Can the ischemic penumbra be identified on noncontrast CT of acute stroke?

<p><b>Background and Purpose:</b> Early ischemic changes on noncontrast CT in acute stroke include both hypoattenuation and brain swelling, which may have different pathophysiological significance.</p> <p><b>Methods:</b> Noncontrast CT and CT perfusion brain scans from patients with suspected acute stroke <6 hours after onset were reviewed. Five raters independently scored noncontrast CTs blind to clinical data using the Alberta Stroke Program Early CT Score (ASPECTS). Each ASPECTS region was scored as hypodense or swollen. A separate reviewer measured time to peak and cerebral blood volume in each ASPECTS region on CT perfusion. Time to peak and cerebral blood volume were compared for each region categorized as normal, hypodense, or isodense and swollen.</p> <p><b>Results:</b> Scans of 32 subjects a median 155 minutes after onset yielded 228 regions with both CT perfusion and noncontrast CT data. Isodense swelling was associated with significantly higher cerebral blood volume (P=0.016) and with penumbral perfusion (posttest:pretest likelihood ratio 1.44 [95% CI: 0.68 to 2.90]), whereas hypodensity was associated with more severe time to peak delay and with core perfusion (likelihood ratio 3.47 [95% CI: 1.87 to 6.34]). Neither isodense swelling nor hypodensity was sensitive for prediction of perfusion pattern, but appearances were highly specific (87.2% and 91.0% for penumbra and core, respectively). Intrarater agreement was good or excellent, but interrater agreement for both hypodensity and swelling was poor.</p> <p><b>Conclusions:</b> Regions exhibiting hypoattenuation are likely to represent the infarct core, whereas regions that are isodense and swollen have increased cerebral blood volume and are more likely to signify penumbral perfusion. Although noncontrast CT is not sensitive for detection of core and penumbra, appearances are specific. Some information on tissue viability can therefore be obtained from noncontrast CT.</p&gt

The F-actin cytoskeleton in syncytia from non-clonal progenitor cells

The actin cytoskeleton of plant syncytia (a multinucleate cell arising through fusion) is poorly known: to date, there have only been reports about F-actin organization in plant syncytia induced by parasitic nematodes. To broaden knowledge regarding this issue, we analyzed F-actin organization in special heterokaryotic Utricularia syncytia, which arise from maternal sporophytic tissues and endosperm haustoria. In contrast to plant syncytia induced by parasitic nematodes, the syncytia of Utricularia have an extensive F-actin network. Abundant F-actin cytoskeleton occurs both in the region where cell walls are digested and the protoplast of nutritive tissue cells fuse with the syncytium and also near a giant amoeboid in the shape nuclei in the central part of the syncytium. An explanation for the presence of an extensive F-actin network and especially F-actin bundles in the syncytia is probably that it is involved in the movement of nuclei and other organelles and also the transport of nutrients in these physiological activity organs which are necessary for the development of embryos in these unique carnivorous plants. We observed that in Utricularia nutritive tissue cells, actin forms a randomly arranged network of F-actin, and later in syncytium, two patterns of F-actin were observed, one characteristic for nutritive cells and second—actin bundles—characteristic for haustoria and suspensors, thus syncytia inherit their F-actin patterns from their progenitors

Lithium side effects and toxicity: prevalence and management strategies

Despite its virtually universal acceptance as the gold standard in treating bipolar disorder, prescription rates for lithium have been decreasing recently. Although this observation is multifactorial, one obvious potential contributor is the side effect and toxicity burden associated with lithium. Additionally, side effect concerns assuredly play some role in lithium nonadherence. This paper summarizes the knowledge base on side effects and toxicity and suggests optimal management of these problems. Thirst and excessive urination, nausea and diarrhea and tremor are rather common side effects that are typically no more than annoying even though they are rather prevalent. A simple set of management strategies that involve the timing of the lithium dose, minimizing lithium levels within the therapeutic range and, in some situations, the prescription of side effect antidotes will minimize the side effect burden for patients. In contrast, weight gain and cognitive impairment from lithium tend to be more distressing to patients, more difficult to manage and more likely to be associated with lithium nonadherence. Lithium has adverse effects on the kidneys, thyroid gland and parathyroid glands, necessitating monitoring of these organ functions through periodic blood tests. In most cases, lithium-associated renal effects are relatively mild. A small but measurable percentage of lithium-treated patients will show progressive renal impairment. Infrequently, lithium will need to be discontinued because of the progressive renal insufficiency. Lithium-induced hypothyroidism is relatively common but easily diagnosed and treated. Hyperparathyroidism from lithium is a relatively more recently recognized phenomenon

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Correcting iron deficiency

Iron deficiency is the most common cause of anaemia. It has many different causes, so further investigations are required to establish an underlying aetiology. An iron study is the first-line investigation and includes serum iron, ferritin, transferrin and transferrin saturation. Serum ferritin is normally a suitable indicator of iron stores but can be increased by inflammation to an extent that makes the ferritin unreliable for assessment of iron deficiency. Oral iron replacement is the most appropriate first-line treatment in the majority of patients. Its efficacy can be limited by poor patient compliance due to the high rate of gastrointestinal adverse effects and the prolonged treatment course needed to replenish body iron stores. Intravenous iron preparations are indicated when oral iron therapy has failed or rapid replenishment is required. Ferric carboxymaltose can rapidly deliver a large dose of iron, making it the preparation of choice for outpatients. Despite their excellent safety profiles, all intravenous iron preparations carry the risk of anaphylaxis. Patients require monitoring and access to resuscitation facilities

Central control of eye movements

Purpose of review: Eye-movement research continues to provide an excellent tool for understanding the central control of motor function, both in health and disease. This article reviews recent findings in relation to saccadic eye movements, particularly antisaccades and microsaccades, with particular emphasis on the control of inaction, something which has recently become topical.Recent findingsMicrosaccades are under the control of the cerebral cortex, particularly the frontal and parietal eye fields. Their frequency and direction alters following presentation of visual stimuli. Spontaneous alterations in their frequency are correlated with alterations in the frequency of the gamma-band activity in the visual cortex as well as, interestingly, the heartbeat. Studies of saccades in Parkinson's disease have demonstrated abnormalities of prosaccade suppression which have variously been shown to correlate with freezing of gait, postural instability, minimal cognitive change and stimulation of the subthalamic nuclei. In stroke patients, abnormal patterns of saccade activity are associated with poor performance on reaching studies when using the weak arm. Summary: Eye-movement studies continue to provide new insights into the control of movement in general but have been particularly useful in investigating the process of suppressing unwanted movement

Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) is primarily a disease of overweight women of childbearing age but it can affect any weight, sex or age. It is a potential cause of blindness and is associated with reduced quality of life due to visual loss, headaches and depression. It consumes significant healthcare resources related to monitoring and treatment. The overall incidence is increasing, probably related to the global increase in obesity. While many conditions can be associated with the syndrome, the cause of IIH remains unknown and the optimal treatment remains uncertain. Typical symptoms include headache, transient visual obscurations, tinnitus and diplopia, though it may be asymptomatic. Papilloedema is essential for the diagnosis of IIH, though IIH without papilloedema (IIHWOP) is a recognised entity. The diagnosis is based on clinical findings, detailed ophthalmic evaluation, imaging (ideally MRI), and lumbar puncture. The cerebrospinal fluid contents must be normal and the opening pressure be above 25 cm H2O in adults and 28 cm H2O in children. The optimal treatment remains uncertain, but options include weight loss, acetazolamide, topiramate, lumbo-peritoneal shunting, optic nerve sheath fenestration and cerebral venous sinus stenting. Bariatric surgery may also help achieve weight loss