Ischemic damage may play an important role in spinal cord injury during dancing

Study design Retrospective analysis. Setting China Rehabilitation Research Center, Beijing, China. Objective To explore possible mechanisms underlying spinal cord injury (SCI) in children caused by hyperextension of the spine while dancing. Methods The clinical records of 88 children with SCI (mean age, 5.97 years; age range, 4–10 years) admitted to our hospital from January 1989 to October 2019 were retrospectively reviewed. Computed tomography and magnetic resonance imaging were performed on the day of injury. The time from injury to development of paralysis, as well as post-injury activities were surveyed, while abnormal patterns on images, the range of the involved vertebrae, and the extents of edema and atrophy were assessed. Results Among the 88 patients, 6 (6.8%) were unable to move immediately after SCI, while paralysis occurred in 42, 23, and 17 patients at <30, 30–60, and >60 min after SCI, respectively. The neurological level of injury of 84 patients was between T4 and T12. On sagittal T2-weighted images (T2WIs), the longitudinal range of spinal cord edema was more than one vertebral body in 65 patients, while spinal cord atrophy below T8 was found in 40 patients. On axial T2WIs, although three patients had none, long T2 signals were found in the central gray matter of seven patients. Meanwhile, necrosis of the central area combined with the peripheral white matter was observed in 57 patients, while three patients had total involvement on a cross section. Conclusion Ischemia-related damage, rather than direct trauma to the spinal cord, may play an important role in SCI due to spinal hyperextension during dancing.

Achieving Adaptive Plasticity in the Spinal Cord

The traditional view of central nervous system function presumed that learning is the province of the brain. From this perspective, the spinal cord functions primarily as a conduit for incoming/outgoing neural impulses, capable of organizing simple reflexes but incapable of learning. Research has challenged this view, demonstrating that neurons within the spinal cord, isolated from the brain by means of a spinal cut (transection), can encode environmental relations and that this experience can have a lasting effect on function. The exploration of this issue has been informed by work in the learning literature that establishes the behavioral criteria and work within the pain literature that has shed light on the underlying neurobiological mechanisms. Studies have shown that spinal systems can exhibit single stimulus learning (habituation and sensitization) and are sensitive to both stimulus–stimulus (Pavlovian) and response–outcome (instrumental) relations. Regular environmental relations can both bring about an alteration in the performance of a spinally mediated response and impact the capacity to learn in future situations. The latter represents a form of behavioral metaplasticity. At the neurobiological level, neurons within the central gray matter of the spinal cord induce lasting alterations by engaging the NMDA receptor and signal pathways implicated in brain-dependent learning and memory. Of particular clinical importance, uncontrollable/unpredictable pain (nociceptive) input can induce a form of neural over-excitation within the dorsal horn (central sensitization) that impairs adaptive learning. Pain input after a contusion injury can increase tissue loss and undermines long-term recovery.

Extensive perivascular dissemination of cerebral miliary tuberculomas: a case report and review of the literature

Cerebral tuberculosis (TB) presents most frequently as meningitis in the basilar cistern; however, it can also manifest in various other ways, such as localized encephalitis, abscess, and tuberculoma. Here, focusing on imaging findings, we report an immunocompetent case who demonstrated multiple parenchymal lesions and was diagnosed with cerebral TB after testing positive on QuantiFERON (QTF); her clinical signs/symptoms and laboratory findings responded well to anti-TB medication therapy. The patient was a 60-year-old woman with the chief complaints of headache and consciousness disturbance. On admission, cerebrospinal fluid (CSF) examination showed increased monocyte predominance. T2-weighted images showed multiple, widely distributed hyperintense lesions in the periventricular and deep white matter. Gadolinium-enhanced three-dimensional gradient echo T1-weighed images revealed numerous granules or faint, small, enhanced foci in lesions in the periventricular and deep white matter, central gray matter, and hippocampus. Some abnormal sulcal enhancement was detected in the pia mater, indicating meningitis. Clinically, the diagnosis was difficult to make, but as the QTF result was positive, anti-TB drugs were administered, after which both the symptoms and CSF cell count showed improvement.

Longitudinal Outcomes in the 2014 Acute Flaccid Paralysis Cluster in Canada

We describe the presenting features and long-term outcome of an unusual cluster of pediatric acute flaccid paralysis cases that occurred in Canada during the 2014 enterovirus D68 outbreak. Children (n = 25; median age 7.8 years) presenting to Canadian centers between July 1 and October 31, 2014, and who met diagnostic criteria for acute flaccid paralysis were evaluated retrospectively. The predominant presenting features included prodromal respiratory illness (n = 22), cerebrospinal fluid lymphocytic pleocytosis (n = 18), pain in neck/back (n = 14) and extremities (n = 10), bowel/bladder dysfunction (n = 9), focal central gray matter lesions found in all regions of the spinal cord within the cohort (n = 16), brain stem lesions (n = 8), and bulbar symptoms (n = 5). Enterovirus D68 was detectable in nasopharyngeal specimens (n = 7) but not in cerebrospinal fluid. Acute therapies (corticosteroids, intravenous immunoglobulins, plasmapheresis) were well tolerated with few side effects. Fourteen of 16 patients who were followed beyond 12 months post onset had neurologic deficits but showed ongoing clinical improvement and motor recovery.

Semisupervised Soft Mumford-Shah Model for MRI Brain Image Segmentation

One challenge of unsupervised MRI brain image segmentation is the central gray matter due to the faint contrast with respect to the surrounding white matter. In this paper, the necessity of supervised image segmentation is addressed, and a soft Mumford-Shah model is introduced. Then, a framework of semisupervised image segmentation based on soft Mumford-Shah model is developed. The main contribution of this paper lies in the development a framework of a semisupervised soft image segmentation using both Bayesian principle and the principle of soft image segmentation. The developed framework classifies pixels using a semisupervised and interactive way, where the class of a pixel is not only determined by its features but also determined by its distance from those known regions. The developed semisupervised soft segmentation model turns out to be an extension of the unsupervised soft Mumford-Shah model. The framework is then applied to MRI brain image segmentation. Experimental results demonstrate that the developed framework outperforms the state-of-the-art methods of unsupervised segmentation. The new method can produce segmentation as precise as required.

The Frequency of Anti-Aquaporin-4 Ig G Antibody in Neuromyelitis Optica and Its Spectrum Disorders at a Single Tertiary Referral Center in Malaysia

Background. In the past the occurrence of neuromyelitis optica in Malaysia was thought to be uncommon and the frequency of anti-aquaporin-4 Ig G antibody was unknown.Objective. To evaluate the frequency of anti-aquaporin-4 Ig G antibody (Anti-AQP4 antibody) amongst patients with neuromyelitis optica (NMO) and its spectrum disorders (NMOSD) and the differences between the seropositive and seronegative groups.Methods. Retrospectively, 96 patients with NMO/high risk syndromes for NMOSD (HRS-NMOSD) were identified out of 266 patients with idiopathic inflammatory demyelinating disease from a single center hospital based registry. Anti-AQP4 seropositivity was found in 38/48 (79.2%) with NMO, 12/21 (57.1%) with brain involvement at high risk for NMOSD, 12/15 (80%) with transverse myelitis (i.e., 11/15 with relapsing transverse myelitis and one with monophasic transverse myelitis), and 3/7 (42.8%) with relapsing optic neuritis. Sixty-five out of 96 patients, that is, 67.7%, with NMO/HRS for NMOSD were seropositive. Seropositivity was significantly associated with female gender, a higher number of mean relapses, that is, 5.15 ± 4.42 versus 2.10 ± 1.68, longer length of spinal cord lesions, that is, 6.6 ± 4.9 versus 2.9 ± 2.5, vertebral bodies, higher EDSS, 4.5 ± 2.4 versus 2.4 ± 2.6, presence of paroxysmal tonic spasms, and blindness (unilateral/bilateral);P<0.001. Longitudinally extensive cord lesions (contiguous or linear), presence of lesions in the cervical and thoracic regions, and involvement of the central gray matter or holocord regions on axial scans, were also significantly associated with seropositivity;P<0.001.Conclusion. NMO and HRS for NMOSD are present in larger numbers than previously thought in Malaysia. More than 2/3rds are seropositive. Seropositive and seronegative NMO/NMOSD have differences that are useful in clinical practice.

“Bright spotty lesions” on spinal magnetic resonance imaging differentiate neuromyelitis optica from multiple sclerosis

Background: Spinal magnetic resonance imaging (MRI) finding of longitudinally extensive spinal cord lesions (LESCL) extending over three vertebral segments and involvements of spinal central gray matter have been reported in patients with neuromyelitis optica (NMO). Objectives: We aimed to review spinal MRI findings in NMO and multiple sclerosis (MS), and to determine whether the “bright spotty lesions” (BSLs) are a discriminative finding of NMO. Methods: For this study, 24 consecutive patients with NMO and 34 patients with MS were enrolled. BSLs were defined as very hyperintense spotty lesions on axial T2WI. We also studied the length, distribution, signal homogeneity, size, and presence of contrast-enhanced lesions. Results: BSLs were more frequently found in patients with NMO (54%) than in those with MS (3%; p < 0.01). LESCL were found in 67% of the NMO patients. BSLs were seen in 63% of the patients without LESCL. BSLs or LESCL were found in 88% of the NMO patients. Inhomogeneous lesions, transversally extensive lesions, and central lesions were more frequently seen in NMO than in MS. Conclusions: BSLs are a newly defined spinal MRI finding specifically seen in NMO. In combination with LESCL, BSLs can help differentiate patients with NMO from those with MS with higher sensitivity than LESCL alone.

Somatosensory Evoked Potentials

SEPs recorded with surface electrodes represent volume-conducted activity arising from myelinated peripheral and central axons, synapses in central gray matter, and changes in the size and shape of the volume conductor. They provide an objective measure of function in large-diameter myelinated sensory afferents peripherally and in proprioceptive pathways centrally. Changes in amplitude and latency can be used to localize lesions in the nervous system, to identify objectively abnormalities in patients with few sensory manifestations or none at all, and to monitor function over time.

The synergetic modulation of the excitability of central gray matter by a neuropeptide: two protocols using excitation waves in chick retina

The isolated chick retina provides an in vitro tissue model, in which two protocols were developed to verify the efficacy of a peptide in the excitability control of the central gray matter. In the first, extra-cellular potassium homeostasis is challenged at long intervals and in the second, a wave is trapped in a ring of tissue causing the system to be under self-sustained challenge. Within the neuropil, the extra-cellular potassium transient observed in the first protocol was affected from the initial rising phase to the final concentration at the end of the five-minute pulse. There was no change in the concomitants of excitation waves elicited by the extra-cellular rise of potassium. However, there was an increase on the elicited waves latency and/or a rise in the threshold potassium concentration for these waves to appear. In the second protocol, the wave concomitants and the propagation velocity were affected by the peptide. The results suggest a synergetic action of the peptide on glial and synaptic membranes: by accelerating the glial Na/KATPase and changing the kinetics of the glial potassium channels, with glia tending to accumulate KCl. At the same time, there is an increase in potassium currents through nerve terminals.