Phenotypic and imaging features of FLNA-negative patients with bilateral periventricular nodular heterotopia and epilepsy.

PURPOSE: Periventricular nodular heterotopia (PVNH) is a malformation of cortical development due to impaired neuronal migration resulting in the formation of nodular masses of neurons and glial cells in close proximity to the ventricular walls. We report the clinical characteristics of the largest case series of FLNA-negative patients with seizures and bilateral periventricular heterotopia. METHODS: Participants were recruited through the Epilepsy Phenome/Genome Project (EPGP), a multicenter collaborative effort to collect detailed phenotypic data and DNA on a large number of individuals with epilepsy, including a cohort with symptomatic epilepsy related to PVNH. Included subjects had epilepsy, and MRI confirmed bilateral PVNH. Magnetic resonance imaging studies were visually and quantitatively reviewed to investigate the topographic extent of PVNH, symmetry, and laterality. KEY FINDINGS: We analyzed data on 71 patients with bilateral PVNH. The incidence of febrile seizures was 16.6%. There was at least one other family member with epilepsy in 36.9% of this population. Developmental delay was present in 21.8%. Focal onset seizures were the most common type of seizure presentation (79.3%). High heterotopia burden was strongly associated with female gender and trigonal nodular localization. There was no evidence for differences in brain volume between PVNH subjects and controls. No relationship was observed between heterotopic volume and gender, developmental delay, location of PVNH, ventricular or cerebellar abnormalities, laterality of seizure onset, age at seizure onset, and duration of epilepsy. SIGNIFICANCE: A direct correlation was observed between high heterotopia burden, female gender, and trigonal location in this large cohort of FLNA-negative bilateral PVNH patients with epilepsy. Quantitative MRI measurements indicated that this correlation is based on the diffuse nature of the heterotopic nodules rather than on the total volume of abnormal heterotopic tissue.

Radiographic criteria for placement of translaminar facet screws.

BACKGROUND CONTEXT: Screw fixation of the facet joint has been reported to stabilize the lumbar spine and facilitate spinal fusion. Accurate placement of translaminar facet screws (TLFSs) requires identification of the posterior spinal elements, and the facet joints in particular, which may be facilitated by intra-operative fluoroscopy. PURPOSE: The purpose of this study was to define the radiographic parameters that will allow for successful placement of TLFSs. STUDY DESIGN: Eighteen TLFSs were placed in three human cadaver spines using fluoroscopic guidance, with screws placed from L3-L4 to L5-S1 bilaterally. After screw placement, the spines were dissected and examined for accuracy of screw placement. METHODS: In the first cadaver spine, TLFSs were placed with direct visualization of the posterior lumbar spine, during which a fluoroscopic image intensifier was used to define the appropriate radiographic parameters for safe placement of the screws. Bilateral TLFSs were then placed percutaneously using the radiographic parameters developed, after which the spines were dissected to examine the positions of the screws. RESULTS: The radiographic views identified to achieve proper TLFS placement were a true lateral, anteroposterior (AP), a 45-degree oblique and an AP view with the X-ray bean at 30- to 45-degree cephalad angle ("spinal outlet" view). Using these views and the defined radiographic criteria, proper positioning of percutaneously placed TLFSs was achieved, with no spinal canal breaches found. CONCLUSIONS: This study defines intra-operative radiographic criteria that will assist in placement of TLFSs. The use of this technique may allow for screw placement with less extensive exposure of the posterior spine.

Techniques in cervical laminoplasty.

BACKGROUND CONTEXT: Laminoplasty provides an alternative to anterior procedures or multilevel laminectomy for patients with multilevel spinal stenosis and myeloradiculopathy. PURPOSE: To review the techniques, results and complications of cervical laminoplasty. STUDY DESIGN: The three basic variations of laminoplasty are the single open door, the French door or midline and the Z-plasty technique. These techniques and their outcome are discussed in detail. RESULTS: The recovery rate after laminoplasty ranges from 50% to 70% without statistical superiority of any one technique over another. Closure of opened laminae, temporary nerve root deficit, decreased neck range of motion and axial pain are the main complications of laminoplasty. CONCLUSIONS: Good to excellent long-term clinical results can be expected for the appropriately selected patients regardless of the specific technique used.

The effects of morphine on human articular cartilage of the knee: an in vitro study.

PURPOSE: The purpose of this study was to determine the metabolic, histologic, and ultrastructural effects of morphine and its combination with saline and bupivacaine on human articular cartilage. TYPE OF STUDY: In vitro study. METHODS: Nonfibrillated human articular cartilage was harvested and transferred into an experimental culture consisting of a control medium, saline, or a combination of morphine/saline or morphine/saline/bupivacaine for 12, 24, or 72 hours. Each sample was radiolabeled to assess proteoglycan synthesis. Histologic and ultrastructural effects were also examined. RESULTS: We found a significant, dose-related, transient decrease in 35SO4 incorporation in the morphine/saline samples at 12 hours, and in the saline only samples at 24 hours. We found no evidence of histologic or ultrastructural damage to the cartilage. CONCLUSIONS: Morphine and saline can both produce a transient decrease in 35SO4 incorporation that normalizes by 72 hours. This study does not suggest any contraindication to the use of intra-articular morphine as a postoperative analgesic.

Intertransverse lumbar interbody fusion.

STUDY DESIGN: Cadaver dissection and case reports were used to describe a novel technique of lumbar interbody arthrodesis that accesses the intervertebral disc through a posterolateral intertransverse process approach. OBJECTIVES: To describe the surgical approach and technique required in performing an intertransverse lumbar interbody fusion. The clinical results in two patients with 2-year follow-up evaluation after intertransverse lumbar interbody fusion are reported. SUMMARY OF BACKGROUND DATA: Many of the complications of lumbar interbody arthrodesis are associated with the surgical approach to the disc space. During an anterior approach, intraabdominal or retroperitoneal structures are at risk, whereas during a posterior approach, the cauda equina and spinal stabilizers may be jeopardized. A minimally invasive posterolateral discectomy for the treatment of herniated lumbar discs has been described. The authors hypothesized that a posterolateral approach might be used for achieving interbody arthrodesis. METHODS: Cadaver studies were performed to determine the feasibility and define the anatomy of a posterolateral, intertransverse process approach used to achieve lumbar interbody arthrodesis. These studies confirmed that this approach is feasible at L3-L4 and L4-L5. In two patients with discogenic low back pain, an intertransverse lumbar interbody fusion was performed using structural allograft bone wedges with supplemental translaminar facet screws. RESULTS: In two patients, an intertransverse lumbar interbody fusion was successfully performed without any complication. Both patients demonstrated good surgical outcomes 2 years after surgery, and radiographic assessment showed stable interbody grafts without motion on flexion-extension studies. CONCLUSIONS: This preliminary report suggests that lumbar interbody arthrodesis can be accomplished with a posterolateral intertransverse process approach. To the authors' knowledge, this is the first published report describing this approach for performing an interbody arthrodesis. The intertransverse lumbar interbody fusion (ILIF) approach avoids the need for either intraabdominal dissection or violation of the spinal canal-neural foramen in accessing the disc. This technique may therefore present an opportunity to accomplish a minimally invasive approach to lumbar fusion.

Managing chronic pain of spinal origin after lumbar surgery: the role of decompressive surgery.

STUDY DESIGN: A literature review was conducted. OBJECTIVE: To provide an evidence-based approach for patients with neurogenic symptoms after lumbar surgery. SUMMARY OF BACKGROUND DATA: Patients may present with chronic pain of spinal origin after lumbar surgery. Failure to decompress the involved neural structures adequately or progression of the underlying degenerative condition may lead to neurologic symptoms. METHODS: A literature search of peer-reviewed publications that investigate etiologies and treatments for neurogenic pain in patients who have undergone previous spinal surgery was conducted. RESULTS: In the absence of profound or progressive neurologic deficits, most patients with chronic back and leg pain who have undergone previous spinal surgery should be treated nonoperatively. Additional decompressive surgical intervention may be justified in patients with well-defined, discrete pathology amenable to surgical correction who have been refractory to conservative care. The surgery typically will include meticulous decompression of the affected neural structures and may include arthrodesis to address any deformity or instability. CONCLUSIONS: In a patient presenting with neurogenic symptoms after lumbar surgery, a meticulous workup is required to elucidate the source of these symptoms. Surgical indications are similar to those for primary lumbar spinal surgery and include a well-defined anatomic source of neural compression that is amenable to a surgical solution.