Pain and spinal cord imaging measures in children with demyelinating disease

Long-term follow-up MR imaging in children with transverse myelitis

BACKGROUND

We recently described magnetic resonance imaging (MRI) features of children with transverse myelitis (TM) at first event with important and unique differences depending on the underlying disease entity.

OBJECTIVE

To study the resolution of lesions over time in children with TM due to MOG-antibody associated disorders (MOGAD), multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD) or double seronegative TM.

PATIENTS AND METHODS

In this prospective study, 78 children from 29 different medical centres with TM as part of MOGAD (n = 34), MS (n = 20), NMOSD (n = 5) and in double seronegative children (n = 19) were included. A grading system consisting of 4 grades (grade 0 = complete resolution; grade 3 = no resolution at all) was used to compare the degree of lesion resolution over time in the different disease entities. Time to lesion resolution was evaluated by Kaplan-Meier statistics and log-rank test.

RESULTS

Significant differences of the interval between first MRI until resolution of lesions were observed between the four disease entities. The most rapid and complete resolution was seen in MOGAD, followed by double seronegative, MS and NMOSD. Median periods until total resolution (grade 0) were 191 days (MOGAD), 750 days (double seronegative), 1117 days (MS), while none of the patients with NMOSD reached a complete resolution during the observation period. The better prognosis of MOGAD compared to MS was independent of sex, age, oligoclonal bands and cell count in the multivariate Cox analysis (P < 0.001).

CONCLUSION

Children with TM and antibodies to MOG show a faster resolution of radiological lesions compared to children with MS and NMOSD.

Health and LifeDomain ResearchPriorities in Children, Adolescents and Young Adults With Pediatric-Onset Spinal Cord Injury: A National Cross-Sectional Survey in England

Background

Although feedback from people with adult-onset spinal cord injury (SCI) has been considered in developing research programs, little is known about pediatric-onset SCI priorities.

Objectives

To describe the health and life (H&L) domain research priorities of youth with pediatric-onset SCI living in England.

Methods

Youth with pediatric-onset SCI (≥6 months) were recruited from five English rehabilitation centers and invited with their parents/caregivers to complete the age-appropriate surveys designed by the Pan-European Paediatric Spinal Cord Injury (PEPSCI) collaboration.

Results

A total of 73 surveys were received (32 from participants with SCI and 41 from their parents/caregivers), providing information on 47 individuals with SCI: 2- to 7-year-olds (29.8%), 8- to 12-year-olds (19.2%), 13- to 17-year-olds (17.0%), and 18 to 25-year-olds (34.0%). The top three research priorities reported by parents/caregivers of 2- to 12-year-old and 13- to 25-year-olds were pain (81%/89%), physical function (91%/83%) and health care access (78%/78%). Eighty-nine percent of 8- to 12-year-olds emphasized schooling, peer relationships, and general mood as their research priorities. The top three research priorities for Health or Life domains reported by 13- to 25-year-olds included spasms (95%), pain (91%), pressure injuries (91%), health care access (83%), physical function (78%), and daily personal needs (74%).

Conclusion

Although there should be an emphasis on addressing important life domain issues for 8- to 12-year-olds with SCI, adolescents and young adults mostly prioritized health domain research priorities in addition to health care access. This survey will aid health care and clinical research organizations to engage stakeholders to implement a comprehensive SCI research strategy in England for the pediatric population.

Revisiting the Pathoetiology of Multiple Sclerosis: Has the Tail Been Wagging the Mouse?

Multiple Sclerosis (MS) is traditionally considered an autoimmune-mediated demyelinating disease, the pathoetiology of which is unknown. However, the key question remains whether autoimmunity is the initiator of the disease (outside-in) or the consequence of a slow and as yet uncharacterized cytodegeneration (oligodendrocytosis), which leads to a subsequent immune response (inside-out). Experimental autoimmune encephalomyelitis has been used to model the later stages of MS during which the autoimmune involvement predominates. In contrast, the cuprizone (CPZ) model is used to model early stages of the disease during which oligodendrocytosis and demyelination predominate and are hypothesized to precede subsequent immune involvement in MS. Recent studies combining a boost, or protection, to the immune system with disruption of the blood brain barrier have shown CPZ-induced oligodendrocytosis with a subsequent immune response. In this Perspective, we review these recent advances and discuss the likelihood of an inside-out vs. an outside-in pathoetiology of MS.

Mechanisms of Below-Level Pain Following Spinal Cord Injury (SCI)

Mechanisms of below-level pain are discoverable as neural adaptations rostral to spinal injury. Accordingly, the strategy of investigations summarized here has been to characterize behavioral and neural responses to below-level stimulation over time following selective lesions of spinal gray and/or white matter. Assessments of human pain and the pain sensitivity of humans and laboratory animals following spinal injury have revealed common disruptions of pain processing. Interruption of the spinothalamic pathway partially deafferents nocireceptive cerebral neurons, rendering them spontaneously active and hypersensitive to remaining inputs. The spontaneous activity among these neurons is disorganized and unlikely to generate pain. However, activation of these neurons by their remaining inputs can result in pain. Also, injury to spinal gray matter results in a cascade of secondary events, including excitotoxicity, with rostral propagation of excitatory influences that contribute to chronic pain. Establishment and maintenance of below-level pain results from combined influences of injured and spared axons in the spinal white matter and injured neurons in spinal gray matter on processing of nociception by hyperexcitable cerebral neurons that are partially deafferented. A model of spinal stenosis suggests that ischemic injury to the core spinal region can generate below-level pain. Additional questions are raised about demyelination, epileptic discharge, autonomic activation, prolonged activity of C nocireceptive neurons, and thalamocortical plasticity in the generation of below-level pain. PERSPECTIVE: An understanding of mechanisms can direct therapeutic approaches to prevent development of below-level pain or arrest it following spinal cord injury. Among the possibilities covered here are surgical and other means of attenuating gray matter excitotoxicity and ascending propagation of excitatory influences from spinal lesions to thalamocortical systems involved in pain encoding and arousal.

Recent Developments in Diffusion Tensor Imaging of Brain

Magnetic resonance imaging (MRI) has come to be known as a unique radiological imaging modality because of its ability to perform tomographic imaging of body without the use of any harmful ionizing radiation. The radiologists use MRI to gain insight into the anatomy of organs, including the brain, while biomedical researchers explore the modality to gain better understanding of the brain structure and function. However, due to limited resolution and contrast, the conventional MRI fails to show the brain microstructure. Diffusion tensor imaging (DTI) harnesses the power of conventional MRI to deduce the diffusion dynamics of water molecules within the tissue and indirectly create a three-dimensional sketch of the brain anatomy. DTI enables visualization of brain tissue microstructure, which is extremely helpful in understanding various neuropathologies and neurodegenerative disorders. In this review, we briefly discuss the background and operating principles of DTI, followed by current trends in DTI applications for biomedical and clinical investigation of various brain diseases and disorders.