Comparison of LED- and LASER-based fNIRS technologies to record the human peri­spinal cord neurovascular response.

Recently, functional Near-Infrared Spectroscopy (fNIRS) was applied to obtain, non-invasively, the human peri­spinal Neuro-Vascular Response (NVR) under a non-noxious electrical stimulation of a peripheral nerve. This method allowed the measurements of changes in the concentration of oxyhemoglobin (O2Hb) and deoxyhemoglobin (HHb) from the peri­spinal vascular network. However, there is a lack of clarity about the potential differences in perispinal NVR recorded by the different fNIRS technologies currently available. In this work, the two main noninvasive fNIRS technologies were compared, i.e., LED and LASER-based. The recording of the human peri­spinal NVR induced by non-noxious electrical stimulation of a peripheral nerve was recorded simultaneously at C7 and T10 vertebral levels. The amplitude, rise time, and full width at half maximum duration of the perispinal NVRs were characterized in healthy volunteers and compared between both systems. The main difference was that the LED-based system shows about one order of magnitude higher values of amplitude than the LASER-based system. No statistical differences were found for rise time and for duration parameters (at thoracic level). The comparison of point-to-point wave patterns did not show significant differences between both systems. In conclusion, the peri­spinal NRV response obtained by different fNIRS technologies was reproducible, and only the amplitude showed differences, probably due to the power of the system which should be considered when assessing the human peri­spinal vascular network.

Contrast enhanced ultrasound for traumatic spinal cord injury: an overview of current and future applications.

STUDY DESIGN: Systematic review. OBJECTIVE: Contrast-enhanced ultrasound (CEUS) is an imaging modality that has only recently seen neurosurgical application. CEUS uses inert microbubbles to intraoperatively visualize vasculature and perfusion of the brain and spinal cord in real time. Observation and augmentation of spinal cord perfusion is vital component of the management of traumatic spinal cord injury, yet there are limited imaging modalities to evaluate spinal cord perfusion. CEUS provides an intraoperative imaging tool to evaluate spinal cord perfusion in real time. The objective of this review is to evaluate the current literature on the various applications and benefits of CEUS in traumatic spinal cord injury. SETTING: South Carolina, USA. METHODS: This review was written according to the PRISMA 2020 guidelines. RESULTS: 143 articles were found in our literature search, with 46 of them being unique. After excluding articles for relevance to CEUS and spinal cord injury, we were left with 10 papers. Studies in animal models have shown CEUS to be an effective non-invasive imaging modality that can detect perfusion changes of injured spinal cords in real time. CONCLUSION: This imaging modality can provide object perfusion data of the nidus of injury, surrounding penumbra and healthy neural tissue in a traumatized spinal cord. Investigation in its use in humans is ongoing and remains promising to be an effective diagnostic and prognostic tool for those suffering from spinal cord injury.

[Application of super-resolution and ultrafast ultrasound to reveal the characteristics of vascular blood flow changes after rat spinal cord injury at different segments].

Objective: To investigate the changes of spinal vascular blood flow in SD rats after cervical, thoracic and lumbar spinal cord injury (SCI) using super-resolution ultrafast ultrasound technology. Methods: A total of 9 SD rats were used to construct SCI models at different segments using a 50 g aneurysm clip. Super-resolution ultrafast ultrasound technology was used to perform vascular blood flow imaging on the spinal cord of rats before and after injury at 6 hours, obtaining quantitative information such as spinal cord vascular density and blood flow velocity. Results: Ultrasound imaging showed that after SCI, the vascular density in the thoracic segment decreased (18.16%±1.04%) more than in the cervical segment (11.42%±1.39%) and lumbar segment (13.88%±1.43%, both P<0.05). The length of the spinal cord with decreased vascular density in the thoracic segment [(4.80±0.34)mm] was longer than that in the cervical segment [(2.80±0.57)mm] and lumbar segment [(3.10±0.36)mm, both P<0.05]. After injury, the decrease of blood flow in the thoracic segment [(8.87±0.85)ml/min] was higher than that in the cervical segment [(4.88±0.56)ml/min] and lumbar segment [(6.19±0.71)ml/min, both P<0.05]. HE staining and Nissl staining showed that the proportion of cavity area after thoracic SCI (11.53%±0.93%) was higher than that in the cervical segment (4.90%±1.72%) and lumbar segment (7.64%±0.84%, both P<0.05). The number of Nissl bodies in the thoracic segment (18.0±5.3) was also lower than that in the cervical segment (32.3±5.1) and lumbar segment (37.0±5.6) (both P<0.05). Conclusions: There are different changes in vascular blood flow after SCI in different segments of rats. The same injury causes the most severe damage to blood vessels in the thoracic spinal cord, followed by the lumbar spinal cord, and the cervical spinal cord has the least damage.

Clinical Approach to Myelopathy Diagnosis.

OBJECTIVE: This article describes an integrative strategy to evaluate patients with suspected myelopathy, provides advice on diagnostic approach, and outlines the framework for the etiologic diagnosis of myelopathies. LATEST DEVELOPMENTS: Advances in diagnostic neuroimaging techniques of the spinal cord and improved understanding of the immune pathogenic mechanisms associated with spinal cord disorders have expanded the knowledge of inflammatory and noninflammatory myelopathies. The discovery of biomarkers of disease, such as anti-aquaporin 4 and anti-myelin oligodendrocyte glycoprotein antibodies involved in myelitis and other immune-related mechanisms, the emergence and identification of infectious disorders that target the spinal cord, and better recognition of myelopathies associated with vascular pathologies have expanded our knowledge about the broad clinical spectrum of myelopathies. ESSENTIAL POINTS: Myelopathies include a group of inflammatory and noninflammatory disorders of the spinal cord that exhibit a wide variety of motor, sensory, gait, and sensory disturbances and produce major neurologic disability. Both inflammatory and noninflammatory myelopathies comprise a broad spectrum of pathophysiologic mechanisms and etiologic factors that lead to specific clinical features and presentations. Knowledge of the clinical variety of myelopathies and understanding of strategies for the precise diagnosis, identification of etiologic factors, and implementation of therapies can help improve outcomes.

Vascular Myelopathies.

OBJECTIVE: Vascular injuries of the spinal cord are less common than those involving the brain; however, they can be equally devastating. This article discusses the diagnosis and management of ischemic and hemorrhagic vascular disorders of the spinal cord. LATEST DEVELOPMENTS: Clinical suspicion remains the mainstay for recognizing vascular myelopathies, yet diagnoses are often delayed and challenging in part because of their rarity and atypical manifestations. Noninvasive imaging such as CT and MRI continues to improve in spatial resolution and diagnostic precision; however, catheter-based spinal angiography remains the gold standard for defining the spinal angioarchitecture. In addition to hemorrhagic and ischemic disease, the contribution of venous dysfunction is increasingly appreciated and informs treatment strategies in conditions such as intracranial hypotension. ESSENTIAL POINTS: Vascular disorders of the spine manifest in variable and often atypical ways, which may lead to delayed diagnosis. Increased awareness of these conditions is critical for early recognition and treatment. The goal of treatment is to minimize long-term morbidity and mortality.

Cervical spinal cord angiography and vessel-selective perfusion imaging in the rat.

Arterial spin labeling (ASL) has been widely used to evaluate arterial blood and perfusion dynamics, particularly in the brain, but its application to the spinal cord has been limited. The purpose of this study was to optimize vessel-selective pseudocontinuous arterial spin labeling (pCASL) for angiographic and perfusion imaging of the rat cervical spinal cord. A pCASL preparation module was combined with a train of gradient echoes for dynamic angiography. The effects of the echo train flip angle, label duration, and a Cartesian or radial readout were compared to examine their effects on visualizing the segmental arteries and anterior spinal artery (ASA) that supply the spinal cord. Lastly, vessel-selective encoding with either vessel-encoded pCASL (VE-pCASL) or super-selective pCASL (SS-pCASL) were compared. Vascular territory maps were obtained with VE-pCASL perfusion imaging of the spinal cord, and the interanimal variability was evaluated. The results demonstrated that longer label durations (200 ms) resulted in greater signal-to-noise ratio in the vertebral arteries, improved the conspicuity of the ASA, and produced better quality maps of blood arrival times. Cartesian and radial readouts demonstrated similar image quality. Both VE-pCASL and SS-pCASL adequately labeled the right or left vertebral arteries, which revealed the interanimal variability in the segmental artery with variations in their location, number, and laterality. VE-pCASL also demonstrated unique interanimal variations in spinal cord perfusion with a right-sided dominance across the six animals. Vessel-selective pCASL successfully achieved visualization of the arterial inflow dynamics and corresponding perfusion territories of the spinal cord. These methodological developments provide unique insights into the interanimal variations in the arterial anatomy and dynamics of spinal cord perfusion.

Isolated spinal artery aneurysm: etiology, clinical characteristics, and outcomes.

OBJECTIVE: Isolated spinal aneurysms (ISAs) are rare causes of subarachnoid hemorrhage (SAH), which encompass a highly heterogeneous group of clinical entities with multifarious pathogeneses, clinical characteristics, and treatment strategies. Therefore, knowledge about the ISAs remains inadequate. In this study, the authors present a comprehensive analysis of clinical data associated with ISAs at their institutions to enhance the understanding of this disease. METHODS: Patients with ISAs confirmed by spinal angiography or surgery at the authors' institutions between 2015 and 2022 were included. Data regarding clinical presentation, lesion location, aneurysm morphology, comorbidities, treatment results, and clinical outcomes were reviewed. RESULTS: Seven patients with ISAs were included in the study. Among them, 4 patients (57.1%) experienced severe headache, and 3 patients (42.9%) reported sudden-onset back pain. Additionally, lower-extremity weakness and urinary retention were observed in 2 of these patients (28.6%). Four of the aneurysms exhibited fusiform morphology, whereas the remaining were saccular. All saccular aneurysms in this series were attributed to hemodynamic factors. Conservative treatment was administered to 3 patients, 2 of whom underwent follow-up digital subtraction angiography, which showed spontaneous occlusion of both aneurysms. Four patients ultimately underwent invasive treatments, including 2 who underwent microsurgery and 2 who received endovascular embolization. One patient died of recurrent SAH, while the remaining 6 patients had a favorable prognosis at the latest follow-up assessment. CONCLUSIONS: The morphology of aneurysms may be associated with their etiology. Saccular ISAs are usually caused by pressure due to abnormally increased blood flow, whereas fusiform lesions may be more likely to be secondary to vessel wall damage. The authors found that a saccular spinal aneurysm in young patients with a significant dilated parent artery may be a vestige of spinal cord arteriovenous shunts. ISAs can be managed by surgical, endovascular, or conservative procedures, and the clinical outcome is generally favorable. However, the heterogeneous nature of the disease necessitates personalized treatment decision-making based on specific clinical features of each patient.

Concomitant Thoracic Spinal Dural Arteriovenous Fistula and Spinal Cavernous Malformation.

Both spinal dural arteriovenous fistula (SDAVF) and spinal cavernous malformation (SCM) are uncommon vascular malformations. To our knowledge, such a case of SDAVF concomitant with SCM has not been reported. We encountered a case of a 55-year-old man who had weakness and numbness in both lower extremities. Magnetic resonance imaging showed a round-shape lesion identified as a cavernous malformation in the middle segment of the thoracic spine, with spinal edema and obvious flow voids. Diagnostic angiography revealed an SDAVF fed by the right T7 radicular artery with venous drainage. The intramedullary venous hypertension due to fistula was suspected of inducing the formation of SCM. This case may provide new insight into the pathogenesis of SCM.

[Prevention and Treatment of Ischemic Spinal Cord Injury].

In recent years, the widespread use of thoracic/thoracoabdominal stent grafting and a better understanding of spinal cord blood supply have led to quite a few change in measures to prevent spinal cord injury. It is essential to understand the characteristics of spinal cord blood flow, which is complicated by collateral pathways, and to strive to maintain spinal cord blood flow during surgery. It is also important to plan staged repair as much as possible in any treatment modality. Particular attention must be paid to the prevention of second attacks, especially after thoracic/thoracoabdominal endovascular aortic repair without segmental artery reconstruction. Systemic circulatory and respiratory management, improvement of anemia, and cerebrospinal fluid drainage with attention to drainage rates, may be effective as preventive and therapeutic measures for spinal cord injury.

What the Musculoskeletal Radiologist Needs to Know About the Vascular Anatomy of the Spine and Spinal Cord.

This article describes the vascular anatomy of the spine and spinal cord, highlighting key structures and anatomical variations relevant to musculoskeletal radiologists. It covers the arterial and venous drainage systems, along with examples of vascular conditions affecting the spine. Understanding the vascular anatomy of the spine and spinal cord is crucial for accurate interpretation of imaging studies and safe spinal interventional procedures. Imaging techniques for evaluating vascular pathology of the spine are discussed and compared. Understanding vascular anatomy and the most common vascular disorders will lead to an accurate diagnosis and suggest the appropriate type of study needed for further characterization and/or patient management.

Spinal cord injury induced exacerbation of Alzheimer's disease like pathophysiology is reduced by topical application of nanowired cerebrolysin with monoclonal antibodies to amyloid beta peptide, p-tau and tumor necrosis factor alpha.

Hallmark of Alzheimer's disease include amyloid beta peptide and phosphorylated tau deposition in brain that could be aggravated following traumatic of concussive head injury. However, amyloid beta peptide or p-tau in spinal cord following injury is not well known. In this investigation we measured amyloid beta peptide and p-tau together with tumor necrosis factor-alpha (TNF-α) in spinal cord and brain following 48 h after spinal cord injury in relation to the blood-spinal cord and blood-brain barrier, edema formation, blood flow changes and cell injury in perifocal regions of the spinal cord and brain areas. A focal spinal cord injury was inflicted over the right dorsal horn of the T10-11 segment (4 mm long and 2 mm deep) and amyloid beta peptide and p-tau was measured in perifocal rostral (T9) and caudal (T12) spinal cord segments as well as in the brain areas. Our observations showed a significant increase in amyloid beta peptide in the T9 and T12 segments as well as in remote areas of brain and spinal cord after 24 and 48 h injury. This is associated with breakdown of the blood-spinal cord (BSCB) and brain barriers (BBB), edema formation, reduction in blood flow and cell injury. After 48 h of spinal cord injury elevation of amyloid beta peptide, phosphorylated tau (p-tau) and tumor necrosis factor-alpha (TNF-α) was seen in T9 and T12 segments of spinal cord in cerebral cortex, hippocampus and brain stem regions associated with microglial activation as seen by upregulation of Iba1 and CD86. Repeated nanowired delivery of cerebrolysin topically over the traumatized segment repeatedly together with monoclonal antibodies (mAb) to amyloid beta peptide (AßP), p-tau and TNF-α significantly attenuated amyloid beta peptide, p-tau deposition and reduces Iba1, CD68 and TNF-α levels in the brain and spinal cord along with blockade of BBB and BSCB, reduction in blood flow, edema formation and cell injury. These observations are the first to show that spinal cord injury induces Alzheimer's disease like symptoms in the CNS, not reported earlier.

Microsurgical disconnection of a T12/L1 ventral intradural perimedullary arteriovenous fistula (type IV) via instrumented trans-pedicular approach.

CASE DESCRIPTION: We present a case of microsurgical disconnection of a PMAVF supplied by the artery of Adamkiewicz with fistulation at the ventral spinal cord.

Clinical outcomes and prognostic factors in the surgical treatment of spinal dural arteriovenous fistulas: a retrospective study of 118 patients.

Spinal dural arteriovenous fistulas (SDAVFs) are the most common type of spinal vascular malformations (AVMs), constituting approximately 70% of all spinal AVMs. The impact of various clinical and radiologic features on the outcomes in patients with SDAVFs is still controversial. The purpose of the study is to investigate the clinical outcomes and prognostic factors in patients with surgically treated SDAVFs in a single center. A retrospective review was performed for all patients with SDAVFs from January 2013 to September 2021 who underwent surgery at our institution. Medical records and pre- and postoperative imaging data were analyzed. Neurological function status was evaluated by modified Aminoff-Logue Scale (mALS). Student's t-test, Wilcoxon rank sum test, χ2 test and logistic regression were used to find significant prognostic factors. P values < 0.05 were considered significant. One hundred and eighteen patients were ultimately included in the study. By comparing preoperative and postoperative mALS, 69 (58.5%) patients experienced improvement, and 49 (41.5%) patients showed no improvement (worse or unchanged). Wilcoxon rank sum test showed that there was a difference between the improvement group and the no improvement group in preoperative mALS Micturition score and preoperative mALS Defecation score. The logistic regression revealed that preoperative mALS Gait score was associated with clinical improvement after surgery in patients with SDAVFs. Surgical treatment of SDAVFs is a safe and effective procedure and can lead to symptom improvement or stabilization in most patients. Preoperative neurological function status was the only factor associated with clinical prognosis.

Development and repair of blood vessels in the zebrafish spinal cord.

The vascular system is inefficiently repaired after spinal cord injury (SCI) in mammals, resulting in secondary tissue damage and immune deregulation that contribute to the limited functional recovery. Unlike mammals, zebrafish can repair the spinal cord (SC) and restore motility, but the vascular response to injury has not been investigated. Here, we describe the zebrafish SC blood vasculature, starting in development with the initial vessel ingression in a body size-dependent manner, the acquisition of perivascular support and the establishment of ventral to dorsal blood circulation. The vascular organization grows in complexity and displays multiple barrier specializations in adulthood. After injury, vessels rapidly regrow into the lesion, preceding the glial bridge and axons. Vascular repair involves an early burst of angiogenesis that creates dysmorphic and leaky vessels. Dysfunctional vessels are later removed, as pericytes are recruited and the blood-SC barrier is re-established. This study demonstrates that zebrafish can successfully re-vascularize the spinal tissue, reinforcing the value of this organism as a regenerative model for SCI.

Two Neighboring Spinal Dural Arteriovenous Fistulas with Multiple Bridging Veins Drainage.

Two neighboring spinal dural arteriovenous fistulas (SDAVFs) with multiple bridging veins drainage are extremely rare. Here, we report a 55-year-old man with 2 neighboring SDAVFs at the levels of T4-T5 supplied by the right T5 intercostal artery (common stem of T4 and T5 arteries) with multiple draining veins. Intraoperatively, 3 draining bridging veins between T4 and T5 nerve roots were identified and resected successfully. This case demonstrated the complex microscopic angioarchitecture features of 2 neighboring SDAVFs with multiple draining veins. Although these complex SDAVFs are extremely rare, the clinicians should be aware of the possibility of 2 neighboring SDAVFs.

"Missing-piece" sign with dural arteriovenous fistula at craniocervical junction: A case report.

OBJECTIVES: Spinal dural arteriovenous fistula (sDAVF) is a rare and often underdiagnosed spinal disease. Early diagnosis is required because the deficits are reversible and delays in treatment cause permanent morbidity. Although the abnormal vascular flow void is a critical radiographic feature of sDAVF, they are not always present. A characteristic enhancement pattern of sDAVF has been recently reported as the "missing-piece" sign which can lead to the early and correct diagnosis. METHODS: We presented imaging findings, treatment decisions, and the outcome of a rare case of sDAVF, in which the "missing-piece" sign appeared atypical. RESULTS: A 60-year-old woman developed numbness and weakness in her extremities. Spinal MRI revealed longitudinal hyperintensity in the T2-weighted image, extending from the thoracic level to medulla oblongata. At first, myelopathy with inflammation or tumor was suspected because of the lack of flow voids and vascular abnormalities in CT-angiography and MR-DSA. However, we administered intravenous methylprednisolone and her symptom got worse with the appearance of the "missing-piece" sign. Then, we successfully diagnosed sDAVF by angiography. The "missing-piece" sign was considered to derive from inconsistency of the intrinsic venous system of spinal cord, with the abrupt segments without enhancement. The same etiology was considered in our case. CONCLUSIONS: Detecting the "missing-piece" sign can lead to the correct diagnosis of sDAVF, even if the sign appeared atypical.