Preoperative ultrasound accurately characterizes surgically confirmed extracranial spinal accessory nerve injuries.

OBJECTIVE: To determine the accuracy of preoperative ultrasound and MRI in surgically confirmed spinal accessory nerve injuries and present the benefits of a multimodality image review. MATERIALS AND METHODS: A retrospective review of 38 consecutive patients referred to a peripheral nerve surgical practice at an academic teaching hospital with surgically confirmed spinal accessory nerve injuries. All cases were reviewed for patient demographics, date and cause of injury, preoperative EMG, and surgical diagnosis and management. Additionally, prospective interpretation of preoperative ultrasound and MRI reports were reviewed for concordance or discordance with the surgical diagnosis. RESULTS: Iatrogenic injury was present in 37 (97%) cases and most commonly a result of an excisional lymph node biopsy (68%). Surgically confirmed spinal accessory nerve injury diagnoses consisted of 25 (66%) stump neuromas and 13 (34%) incomplete nerve injuries. Nine months was the average time from injury to surgery. Twenty-nine patients underwent preoperative ultrasound and/or MRI evaluation: 12 ultrasound only, 10 MRI only, and seven with both ultrasound and MRI. Eighteen (95%) preoperative ultrasound reports compared to four (24%) preoperative MRI reports were concordant with the surgical diagnosis. In the seven cases with both preoperative ultrasound and MRI, six had discordant ultrasound and MRI imaging diagnoses for which the ultrasound was concordant with the surgical diagnoses in all cases. CONCLUSION: Preoperative ultrasound more accurately characterizes spinal accessory nerve injuries compared to MRI and should serve as the modality of choice when a spinal accessory nerve injury is suspected.

Fat quantification of the rotator cuff musculature using dual-energy CT-A pilot study.

PURPOSE: To assess the ability of dual-energy CT (DECT) as a novel technique to quantify the degree of rotator cuff fat degeneration. METHOD: Clinically indicated shoulder CT exams for evaluation of osteoarthritis, rotator cuff arthropathy, pain or instability, or preoperative planning were acquired using dual-source CT systems. Rotator cuff DECT fat fraction after material decomposition was calculated off the sagittal image. Fat fractions were also assessed using CT numbers from dual energy virtual monochromatic images (70 keV) and single-energy CT (SECT) images (100 kV). Visual subjective Goutallier scores of the rotator cuff muscles were used as the reference standard. RESULTS: 12 shoulders from 10 patients were analyzed, with bilateral shoulders evaluated in two patients (mean age 69 years (range 19-97)). Three patients were male and seven were female, with mean BMI of 32 (range 26-41). Mean fat fraction of the teres major and subcutaneous fat were, 2.9 % ± 4.0 % and 99.5 % ± 2.6 %, respectively, rendering these as reliable internal standards for 0% and 100 % fat. Mean DECT fat fractions of the rotator cuff were compared to Goutallier scores, revealing a high strength of rank correlation: ρ = 0.92, p < 0.0001. Mean fat fraction assessed with CT numbers also revealed high strengths of linear associations: ρ = 0.83, p < 0.0001 and ρ = 0.82, p < 0.0001, for DECT 70 keV and SECT 100 kV, respectively. CONCLUSIONS: DECT direct fat fraction after material decomposition presents a novel approach to quantitative assessment of fatty degeneration, which has excellent correlation with clinically accepted standards.

Intranasal deferoxamine can improve memory in healthy C57 mice, suggesting a partially non-disease-specific pathway of functional neurologic improvement.

INTRODUCTION: Intranasal deferoxamine (IN DFO) has been shown to decrease memory loss and have beneficial impacts across several models of neurologic disease and injury, including rodent models of Alzheimer's and Parkinson's disease. METHODS: In order to assess the mechanism of DFO, determine its ability to improve memory from baseline in the absence of a diseased state, and assess targeting ability of intranasal delivery, we treated healthy mice with IN DFO (2.4 mg) or intraperitoneal (IP) DFO and compared behavioral and biochemical changes with saline-treated controls. Mice were treated 5 days/week for 4 weeks and subjected to behavioral tests 30 min after dosing. RESULTS: We found that IN DFO, but not IP DFO, significantly enhanced working memory in the radial arm water maze, suggesting that IN administration is more efficacious as a targeted delivery route to the brain. Moreover, the ability of DFO to improve memory from baseline in healthy mice suggests a non-disease-specific mechanism of memory improvement. IN DFO treatment was accompanied by decreased GSK-3ß activity and increased HIF-1α activity. CONCLUSIONS: These pathways are suspected in DFO's ability to improve memory and perhaps represent a component of the common mechanism through which DFO enacts beneficial change in models of neurologic disease and injury.

Food consumption and activity levels increase in rats following intranasal Hypocretin-1.

Hypocretin-1 (HC, orexin-A) is a neuropeptide involved in regulating physiological functions of sleep, appetite and arousal, and it has been shown that intranasal (IN) administration can target HC to the brain. Recent clinical studies have shown that IN HC has functional effects in human clinical trials. In this study, we use rats to determine whether IN HC has an immediate effect on food consumption and locomotor activity, whether distribution in the brain after IN delivery is dose-dependent, and whether MAPK and PDK1 are affected after IN delivery. Food intake and wheel-running activity were quantified for 24h after IN delivery. Biodistribution was determined 30min after IN delivery of both a high and low dose of 125I-radiolabelled HC throughout the brain and other bodily tissues, while Western blots were used to quantify changes in cell signaling pathways (MAPK and PDK1) in the brain. Intranasal HC significantly increased food intake and wheel activity within 4h after delivery, but balanced out over the course of 24h. The distribution studies showed dose-dependent delivery in the CNS and peripheral tissues, while PDK1 was significantly increased in the brain 30min after IN delivery of HC. This study adds to the growing body of evidence that IN administration of HC is a promising strategy for treatment of HC related behaviors.