Highlights: • Post-operative thoracolumbar spinal bracing is a common practice without quality biomechanical justification • When comparing outcomes from reviewed studies that used or did not use ...post-operative bracing, pain, return to work, Frankel score improvement, and instrumentation failure rates were not found to be significantly different • There were some small but statistically significant differences between complication rates and pseudoarthrosis rates when data was compared between groups that used versus did not used post-operative bracing • The studies reviewed in this series were not designed specifically to look at bracing as a dependent variable but the findings point to criteria that should be analyzed in controlled investigations
Abstract The lateral lumbar interbody fusion approach (LLIF), which encompasses the extreme lateral interbody fusion or direct lateral interbody fusion techniques, has gained popularity as an ...alternative to traditional posterior approaches. With rapidly expanding applications, this minimally invasive surgery (MIS) approach is now utilized in basic degenerative pathologies as well as complex lumbar degenerative deformities and tumors. Given the intimate relationship of the psoas muscle, and hence the lumbar plexus, to this MIS approach, several authors have examined the surgical anatomy of this approach. Understanding this regional neural anatomy is imperative given the potential for serious injuries to both the motor and sensory nerves of the lumbar plexus. In this review, we critically and comprehensively discuss all published studies detailing the surgical anatomy of the lateral lumbar approach with respect to the MIS LLIF techniques. This is a timely review given the rapidly growing number of surgeons utilizing this technique.
Neuritic plaques are a defining feature of Alzheimer disease (AD) pathology. These structures are composed of extracellular accumulations of amyloid-beta peptide (Abeta) and other plaque-associated ...proteins, surrounded by large, swollen axons and dendrites (dystrophic neurites) and activated glia. Dystrophic neurites are thought to disrupt neuronal function, but whether this damage is static, dynamic, or reversible is unknown. To address this, we monitored neuritic plaques in the brains of living PDAPP;Thy-1:YFP transgenic mice, a model that develops AD-like pathology and also stably expresses yellow fluorescent protein (YFP) in a subset of neurons in the brain. Using multiphoton microscopy, we observed and monitored amyloid through cranial windows in PDAPP;Thy-1:YFP double-transgenic mice using the in vivo amyloid-imaging fluorophore methoxy-X04, and individual YFP-labeled dystrophic neurites by their inherent fluorescence. In vivo studies using this system suggest that amyloid-associated dystrophic neurites are relatively stable structures in PDAPP;Thy-1:YFP transgenic mice over several days. However, a significant reduction in the number and size of dystrophic neurites was seen 3 days after Abeta deposits were cleared by anti-Abeta antibody treatment. This analysis suggests that ongoing axonal and dendritic damage is secondary to Abeta and is, in part, rapidly reversible.
The lack of a specific biomarker makes preclinical diagnosis of Alzheimer's disease (AD) impossible, and it precludes assessment of therapies aimed at preventing or reversing the course of the ...disease. The development of a tool that enables direct, quantitative detection of the amyloid-β deposits found in the disease would provide an excellent biomarker. This article demonstrates the real-time biodistribution kinetics of an imaging agent in transgenic mouse models of AD. Using multiphoton microscopy, Pittsburgh compound B (PIB) was imaged with sub-µm resolution in the brains of living transgenic mice during peripheral administration. PIB entered the brain quickly and labeled amyloid deposits within minutes. The nonspecific binding was cleared rapidly, whereas specific labeling was prolonged. WT mice showed rapid brain entry and clearance of PIB without any binding. These results demonstrate that the compound PIB has the properties required for a good amyloid-imaging agent in humans with or at risk for AD.
Highlights • Traumatic atlanto-occipital dislocation (AOD) is a devastating injury with a high percentage of morbidity and mortality. • Traumatic AOD is usually associated with other injuries that ...could potential affect survival. • We reviewed the literature and performed a logistic regression in order to elucidate prognostic factors for survival. • Only traumatic brain injury (TBI) was associated with worse survival after AOD, that was statistically significant. • Further studies are needed to better elucidate the role of these factors in survival of traumatic AOD.
Recent attention has focused on understanding the role of the brain-renin-angiotensin-system (RAS) in stroke and neurodegenerative diseases. Direct evidence of a role for the brain-RAS in Parkinson's ...disease (PD) comes from studies demonstrating the neuroprotective effect of RAS inhibitors in several neurotoxin based PD models. In this study, we show that an antagonist of the angiotensin II (Ang II) type 1 (AT1) receptor, losartan, protects dopaminergic (DA) neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity both in primary ventral mesencephalic (VM) cultures as well as in the substantia nigra pars compacta (SNpc) of C57BL/6 mice (Fig. 1).
In the presence of exogenous Ang II, losartan reduced MPP+ (5 muM) induced DA neuronal loss by 72% in vitro. Mice challenged with MPTP showed a 62% reduction in the number of DA neurons in the SNpc and a 71% decrease in tyrosine hydroxylase (TH) immunostaining of the striatum, whereas daily treatment with losartan lessened MPTP-induced loss of DA neurons to 25% and reduced the decrease in striatal TH+ immunostaining to 34% of control.
Our study demonstrates that the brain-RAS plays an important neuroprotective role in the MPTP model of PD and points to AT1 receptor as a potential novel target for neuroprotection.
The anatomic area delineated medially by the lateral part of the L4-L5 vertebral bodies, distally by the anterior-superior surface of the sacral wing, and laterally by an imaginary line joining the ...base of the L4 transverse process to the proximal part of the sacroiliac joint, is of particular interest to spine surgeons. We are referring to this area as the lumbo-sacro-iliac triangle (LSIT). Knowledge of LSIT anatomy is necessary during approaches for L5 vertebral and sacral fractures, sacral and iliac tumors, and extraforaminal decompression of the L5 nerve roots.
We performed an anatomic dissection of the LSIT in 3 embalmed cadavers (6 triangles), using an anterior and posterior approach.
We identified 3 key tissue planes: the neurological plexus plane, constituted by L4 and L5 nerve roots; an intermediate level constituted by the ileosacral tunnel; and posteriorly, by the lumbosacral ligament, and the posterior muscular plane.
Improving anatomic knowledge of the LSIT may help surgeons decrease the risk of possible complications. When LSIT pathology is present, a lateral approach corresponding to the tip of the L4 transverse process, medially, is suggested to decrease the risk of vessel and nerve root damage.
Abstract Titanium craniofacial hardware has become commonplace for reconstruction and bone flap fixation following craniotomy. Complications of titanium hardware include palpability, visibility, ...infection, exposure, pain, and hardware malfunction, which can necessitate hardware removal. We describe three patients who underwent craniofacial reconstruction following craniotomies for trauma with post-operative courses complicated by medically intractable facial pain. All three patients subsequently underwent removal of the symptomatic craniofacial titanium hardware and experienced rapid resolution of their painful parasthesias. Symptomatic plates were found in the region of the frontozygomatic suture or MacCarty keyhole, or in close proximity with the supraorbital nerve. Titanium plates, though relatively safe and low profile, can cause local nerve irritation or neuropathy. Surgeons should be cognizant of the potential complications of titanium craniofacial hardware and locations that are at higher risk for becoming symptomatic necessitating a second surgery for removal.
Background: The requirement for frequent intraventricular drug delivery in the setting of shunt dependence is particularly challenging in the treatment of central nervous system infection, neoplastic ...disease, and hemorrhage. This is especially relevant in the pediatric population where both hematogenous malignancy requiring intrathecal drug delivery and shunt-dependent hydrocephalus are more prevalent. Intrathecal and intraventricular chemotherapy agents can be prematurely diverted in these shunt-dependent patients. Case Description: We report the use of a stop-flow programmable shunt valve to maximize delivery of intraventricular chemotherapy in a child with acute lymphoblastic leukemia and disseminated intravascular coagulation who presented with spontaneous intracerebral and intraventricular hemorrhages. The patient then developed posthemorrhagic hydrocephalus and eventually progressed to shunt dependence but still required frequent intraventricular chemotherapy administration. A ventriculoperitoneal shunt, equipped with a valve that allows for near cessation of cerebrospinal fluid flow (Certas; , Codman, Raynham, MA), and a contralateral Ommaya reservoir were inserted to maximize intraventricular dissemination of chemotherapy. Conclusions: To the best of our knowledge, this is the first reported case of the use of a high-resistance programmable valve being used to virtually cease cerebrospinal fluid flow through the distal catheter temporarily in order to maximize intraventricular drug dissemination in a pediatric patient with acute lymphoblastic leukemia.
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