Diagnosis of dizziness in the emergency department: A 1-year prospective single-center study.

BACKGROUND: The management of dizziness and vertigo can be challenging in the emergency department (ED). It is important to rapidly diagnose vertebrobasilar stroke (VBS), as therapeutic options such as thrombolysis and anticoagulation require prompt decisions. OBJECTIVE: This study aims to assess the rate of misdiagnosis in patients with dizziness caused by VBS in the ED. METHODS AND RESULTS: The cohort was comprised of 66 patients with a mean age 56 years; 48% were women and 52% men. Among dizzy patients, 14% had VBS. We used Cohen's kappa test to quantify the agreement between two raters -namely, emergency physicians and neurologists -regarding the causes of dizziness in the ED. The Kappa value was 0.27 regarding the final diagnosis of central vertigo disorders and VBS, thus showing the low agreement. We used the χi2 test to show the association between the presence of two or more cardiovascular risk factors and admission to the stroke unit (p = 0.015). CONCLUSION: There is a substantial rate of misdiagnosis in patients with dizziness caused by VBS in the ED. To reduce the number of missing diagnoses of VBS in the future, there is a need to train emergency physicians in neurovestibular examinations, including the HINTS examination for acute vestibular syndrome (AVS) and the Dix-Hallpike (DH) maneuver for episodic vestibular syndrome. Using video head impulse test could help reduce the rate of misdiagnosis of VBS in the ED.

Post-surgical left oculomotor nerve neuromyotonia: Cause or coincidence?

Ocular neuromyotonia (ONM) is characterized by episodes of binocular diplopia usually triggered by an eye movement requiring contraction of the affected extraocular muscle. It consists of an involuntary, sometimes painful contraction of one or more extraocular muscles. It is most often secondary to radiotherapy of the para-sellar region, although other aetiologies have been reported. Some cases do not have a clearly identified aetiology and are classified as idiopathic. Most cases of ONMs are unilateral but bilateral ONMs have also been described.1-4 We report a case of left ONM in a 55-year-old female patient, several weeks after simultaneous surgical resection of two meningiomas, situated on the right side (Simpson II). The particularity of this case is linked to its puzzling presentation, its similarity with spasm of the near reflex and the putative mechanism through which surgery might have precipitated the symptoms.

Occipital Epilepsy With Subcortical Atrophy in Celiac Disease: A Case Report.

We report a 50-year-old man with celiac disease who presented with occipital epilepsy. Brain MRI showed right occipital subcortical white matter hyperintensities, consistent with the posterior epileptic focus suggested by the clinical features of the seizures and documented on EEG. Shortly after the introduction of a gluten-free diet, the white matter abnormalities resolved. The patient went on to develop simultagnosia. Follow-up MRI showed right occipital lobe atrophy. This report emphasizes the importance of recognizing gluten-associated neurologic manifestations and usefulness of thegluten-free diet.

West Nile Virus Neuroinvasive Disease Accelerating Probable Dementia With Lewy Bodies.

We describe a case of dementia with Lewy bodies immediately following encephalitis due to West Nile virus (WNV). The patient had rapid eye movement-sleep behavior disorder and constipation before the onset of encephalitis, which suggests that he would have ultimately developed dementia with Lewy bodies even without WNV infection. Our case illustrates the interactions between α-synuclein and WNV, as observed in mouse models, wherein synuclein expression augments after WNV infection and protects neurons against the virus.

Visual Input Is the Main Trigger and Parametric Determinant for Catch-Up Saccades During Video Head Impulse Test in Bilateral Vestibular Loss.

Patients with vestibular deficit use slow eye movements or catch-up saccades (CUS) to compensate for impaired vestibulo-ocular reflex (VOR). The purpose of CUS is to bring the eyes back to the visual target. Covert CUS occur during high-velocity head rotation and overt CUS are generated after head rotation has stopped. Dynamic visual acuity is improved with an increased rate and gain of CUS. Nevertheless, the trigger and the parametric determinants of CUS are still under debate. To clarify the underlying mechanism, especially the visual contribution, we analyzed the number, amplitude and latencies of the CUS in relation with the extent of VOR deficiency. The head and eye movements were recorded in 17 patients with bilateral vestibular loss (BVL) and in 33 subjects with normal VOR gain using the Video Head Impulse Test (vHIT) in two conditions: with visible target and in darkness with an imaginary target. Our study shows that in darkness without visible target the number of CUS is significantly reduced and the relationship between the amplitude of CUS and gaze position error is lost. Results showed that there is a correlation between the number of CUS and the drop in VOR gain. CUS occurring during the head movement and when the head remained still were not always sufficiently accurate. Up to four consecutive CUS could be required to bring eyes back to the visible target. A positive correlation was found between the amplitude of overt saccades with visible target and the gaze position error, namely the remaining eye movement to reach the target. These results suggest that the visual inputs are the main trigger and parametric determinant of the CUS or at least the presence of a visual target is necessary in most cases for a CUS to occur.

Novel mutation in spacer region of POLG associated with ataxia neuropathy spectrum and gastroparesis.

Clinical expression of POLG mutations is largely variable. We present a patient with a new mutation in spacer region of mitochondrial polymerase gamma protein (P765T). The clinical picture is characterized by the presence of sensory-ataxic neuropathy, ophthalmoplegia, dysarthria and gastroparesis, which had not been previously observed in ataxia neuropathy spectrum.

Multicenter assessment of HIV-1 RNA quantitation in semen in the CREAThE network.

Detection of HIV-1 RNA in semen is used commonly to determine the safety of semen processing procedures before assisted reproductive technology (ART). Using two panels of prepared semen samples containing HIV-1 the performances of protocols from 14 centers have been compared. No false-positive results were detected but false-negative results were frequent when the concentration was below 500 HIV-1 RNA copies/ml of seminal plasma. Frequency of HIV-1 RNA detection was higher on seminal cells than on seminal plasma. Assays (or protocols) for quantifying HIV-1 RNA in semen performed less well than standardized blood plasma assays. The HIV load in seminal plasma could be a useful marker of the risk of sexual transmission of the virus. Its use as a marker of global HAART efficiency in the HIV reservoir needs further study. Standardized assays are required for detection and measurement of HIV-1 RNA in semen samples.

Nucleoside analog stavudine depletes mitochondrial DNA with no organelle loss in mouse oocytes.

Nucleoside reverse transcriptase inhibitors (NRTIs) are the basis of antiretroviral treatment of HIV-positive patients. Several studies have shown decreased fertility and fecundity among HIV-positive women under antiretroviral treatment. Oocyte impaired competence has been hypothesized to be one of the main mechanisms underlying of this decreased fertility. NRTI side effects are thought to be due to the induced mitochondrial dysfunction. Stavudine, a widely used NRTI, causes persistent mitochondrial damage in various tissues. In order to gain insights into possible mechanisms of HIV-related diminished fertility, we studied the effects of stavudine on mouse oocyte mitochondria. Mitochondrial volume, protein assay and ATP contents were unaltered by stavudine treatment, but we found mitochondrial Cox I depletion in liver and oocytes. Our findings suggest that stavudine induces mtDNA depletion without organelle loss in mouse oocytes. The decrease in Cox I DNA in treated oocytes likely points to mitochondrial dysfunction, which can impair chances of pregnancy and embryo viability. We propose that the competence of oocytes depends primarily on functional capacity of mitochondria and less on their number.

Development and evaluation of single sperm washing for risk reduction in artificial reproductive technology (ART) for extreme oligospermic HIV positive patients.

The serodiscordant couples, where the male is HIV-positive, are treated in fertility clinics, using the sperm washing technique by gradient centrifugation. This protocol cannot be carried out in oligo-azoospermic patients, where spermatozoa retrieval from the epididymis and testis must be performed. We developed a single sperm washing technique, where the spermatozoa, after the retrieval, are washed with the aid of a micromanipulator, to obtain virus decontamination and then used for the intracytoplasmic sperm injection (ICSI). The experiment was performed by using sperm samples containing three different viral loads. After one hour of incubation, spermatozoa were taken one by one from the HIV loaded drop and washed in four different microdrops. Before each passage into the next washing drop, the pipette was emptied in a first waste drop and then loaded with new washing medium from a second separate loading drop. After transferring of 10 spermatozoa in these four successive drops, the washing medium and the virus-loaded drops were tested for the HIV RNA presence by the nested RT-PCR technique. The presence of the virus was detected in the waste drop of all three viral loads. The four washing microdrops were each time negative for the presence of HIV-1 RNA, tested by the nested RT-PCR technique. The results show that by rinsing the spermatozoa four times, we are able to diminish the viral load to an undetectable level. Our data demonstrate that single sperm washing can be performed in the cases of extreme male sterility in HIV-positive men. From now on the couples, where the male is oligoazoospermic and HIV positive, could be included in our ICSI program, respecting the usual viral safety level of the ART techniques for the embryo.

The absence of expression of the three isoenzymes of the inositol 1,4,5-trisphosphate 3-kinase does not prevent the formation of inositol pentakisphosphate and hexakisphosphate in mouse embryonic fibroblasts.

The activation of phospholipase C leads to the formation of both I(1,4,5)P(3) and diacylglycerol (DAG). I(1,4,5)P(3) can be metabolized by dephosphorylation catalyzed by Type I I(1,4,5)P(3) 5-phosphatase and by enzymatic phosphorylation to various inositol phosphates. This last step is catalyzed by three mammalian isoenzymes that specifically phosphorylate the 3-phosphate position of the inositol ring Itpka, Itpkb and Itpkc and a less specific enzyme Ipmk (or inositol multikinase) that phosphorylates I(1,4,5)P(3) at the D-3 and D-6 positions. This study was performed in mice cells in order to understand the synthetic pathway of IP5 and IP6 following PLC stimulation and possible link with Itpk activity. Mouse embryonic fibroblasts (MEF) were prepared from Itpkb(-/-) Itpkc(-/-) mice. Western blot and RT-PCR analysis show that the cells do not express Itpka. In contrast, they do express Ipmk. The cells still produce IP5 and IP6. Our data show that the absence of expression of the three isoenzymes of Itpk does not prevent the formation of IP5 and IP6, at least in mouse embryonic fibroblasts. The nuclear Ipmk plays therefore a critical role in the metabolism of I(1,4,5)P(3) and production of highly phosphorylated IP5 and IP6.