Effect of Childhood Disease on Hospital Presentation: A Survey of Pediatricians.

BACKGROUND: Determining when caregivers should take their children to a hospital is crucial in ensuring the health and safety of children. Because children cannot make these decisions on their own, caregivers bear the core responsibility for the wellness of their children. The aim of this study was to determine how disease, disability, and child behavior affect when and how often caregivers take their children to a hospital. METHODS: A structured anonymous online survey was circulated to pediatricians in Japan. Pediatricians were queried about the characteristics of their patients, including reactivity to pain, expression of pain, behavior at the hospital, and the timing of presentation. Patients were school-aged children and included those with autism spectrum disorder, attention-deficit hyperactivity disorder, Down syndrome, mental retardation, epilepsy, premature birth, and allergies. RESULTS: Sixty-eight of 80 pediatricians responded to the survey (85% response rate). The results indicated that caregivers of children with autism spectrum disorder, attention-deficit hyperactivity disorder, and mental retardation took them to the hospital later than was optimal. Conversely, children born prematurely and those with allergies were taken to hospitals even when symptoms were mild. CONCLUSIONS: Caregivers make decisions on when to present to hospital on the basis of their child's expression of pain and behavior. Guidelines should be developed to assist caregivers in determining when to present for treatment at a hospital.

Head-down posture induces PERG alterations in early glaucoma.

PURPOSE: To probe susceptibility of retinal ganglion cells (RGC) to physiological stressors associated with moderate head-down body tilt in patients with suspicion of glaucoma or early manifest glaucoma (EMG). METHODS: One hundred nine subjects with best corrected visual acuity (BCVA) ≥ 20/20 and no disease other than glaucoma [glaucoma suspects (GS)=79, EMG=14, normal controls (NC)=16 and comparable age range were tested. Noncontact intraocular pressure (IOP), pattern electroretinogram (PERG), and brachial blood pressure/heart rate measurements were performed in 3 consecutive conditions (∼0038 min apart): seated (baseline), -10-degree whole body head-down tilt (HDT), and seated again (recovery). PERG amplitude and latency, IOP, and systolic/diastolic blood pressures, heart rate, calculated mean central retinal artery pressure, ocular perfusion pressure, and systolic/diastolic perfusion pressures were evaluated. RESULTS: During HDT, IOP significantly (P<0.001) increased in all groups approximately to the same extent (approximately 20%). PERG amplitude did not change in NC but decreased significantly (P<0.001) in patients (GS, -25%, EMG -23%). PERG phase become delayed in NC (-1.6%, P=0.04) but more so in patients (GS, -2.7%, P<0.001; EMG, -6.0%, P<0.001). The proportion of patients with PERG alterations significantly (P<0.05) exceeding those occurring in age-adjusted and baseline-adjusted NC were, GS: amplitude 20%, phase 15%; EMG: amplitude 14%, phase 50%. All measures recovered baseline values after HDT. CONCLUSIONS: Moderate HDT induces temporary worsening of RGC function in a subpopulation of GS and EMG patients. This noninvasive protocol may help disclose abnormal susceptibility of RGCs in a subset of the patients at risk of glaucoma.

Are ultrasound-guided ophthalmic blocks injurious to the eye? A comparative rabbit model study of two ultrasound devices evaluating intraorbital thermal and structural changes.

BACKGROUND: Since Atkinson's original description of retrobulbar block in 1936, needle-based anesthetic techniques have become integral to ophthalmic anesthesia. These techniques are unfortunately associated with rare, grave complications such as globe perforation. Ultrasound has gained widespread acceptance for peripheral nerve blockade, but its translation to ocular anesthesia has been hampered because sonic energy, in the guise of thermal or biomechanical insult, is potentially injurious to vulnerable eye tissue. The US Food and Drug Administration (FDA) has defined guidelines for safe use of ultrasound for ophthalmic examination, but most ultrasound devices used by anesthesiologists are not FDA-approved for ocular application because they generate excessive energy. Regulating agencies state that ultrasound examinations can be safely undertaken as long as tissue temperatures do not increase >1.5°C above physiological levels. METHODS: Using a rabbit model, we investigated the thermal and mechanical ocular effects after prolonged ultrasonic exposure to single orbital- and nonorbital-rated devices. In a dual-phase study, aimed at detecting ocular injury, the eyes of 8 rabbits were exposed to continuous 10-minute ultrasound examinations from 2 devices: (1) the Sonosite Micromaxx (nonorbital rated) and (2) the Sonomed VuMax (orbital rated) machines. In phase I, temperatures were continuously monitored via thermocouples implanted within specific eye structures (n = 4). In phase II the eyes were subjected to ultrasonic exposure without surgical intervention (n = 4). All eyes underwent light microscopy examinations, followed at different intervals by histology evaluations conducted by an ophthalmic pathologist. RESULTS: Temperature changes were monitored in the eyes of 4 rabbits. The nonorbital-rated transducer produced increases in ocular tissue temperature that surpassed the safe limit (increases >1.5°C) in the lens of 3 rabbits (at 5.0, 5.5, and 1.5 minutes) and cornea of 2 rabbits (both at 1.5 minutes). A secondary analysis of temporal temperature differences between the orbital-rated and nonorbital transducers revealed statistically significant differences (Bonferroni-adjusted P < 0.05) in the cornea at 3.5 minutes, the lens at 2.5 minutes, and the vitreous at 4.0 minutes. Light microscopy and histology failed to elicit ocular injury in either group. CONCLUSIONS: The nonorbital-rated ultrasound machine (Sonosite Micromaxx) increases the ocular tissue temperature. A larger study is needed to establish safety. Until then, ophthalmic ultrasound-guided blocks should only be performed with ocular-rated devices.

Perception of object motion in three-dimensional space induced by cast shadows.

Cast shadows can be salient depth cues in three-dimensional (3D) vision. Using a motion illusion in which a ball is perceived to roll in depth on the bottom or to flow in the front plane depending on the slope of the trajectory of its cast shadow, we investigated cortical mechanisms underlying 3D vision based on cast shadows using fMRI techniques. When modified versions of the original illusion, in which the slope of the shadow trajectory (shadow slope) was changed in 5 steps from the same one as the ball trajectory to the horizontal, were presented to participants, their perceived ball trajectory shifted gradually from rolling on the bottom to floating in the front plane as the change of the shadow slope. This observation suggests that the perception of the ball trajectory in this illusion is strongly affected by the motion of the cast shadow. In the fMRI study, cortical activity during observation of the movies of the illusion was investigated. We found that the bilateral posterior-occipital sulcus (POS) and right ventral precuneus showed activation related to the perception of the ball trajectory induced by the cast shadows in the illusion. Of these areas, it was suggested that the right POS may be involved in the inferring of the ball trajectory by the given spatial relation between the ball and the shadow. Our present results suggest that the posterior portion of the medial parietal cortex may be involved in 3D vision by cast shadows.

Disclosing concealed information on the basis of cortical activations.

Concealed information, which is information only known to oneself is sometimes crucial for criminal investigation. In this study, we examined cortical activations related to incidental responses to concealed information. We found that cortical responses to stimuli related to concealed information were different from those to other stimuli; the bilateral ventrolateral prefrontal (VLPF) areas, left inferior frontal gyrus, right middle frontal gyrus and right inferior parietal lobule were activated, and among those activated areas, the right VLPF was found to be crucial. Furthermore, we examined by discriminant analysis which cortical areas contribute to the determination of whether the subjects had concealed information. On the basis of the activity in the right VLPF, we were able to correctly identify 32 of the 38 subjects (84.21%) as who had concealed information. These results suggest that the right VLPF may play a crucial role in the incidental processing of concealed information, and we were able to determine whether a subject had concealed information without the need for deceptive responses.

Estimation of intraocular pressure in rabbits with commonly used tonometers.

BACKGROUND AND OBJECTIVES: To validate accuracy and reproducibility of the Perkins tonometer, pneumatonometer, and Tono-Pen XL (Medtronic Solan, Jacksonville, FL) in estimating intraocular pressure (IOP) in rabbits. MATERIALS AND METHODS: IOP was increased from 5 to 50 mm Hg in 5-mm increments. Measurements were compared to readings of two digital manometers simultaneously measuring real IOP in the anterior chamber and vitreous cavity. Interobserver accuracy was evaluated using 4 eyes with the Perkins tonometer. RESULTS: The Perkins tonometer and Tono-Pen XL underestimated IOP and were more accurate at pressures less than 30 mm Hg. No statistically significant difference was found between real IOP and Tono-Pen XL readings. The pneumatonometer overestimated pressures in the low ranges but was accurate at pressures greater than 40 mm Hg. The Tono-Pen XL had more variability than the Perkins tonometer and pneumatonometer at high IOP. CONCLUSIONS: None of the tonometers are accurate or reproducible in estimating IOP in rabbits over the tested range. Pneumatonometry, although not very accurate, has the advantage of having acceptable variability.

Validation of the Barraquer tonometer for high intraocular pressure estimation.

PURPOSE: To compare the pneumatonometer and the Tono-Pen XL in a closed ex-vivo system in human eye bank eyes at high intraocular pressures (IOP) and evaluate the validity of high IOP measurements with the Barraquer tonometer. METHODS: Intraocular pressure was monitored by cannulation of the anterior chamber and vitreous cavity in eight human cadaver eyes (mean donor age: 77.3 +/- 4.9 years, range: 72 to 84 years). Intraocular pressure measurements were taken at 50, 65, and 90 mmHg with the Tono-Pen XL and pneumatonometer. Intraocular pressure was raised to 110 mmHg and then the eyes were deflated slowly until they reached 50 mmHg. Pressure readings with the Barraquer tonometer were recorded when the corneal tonometer interface reached the inner and outer rings. RESULTS: The Tono-Pen XL underestimated IOP, a tendency that was more evident at higher IOP In contrast, the pneumatonometer was more accurate and reliable at IOP of 50 and 65 mmHg but its readings underestimated IOP at 90 mmHg. The Barraquer tonometer used in this experiment accurately estimated high IOP A variability of 5.9 mmHg and 5.8 mmHg were recorded for the inner and outer ring, respectively. CONCLUSIONS: The Tono-pen XL is an inadequate instrument to assess pressures normally encountered during LASIK flap creation in an ex vivo model using human cadaver eyes. The pneumatonometer and the Barraquer tonometer are accurate instruments at high IOP; however, the pneumatonometer underestimated pressures around 90 mmHg.

The neural mechanism associated with the processing of onomatopoeic sounds.

This event-related fMRI study was conducted to examine the blood-oxygen-level-dependent responses to the processing of auditory onomatopoeic sounds. We used a sound categorization task in which the participants heard four types of stimuli: onomatopoeic sounds, nouns (verbal), animal (nonverbal) sounds, and pure tone/noise (control). By discriminating between the categories of target sounds (birds/nonbirds), the nouns resulted in activations in the left anterior superior temporal gyrus (STG), whereas the animal sounds resulted in activations in the bilateral superior temporal sulcus (STS) and the left inferior frontal gyrus (IFG). In contrast, the onomatopoeias activated extensive brain regions, including the left anterior STG, the region from the bilateral STS to the middle temporal gyrus, and the bilateral IFG. The onomatopoeic sounds showed greater activation in the right middle STS than did the nouns and environmental sounds. These results indicate that onomatopoeic sounds are processed by extensive brain regions involved in the processing of both verbal and nonverbal sounds. Thus, we can posit that onomatopoeic sounds can serve as a bridge between nouns and animal sounds. This is the first evidence to demonstrate the way in which onomatopoeic sounds are processed in the human brain.

Information processing of geometrical features of a surface based on binocular disparity cues: an fMRI study.

Cortical areas related to the information processing of binocular disparity-defined geometrical features of a surface, such as depth, orientation and shape are examined by functional magnetic resonance imaging while subjects discriminated these three types of geometrical feature in random dot stereograms. Results indicate that disparity-defined information of depth and that of orientation are processed in the parietal area. Furthermore, the visual system for 3D vision in the parietal area may be organized in a hierarchical manner and the posterior part of the right intraparietal sulcus may be involved in cognitive process of 3D vision. On the other hand, disparity-defined shape information seems to be processed in the occipital visual areas and the crucial involvement of human LOS for this process is suggested.

Reading in a regular orthography: an FMRI study investigating the role of visual familiarity.

In order to separate the cognitive processes associated with phonological encoding and the use of a visual word form lexicon in reading, it is desirable to compare the processing of words presented in a visually familiar form with words in a visually unfamiliar form. Japanese Kana orthography offers this possibility. Two phonologically equivalent but visually dissimilar syllabaries allow the writing of, for example, foreign loanwords in two ways, only one of which is visually familiar. Familiarly written words, unfamiliarly written words, and pseudowords were presented in both Kana syllabaries (yielding six conditions in total) to participants during an fMRI measurement with a silent articulation task (Experiment 1) and a phonological lexical decision task (Experiment 2) using an event-related design. Consistent over two experimental tasks, the three different stimulus types (familiar, unfamiliar, and pseudoword) were found to activate selectively different brain regions previously associated with phonological encoding and word retrieval or meaning. Compatible with the predictions of the dual-route model for reading, pseudowords and visually unfamiliar words, which have to be read using phonological assembly, caused an increase in brain activity in left inferior frontal regions (BA 44/47), as compared to visually familiar words. Visually familiar and unfamiliar words were found to activate a range of areas associated with lexico-semantic processing more strongly than pseudowords, such as the left and right temporo-parietal region (BA 39/40), a region in the left middle/inferior temporal gyrus (BA 20/21), and the posterior cingulate (BA 31).

Laser interstitial thermotherapy (LITT) monitoring using high-resolution digital mammography: theory and experimental studies.

Laser interstitial thermotherapy (LITT) is a minimally-invasive laser hyperthermia procedure for the treatment of localized tumours. Real-time monitoring of LITT is essential to control the extent of tumour destruction and ensure safe and effective treatments. The feasibility of using high-resolution digital x-ray mammography to monitor LITT of breast cancer was evaluated. Tissue phantoms including polyacrylamide hydrogel and cadaver porcine tissue were heated using a 980 nm diode laser delivered through optical fibres with diffusing tips. Digital images of the tissue phantoms were recorded with a high-resolution digital stereotactic breast biopsy system during heating. The recorded images were processed and analysed to detect heat-induced changes. No changes were detected during heating of the hydrogel. Pixel-by-pixel subtraction of the initial image from images taken during laser heating shows observable thermally-induced changes around the fibre during laser irradiation that correlate with the thermal denaturation zone observed by gross anatomy. These experiments demonstrate that high-resolution digital x-ray mammography can be used to detect heat-induced tissue changes during experimental LITT in fibro-fatty tissue.