Superior oblique myokymia: efficacy of medical treatment.

PURPOSE: Superior oblique myokymia (SOM) is an uncommon disorder characterized by episodic monocular oscillopsia. Several medications have been reported to be of benefit for some patients with this condition, but the efficacy of medical treatment has not been well established and little long-term follow-up data are available. The purpose of this study was to better clarify the role of medical therapy in the management of SOM. METHODS: A retrospective review of patients with this disorder seen in an outpatient neuro-ophthalmology clinic. The diagnosis of SOM was based on a history of episodic unilateral oscillopsia with or without torsional diplopia. Twenty-seven patients with SOM were identified. Twenty of these were treated medically and these formed the basis of the study. Follow-up interval ranged from 1 to 12.5 years (mean, 6.5 years). The main outcome measure was relief of oscillopsia. RESULTS: Fifteen of the 18 patients treated with carbamazepine (83%) reported some benefit, 6 of whom continue to do well on medication 9 months to 5 years later. In four patients improvement was only transient and in five others treatment was subsequently discontinued for various reasons. In addition, one patient had sustained benefit from phenytoin, one from propranolol, and one from propranolol plus valproic acid. We found no treatment success with baclofen. Overall, nine patients (45%) enjoy sustained benefit unassociated with adverse side effects. CONCLUSIONS: In contrast to previous reports emphasizing the efficacy of surgery for SOM, our data demonstrate the potential benefits of medical treatment for patients with this disorder.

Pulmonary thrombembolism as cause of death on unenhanced postmortem 3T MRI.

OBJECTIVES: To investigate unenhanced postmortem 3-T MR imaging (pmMRI) for the detection of pulmonary thrombembolism (PTE) as cause of death. METHODS: In eight forensic cases dying from a possible cardiac cause but with homogeneous myocardium at cardiac pmMRI, additional T2w imaging of the pulmonary artery was performed before forensic autopsy. Imaging was carried out on a 3-T MR system in the axial and main pulmonary artery adapted oblique orientation in situ. In three cases axial T2w pmMRI of the lower legs was added. Validation of imaging findings was performed during forensic autopsy. RESULTS: All eight cases showed homogeneous material of intermediate signal intensity within the main pulmonary artery and/or pulmonary artery branches. Autopsy confirmed the MR findings as pulmonary artery thrombembolism. At lower leg imaging unilateral dilated veins and subcutaneous oedema with or without homogeneous material of intermediate signal intensity within the popliteal vein were found. CONCLUSIONS: Unenhanced pmMRI demonstrates pulmonary thrombembolism in situ. PmMR may serve as an alternative to clinical autopsy, especially when consent cannot be obtained. KEY POINTS: ? Postmortem MRI (pmMRI) provides an alternative to clinical autopsy ? Fatal pulmonary thrombembolism (PTE) can now be diagnosed using postmortem MRI (pmMRI). ? Special attention has to be drawn to the differentiation of postmortem clots.

Accuracy and predictability in use of AO three-dimensionally preformed titanium mesh plates for posttraumatic orbital reconstruction: a pilot study.

The aim of this study was to prospectively evaluate the accuracy and predictability of new three-dimensionally preformed AO titanium mesh plates for posttraumatic orbital wall reconstruction.We analyzed the preoperative and postoperative clinical and radiologic data of 10 patients with isolated blow-out orbital fractures. Fracture locations were as follows: floor (N = 7; 70%), medial wall (N = 1; 1%), and floor/medial wall (N = 2; 2%). The floor fractures were exposed by a standard transconjunctival approach, whereas a combined transcaruncular transconjunctival approach was used in patients with medial wall fractures. A three-dimensional preformed AO titanium mesh plate (0.4 mm in thickness) was selected according to the size of the defect previously measured on the preoperative computed tomographic (CT) scan examination and fixed at the inferior orbital rim with 1 or 2 screws. The accuracy of plate positioning of the reconstructed orbit was assessed on the postoperative CT scan. Coronal CT scan slices were used to measure bony orbital volume using OsiriX Medical Image software. Reconstructed versus uninjured orbital volume were statistically correlated.Nine patients (90%) had a successful treatment outcome without complications. One patient (10%) developed a mechanical limitation of upward gaze with a resulting handicapping diplopia requiring hardware removal. Postoperative orbital CT scan showed an anatomic three-dimensional placement of the orbital mesh plates in all of the patients. Volume data of the reconstructed orbit fitted that of the contralateral uninjured orbit with accuracy to within 2.5 cm(3). There was no significant difference in volume between the reconstructed and uninjured orbits.This preliminary study has demonstrated that three-dimensionally preformed AO titanium mesh plates for posttraumatic orbital wall reconstruction results in (1) a high rate of success with an acceptable rate of major clinical complications (10%) and (2) an anatomic restoration of the bony orbital contour and volume that closely approximates that of the contralateral uninjured orbit.

Bilateral anterior ischemic optic neuropathy following influenza vaccination.

Optic neuritis is an occasional complication of vaccination. Visual loss can be unilateral or bilateral, and most patients recover substantially without treatment. The presumptive mechanism is an immune-mediated demyelinating injury of the optic nerve. We report two patients who had permanent visual loss following influenza vaccination. Their pattern of visual loss, segmental optic disc changes, and failure of visual recovery were atypical for demyelinating optic neuritis and reminiscent of a primary ischemic injury to the optic nerve. We speculate that an immune complex-mediated vasculopathy following vaccination can cause anterior ischemic optic neuropathy. Clinicians should be aware of this entity because of the less favorable prognosis for visual recovery in these cases.

Effect of dark chocolate on renal tissue oxygenation as measured by BOLD-MRI in healthy volunteers.

Background: Cocoa is rich in flavonoids, has anti-oxidative properties and increases the bioavailability of nitric oxide (NO). Adequate renal tissue oxygenation is crucial for the maintenance of renal function. The goal of this study was to investigate the effect of cocoa-rich dark chocolate (DC) on renal tissue oxygenation in humans, as compared to flavonoid-poor white chocolate (WC). Methods: Ten healthy volunteers with preserved kidney function (mean age ± SD 35 ± 12 years, 70% women, BMI 21 ± 3 kg/m2) underwent blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) before and 2 hours after the ingestion of 1 g/kg of DC (70% cocoa). Renal tissue oxygenation was determined by the measurement of R2* maps on 4 coronal slices covering both kidneys. The mean R2* (= 1/T2*) values in the medulla and cortex were calculated, a low R2* indicating high tissue oxygenation. Eight participants also underwent BOLD-MRI at least 1 week later, before and 2 hours after the intake of 1 g/kg WC. Results: The mean medullary R2* was lower after DC intake compared to baseline (28.2 ± 1.3 s-1 vs. 29.6 ± 1.3 s-1, p = 0.04), whereas cortical and medullary R2* values did not change after WC intake. The change in medullary R2* correlated with the level of circulating (epi)catechines, metabolites of flavonoids (r = 0.74, p = 0.037), and was independent of plasma renin activity. Conclusion: This study suggests for the first time an increase of renal medullary oxygenation after intake of dark chocolate. Whether this is linked to flavonoid-induced changes in renal perfusion or oxygen consumption, and whether cocoa has potentially renoprotective properties, merits further study.

Prevalence of subfoveal nodules in Coat's disease

Purpose:Coats' disease is a non-hereditary condition characterized by idiopathic retinal telangiectasia, and exudative retinopathy. Although the exudation often spreads from the main areas of telangiectasia, there is a preferential accumulation of exudation in the macular area in Coats' disease. A subfoveal nodule has usually been described in the context of resolution of macular exudates after treatment of peripheral retinal telangiectasis. Nevertheless, a recent reports stressed out an uncommon prominent subfoveal nodule with peripheral exudates as initial presentation of Coats'disease. The purpose of this study was to report the prevalence of this presentation in a cohort of patients. Methods:All consecutive patients with Coats' disease referred to the Jules Gonin Eye Hospital between January 1979 and July 2006 were included. All charts were screened for a clear cut subfoveal circular lesion on fundus photographies at initial presentation. Results:95 patients suffering of Coat's disease were enrolled. 33 out of 95 patients had subtotal or total exudative retinal detachment, which impeded macular examination. 14 out of 62 (22.6%) resting patients presented with a clear cut prominent circular subfoveal lesion at initial presentation. All patients had unilateral disease. Mean age was 5.6 ± 3.5 year old at initial presentation. There were 4 females and 10 males. Pigmentation and size of the nodule were not homogenous. Mean diameter was 1.1 ± 0.5 optic disc diameter. Conclusions:The present study shows that subfoveal nodule is not such a rare primary presentation of Coats' disease in contrast to what it has been previously reported in the literature. Thus the initial finding of prominent subfoveal nodule associated with peripheral retinal findings made the diagnosis of Coats' disease highly likely.Physicians should be aware that a proeminent subfoveal nodule is a common initial presentation of Coats' disease as it can be confused clinically with Retinoblastoma.

Can MRI replace CT in evaluating semicircular canal dehiscence?

BACKGROUND AND PURPOSE: Patients with symptoms of semicircular canal dehiscence often undergo both CT and MR imaging. We assessed whether FIESTA can replace temporal bone CT in evaluating patients for SC dehiscence. MATERIALS AND METHODS: We retrospectively reviewed 112 consecutive patients (224 ears) with vestibulocochlear symptoms who underwent concurrent MR imaging and CT of the temporal bones between 2007 and 2009. MR imaging protocol included a FIESTA sequence covering the temporal bone (axial 0.8-mm section thickness, 0.4-mm spacing, coronal/oblique reformations; 41 patients at 1.5T, 71 patients at 3T). CT was performed on a 64-row multidetector row scanner (0.625-mm axial acquisition, with coronal/oblique reformations). Both ears of each patient were evaluated for dehiscence of the superior and posterior semicircular canals in consensual fashion by 2 neuroradiologists. Analysis of the FIESTA sequence and reformations was performed first for the MR imaging evaluation. CT evaluation was performed at least 2 weeks after the MR imaging review, resulting in a blinded comparison of CT with MR imaging. CT was used as the reference standard to evaluate the MR imaging results. RESULTS: For SSC dehiscence, MR imaging sensitivity was 100%, specificity was 96.5%, positive predictive value was 61.1%, and negative predictive value was 100% in comparison with CT. For PSC dehiscence, MR imaging sensitivity was 100%, specificity was 99.1%, positive predictive value was 33.3%, and negative predictive value was 100% in comparison with CT. CONCLUSIONS: MR imaging, with a sensitivity and negative predictive value of 100%, conclusively excludes SSC or PSC dehiscence. Negative findings on MR imaging preclude the need for CT to detect SC dehiscence. Only patients with positive findings on MR imaging should undergo CT evaluation.

Transcranial direct current stimulation for the treatment of focal hand dystonia.

The treatment of writer's cramp, a task-specific focal hand dystonia, needs new approaches. A deficiency of inhibition in the motor cortex might cause writer's cramp. Transcranial direct current stimulation modulates cortical excitability and may provide a therapeutic alternative. In this randomized, double-blind, sham-controlled study, we investigated the efficacy of cathodal stimulation of the contralateral motor cortex in 3 sessions in 1 week. Assessment over a 2-week period included clinical scales, subjective ratings, kinematic handwriting analysis, and neurophysiological evaluation. Twelve patients with unilateral dystonic writer's cramp were investigated; 6 received transcranial direct current and 6 sham stimulation. Cathodal transcranial direct current stimulation had no favorable effects on clinical scales and failed to restore normal handwriting kinematics and cortical inhibition. Subjective worsening remained unexplained, leading to premature study termination. Repeated sessions of cathodal transcranial direct current stimulation of the motor cortex yielded no favorable results supporting a therapeutic potential in writer's cramp.

Mouvements anormaux et accident vasculaire cérébral [Movement disorders in stroke]

Dyskinesias are infrequent presentations in acute stroke (1%). They can be found more frequently as delayed presentations after a stroke, but the prevalence is not available from the literature. The full spectrum of hyper- and hypo-akinetic syndromes has been described, but three main pictures are rather specific of an acute stroke: limb shaking, hemichorea-hemiballism and unilateral asterixis. Besides limb shaking, that seems to reflect a transient diffuse ischemia of the frontosubcortical motor pathway, lesions are described at all levels of the frontosubcortical motor circuit including the sensorimotor frontoparietal cortex, the striatum, the pallidum, the thalamic nuclei, the subthalamic nucleus, the substantia nigra, the cerebellum, the brainstem and their interconnecting pathways, as ischemic or hemorrhagic strokes. The preferentially late development of dyskinesia could reflect the return to a more ancestral motor control level, the most functional possible with the remaining configuration of structures, elaborated by brain plasticity after stroke.

Mutations in ALDH1A3 represent a frequent cause of microphthalmia/anophthalmia in consanguineous families.

Anophthalmia or microphthalmia (A/M), characterized by absent or small eye, can be unilateral or bilateral and represent developmental anomalies due to the mutations in several genes. Recently, mutations in aldehyde dehydrogenase family 1, member A3 (ALDH1A3) also known as retinaldehyde dehydrogenase 3, have been reported to cause A/M. Here, we screened a cohort of 75 patients with A/M and showed that mutations in ALDH1A3 occurred in six families. Based on this series, we estimate that mutations in ALDH1A3 represent a major cause of A/M in consanguineous families, and may be responsible for approximately 10% of the cases. Screening of this gene should be performed in a first line of investigation, together with SOX2.

Oculopalatal tremor: variations on a theme by Guillain and Mollaret.

BACKGROUND: Oculopalatal tremor (OPT) is a delayed complication of a brainstem lesion, characterized by involuntary contractions of the soft palate associated with a synchronized ocular pendular nystagmus. MRI reveals inferior olivary nucleus hypersignal/hypertrophy (IONH). Our objective was to refine the clinical profile of patients with OPT and to report a few oddities in both presentation and evolution. METHODS: We performed a retrospective study of patients diagnosed with OPT and a literature search. RESULTS: From our database, we retrieved 5 men and 3 women with a diagnosis of OPT. Eighty-two patients with OPT were retrieved from the literature and were compiled with our series. The average age was 54 years and there was a male predominance. Brainstem vascular lesion was the most common etiology (80%). Prominent vertical pendular nystagmus was found in 90%. Dissociated nystagmus was mostly associated to unilateral contralateral IONH on MRI, while bilateral symmetrical nystagmus was due to a bilateral IONH in the majority of cases. Three oddities were found amongst our 8 patients: prominent nystagmus ipsilateral to IONH; disappearance of IONH on MRI despite persisting nystagmus, and asymptomatic OPT. CONCLUSION: The clinical profile of OPT is rather stereotyped. Rarely do patients deviate from the classical description of OPT.

Role of JNK isoforms in the development of neuropathic pain following sciatic nerve transection in the mouse.

ABSTRACT: BACKGROUND: Current tools for analgesia are often only partially successful, thus investigations of new targets for pain therapy stimulate great interest. Consequent to peripheral nerve injury, c-Jun N-terminal kinase (JNK) activity in cells of the dorsal root ganglia (DRGs) and spinal cord is involved in triggering neuropathic pain. However, the relative contribution of distinct JNK isoforms is unclear. Using knockout mice for single isoforms, and blockade of JNK activity by a peptide inhibitor, we have used behavioral tests to analyze the contribution of JNK in the development of neuropathic pain after unilateral sciatic nerve transection. In addition, immunohistochemical labelling for the growth associated protein (GAP)-43 and Calcitonin Gene Related Peptide (CGRP) in DRGs was used to relate injury related compensatory growth to altered sensory function. RESULTS: Peripheral nerve injury produced pain-related behavior on the ipsilateral hindpaw, accompanied by an increase in the percentage of GAP43-immunoreactive (IR) neurons and a decrease in the percentage of CGRP-IR neurons in the lumbar DRGs. The JNK inhibitor, D-JNKI-1, successfully modulated the effects of the sciatic nerve transection. The onset of neuropathic pain was not prevented by the deletion of a single JNK isoform, leading us to conclude that all JNK isoforms collectively contribute to maintain neuropathy. Autotomy behavior, typically induced by sciatic nerve axotomy, was absent in both the JNK1 and JNK3 knockout mice. CONCLUSIONS: JNK signaling plays an important role in regulating pain threshold: the inhibition of all of the JNK isoforms prevents the onset of neuropathic pain, while the deletion of a single splice JNK isoform mitigates established sensory abnormalities. JNK inactivation also has an effect on axonal sprouting following peripheral nerve injury.

3D noise power spectrum applied on clinical mdct scanners: effects of reconstruction algorithms and reconstruction filters

The noise power spectrum (NPS) is the reference metric for understanding the noise content in computed tomography (CT) images. To evaluate the noise properties of clinical multidetector (MDCT) scanners, local 2D and 3D NPSs were computed for different acquisition reconstruction parameters.A 64- and a 128-MDCT scanners were employed. Measurements were performed on a water phantom in axial and helical acquisition modes. CT dose index was identical for both installations. Influence of parameters such as the pitch, the reconstruction filter (soft, standard and bone) and the reconstruction algorithm (filtered-back projection (FBP), adaptive statistical iterative reconstruction (ASIR)) were investigated. Images were also reconstructed in the coronal plane using a reformat process. Then 2D and 3D NPS methods were computed.In axial acquisition mode, the 2D axial NPS showed an important magnitude variation as a function of the z-direction when measured at the phantom center. In helical mode, a directional dependency with lobular shape was observed while the magnitude of the NPS was kept constant. Important effects of the reconstruction filter, pitch and reconstruction algorithm were observed on 3D NPS results for both MDCTs. With ASIR, a reduction of the NPS magnitude and a shift of the NPS peak to the low frequency range were visible. 2D coronal NPS obtained from the reformat images was impacted by the interpolation when compared to 2D coronal NPS obtained from 3D measurements.The noise properties of volume measured in last generation MDCTs was studied using local 3D NPS metric. However, impact of the non-stationarity noise effect may need further investigations.

Shoulder pathology: estimating dominant upper-limb activity using 3D kinematic sensors.

Introduction. Quantification of daily upper-limb activity is a key determinant in evaluation of shoulder surgery. For a number of shoulder diseases, problem in performing daily activities have been expressed in terms of upper-limb usage and non-usage. Many instruments measure upper-limb movement but do not focus on the differentiations between the use of left or right shoulder. Several methods have been used to measure it using only accelerometers, pressure sensors or video-based analysis. However, there is no standard or widely used objective measure for upper-limb movement. We report here on an objective method to measure the movement of upper-limb and we examined the use of 3D accelerometers and 3D gyroscopes for that purpose. Methods. We studied 8 subjects with unilateral pathological shoulder (8 rotator cuff disease: 53 years old ± 8) and compared them to 18 control subjects (10 right handed, 8 left handed: 32 years old ± 8, younger than the patient group to be almost sure they don_t have any unrecognized shoulder pathology). The Simple Shoulder Test (SST) and Disabilities of the Arm and Shoulder Score (DASH) questionnaires were completed by each subject. Two modules with 3 miniature capacitive gyroscopes and 3 miniature accelerometers were fixed by a patch on the dorsal side of the distal humerus, and one module with 3 gyroscopes and 3 accelerometers were fixed on the thorax. The subject wore the system during one day (8 hours), at home or wherever he/she went. We used a technique based on the 3D acceleration and the 3D angular velocities from the modules attached on the humerus. Results. As expected, we observed that for the stand and sit postures the right side is more used than the left side for a healthy right-handed person(idem on the left side for a healthy left-handed person). Subjects used their dominant upper-limb 18% more than the non-dominant upper-limb. The measurements on patients in daily life have shown that the patient has used more his non affected and non dominant side during daily activity if the dominant side = affected shoulder. If the dominant side affected shoulder, the difference can be showed only during walking period. Discussion-Conclusion. The technique developed and used allowed the quantification of the difference between dominant and non dominant side, affected and unaffected upper-limb activity. These results were encouraging for future evaluation of patients with shoulder injuries, before and after surgery. The feasibility and patient acceptability of the method using body fixed sensors for ambulatory evaluation of upper limbs kinematics was shown.

A new technique with high reproducibility to estimate renal oxygenation using BOLD-MRI in chronic kidney disease.

OBJECTIVES: To assess inter-observer variability of renal blood oxygenation level-dependent MRI (BOLD-MRI) using a new method of analysis, called the concentric objects (CO) technique, in comparison with the classical ROI (region of interest)-based technique. METHODS: MR imaging (3T) was performed before and after furosemide in 10 chronic kidney disease (CKD) patients (mean eGFR 43±24ml/min/1.73m(2)) and 10 healthy volunteers (eGFR 101±28ml/min1.73m(2)), and R2* maps were determined on four coronal slices. In the CO-technique, R2* values were based on a semi-automatic procedure that divided each kidney in six equal layers, whereas in the ROI-technique, all circles (ROIs) were placed manually in the cortex and medulla. The mean R2*values as assessed by two independent investigators were compared. RESULTS: With the CO-technique, inter-observer variability was 0.7%-1.9% across all layers in non-CKD, versus 1.6%-3.8% in CKD. With the ROI-technique, median variability for cortical and medullary R2* values was 3.6 and 6.8% in non-CKD, versus 4.7 and 12.5% in CKD; similar results were observed after furosemide. CONCLUSION: The CO-technique offers a new, investigator-independent, highly reproducible alternative to the ROI-based technique to estimate renal tissue oxygenation in CKD.