Training to improve temporal processing of letters benefits reading speed for people with central vision loss

Reading is slow and difficult for many people with central vision loss. A previous study showed that the temporal threshold for letter recognition is a major factor limiting reading speed for people with central vision loss. Here, we asked whether the temporal threshold for letter recognition for people with central vision loss could be improved through training and, if so, whether that would benefit reading. Training consisted of six sessions (3000 trials) of recognizing letter trigrams presented at fixation. Trigrams were initially presented at a baseline temporal threshold that was decreased by 0.1 log step when observers’ letter recognition accuracies reached 80% or higher for four consecutive blocks. Before and after training, we measured observers’ visual acuity, preferred retinal locus for fixation, fixation stability, reading speeds using the rapid serial visual presentation (RSVP) paradigm, the MNREAD Acuity Chart and 100-word passages, the baseline temporal threshold for letter recognition at 80% accuracy, and a visual-span profile. After training, the temporal threshold was decreased by 68%. This improvement was accompanied by a higher RSVP maximum reading speed (but no change in MNREAD and passage reading speeds) and a larger visual span. A mediation analysis showed that the relationship between the temporal threshold and RSVP maximum reading speed was mainly mediated by the information transfer rate (size of visual span/temporal duration). Our results showed that the temporal threshold for letter recognition is amenable to training and can improve RSVP reading speeds, offering a practical means to improve reading speed for people with central vision loss.     

Transient receptor potential melastatin 2 contributes to neuroinflammation and negatively regulates cognitive outcomes in a pilocarpine-induced mouse model of epilepsy

Neuroinflammation contributes to the generation of epileptic seizures and is associate with neuropathology and comorbidities. Transient receptor potential melastatin 2 (TRPM2) expresses in various cell types in the brain. It plays a pathological role in a wide range of neuroinflammatory diseases, but has yet been studied in epilepsy. Here, a temporal lobe epilepsy model was generated by pilocarpine administration in mice. At 24 h, knockout (KO) TRPM2 alleviated the level of neuroinflammation, showing a reduction of IL-1β, TNF-α, CXCL2 and IL-6 mRNA production, NLRP3, ASC, and Caspase-1 protein expression and glial activation. Moreover, KO TRPM2 alleviated neurodegeneration, concurrent with reduced Beclin-1 and ATG5 protein expression. Later, KO TRPM2 ameliorated the epilepsy-induced psychological disorders, with improved performance in the open-field, Y maze and novel object recognition test. Together, these results suggest that TRPM2 facilitates epilepsy-related brain injury and may shed light on its potential as a therapeutic target for epilepsy-associated neuropathology and comorbidities.     

Analysis of temporal bone thickness outside of the petrous temporal bone between superior semicircular canal dehiscence and normal patients

BackgroundSSCD is a rare inner ear disorder. This study aims to compare the thickness of the temporal bone beyond the petrous portion between healthy subjects and those with SSCD to determine whether the etiopathology of SSCD is localized to the petrous temporal bone or generalized to other parts of the temporal bone.MethodsA retrospective chart review of electronic medical records from September 2011 to February 2018 was conducted at a single-institution study at the University of California, Los Angeles. Participants were divided into two groups: Group 1 had a confirmed diagnosis of SSCD, while Group 2 had no known ear or temporal bone pathology. Participants’ high-resolution coronal and axial temporal bone computed tomography scans were analyzed. Regions within the temporal bone were measured and compared between the two groups.ResultsA total of 262 scans were included. Group 1 consisted of 103 scans, while Group 2 consisted of 159 scans. There was no statistically significant difference in the thickness of temporal bones between patients diagnosed with SSCD and patients without otologic disease.ConclusionThe results suggest that the etiology of SSCD is limited to the petrous portion of the temporal bone. SSCD may be unrelated to a larger process of global temporal bone degeneration. Additional clinical screening for regions outside the petrous temporal bone is not warranted unless SSCD patients present with symptoms characteristic of other temporal bone pathologies.     

Selective use of superficial temporal artery cannulation in infants undergoing cardiac surgery

Arterial cannulation is routinely performed in children undergoing cardiac surgery to aid the intraoperative and intensive care management. Most commonly cannulated peripheral site in children is radial artery, and alternatives include posterior tibial, dorsalis pedis, and rarely superficial temporal artery (STA). Two specific situations in cardiac surgery where STA cannulation and monitoring was useful during the surgical procedure are reported. To our knowledge, such selective use of STA pressure monitoring has not been reported in the literature previously. Our experience suggests that STA monitoring can be useful and reliable during repair of coarctation of aorta or administration of anterograde cerebral perfusion in patients having associated aberrant origin of the right subclavian artery.     

The electrophysiology of axonal neuropathies: More than just evidence of axonal loss

It is common belief that axonal neuropathies are characterized by simple axonal degeneration and loss and that the electrophysiological correlates are just reduced compound muscle action potential and sensory nerve action potential amplitudes with normal or slightly slow conduction velocity. However, axonal autoimmune neuropathies with involvement of the nodal region and axonal neuropathies due to energy restriction such as occurring in nerve ischemia, thiamine deficiency, critical illness, and mitochondrial disorders present conduction failure that can be either reversible with prompt recovery or progress to axonal degeneration with poor outcome. Moreover autoimmune axonal neuropathies due to nodal voltage gated sodium channels dysfunction/disruption may show slowing of conduction velocity, even in the demyelinating range, possibly due to prolongation of the depolarization time required to reach the threshold for action potential regeneration at subsequent nodes. These observations widen the spectrum of the electrophysiological features in some axonal neuropathies, should be taken into account to avoid misdiagnoses and for correct prognostication, and should stimulate the quest of timely targeted treatments that can eventually halt the progression from conduction failure to axonal degeneration.     

Assessing the connectional anatomy of superior and lateral surgical approaches for medial temporal lobe epilepsy

The most common approaches in the treatment of epilepsy, the trans-sylvian selective amygdalohippocampectomy (SAH) and the anterior temporal lobe resection (ATLR) reach the medial temporal lobe through different surgical routes. Our aim was to delineate the white matter (WM) fiber tracts at risk in relation to trans-sylvian SAH and ATLR by defining each fascicle en route to medial temporal lobe during each approach.ATLR and trans-sylvian SAH were performed and related WM tracts en route to medial temporal region were presented in relation to the relevant approaches and surrounding neurovascular structures.The WM tracts most likely to be disrupted during trans-sylvian SAH along the roof of the temporal horn were the UF – and less commonly IFOF – at the layer of the external capsule, anterior commissure, anterior bend of optic radiations, and sublenticular internal capsule. Amygdaloid projections to the claustrum, putamen and globus pallidus, the tail of caudate and the peduncle of the lentiform nucleus were also in close proximity to the resection cavity. Fiber tracts most likely to be impaired during ATLR included the UF, ILF, IFOF, anterior commissure, optic radiations, and, less likely, the vertical ventral segment of the arcuate fascicle.Both ATLR and trans-sylvian SAH carry the risk of injury to WM pathways, which may result in unpredictable functional loss. A detailed 3-D knowledge of the related connectional anatomy will help subside neurocognitive, neuroophtalmologic, neurolinguistic complications of epilepsy surgery, providing an opportunity to tailor the surgery according to patient's unique connectional and functional anatomy.     

Systematic Review of the Yield of Temporal Artery Biopsy for Suspected Giant Cell Arteritis

Purpose: To determine the positive yield (utility rate) of temporal artery biopsy (TAB) in patients with suspected giant cell arteritis (GCA).

Study Design: Systematic review (CRD42017078508) and meta-regression.

Materials and Methods: All articles concerning TAB for suspected GCA with English language abstracts from 1998 to 2017 were retrieved. Articles were excluded if they exclusively reported positive TAB, or only cases of known GCA. Where available, the pre-specified predictors of age, sex, vision symptoms, jaw claudication, duration of steroid treatment prior to TAB, specimen length, bilateral TAB, and use of ultrasound/MRI (imaging) were recorded for meta-regression.

Results: One hundred and thirteen articles met eligibility criteria. The I² was 92%, and with such high heterogeneity, meta-analysis is unsuitable. The median yield of TAB was 0.25 (95% confidence interval 0.21 to 0.27), with interquartile range 0.17 to 0.34. On univariate meta-regression age (coefficient 0.012, p = 0.025) was the only statistically significant patient factor associated with TAB yield.

Conclusions: Systematic review revealed high heterogeneity in the yield of TAB. The median utility rate of 25% and its interquartile range provides a benchmark for decisions regarding the under/overutilization of TAB and aids in the evaluation of non-invasive alternatives for the investigation of GCA.     

Clinical features,surgical treatment,and outcome of intracranial aneurysms associated with moyamoya disease

The objective of this study was to elucidate the clinical features, surgical treatment, and outcome of intracranial aneurysms associated with moyamoya disease. We retrospectively reviewed a consecutive cohort of 79 moyamoya disease patients with 98 intracranial aneurysms at Beijing Tiantan Hospital. Clinical features, radiological findings, and outcomes were analyzed. Prevalence of intracranial aneurysms in patients with moyamoya disease was 3.9%. The mean age at diagnosis was 39.0 ± 12.4 years, with 1 peak distribution in patients from 40 to 50 years of age. The ratio of women to men was 1.00:1.03. Familial occurrence was 2.5%. The initial symptom was hemorrhage or ischemia in 56 (70.9%) and 23 patients (30.4%), respectively. Most patients presented with Suzuki stage 3 or 4. Seventy-nine cases had 98 aneurysms. Of the 98 aneurysms, sixteen aneurysms (16.3%) were treated by microsurgery and 7 by endovascular procedures, 13 aneurysms were conservatively managed, the remaining 62 were treated with revascularization alone. After a median nine-month angiographic follow-up, 18 aneurysms received clipped or embolized were completed occlusion, 18 aneurysms received conservative treated or coating were remained stable. Of the remaining 63 aneurysms that were treated with revascularization alone, 59 of 63 aneurysms remained stable, and 2 were obliterated, whereas 1 aneurysm ruptured during the follow-up. Hemorrhage was the most common symptom in intracranial aneurysms associated with moyamoya disease. Revascularization surgery may improve cerebral circulation, decreases hemodynamic stress and prevent the rupture of intracranial aneurysms.