Reduced Reflex Autonomic Responses Following Intradetrusor OnabotulinumtoxinA Injections: A Pre-/Post-study in Individuals With Cervical and Upper Thoracic Spinal Cord Injury

Urodynamic studies (UDS) can provoke autonomic dysreflexia (AD) in individuals with spinal cord injury (SCI) at and above the sixth thoracic spinal segment potentially leading to profound vagally mediated heart rate (HR) reductions. In this study,1 we test the hypothesis that intradetrusor onabotulinumtoxinA injections will improve HR and its variability (HRV) responses to UDS in individuals with cervical and thoracic SCI. A total of 19 participants with chronic SCI (5 women, mean age 42.5 ± 7.9 years) with confirmed neurogenic detrusor overactivity underwent UDS before (i.e., baseline) and 1 month after intradetrusor onabotulinumtoxinA (200 U) injections (post-treatment). Continuous electrocardiography and blood pressure (BP) recordings were used to assess RR-interval, time, and frequency domain metrics of HRV (a surrogate marker of autonomic nervous system activity), and AD pre- and post-treatment. UDS pre-treatment resulted in increased RR-interval as well as time and frequency domain metrics of HRV. Vagally mediated increases in high-frequency (HF) power during UDS were larger in participants with cervical compared to upper thoracic SCI. Post-treatment, UDS had no effect on RR-interval and significantly reduced instances of bradycardia. Furthermore, intradetrusor onabotulinumtoxinA injections significantly reduced time domain metrics of HRV and HF power responses to UDS across all participants. Changes in HRV during UDS could be a potential indicator of improved autonomic cardiovascular function following interventions such as intradetrusor onabotulinumtoxinA injections.

biPACT: a method for three-dimensional visualization of mouse spinal cord circuits of long segments with high resolution

Background: The spatial complexity of neuronal circuits in the central nervous system is an hurdle in understanding and treating brain and spinal cord injuries. Although several methods have recently been developed to render the spinal cord transparent and label specific neural circuits, three-dimensional visualization of long segments of spinal cord with high resolution remains challenging. New Method: We have established a method that combines tissue staining of neuronal tracts traced with biotinylated dextran amine (BDA) and a modified passive clarity clearing protocol. Results: BDA was injected into the unilateral sensorimotor cortex of a mouse model of thoracic spinal cord contusional injury. Ten days later, the spinal cord was removed and immersed first in staining solution and then in hydrogel solution. The spinal cord was then sealed with a syringe and underwent gelation process, followed by clearing with clearing solution and observation solution. Staining and clearing took a total of two weeks. The samples were observed with a lightsheet microscope, and three-dimensional reconstruction was performed with ImageJ software. With the lightsheet microscope, high resolution-images comparable with tissue sections were obtained continuously and circumferentially. By tiling, it was possible to obtain high-resolution images of long segments of the spinal cord, in which each fiber could be traced. The tissue could be easily re-stained in case of fading. Comparison with Existing Methods: The present method does not require special equipment, can label specific circuits without genetic technology, and re-staining rounds can be easily implemented. It enables to visualize specific neural circuit of long spinal cord segments with high resolution up to individual nerve fiber. Conclusions: By using simple neural labeling, staining, and transparency methods, it was possible to acquire a wide range of high-resolution three-dimensional images of the spinal cord.

Symptomatic thoracic ossification of the ligamentum flavum in a patient with ankylosing spondylitis: Report of a case and review

Background: Thoracic spinal cord compression due to both ankylosing spondylitis (AS) and ossification of the ligamentum flavum (OLF) is rare. Case Description: A 33-year-old male with AS presented with a paraparesis attributed to MR documented T9-T10 OLF/stenosis. He was successfully managed with a decompressive laminectomy; this resulted in marked improvement of his deficit. Conclusion: Thoracic OLF and AS rarely contribute T9-T10 spinal cord compression that may be readily relieved with a decompressive laminectomy.

Multifocal spinal glioblastoma and leptomeningeal carcinomatosis in an elderly male with hydrocephalus and myelopathy

Background: Primary spinal glioblastoma multiforme with multifocal leptomeningeal enhancement is rarely diagnosed or documented. We describe a rare case of multifocal spinal isocitrate dehydrogenase (IDH) wild type glioblastoma with leptomeningeal carcinomatosis in an elderly male presenting with a chronic subdural hematoma, progressive myelopathy, and communicating hydrocephalus. Case Description: A 77-year-old male with a medical history of an acoustic schwannoma, anterior cranial fossa meningioma, and immune thrombocytopenic purpura presented with right-sided weakness after repeated falls. Magnetic resonance imaging of the brain and spine demonstrated a left-sided subdural hematoma, leptomeningeal enhancement of the brain and skull base, ventricles, and the cranial nerves, and along with florid enhancement of the leptomeninges from the cervicomedullary junction to the cauda equina. Most pertinent was focal thickening of the leptomeninges at T1 and T6 with mass effect on the spinal cord. A T6 laminectomy with excisional biopsy of the lesion was planned and completed. Findings were significant for glioblastoma the World Health Organization Grade IV IDH 1 wild type of the thoracic spinal cord. Subsequently, his mental status declined, and he developed progressive hydrocephalus which required cerebrospinal fluid diversion. Unfortunately, the patient had minimal improvement in his neurological exam and unfortunately died 2 months later. Conclusion: In a review of the limited literature describing similar cases of primary spinal glioblastoma, the prognosis of this aggressive tumor remains unfavorable, despite aggressive treatment options. The purpose of this report is to increase awareness of this rare condition as a potential differential diagnosis in patients presenting with multifocal invasive spinal lesions.

Imaging aspect of neuromyelitis optica: a case report and review of the literature

The case report presents a neuromyelitis optica in a 19 years old male. Brain and spinal cord MRI showed bilateral optic neuropathy, multiphasic demyelinating process involving the cervical and thoracic spinal cord. Cerebrospinal fluid showed negative NMO Ig G. We will describe the radiological aspect of neuromyelitis optica with a review of the literature.

Age-Dependent Aggregation of α-Synuclein in the Nervous System of Gut-Brain Axis is Associated with Caspase-1 Activation

α-Synuclein (α-Syn) plays a key role in the development of Parkinson’ desease (PD). As aging is acknowledged to be the greatest risk factor for PD, here we investigated α-Syn expression in the ileum, thoracic spinal cord, and midbrain of young (1-month-old), middle-aged (6-, 12-month-old) to old (18-month-old) mice. We demonstrated that both the levels of α-Syn monomers, oligomers and ratios of oligomers to monomers were increased with aging in the ileum, thoracic spinal cord, and midbrain. Whereas, the expression of tyrosine hydroxylase (TH), the rate-limiting enzyme for dopamine synthesis, was decreased with aging in the midbrain. We failed to find corresponding α-Syn mRNA increase with aging. However, we found an increased expression of caspase-1 in the ileum, thoracic spinal cord, and midbrain. A specific caspase-1 inhibitor VX765 significantly reduced levels of both the α-Syn monomers and oligomers triggered by the rotenone in vitro. Taken together, the increase in α-Syn aggregation with aging might not occur first in the gut, but simultaneously in the nervous system of gut-brain axis.. The mechanism of the age-dependent aggregation of α-Syn in nervous system is likely triggered by the aging-related caspase-1 activation.

Silencing long ascending propriospinal neurons after spinal cord injury improves hindlimb stepping in the adult rat

Long ascending propriospinal neurons (LAPNs) are a subpopulation of spinal cord interneurons that directly connect the lumbar and cervical enlargements. Previously we showed, in uninjured animals, that conditionally silencing LAPNs disrupted left-right coordination of the hindlimbs and forelimbs in a context-dependent manner, demonstrating that LAPNs secure alternation of the fore- and hindlimb pairs during overground stepping. Given the ventrolateral location of LAPN axons in the spinal cord white matter, many likely remain intact following incomplete, contusive, thoracic spinal cord injury (SCI), suggesting a potential role in the recovery of stepping. Thus, we hypothesized that silencing LAPNs after SCI would disrupt recovered locomotion. Instead, we found that silencing spared LAPNs post-SCI improved locomotor function, including paw placement order and timing, and a decrease in the number of dorsal steps. Silencing also restored left-right hindlimb coordination and normalized spatiotemporal features of gait such as stance and swing time. However, hindlimb-forelimb coordination was not restored. These data indicate that the temporal information carried between the spinal enlargements by the spared LAPNs post-SCI is detrimental to recovered hindlimb locomotor function. These findings are an illustration of a post-SCI neuroanatomical-functional paradox and have implications for the development of neuronal- and axonal-protective therapeutic strategies and the clinical study/implementation of neuromodulation strategies.

Diffuse Necrotizing Myelitis following Intracystic Bleomycin Chemotherapy for Craniopharyngioma

A child with recurrent adamantinomatous craniopharyngioma was treated with surgery and radiosurgery followed by 12 cycles of intracystic bleomycin injections. One month after treatment, he developed progressive lower extremity paresthesia, pain, wide-based gait, and urinary incontinence. MR imaging showed extensive T2 hyperintensity, enlargement, and enhancement extending from the medulla to the lower thoracic spinal cord. Spinal cord biopsy showed necrotizing myelitis. To our knowledge, this is the first histologically proven case of bleomycin spinal cord neurotoxicity.

The Preventive Effect of Cardiac Sympathetic Denervation Induced by 6-OHDA on Myocardial Ischemia–Reperfusion Injury: The Changes of lncRNA/circRNAs-miRNA-mRNA Network of the Upper Thoracic Spinal Cord in Rats

In this study, we investigated whether chemical 6-hydroxydopamine (6-OHDA) stimuli caused cardiac sympathetic denervation (SD), and we analyzed gene expression profiles to determine the changes in the lncRNA/circRNAs-miRNA-mRNA network in the affected spinal cord segments to identify putative target genes and molecular pathways in rats with myocardial ischemia–reperfusion injury (MIRI). Our results showed that cardiac sympathetic denervation induced by 6-OHDA alleviated MIRI. Compared with the ischemia reperfusion (IR, MIRI model) group, there were 148 upregulated and 51 downregulated mRNAs, 165 upregulated and 168 downregulated lncRNAs, 70 upregulated and 52 downregulated circRNAs, and 12 upregulated and 11 downregulated miRNAs in the upper thoracic spinal cord of the SD-IR group. Furthermore, we found that the differential genes related to cellular components were mainly enriched in extracellular and cortical cytoskeleton, and molecular functions were mainly enriched in chemokine activity. Pathway analysis showed that the differentially expressed genes were mainly related to the interaction of cytokines and cytokine receptors, sodium ion reabsorption, cysteine and methionine metabolism, mucoglycan biosynthesis, cGMP-PKG signaling pathway, and MAPK signaling pathway. In conclusion, the lncRNA/circRNAs-miRNA-mRNA networks in the upper thoracic spinal cord play an important role in the preventive effect of cardiac sympathetic denervation induced by 6-OHDA on MIRI, which offers new insights into the pathogenesis of MIRI and provides new targets for MIRI.