The time window of MRI of murine atherosclerotic plaques after administration of CB2 receptor targeted micelles: inter-scan variability and relation between plaque signal intensity increase and gadolinium content of inversion recovery prepared versus non-prepared fast spin echo.

Single fast spin echo scans covering limited time frames are mostly used for contrast-enhanced MRI of atherosclerotic plaque biomarkers. Knowledge on inter-scan variability of the normalized enhancement ratio of plaque (NER(plaque)) and relation between NER(plaque) and gadolinium content for inversion-recovery fast spin echo is limited. Study aims were: evaluation of (1) timing of MRI after intravenous injection of cannabinoid-2 receptor (CB2-R) (expressed by human and mouse plaque macrophages) targeted micelles; (2) inter-scan variability of inversion-recovery fast spin echo and fast spin echo; (3) relation between NER(plaque) and gadolinium content for inversion-recovery fast spin echo and fast spin echo. Inversion-recovery fast spin echo/fast spin echo imaging was performed before and every 15 min up to 48 h after injection of CB2-R targeted or control micelles using several groups of mice measured in an interleaved fashion. NER(plaque) (determined on inversion-recovery fast spin echo images) remained high (∼2) until 48 h after injection of CB2-R targeted micelles, whereas NER(plaque) decreased after 36 h in the control group. The inter-scan variability and relation between NER(plaque) and gadolinium (assessed with inductively coupled plasma- mass spectrometry) were compared between inversion-recovery fast spin echo and fast spin echo. Inter-scan variability was higher for inversion-recovery fast spin echo than for fast spin echo. Although gadolinium and NER(plaque) correlated well for both techniques, the NER of plaque was higher for inversion-recovery fast spin echo than for fast spin echo. In mice injected with CB2-R targeted micelles, NER(plaque) can be best evaluated at 36-48 h post-injection. Because NER(plaque) was higher for inversion-recovery fast spin echo than for fast spin echo, but with high inter-scan variability, repeated inversion-recovery fast spin echo imaging and averaging of the obtained NER(plaque) values is recommended.

Face validity and reliability of the first digital assessment scheme of pelvic floor muscle function conform the new standardized terminology of the International Continence Society.

AIMS: To test the face validity and reliability of a new digital pelvic floor muscle function (PFMF) assessment scheme that was designed on the basis of the recently standardized terminology of the International Continence Society. METHODS: Study participants comprised 41 women, age 18-85 years. Data on age and parity were obtained. Face validity of the new assessment scheme was tested by three senior and one junior pelvic physiotherapists, using the Delphi technique. PFMF of each woman was assessed four times by three specially trained pelvic physiotherapists. Examiners were blinded to parity and other findings. To test reliability, Kappa (K) was used for the dichotomous variables and Weighted Kappa (K(w)) for the items with more than two categories. RESULTS: Mean age of the women was 41 years (SD 10.5); 14 were nulliparous (34.1%), 6 primiparous (14.6%), and 21 multiparous (51.2%). The new assessment scheme showed satisfactory face validity and intra-observer reliability but low inter-observer reliability. CONCLUSIONS: The new assessment scheme based on the terminology of the ICS showed satisfactory face validity and intra-observer reliability. It can therefore be considered suitable for use in clinical practice. More detailed redefinition of the described outcome measures is necessary to improve the inter-observer reliability.

MR of vasculitis-induced optic neuropathy.

PURPOSE: To describe the MR characteristics of optic neuropathy caused by vasculitis. METHODS: Nine cases of optic neuropathy with diagnosis of vasculitis (six with systemic lupus erythematosis and one each with rheumatoid arthritis, Sjögren disease, and radiation vasculitis) were reviewed retrospectively. Patients were 31 to 62 years old, and all but one were women. All patients had MR imaging through the orbits and anterior visual pathways, five with fat suppression, with and without gadopentetate dimeglumine. Five patients also had MR imaging of the entire brain. The size and enhancement of various segments of the optic nerve and anterior visual pathways were studied. RESULTS: MR imaging with contrast material showed enhancement and enlargement of segments of the optic nerves and/or chiasm in six of the nine patients (all but three with systemic lupus erythematosis). Enlargement of a segment of the anterior visual pathway never occurred without enhancement, but enhancement alone did occur in three cases. Of the five patients who had MR imaging of the whole brain, abnormalities were seen in three: periventricular hyperintensity in two and a lacunar infarct in one; none had vessel abnormalities. CONCLUSION: Because the MR enhancement seen represents disruption of the blood-brain barrier within the optic nerve, MR imaging with gadopentetate dimeglumine and fat suppression should be performed to detect increased permeability of the blood-brain barrier in acute optic neuropathy.

Rotational acceleration measurements--evaluating helmet protection.

PURPOSE: Current helmet testing standards do not address the rotational components of an impact to the head. We describe a new testing paradigm used to measure the rotational acceleration of a headform and a protective helmet following an impact to the head in the horizontal plane. This impact simulation allows for the testing of currently available head protection devices in conditions thought to be important for the generation of cerebral concussion. The degree to which a particular helmet dampens rotational acceleration, and thus protects against concussion, can be assessed. METHODS: Our testing device consists of a pneumatic piston that provides a measured impact to a standard headform. Four different helmets were tested using the described paradigm. RESULTS: Acceleration curves for each helmet and the corresponding headform are presented. CONCLUSIONS: Clear differences in rotational acceleration were demonstrated. Possible avenues of further investigation are discussed.

Interobserver agreement in the evaluation of acute retinal artery occlusion.

OBJECTIVE: To determine the agreement between two ophthalmologists in the evaluation of two important funduscopic features related to acute retinal artery occlusion: retinal cloudy swelling and visible retinal emboli. DESIGN: An interobserver variability study in which two ophthalmologists (one trained in glaucoma, the other in neuro-ophthalmology) independently viewed fundus photographs and categorized them with respect to the presence or absence of cloudy swelling and retinal emboli. Inter- and intraobserver agreement was calculated with the kappa statistic. SETTING: Retina service at a university-affiliated hospital in Kingston, Ont. PATIENTS: The fundus photographs of 102 patients were included: 60 with acute retinal artery occlusion, 30 with conditions mimicking acute retinal artery occlusion and 12 healthy patients. RESULTS: Both interobserver and intraobserver agreement as to the presence of retinal cloudy swelling were very high (kappa = 0.835 and 0.866 respectively). More variability was seen for the presence of retinal emboli, but, overall, interobserver and intraobserver agreement were still high (kappa = 0.726 and 0.629 respectively). CONCLUSIONS: Our results suggest that clinicians use similar visual clues to categorize fundi with respect to retinal cloudy swelling and visible retinal emboli.

[No increased urinary arsenic levels in children living on naturally arsenic-rich soil]. / Geen verhoogde arsenicumconcentratie in urine bij kinderen woonachtig op van nature arsenicumrijke grond.

In order to assess the health effect of environmental exposure to arsenic, the urinary arsenic concentrations were determined in 25 children aged 2-5 yr in the De Huet quarter in Doetinchem, an area with an increased amount of naturally occurring arsenic in the upper soil, and in 25 children from the other quarters of Doetinchem. With a questionnaire information was obtained regarding playing outdoors and eating fish (also a source of arsenic intake). There were no statistically significant differences in urinary arsenic concentrations between the subgroups of children.

The prevalence and factors associated with previous surgery for pelvic organ prolapse and/or urinary incontinence in a cross-sectional study in The Netherlands.

OBJECTIVE: To estimate the prevalence and identify the factors associated with previous pelvic organ prolapse (POP) and/or incontinence surgery. STUDY DESIGN: In a cross-sectional study, all women who were aged 45-85 years and registered in eight general practices were invited to participate. They completed standardised questionnaires (the urinary distress inventory (UDI) and the defaecatory distress inventory (DDI)) and answered questions on previous pelvic floor surgery. RESULTS: Out of 2979 women eligible for this study, 1380 women were included. Previous surgery had been performed in 119 women. The prevalence of surgery increased with age, with a prevalence of 20.3% in the age group 76-85 years. Pelvic floor symptoms were more prevalent in women who had undergone previous surgery, with higher UDI and DDI scores. Factors associated with previous surgery were age, higher BMI, POP symptoms during pregnancy and previous hernia surgery. CONCLUSION: In The Netherlands, approximately one in five women will undergo surgery for POP and/or incontinence during her lifetime. The women who underwent surgery were more likely to have symptoms of pelvic floor dysfunction than those who did not undergo surgery.

Audiovisual integration of speech in a bistable illusion.

Visible speech enhances the intelligibility of auditory speech when listening conditions are poor [1], and can modify the perception of otherwise perfectly audible utterances [2]. This audiovisual perception is our most natural form of communication and one of our most common multisensory phenomena. However, where and in what form the visual and auditory representations interact is still not completely understood. Although there are longstanding proposals that multisensory integration occurs relatively late in the speech-processing sequence [3], considerable neurophysiological evidence suggests that audiovisual interactions can occur in the brain stem and primary sensory cortices [4, 5]. A difficulty testing such hypotheses is that when the degree of integration is manipulated experimentally, the visual and/or auditory stimulus conditions are drastically modified [6, 7]; thus, the perceptual processing within a modality and the corresponding processing loads are affected [8]. Here, we used a bistable speech stimulus to examine the conditions under which there is a visual influence on auditory perception in speech. The results indicate that visual influences on auditory speech processing, at least for the McGurk illusion, necessitate the conscious perception of the visual speech gestures, thus supporting the hypothesis that multisensory speech integration is not completed in early processing stages.

Electrophysiological effects of intravitreal Avastin (bevacizumab) in the treatment of exudative age-related macular degeneration.

OBJECTIVE: To examine the sensitivity of the multifocal electroretinogram (mf-ERG) at measuring changes in retinal electrical activity in response to Avastin (bevacizumab) treatment for age-related macular degeneration (ARMD). METHODS: Nine subjects with exudative ARMD, not previously treated with bevacizumab in the investigated eye, underwent pretreatment testing with mf-ERG and intravenous fluorescein angiography (IVFA). A second mf-ERG test was conducted post-treatment. The P1 response amplitudes were examined for the hexagons corresponding to areas of pathology on the IVFA. Intertest variability was accounted for by examining areas without pathology. Aggregate responses were also generated for central and lesion-associated responses. RESULTS: Changes in P1 response amplitude correlated with changes in visual acuity (R(2)>0.96). An improvement in Snellen visual acuity correlated with a significant improvement in P1 response amplitude from lesion associated recordings (p<0.03). Changes in P1 response amplitudes were not observed when aggregate responses were generated. CONCLUSION: This study represents a novel method for assessing an improvement of mf-ERG responses. This is the first study to demonstrate a statistically significant change in retinal electrical activity postbevacizumab in patients with ARMD. This study demonstrates a method for utilising mf-ERG to assess changes in retinal electrical activity and to assess the effectiveness of treatments such as bevacizumab.

Foveal cone dysfunction syndrome.

Our objective was to describe and expand the clinical spectrum of a rarely detected, previously reported photoreceptor disorder restricted to the foveal cones. Three patients with bilaterally decreased acuity and hemeralopia were examined to exclude a structural, vascular, inflammatory, or degenerative process. Each patient underwent a full neuroophthalmic examination, including full-field and focal cone electroretinogram (ERG). All three patients had normal-appearing fundi, mild dyschromatopsia, central or paracentral visual field depressions, normal full-field photopic and scotopic ERGs, and markedly reduced focal, foveal cone ERG responses. One patient had a ring scotoma and an asymptomatic family member with abnormal full-field and focal cone ERG. The syndrome of acquired foveal cone dysfunction presents as a bilateral, painless, progressive central visual loss with minimal or absent fundus changes. It eludes diagnosis until focal, foveal cone ERG is performed.

Occult perineural tumor infiltration of the trigeminal nerve. Diagnostic considerations.

Cutaneous carcinomas of the face, and some nasopharyngeal carcinomas, may present with facial dysesthesias and/or facial nerve palsies in the absence of visible masses. Even with frank ophthalmoplegia, occult tumors that present in this matter may elude detection, for which reason specific diagnostic studies must be employed. We report seven cases of trigeminal nerve infiltration by occult tumors (five squamous cell carcinomas, one basal cell carcinoma, and one adenoid cystic carcinoma), and outline the clinical course, diagnostic investigations, and the subsequent management of these patients. The importance of establishing an early diagnosis before the tumor has transgressed the basal foramina is emphasized, as tumor infiltration of the cavernous sinus carries a more guarded prognosis. The use of magnetic resonance imaging to identify involved peripheral nerve branches that may then be biopsied is suggested. The patho-physiological mechanisms of neurotropic spread of tumor are reviewed.