Neuropathological and Motor Impairments after Incomplete Cervical Spinal Cord Injury in Pigs.

Humans, primates, and rodents with cervical spinal cord injury (SCI) show permanent sensorimotor dysfunction of the upper/forelimb as consequence of axonal damage and local neuronal death. This work aimed at characterizing a model of cervical SCI in domestic pigs in which hemisection with excision of 1 cm of spinal cord was performed to reproduce the loss of neural tissue observed in human neuropathology. Posture and motor control were assessed over 3 months by scales and kinematics of treadmill locomotion. Histological measurements included lesion length, atrophy of the adjacent spinal cord segments, and neuronal death. In some animals, the retrograde neural tracer aminostilbamidine was injected in segments caudal to the lesion to visualize propriospinal projection neurons. Neuronal loss extended for 4-6 mm from the lesion borders and was more severe in the ipsilateral, caudal spinal cord stump. Axonal Wallerian degeneration was observed caudally and rostrally, associated with marked atrophy of the white matter in the spinal cord segments adjacent to the lesion. The pigs showed chronic monoplegia or severe monoparesis of the foreleg ipsilateral to the lesion, whereas the trunk and the other legs had postural and motor impairments that substantially improved during the first month post-lesion. Adaptations of the walking cycle such as those reported for rats and humans ameliorated the negative impact of focal neurological deficits on locomotor performance. These results provide a baseline of behavior and histology in a porcine model of cervical spinal cord hemisection that can be used for translational research in SCI therapeutics.

Spanish Version of the Whiplash Disability Questionnaire in Adults With Acute Whiplash-Associated Disorders.

OBJECTIVE: The purpose of this study was to develop and validate a Spanish version of the Whiplash Disability Questionnaire (WDQ) for the Spanish population with acute whiplash-associated disorder (WAD). METHODS: This was a cross-sectional questionnaire validation study. Adults with acute WAD (grade I to III) were enrolled within 3 weeks of their injury. A blinded forward and back translation of the WDQ was made from English to Spanish, and the resulting back-translation version was compared with the original. Patients with WAD completed the Spanish version of the 13-item WDQ. The developed questionnaire was assessed using psychometric statistical analysis including correlation with the numerical rating score for pain, Northwick Park Neck Pain Questionnaire, Neck Disability Index, and 36-item Short Form Health Survey. RESULTS: Fifty-six patients completed the questionnaire, the mean age was 33.9 years (standard deviation [SD] = 10.5), and 76.8% were women. Participants were enrolled 13.9 days (SD 4.9) after the injury, with 14.3% presenting with WAD grade I and 85.7% with WAD grade II. The mean WDQ score was 62 (SD = 31). Two factors were detected, and the factor structure remained stable after translation. Positive correlations were identified between the total WDQ score and the numerical rating score, Neck Pain Questionnaire, and Neck Disability Index results, with a strong negative correlation with the 36-item Short Form Health Survey. CONCLUSION: The Spanish version of WDQ is psychometrically reliable and a valid instrument to measure the disability status in patients with acute WAD within the clinic.

Deficient Inhibitory Endogenous Pain Modulation Correlates With Periaqueductal Gray Matter Metabolites During Chronic Whiplash Injury.

OBJECTIVES: This study examined predictive correlations between periaqueductal gray (PAG) and anterior cingulate cortex (ACC) metabolite levels with deficient inhibitory endogenous pain modulation (EPM), including sensory and affective measures of pain during chronic whiplash injury (WHI). MATERIALS AND METHODS: Healthy patients, and participants with chronic WHI, without (WHI-noP) or with pain (WHI-P), were screened with the Douleur Neuropathique 4 tool (DN4). EPM was assessed with C6 tonic heat pain stimuli with a Conditioned Pain Modulation (CPM) protocol. Magnetic resonance spectroscopy quantified ACC and PAG metabolite levels. RESULTS: WHI-P participants were characterized with high pain intensity and interference, and lower quality of life scores, compared with WHI-noP. Inhibitory CPM at 30 seconds was identified in the healthy noninjured (-45±16%; P<0.001) and WHI-noP groups (-36±8%; P<0.001). However, inhibitory EPM was not detected in the WHI-P group (-25±15%; P=0.06). Best fit and stepwise multiple regression revealed that the PAG glutamate/myoinositol metabolite ratio (P=0.01) and total creatine levels (P=0.02) predicted loss of EPM in the WHI-P group (r=0.71, α=0.97). Although myoinositol predicted loss of EPM in the ACC (P=0.04), this was below statistical power (r=0.31; α=0.56). The ACC N-acetyl-aspartate/myoinositol ratio (P=0.006) predicted chronic pain (DN4, r=0.53; α=0.87). DISCUSSION: The results of this study demonstrate deficient EPM at 30 seconds during tonic heat pain stimulation in WHI-P participants, compared with noninjured healthy volunteers or individuals with WHI-noP. In addition, quantification of PAG and ACC metabolites related to glutamate and glia predicted central chronic pain mechanisms related to loss of inhibitory EPM, while ACC metabolites characterized chronic pain described by descriptors and sensory changes.

Hernia intraesponjosa de Schmörl sintomática / Symptomatic intraosseous Schmörl herniation

Las hernias discales intraesponjosas vertebrales o nódulos de Schmörl consisten en una herniación o una extrusión del núcleo pulposo del disco intervertebral a través del platillo vertebral hacia el cuerpo adyacente. Suelen asociarse a deformidades vertebrales, como la enfermedad de Scheuermann, o a enfermedades reumáticas, como la espondilitis anquilopoyética. En general, son hallazgos casuales y cuadros asintomáticos; son pocos los casos publicados de nódulos sintomáticos. Su aparición estaría relacionada con un platillo vertebral debilitado por traumatismo o estrés repetido. Cuando el nódulo es agudo o reciente, puede ser difícil diferenciar la degeneración benigna de una infiltración maligna o una infección. Presentamos un caso inusual de un nódulo de Schmörl doloroso en un hombre sin antecedentes de relevancia, que enmascaró una lesión metastásica de carcinoma pancreático a nivel lumbar. Se realiza una revisión bibliográfica. Nivel de Evidencia: IV

Intraosseous disc herniation -or Schmörl nodes (SN)- are a herniation or prolapse of the nucleus pulposus of the intervertebral disc through the vertebral plate and into the adjacent vertebral body. They are usually associated with vertebral deformities, such as Scheuermann's disease, or rheumatic diseases, such as ankylopoietic spondylitis. In general, they are spontaneous and asymptomatic findings, and there are only a few reported cases of symptomatic nodes. The etiology is supposedly related to a weakened spinal plate due to trauma or repeated stress. When the node is acute or recent, it can be difficult to differentiate a benign degeneration from a malignant infiltration or infection. In this paper, we discuss the unusual case of a painful Schmörl node in a man with no relevant history and a masked metastatic lumbar spinal tumor originated from pancreatic cancer. We performed a literature review. Level of Evidence: IV

Acute compartment syndrome of the forearm caused by calcific tendinitis of the distal biceps.

Acute compartment syndrome of the forearm requires immediate treatment to avoid damage of the soft tissues and a poor functional outcome for the forearm. Muscular and bone lesions are the main causes of acute compartment syndromes. We report a case of acute compartment syndrome of the forearm caused by a calcific tendinitis of the distal biceps.