal intensity on T2-weighted MRI images correlated with lower Frankel and JOA scores compared to those without. Decompression for thoracic stenosis is associated with neurological improvement.

Endoscopic transnasal resection of ameloblastoma with intracranial extension

Ameloblastoma is a rare odontogenic tumor with characteristics of epithelial tissue that produces enamel for the developing tooth. This lesion is generally considered benign, but has malignant forms that invade locally and metastasize. We present a 60-year-old man with maxillary ameloblastoma that after multiple recurrences developed intracranial extension with dural involvement of the middle cranial fossa and was treated by endoscopic transnasal resection followed by radiation therapy. Our technique and intraoperative findings are described with a review of the literature on intracranial ameloblastoma. This patient represents a unique account of endoscopic transnasal resection being utilized in the treatment of intracranial extension of ameloblastoma and demonstrates potential for application in similar cases.

Acutely unstable cervical spine injury with normal CT scan findings: MRI detects ligamentous injury

MRI can detect ligamentous injury not detectable with CT scan. The authors present a trauma patient with normal CT imaging despite dislocation on standing radiograph. MRI detected disruption of the C5-C6 posterior ligamentous complex that requires surgery.

Multicentric chordoma: a case report and review of the literature.

BACKGROUND AND IMPORTANCE Chordomas are relatively rare tumors that arise from the neuraxis. Most often, chordomas are single lesions that metastasize late. There have been very few cases of chordomas arising from multiple foci along the neuraxis. Here, we present a case of a multicentric chordoma. CLINICAL PRESENTATION The patient presented with pain in her right neck and soreness in her right shoulder that she had experienced for about 2.5 years that she attributed to a muscle strain. She experienced worsening of her symptoms, which prompted her to seek medical care. The patient underwent an occiput-to-C6 posterolateral fusion with autograft and an occiput-to-C6 posterior segmental instrumentation, along with decompression of the spinal cord. One month after the initial surgery, the patient underwent a second surgery. The C2 and C3 vertebral bodies were completely resected, and a C1-C4 anterior fusion was then carried out. A C5 vertebrectomy and C4-C6 fusion were also performed at this time. The patient then received proton beam radiation to the entire affected area. CONCLUSION Recent studies have suggested that chordomas arise from benign notochordal tumors. We suggest that our patient suffered from multicentric chordomas with possible benign notochordal tumors. Although benign notochordal tumors do not require surgical resection, the possibility of transformation to a malignant lesion requires close follow-up.