Highlights • Spinal deformity after surgery for intradural spinal cord tumors is relatively common. • We reviewed the literature for fusion criteria after removing intradural spine tumors. • We ...propose a decision algorithm to consider the use of fixation in adult patients based on the literature.
Purpose
Near-infrared fluorescent probes for amyloid-beta (Aβ) are an exciting option for molecular imaging in Alzheimer’s disease research and may translate to clinical diagnostics. However, ...Aβ-targeted optical probes often suffer from poor specificity and slow clearance from the brain. We are designing smart optical probes that emit characteristic fluorescence signal only when bound to Aβ.
Methods
We synthesized a family of dyes and tested Aβ-binding sensitivity with fluorescence spectroscopy and tissue-staining.
Results
Select compounds exhibited Aβ-dependent changes in fluorescence quantum yield, lifetime, and emission spectra that may be imaged microscopically or in vivo using new lifetime and spectral fluorescence imaging techniques.
Conclusion
Smart optical probes that turn on when bound to Aβ will improve amyloid detection and may enable quantitative molecular imaging in vivo.
Intraoperative applications of near-infrared (NIR) fluorescent contrast agents can be aided by instrumentation capable of merging the view of surgical field with that of NIR fluorescence. We ...demonstrate augmented microscopy, an intraoperative imaging technique in which bright-field (real) and electronically processed NIR fluorescence (synthetic) images are merged within the optical path of a stereomicroscope. Under luminance of 100,000 lx, representing typical illumination of the surgical field, the augmented microscope detects 189 nM concentration of indocyanine green and produces a composite of the real and synthetic images within the eyepiece of the microscope at 20 fps. Augmentation described here can be implemented as an add-on module to visualize NIR contrast agents, laser beams, or various types of electronic data within the surgical microscopes commonly used in neurosurgical, cerebrovascular, otolaryngological, and ophthalmic procedures.
Neuritic plaques are a defining feature of Alzheimer disease (AD) pathology. These structures are composed of extracellular accumulations of amyloid-β peptide (Aβ) 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 Aβ deposits were cleared by anti-Aβ antibody treatment. This analysis suggests that ongoing axonal and dendritic damage is secondary to Aβ and is, in part, rapidly reversible.
We derive a novel algorithm to recover the in vivo distributions of fluorophores based on an asymptotic life-time analysis of time-domain fluorescence measurements with turbid tissue. We ...experimentally demonstrate the advantage offered by this method in localizing fluorophores with distinct lifetimes. This algorithm has wide applicability for diagnostic fluorescence imaging in the presence of several-centimeter-thick biological tissue, since fluorescence lifetime is a sensitive indicator of local tissue environment and interactions at the molecular level.
Posterior quadrant disconnection (PQD) has been described as a treatment for patients with refractory posterior quadrant subhemispheric epilepsy. Surgical outcomes are difficult to interpret because ...of limited literature.
To provide insight regarding the operative technique and postsurgical seizure freedom in young pediatric patients who underwent surgical disconnection for the treatment of posterior quadrant subhemispheric epilepsy at our institution.
The authors retrospectively analyzed a series of 5 patients who underwent PQD between 2019 and 2021. Charts were reviewed for preoperative workup including noninvasive/invasive testing, operative reports, and postoperative follow-up data which included degree of seizure freedom, completion of disconnection, and complications.
Five patients were included in this series. The median age at seizure onset was 12 months (range 3-24 months), and the median age at surgery was 36 months (range 22-72 months). Histopathology confirmed focal cortical dysplasia in 3 of 5 patients (2 patients with type IB; 1 with type IIID). The average length of follow-up after surgery was 16.8 months (range 12-24 months). All patients underwent complete disconnection of the posterior quadrant without complications. Four of 5 patients (80%) had Engel score of I, while the remaining patient had an Engel score of IIB.
Our early results demonstrate that complete PQD can be successful at providing excellent seizure freedom and functional outcomes in carefully selected young pediatric patients who have concordant seizure semiology, noninvasive/invasive testing, and imaging findings with primary seizure onset zone within the ipsilateral posterior quadrant. Meticulous surgical planning and thorough understanding of the surgical anatomy and technique are critical to achieving complete disconnection.
Abstract We evaluated the anatomical considerations specific to the high anterior retropharyngeal approach to the cervical spine. Surgical exposure of the anterior upper cervical spine can sometimes ...be challenging due to the surrounding neurovascular structures. Using three adult cadavers, we performed high anterior retropharyngeal cervical dissection of the left and right side for a total of six approaches (six sides). During the dissection, all important neurovascular elements were noted and photographed, and anatomical relationships to the spinal vertebral bodies and disc spaces were analyzed. There are certain anatomic considerations that are unique to the high anterior cervical spine. The unique structures include the hypoglossal nerve and the superior thyroid artery/nerve. Only the superior thyroid artery in this region has numerous anatomical variations. Awareness of other structures, including the carotid artery, recurrent laryngeal nerve, and esophagus also remains important. Awareness of the anatomical structures in the anterior upper cervical spine is essential for performing safe anterior upper cervical spinal surgery, avoiding serious complications.
Whole genome analyses were performed to test the hypothesis that temporal cortical gene expression differs between epilepsy patients rendered seizure-free versus non-seizure-free following anterior ...temporal lobectomy with amygdalohippocampectomy (ATL/AH). Twenty four patients underwent ATL/AH to treat medically intractable seizures of temporal lobe origin (mean age 35.5 years, mean follow-up 42.2 months); they were then dichotomized into seizure-free and non-seizure-free groups. Tissue RNA was isolated from the lateral temporal cortex and gene expression analysis was performed. Whole genome data were analyzed for prognostic value for seizure-free outcome following ATL/AH by logistic regression. Genes that could distinguish seizure outcome groups were identified based on providing an accuracy of >0.90 judging by area under the receiver operating characteristic curve, AUC, with a
P
value of the slope coefficient of <0.05. Four genes and seven RNA probes were with prognostic value for post-operative seizure-free outcome. Gene expression associated with seizure-free outcome included relative down-regulation of zinc finger protein 852 (ZNF852), CUB domain-containing protein 2 (CDCP2), proline-rich transmembrane protein 1 (PRRT1), hypothetical LOC440200 (FLJ41170), RNA probe 8047763, RNA probe 8126238, RNA probe 8113489, RNA probe 8092883, RNA probe 7935228, RNA probe 806293, and RNA probe 8104131. This study describes the predictive value of temporal cortical gene expression for seizure-free outcome after ATL/AH. Four genes and seven RNA probes were found to predict post-operative seizure-free outcome. Future prospective investigation of these genes and probes in human brain tissue and blood could establish new biomarkers predictive of seizure outcome following ATL/AH.
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