Evaluation of a Clinical Protocol to Assess and Diagnose Neuropathic Pain During Acute Hospital Admission: Results From Traumatic Spinal Cord Injury

Genetic etiology study in a large cohort with congenital insensitivity to pain with anhidrosis

ABSTRACT

Pathogenic variations in the NTRK1 can cause congenital insensitivity to pain with anhidrosis (CIPA), a rare autosomal recessive inherited neuropathy. The precise diagnosis of CIPA relies on the identification of pathogenic genotypes. Therefore, it is essential to expand the NTRK1 variation spectrum and improve molecular diagnosis methods. In this study, 74 probands with typical manifestations of CIPA but unknown genotypes were recruited. A comprehensive molecular genetic analysis was performed to identify variations in the NTRK1 , using techniques including Sanger and next-generation sequencing, bioinformatic analysis, quantitative polymerase chain reaction (qPCR), gap-PCR, short tandem repeat (STR) genotyping, and reverse-transcription PCR. In addition, functional assays were conducted to determine the pathogenicity of variants of uncertain significance (VUS) and further characterized changes in glycosylation and phosphorylation of 14 overexpressed mutant vectors with variants at different domains in the TrkA protein, which is encoded by NTRK1 . A total of 48 variations in the NTRK1 were identified, including 22 novel ones. When combined with data from another 53 CIPA patients examined in our previous work, this study establishes the largest genotypic and phenotypic spectra of CIPA worldwide, including 127 CIPA families. Moreover, functional studies indicated that the pathogenicity of VUS mainly affected insufficient glycosylation in the extracellular domain and abnormal phosphorylation in the intracellular domain. This study not only provides important evidence for precise diagnosis of CIPA but also further enriches our understanding of the pathogenesis of this disease.

Characterization of Hyperacute Neuropathic Pain after Spinal Cord Injury: A Prospective Study

There is currently a lack of information regarding neuropathic pain in the very early stages of spinal cord injury (SCI). In the present study, neuropathic pain was assessed using the Douleur Neuropathique 4 Questions (DN4) for the patient's worst pain within the first 5 days of injury (i.e., hyperacute) and on follow-up at 3, 6, and 12 months. Within the hyperacute time frame (i.e., 5 days), at- and below-level neuropathic pain were reported as the worst pain in 23% (n = 18) and 5% (n = 4) of individuals with SCI, respectively. Compared to the neuropathic pain observed in this hyperacute setting, late presenting neuropathic pain was characterized by more intense painful electrical and cold sensations, but less itching sensations. Phenotypic differences between acute and late neuropathic pain support the incorporation of timing into a mechanism-based classification of neuropathic pain after SCI. The diagnosis of acute neuropathic pain after SCI is challenged by the presence of nociceptive and neuropathic pains, with the former potentially masking the latter. This may lead to an underestimation of the incidence of neuropathic pain during the very early, hyperacute time points post-injury. TRIAL REGISTRATION: ClinicalTrials.gov (Identifier: NCT01279811) PERSPECTIVE: This article presents distinct pain phenotypes of hyperacute and late presenting neuropathic pain after spinal cord injury and highlights the challenges of pain assessments in the acute phase after injury. This information may be relevant to clinical trial design and broaden our understanding of neuropathic pain mechanisms after spinal cord injury.

Spinal cord injury and gut microbiota: A review

After spinal cord injury (SCI), intestinal dysfunction has a serious impact on physical and mental health, quality of life, and social participation. Recent data from rodent and human studies indicated that SCI causes gut dysbiosis. Remodeling gut microbiota could be beneficial for the recovery of intestinal function and motor function after SCI. However, few studies have explored SCI with focus on the gut microbiota and "microbiota-gut-brain" axis. In this review, the complications following SCI, including intestinal dysfunction, anxiety and depression, metabolic disorders, and neuropathic pain, are directly or indirectly related to gut dysbiosis, which may be mediated by "gut-brain" interactions. Furthermore, we discuss the research strategies that can be beneficial in this regard, including germ-free animals, fecal microbiota transplantation, probiotics, phages, and brain imaging techniques. The current microbial research has shifted from descriptive to mechanismal perspective, and future research using new technologies may further demonstrate the pathophysiological mechanism of association of SCI with gut microbiota, elucidate the mode of interaction of gut microbiota and hosts, and help develop personalized microbiota-targeted therapies and drugs based on microbiota or corresponding metabolites.

Traumatic vs non-traumatic spinal cord injury: A comparison of primary rehabilitation outcomes and complications during hospitalization

Objective: To compare outcome for patients with traumatic (TSCI) and non-traumatic spinal cord injuries (NTSCI) after primary rehabilitation regarding neurological improvement measured by the American Spinal Injury Association Impairment Scale (AIS), length of stay and complications.Design: Retrospective comparative cohort study on patients with TSCI and NTSCI, hospitalized during a ten-year period at Haukeland University Hospital, Norway. Impairment, length of stay and complications during first in-patient rehabilitation period were analyzed. Uni- and multivariate analysis was performed.Setting: Spinal Cord Rehabilitation Unit, Haukeland University Hospital, NorwayParticipants: A total of 174 persons with a spinal cord injury (SCI) were included; 102 with TSCI and 72 with NTSCI.Outcome measures: Neurological improvement measured by AIS from admission to discharge, number of weeks in the hospital, frequency and significance of complications were compared.Results: Improvement in AIS after primary rehabilitation did not differ between TSCI and NTSCI. Length of stay was in average 3.4 weeks longer for TSCI. Urinary tract infections and pressure ulcers significantly influenced length of stay in both groups. Urinary tract infections were more frequent in TSCI (67%) vs NTSCI (42%). Pressure ulcers were more frequent among NTSCI (24%) vs TSCI (14%). Pneumonia and neuropathic pain did not depend on etiology and did not influence length of stay.Conclusions: Patients with SCI have a rehabilitation potential regardless of etiology. Complications are frequent in both groups and often prolong hospitalization. Complication patterns differ in the two groups, and specific prevention and optimal treatment will shorten and optimize the length of primary rehabilitation.