The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform
Saad Ali - One of the best experts on this subject based on the ideXlab platform.
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Neoplastic cauda equina syndrome: a neuroimaging-based review
Practical neurology, 2015Co-Authors: Shelby J. Bennett, Gregory L. Katzman, Raymond P. Roos, Amar S. Mehta, Saad AliAbstract:Cauda equina syndrome refers to dysfunction of the cauda equina, the collection of ventral and dorsal lumbar, sacral and Coccygeal Nerve roots that surround the filum terminale. This most commonly occurs as a result of compression by a herniated lumbosacral disc. However, the syndrome may also complicate metastatic cancer or a primary neoplasm within or infiltrating the spinal canal. An accurate and timely diagnosis is critical to avoid irreversible loss of neurological function. The clinician and radiologist must therefore be aware of the many possible causes to guide timely management. Here we review the diverse neoplastic causes affecting the cauda equina Nerve roots from a neuroimaging-based perspective. We divide them by location into intramedullary neoplasms at the conus (such as astrocytoma), intradural–extramedullary neoplasms (such as schwannoma and leptomeningeal metastases) and extradural neoplasms (such as spinal metastases from systemic neoplasms). We also discuss the clinical features associated with cauda equina tumours, with special focus on cauda equina syndrome.
Shelby J. Bennett - One of the best experts on this subject based on the ideXlab platform.
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Neoplastic cauda equina syndrome: a neuroimaging-based review
Practical neurology, 2015Co-Authors: Shelby J. Bennett, Gregory L. Katzman, Raymond P. Roos, Amar S. Mehta, Saad AliAbstract:Cauda equina syndrome refers to dysfunction of the cauda equina, the collection of ventral and dorsal lumbar, sacral and Coccygeal Nerve roots that surround the filum terminale. This most commonly occurs as a result of compression by a herniated lumbosacral disc. However, the syndrome may also complicate metastatic cancer or a primary neoplasm within or infiltrating the spinal canal. An accurate and timely diagnosis is critical to avoid irreversible loss of neurological function. The clinician and radiologist must therefore be aware of the many possible causes to guide timely management. Here we review the diverse neoplastic causes affecting the cauda equina Nerve roots from a neuroimaging-based perspective. We divide them by location into intramedullary neoplasms at the conus (such as astrocytoma), intradural–extramedullary neoplasms (such as schwannoma and leptomeningeal metastases) and extradural neoplasms (such as spinal metastases from systemic neoplasms). We also discuss the clinical features associated with cauda equina tumours, with special focus on cauda equina syndrome.
Jianhong Duan - One of the best experts on this subject based on the ideXlab platform.
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α dendrotoxin sensitive kv1 channels contribute to conduction failure of polymodal nociceptive c fibers from rat Coccygeal Nerve
Journal of Neurophysiology, 2016Co-Authors: Xiuchao Wang, Shan Wang, Ming Zhang, Fang Gao, Chun Yin, Ying Zhang, Jianhong DuanAbstract:It is known that some patients with diabetic neuropathy are usually accompanied by abnormal painful sensations. Evidence has accumulated that diabetic neuropathic pain is associated with the hyperexcitability of peripheral nociceptors. Previously, we demonstrated that reduced conduction failure of polymodal nociceptive C-fibers and enhanced voltage-dependent sodium currents of small dorsal root ganglion (DRG) neurons contribute to diabetic hyperalgesia. To further investigate whether and how potassium channels are involved in the conduction failure, α-dendrotoxin (α-DTX), a selective blocker of the low-threshold sustained Kv1 channel, was chosen to examine its functional capability in modulating the conduction properties of polymodal nociceptive C-fibers and the excitability of sensory neurons. We found that α-DTX reduced the conduction failure of C-fibers from Coccygeal Nerve in vivo accompanied by an increased initial conduction velocity but a decreased activity-dependent slowing of conduction velocity. In addition, the number of APs evoked by step currents was significantly enhanced after the treatment with α-DTX in small-diameter sensory neurons. Further study of the mechanism indicates α-DTX-sensitive K(+) current significantly reduced and the activation of this current in peak and steady state shifted to depolarization for diabetic neurons. Expression of Kv channel subunits Kv1.2 and Kv1.6 was downregulated in both small dorsal root ganglion neurons and peripheral C-fibers. Taken together, these results suggest that α-DTX-sensitive Kv1 channels might play an important role in regulating the conduction properties of polymodal nociceptive C-fibers and firing properties of sensory neurons.
Donlin M Long - One of the best experts on this subject based on the ideXlab platform.
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microsurgical treatment of sacral perineural tarlov cysts case series and review of the literature
Journal of Neurosurgery, 2016Co-Authors: John F Burke, Jayesh P Thawani, Ian Berger, Nikhil R Nayak, James H Stephen, Tunde Farkas, Hovik John Aschyan, John T Pierce, Suhail K Kanchwala, Donlin M LongAbstract:OBJECTIVE Tarlov cysts (TCs) occur most commonly on extradural components of the sacral and Coccygeal Nerve roots. These lesions are often found incidentally, with an estimated prevalence of 4%-9%. Given the low estimated rates of symptomatic TC and the fact that symptoms can overlap with other common causes of low-back pain, optimal management of this entity is a matter of ongoing debate. Here, the authors investigate the effects of surgical intervention on symptomatic TCs and aim to solidify the surgical criteria for this disease process. METHODS The authors performed a retrospective review of data from consecutive patients who were surgically treated for symptomatic TCs from September 2011 to March 2013. Clinical evaluations and results from surveying pain and overall health were used. Univariate statistical analyses were performed. RESULTS Twenty-three adults (4 males, 19 females) who had been symptomatic for a mean of 47.4 months were treated with laminectomy, microsurgical exposure and/or imbrication, and paraspinous muscle flap closure. Eighteen patients (78.3%) had undergone prior interventions without sustained improvement. Thirteen patients (56.5%) underwent lumbar drainage for an average of 8.7 days following surgery. The mean follow-up was 14.4 months. Univariate analyses demonstrated that an advanced age (p = 0.045), the number of noted perineural cysts on preoperative imaging (p = 0.02), and the duration of preoperative symptoms (p = 0.03) were associated with a poor postoperative outcome. Although 47.8% of the patients were able to return to normal activities, 93.8% of those surveyed reported that they would undergo the operation again if given the choice. CONCLUSIONS This is one of the largest published studies on patients with TCs treated microsurgically. The data suggest that patients with symptomatic TCs may benefit from open microsurgical treatment. Although outcomes seem related to patient age, duration of symptoms, and extent of disease demonstrated on imaging, further study is warranted and underway.
Amar S. Mehta - One of the best experts on this subject based on the ideXlab platform.
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Neoplastic cauda equina syndrome: a neuroimaging-based review
Practical neurology, 2015Co-Authors: Shelby J. Bennett, Gregory L. Katzman, Raymond P. Roos, Amar S. Mehta, Saad AliAbstract:Cauda equina syndrome refers to dysfunction of the cauda equina, the collection of ventral and dorsal lumbar, sacral and Coccygeal Nerve roots that surround the filum terminale. This most commonly occurs as a result of compression by a herniated lumbosacral disc. However, the syndrome may also complicate metastatic cancer or a primary neoplasm within or infiltrating the spinal canal. An accurate and timely diagnosis is critical to avoid irreversible loss of neurological function. The clinician and radiologist must therefore be aware of the many possible causes to guide timely management. Here we review the diverse neoplastic causes affecting the cauda equina Nerve roots from a neuroimaging-based perspective. We divide them by location into intramedullary neoplasms at the conus (such as astrocytoma), intradural–extramedullary neoplasms (such as schwannoma and leptomeningeal metastases) and extradural neoplasms (such as spinal metastases from systemic neoplasms). We also discuss the clinical features associated with cauda equina tumours, with special focus on cauda equina syndrome.