Cervical spine assessment in the unconscious trauma patient: a major trauma service's experience with passive flexion-extension radiography

BACKGROUND: There is no consensus on the most appropriate method of cervical spine assessment in unconscious trauma patients. Passive flexion-extension imaging is one option for further investigating unconscious patients whose plain cervical radiographs are normal. This study examines the usefulness of this passive imaging in investigating for occult cervical injury. METHODS: All unconscious patients admitted to The Alfred Trauma Intensive Care Unit over 1 year (January 1-December 31, 1998), who could not be clinically assessed within 48 hours in regard to their cervical spine, were identified. Results of passive flexion-extension radiography were compared with final injury status and clinical outcome as determined by retrospective review of the imaging reports, radiographic films, and case notes. RESULTS: One hundred twenty-three patients with normal three-view plain radiographs proceeded to passive functional investigation. These were false-negative in four of the seven patients with cervical spine injuries at presentation. No patients suffered any adverse neurologic events from their delayed diagnoses or from the flexion-extension procedure. CONCLUSION: Passive flexion-extension imaging has inadequate sensitivity for detecting occult cervical spine injuries. Although no patients suffered adverse neurologic complications, the potential for devastating consequences from missed cervical injury has resulted in the removal of passive flexion-extension imaging from the screening protocol.     

Rosiglitazone for prevention or adjuvant treatment of Nelson's syndrome after bilateral adrenalectomy

OBJECTIVE: To investigate the effect of Rosiglitazone in three patients treated with bilateral adrenalectomy followed by hyperpigmentation and hypersecretion of ACTH. PATIENTS AND METHODS: One patient had increasing ACTH after previous transsphenoidal surgery for Nelson's syndrome, and two patients without pituitary adenomas had recurrence of Cushing's disease after primary and repeated transsphenoidal surgery with need for bilateral adrenalectomy. The patients developed hyperpigmentation and increasing ACTH at nadir 2-4 h after morning hydrocortisone dose. ACTH during Rosiglitazone therapy (4 mg/day for 4 weeks and then 8 mg/day) was measured at regular intervals 24 h after the latest dose of hydrocortisone. RESULTS: In two patients there was a decrease in ACTH by 40% after 5 months. The first of these patients showed an escape with increasing ACTH to the initial value after 11 months. In the third patient no effect was observed. Tumour development or progression on magnetic resonance imaging was not observed. CONCLUSION: Rosiglitazone might represent an adjuvant therapy in patients with ACTH hypersecretion. Larger long-term studies are needed.     

Os odontoideum: report of three cases.

Os odontoideum is a condition in which a smoothly corticated ossicle exists dorsal to the anterior arch of C1, taking the place of the rostral dens, but with no bony connection to the body of the axis. Three patients presented with this condition: the first with Lhermitte's phenomenon 10 years after significant trauma, the second as an incidental finding during routine cervical spine imaging following a road traffic accident, and the third with recurrent transient quadriparesis precipitated by falls from a surfboard. Patients had at least 10 mm of sagittal instability on dynamic imaging and the second patient had a minimum sagittal canal diameter of only 11.5 mm. Posterior atlanto-axial fixation was successfully achieved in all cases using polyaxial screws and rods with the assistance of computed tomography-based image guidance. Image guidance provided an invaluable aid to preoperative planning and intraoperative placement of the posterior spinal instrumentation.     

57miRNA regulation during oncogene-induced senescence

Aberrant oncogene activation induces cellular senescence, an irreversible growth arrest which acts as a barrier against tumor formation. To identify miRNAs involved in oncogene-induced senescence we arrayed miRNA expression in primary human fibroblasts (Tig3) following over-expression of B-RAF. 18 miRNA were significantly regulated (P<0.001) 4 days after B-RAF activation; in particular, miR-34a expression increased ∼8-fold. In addition, miR-34a is up-regulated in mouse fibroblasts undergoing replicative senescence. In agreement with previous reports, we find that miR-34a reduces cellular proliferation and induces cell cycle arrest. Using microarrays, we have identified a number of putative miR-34a targets involved in oncogene-induced senescence and we are now evaluating their ability to mediate the cellular effects of miR-34a. Although members of the miR-34 family are known p53 target genes, our data indicate that miR-34a is regulated independently of p53 during oncogene-induced senescence. Hence, miR-34a responds to several independent cancer-related pathways thereby underlining the importance of miR-34a as an important tumor suppressor. We are currently investigating the regulation of miR-34a in normal and senescent cells using ChIP and promoter reporter assays.     

Automatic thalamus and hippocampus segmentation from MP2RAGE: comparison of publicly available methods and implications for DTI quantification

Purpose

In both structural and functional MRI, there is a need for accurate and reliable automatic segmentation of brain regions. Inconsistent segmentation reduces sensitivity and may bias results in clinical studies. The current study compares the performance of publicly available segmentation tools and their impact on diffusion quantification, emphasizing the importance of using recently developed segmentation algorithms and imaging techniques.

Methods

Four publicly available, automatic segmentation methods (volBrain, FSL, FreeSurfer and SPM) are compared to manual segmentation of the thalamus and hippocampus imaged with a recently proposed T1-weighted MRI sequence (MP2RAGE). We evaluate morphometric accuracy on 22 healthy subjects and impact on diffusivity measurements obtained from aligned diffusion-weighted images on a subset of 10 subjects.

Results

Compared to manual segmentation, the highest Dice similarity index of the thalamus is obtained with volBrain using a local library (\(M=0.913\), \(\hbox {SD}=0.014\)) followed by volBrain using an external library (\(M=0.868\), \(\hbox {SD}=0.024\)), FSL (\({M}=0.806\), \(\mathrm{SD}=0.034\)), FreeSurfer (\({M}=0.798\), \(\mathrm{SD}=0.049\)) and SPM (\({M}=0.787\), \(\mathrm{SD}=0.031\)). The same order is found for hippocampus with volBrain local (\({M}=0.892\), \(\mathrm{SD}=0.016\)), volBrain external (\({M}=0.859\), \(\mathrm{SD}=0.014\)), FSL (\({M}=0.808\), \(\mathrm{SD}=0.017\)), FreeSurfer (\({M}=0.771\), \(\mathrm{SD}=0.023\)) and SPM (\({M}=0.735\), \(\mathrm{SD}=0.038\)). For diffusivity measurements, volBrain provides values closest to those obtained from manual segmentations. volBrain is the only method where FA values do not differ significantly from manual segmentation of the thalamus.

Conclusions

Overall we find that volBrain is superior in thalamus and hippocampus segmentation compared to FSL, FreeSurfer and SPM. Furthermore, the choice of segmentation technique and training library affects quantitative results from diffusivity measures in thalamus and hippocampus.

     

Factors related to monitoring during admission of acute patients

Understanding the use of patient monitoring systems in emergency and acute facilities may help to identify reasons for failure to identify risk patients in these settings. Hence, we investigate factors related to the utilization of automated monitoring for patients admitted to an acute admission unit by introducing monitor load as the proportion between monitored time and length of stay. A cohort study of patients admitted and registered to patient monitors in the period from 10/10/2013 to 1/10/2014 at the acute admission unit of Odense University Hospital in Denmark. Admissions with at least one measurement were analyzed using quantile regression by looking at the impact of distance from nursing office, number of concurrent patients, wing type (medical/surgical), age, sex, comorbidities, and severity conditioned on how much patients were monitored during their admissions. We registered 11,848 admissions, of which we were able to link patient monitor readings to 3149 (26.6 %) with 50 % being monitored <1.4 % of total admission time. Distance from nursing office had little influence on patients monitored <10 % of their admission time. But for other patients, being positioned further away from the office reduced the level of monitoring. Higher levels of severity were related to higher degrees of monitoring, but being admitted to the surgical wing reduce how much patients were monitored, and periods with many concurrent patients lead to a small increase in monitoring. We found a significant variation concerning how much patients were monitored during admission to an acute admission unit. Our results point to potential patient safety improvements in clinical procedures, and advocate an awareness of how patient monitoring systems are utilized.