Dosimetric Analysis of Neural and Vascular Structures in Skull Base Tumors Treated with Stereotactic Radiosurgery.

Objective To examine the relationship between the prescribed target dose and the dose to healthy neurovascular structures in patients with vestibular schwannomas treated with stereotactic radiosurgery (SRS). Study Design Case series with chart review. Setting SRS center from 2011 to 2013. Subjects Twenty patients with vestibular schwannomas treated at the center from 2011 to 2013. Methods Twenty patients with vestibular schwannomas were included. The average radiation dose delivered to healthy neurovascular structures (eg, carotid artery, basilar artery, facial nerve, trigeminal nerve, and cochlea) was analyzed. Results Twenty patients with vestibular schwannomas who were treated with fused computed tomography/magnetic resonance imaging-guided SRS were included in the study. The prescribed dose ranged from 10.58 to 17.40 Gy over 1 to 3 hypofractions to cover 95% of the target tumor volume. The mean dose to the carotid artery was 5.66 Gy (95% confidence interval [CI], 4.53-6.80 Gy), anterior inferior cerebellar artery was 8.70 Gy (95% CI, 4.54-12.86 Gy), intratemporal facial nerve was 3.76 Gy (95% CI, 3.04-4.08 Gy), trigeminal nerve was 5.21 Gy (95% CI, 3.31-7.11 Gy), and the cochlea was 8.70 Gy (95% CI, 7.81-9.59 Gy). Conclusions SRS for certain vestibular schwannomas can expose the anterior inferior cerebellar artery (AICA) and carotid artery to radiation doses that can potentially initiate atherosclerotic processes. The higher doses to the AICA and carotid artery correlated with increasing tumor volume. The dose delivered to other structures such as the cochlea and intratemporal facial nerve appears to be lower and much less likely to cause immediate complications when shielded

False-Positive Cholesteatomas on Non-Echoplanar Diffusion-Weighted Magnetic Resonance Imaging.

ObjectivesTo investigate false-positive findings on non-echoplanar (non-EPI) diffusion-weighted magnetic resonance imaging (DWI) in patients under surveillance post-cholesteatoma surgery.Study design, setting, subjects, and methodsA retrospective review was performed on patients diagnosed with cholesteatoma who underwent surgical resection and were then followed by serial non-EPI DWI using half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence. All patients had at least two annual follow-up imaging studies.ResultsFalse-positive findings were identified in four patients. The size of the suspected lesions was 4 to 12 mm. Otoendoscopy was used during all primary cases and Argon laser was used in one case. In all cases, the entire cholesteatoma was removed, and no residual disease was detected at the end of the procedures. One patient underwent revision surgery but only cartilage graft was found in the area of concern. All patients had stable or resolved hyperintense areas in the subsequent HASTE sequences.ConclusionFalse positive findings can occur with non-EPI DWI MRI and patients need to be counseled accordingly before revision surgery. Decreasing intensity and dimension of a suspected lesion and a positive finding in an area other than the location of the initial cholesteatoma may favor a false positive. If a false positive finding is suspected when the surgeon is confident of complete resection of the cholesteatoma, an MRI can be repeated in 6 to 12 months to assess changes in the dimension and intensity of the area of concern. Cartilage grafts may cause restricted diffusion on DWI sequences

Efficacy of Multi-Modal Migraine Prophylaxis Therapy on Hyperacusis Patients.

ObjectivesTo evaluate the efficacy of a multi-modal migraine prophylaxis therapy for patients with hyperacusis.MethodsIn a prospective cohort, patients with hyperacusis were treated with a multi-modal step-wise migraine prophylactic regimen (nortriptyline, verapamil, topiramate, or a combination thereof) as well as lifestyle and dietary modifications. Pre- and post-treatment average loudness discomfort level (LDL), hyperacusis discomfort level measured by a visual analogue scale (VAS), and scores on the modified Khalfa questionnaire for severity of hyperacusis were compared.ResultsTwenty-two of the 25 patients (88%) reported subjective resolution of their symptoms following treatment. Post-treatment audiograms showed significant improvement in average LDL from 81.3 ± 3.2 dB to 86.4 ± 2.6 dB (P < .001), indicating increased sound tolerability. The VAS discomfort level also showed significant improvement from a pre-treatment average of 7.7 ± 1.1 to 3.7 ± 1.6 post-treatment (P < .001). There was also significant improvement in the average total score on modified Khalfa questionnaire (32.2 ± 3.6 vs 22.0 ± 5.7, P < .001).ConclusionsThe majority of patients with hyperacusis demonstrated symptomatic improvement from migraine prophylaxis therapy, as indicated by self-reported and audiometric measures. Our findings indicate that, for some patients, hyperacusis may share a pathophysiologic basis with migraine disorder and may be successfully managed with multimodal migraine prophylaxis therapy

Dilemma of Retained Intraorbital Fragment of Pencil

Juvenile injuries by intraorbital foreign body in extremities are common and usually trivial (1) but they may lead to debilitating sequels in the head and neck. Because of their availability in comparison to other sources of trauma, accidental injuries may occur while children play with their friends. Injuries by pencils are special types of intraorbital foreign body, the final outcome of which is dependent to concurrent injuries of the ocular and also neurologic structure and comorbiditie. Orbital injury requires comprehensive evaluation, especially in child victims when there is not sufficient information regarding trauma mechanism and the intraorbital foreign body should be ruled out before any closure of wounds, as shown in the sample case presented here. In school age children with a history of falling, intraorbital fragments of pencils should be kept in mind. Preoperative information about the true number and exact location of retained fragments is paramount for an appropriate management. When there is high suspicion for retained foreign body, further detailed studies with CT and if needed MR scans and in selected cases plain X- ray are very helpful

Loudness and acoustic parameters of popular children's toys

ObjectiveThis project was conducted to evaluate the loudness and acoustic parameters of toys designed for children. In addition, we investigated whether occluding the toys' speaker with tape would result in a significant loudness reduction; thereby potentially reducing the risk of noise induced hearing loss.MethodsTwenty-six toys were selected after an initial screening at two national retailers. Noise amplitudes at 0.25, 0.5, 1, 2, 4, and 8kHz were measured using a digital sound level meter at a distance of 0 and 30cm. The toys' speakers were then occluded using adhesive tape and the same acoustic parameters were re-measured.ResultsMean maximum noise amplitude of the toys at 0cm and 30cm was 104dBA (range, 97-125dBA) and 76dBA (range, 67-86dBA), respectively. Mean maximum noise amplitude after occlusion at 0cm and 30cm distances was 88dBA (range, 73-110dBA) and 66dBA (range, 55-82dBA), respectively, with a p-value <0.001.ConclusionsProper use of the loudest toys at a distant of 30cm between the speaker and the child's ear will likely not pose a risk of noise-induced hearing loss. However, since most toys are used at closer distances, use of adhesive tape is recommended as an effective modification to decrease the risk of hearing loss

Ascitic Fluid to Serum Bilirubin Ratio for Differentiation of Exudates From Transudates

Background:Regarding the diagnostic errors of the classic criteria including serum ascites albumin gradient (SAAG),total protein concentration and the adapted Light et al’s criteria in distinguishing transudate versus exudates, we evaluated the ascitic fluid to serum bilirubin ratio as a new criteria in this regard. We also evaluated whether the combination of bilirubin ratio with each of these classic criteria improves the diagnostic accuracy.   Methods: One-hundred ascitic fluid specimens were analysed prospectively whereas the   category of fluid was assessed according to the clinical diagnosis. Sensitivity, specificity,   positive predictive value (PPV), negative predictive value (NPV), overall accuracy, positive likelihood ratio (LR+), negative likelihood ratio (LR-) and the Youden’s index of each criterion alone and in combination with the bilirubin ratio were calculated.Results: SAAG seems to be the best criterion (specificity = 0.9090, PPV = 0.97, LR+ = 8.03, Youden’s index = 0.64). Bilirubin and LDH ratio criteria had equivalent specificity (0.8333 and 0.8205, respectively), accuracy (0.80 and 0.81, respectively), PPV (0.54 and 0.55, respectively),NPV (0.90 and 0.93, respectively) and LR+ (4.09 and 4.30, respectively)which generally were better than fluid total protein and total protein ratio but not as predictive   as SAAG. The addition of bilirubin ratio to any criterion did not make any improvement.Conclusion: Ascitic fluid to serum bilirubin ratio, although not more predictive than   SAAG, can be used as an alternative criterion in distinguishing exudative versus transudative ascitic fluid as it is more cost-effective in terms of laboratory processing and also more available.