Sinus compromise is common in patients with overlying skull fractures. Sinus compression can be distinguished from DVST on MDCT venography and is likely more prevalent than previously estimated. The fracture site may in part determine the pattern of compromise because fractures involving the transverse sinus-sigmoid sinus complex or multiple dural sinuses seem more likely to be affected by thrombosis than fractures involving the SSS.
Background and purposeEvaluating chronic sequelae of optic neuritis, such as optic neuropathy with or without optic nerve atrophy, can be challenging on whole brain MRI. This study evaluated the utility of dedicated coronal contrast-enhanced fat-suppressed FLAIR (CE-FS-FLAIR) MR imaging to detect optic neuropathy and optic nerve atrophy.Materials and methodsOver 4.5 years, a 3 mm coronal CE-FS-FLAIR sequence at 1.5T was added to the routine brain MRIs of 124 consecutive patients, 102 of whom had suspected or known demyelinating disease. Retrospective record reviews confirmed that 28 of these 102 had documented onset of optic neuritis >4 weeks prior to the brain MRI. These 28 were compared to the other 22 (“controls”) of the 124 patients who lacked a history of demyelinating disease or visual symptoms. Using coronal CE-FS-FLAIR, two neuroradiologists separately graded each optic nerve (n = 50 patients, 100 total nerves) as either negative, equivocal, or positive for optic neuropathy or atrophy. The scoring was later repeated.ResultsThe mean time from acute optic neuritis onset to MRI was 4.1 ± 4.6 years (range 34 days-17.4 years). Per individual nerve grading, the range of sensitivity, specificity, and accuracy of coronal CE-FS-FLAIR in detecting optic neuropathy was 71.4–77.1%, 93.8–95.4%, and 85.5–89.0%, respectively, with strong interobserver (k = 0.667 − 0.678, p < 0.0001), and intraobserver (k = 0.706 − 0.763, p < 0.0001) agreement. For optic atrophy, interobserver agreement was moderate (k = 0.437 − 0.484, p < 0.0001), while intraobserver agreement was moderate-strong (k = 0.491 − 0.596, p < 0.0001).ConclusionCoronal CE-FS-FLAIR is quite specific in detecting optic neuropathy years after the onset of acute optic neuritis, but is less useful in detecting optic nerve atrophy.
Background
Experimental data suggest γ-aminobutyric acid-A receptor preferring general anesthetics (GA) may increase post-operative pain in patients with persistent inflammation (PI). This study was designed to begin to test this prediction.
Methods
Groups of rats were defined by the presence of inflammation, surgical intervention and/or the type of GA used for a three-hour period of anesthesia. PI was induced with complete Freund's adjuvant. The surgical intervention was a plantar incision. Three mechanistically distinct GAs were used: pentobarbital, ketamine/xylazine and isoflurane. Ongoing pain and hypersensitivity was assessed with guarding behavior analysis and the von Frey test, respectively.
Results
There was no influence of GA type on the magnitude or time course of recovery from post-operative hypersensitivity in the absence of PI. In the presence of PI, however, recovery from hypersensitivity was significantly slower in the pentobarbital group than in ketamine/xylazine or isoflurane groups. The pentobarbital effect was significant within three days of surgery, and persisted through the remainder of the testing period. A comparable delay in recovery was observed in pentobarbital-anesthetized inflamed rats not subjected to hindpaw incision. The time to 50% recovery in pentobarbital treated inflamed groups was almost double that in the other groups. No differences were observed between ketamine/xylazine and isoflurane. Pentobarbital exposure did not increase guarding scores.
Conclusions
These results suggest that γ-aminobutyric acid-A receptor preferring GAs may have deleterious consequences when used in the presence of PI.
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