Opioid Usage in Lumbar Disc Herniation Patients with Nonsurgical, Early Surgical, and Late Surgical Treatments.

OBJECTIVE: To assess opioid usage in surgical and nonsurgical patients with lumbar disc herniation receiving different treatments and timing of treatments. METHODS: Individuals with newly diagnosed lumbar intervertebral disc herniation without myelopathy were queried from a health claims database. Patients were categorized into 3 cohorts: nonsurgical, early surgery, and late surgery. Early surgery cohort patients underwent surgery within 30 days postdiagnosis; late surgery cohort patients had surgery after 30 days but before 1 year postdiagnosis. The index date was defined as the diagnosis date for nonsurgical patients and the initial surgery date for surgical patients. The primary outcome was the average daily opioid morphine milligram equivalents (MME) prescribed. Additional outcomes included percentage of opioid-using patients and cumulative opioid burden. RESULTS: Inclusion criteria were met by 573,082 patients: 533,226 patients received nonsurgical treatments, 22,312 patients received early surgery, and 17,544 patients received late surgery. Both surgical cohorts experienced a postsurgical increase in opioid usage, which then sharply declined and gradually plateaued, with daily opioid MME consistently lower in the early versus late surgery cohort. The early surgery cohort also consistently had a lower prevalence of opioid-using patients than the late surgery cohort. Patients receiving nonsurgical treatment demonstrated the highest 1-year post index cumulative opioid burden, and the early surgery cohort consistently had lower cumulative opioid MME than the late surgery cohort. CONCLUSIONS: Early surgery in patients with lumbar disc herniation is associated with lower long-term average daily MME, incidence of opioid use, and 1-year cumulative MME burden compared with nonsurgical and late surgery treatment approaches.

Do We Swallow the Waste From Our Brain?

Ferumoxytol, an iron oxide nanoparticle, was infused into the lateral cerebroventricle of awake rats to follow its movement and clearance from the brain using magnetic resonance imaging. Within minutes the contrast agent could be observed accumulating in the subarachnoid space, nasal cavity, nasal pharynx, and soft palate at the back of the throat. In a subsequent study fluorescent quantum dots were infused into the brain of rats and within 15 min could be observed in the esophagus using microscopy. These imaging studies clearly show that these large nanoparticle tracers (∼20 nm in diameter) leave the brain through the nasal cavity and end up in the gut. There are numerous studies going back decades reporting the clearance of tracers put directly into the brain. While these studies show the slow accumulation of trace in the blood and lymphatics, they report only accounting for less than 50% of what was originally put in the brain.

Quantitative Imaging of Blood-Brain Barrier Permeability Following Repetitive Mild Head Impacts.

This was an exploratory study designed to evaluate the feasibility of a recently established imaging modality, quantitative ultrashort time-to-echo contrast enhanced (QUTE-CE), to follow the early pathology and vulnerability of the blood brain barrier in response to single and repetitive mild head impacts. A closed-head, momentum exchange model was used to produce three consecutive mild head impacts aimed at the forebrain separated by 24 h each. Animals were measured at baseline and within 1 h of impact. Anatomical images were collected to assess the extent of structural damage. QUTE-CE biomarkers for BBB permeability were calculated on 420,000 voxels in the brain and were registered to a bilateral 3D brain atlas providing site-specific information on 118 anatomical regions. Blood brain barrier permeability was confirmed by extravasation of labeled dextran. All head impacts occurred in the absence of any structural brain damage. A single mild head impact had measurable effects on blood brain barrier permeability and was more significant after the second and third impacts. Affected regions included the prefrontal ctx, basal ganglia, hippocampus, amygdala, and brainstem. Our findings support the concerns raised by the healthcare community regarding mild head injuries in participants in organized contact sports and military personnel in basic training and combat.

Neurovascular imaging with QUTE-CE MRI in APOE4 rats reveals early vascular abnormalities.

Cerebrovascular abnormality is linked to Alzheimer's disease and related dementias (ADRDs). ApoE-Ɛ4 (APOE4) is known to play a critical role in neurovascular dysfunction, however current medical imaging technologies are limited in quantification. This cross-sectional study tested the feasibility of a recently established imaging modality, quantitative ultra-short time-to-echo contrast-enhanced magnetic resonance imaging (QUTE-CE MRI), to identify small vessel abnormality early in development of human APOE4 knock-in female rat (TGRA8960) animal model. At 8 months, 48.3% of the brain volume was found to have significant signal increase (75/173 anatomically segmented regions; q<0.05 for multiple comparisons). Notably, vascular abnormality was detected in the tri-synaptic circuit, cerebellum, and amygdala, all of which are known to functionally decline throughout AD pathology and have implications in learning and memory. The detected abnormality quantified with QUTE-CE MRI is likely a result of hyper-vascularization, but may also be partly, or wholly, due to contributions from blood-brain-barrier leakage. Further exploration with histological validation is warranted to verify the pathological cause. Regardless, these results indicate that QUTE-CE MRI can detect neurovascular dysfunction with high sensitivity with APOE4 and may be helpful to provide new insights into health and disease.