Disease burdens from environmental tobacco smoke in Korean adults

In this study, we estimated the disease burdens attributable to environmental tobacco smoke (ETS) exposure in Korean adults in 2010 and analyzed the trend of that from 2005 to 2010. We obtained information on the study population from the 2010 Cause of Death Statistic and estimated the ETS-attributable fraction using data from the Korean Community Health Survey and the Korean National Health and Nutrition Examination Survey. The numbers of ETS-attributable deaths in female and male non-smokers were estimated to be 4.1 and 69.6?% of the numbers of deaths attributable to current smoke, respectively. The deaths attributable to ETS were larger in female than in male non-smokers (710 vs. 420). The ETS-attributable deaths increased slightly in 2005–2008 but decreased in 2009–2010. The number of potential years of life lost from ETS was 9077.24?years in 2010. If there were no exposure to ETS in adult non-smokers, we would expect to see 1130 fewer deaths (9.9?% of the deaths from current smoke). The results suggest that ETS poses considerable disease burdens for non-smokers, especially women, in Korea.     

A modality-specific somatosensory evoked potential test protocol for clinical evaluation: A feasibility study

ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.     

Long-term effects of concussion on relevancy-based modulation of somatosensory-evoked potentials

ObjectiveThe purpose of this investigation was to better understand the effects of concussions on the ability to selectively up or down-regulate incoming somatosensory information based on relevance.MethodsMedian nerve somatosensory-evoked potentials (SEPs) were elicited from electrical stimulation and recorded from scalp electrodes while participants completed tasks that altered the relevance of specific somatosensory information being conveyed along the stimulated nerve.ResultsWithin the control group, SEP amplitudes for task-relevant somatosensory information were significantly greater than for non-relevant somatosensory information at the earliest cortical processing potentials (N20-P27). Alternatively, the concussion history group showed similar SEP amplitudes for all conditions at early processing potentials, however a pattern similar to controls emerged later in the processing stream (P100) where both movement-related gating and facilitation of task-relevant information were present.ConclusionsPreviously concussed participants demonstrated impairments in the ability to up-regulate relevant somatosensory information at early processing stages. These effects appear to be chronic, as this pattern was observed on average several years after participants’ most recent concussion.SignificanceGiven the role of the prefrontal cortex in relevancy-based facilitation during movement-related gating, these findings lend support to the notion that this brain area may be particularly vulnerable to concussive forces.     

Advances in understanding the mechanisms of retinal degenerations

Photoreceptor death is an important contributor to irreversible vision loss worldwide. In this review, I outline our work examining the role that purines, such as adenosine triphosphate (ATP), have in normal retinal function and in retinal disease. Our work shows that the actions of ATP, mediated by P2X receptors, are expressed in various retinal layers including photoreceptor terminals, and when stimulated by excessive levels of ATP is associated with rapid death of neurons. Treatment with a compound that blocks the action of P2X and some P2Y receptors reduces photoreceptor death in a mouse model of retinal degeneration. Our observations not only provide a means for developing a potential treatment for reducing photoreceptor death, but also provides a novel way of studying the neural plasticity effects that develop in the inner retina following photoreceptor death. There are a range of inner retinal changes that could influence the effectiveness of retinal prostheses. Indeed, using an ATP-induced degeneration model, we established that the amount of electrical stimulation required to elicit a response in the visual cortex was affected by the level of glial scarring. However, changes in P2X7 receptor expression by OFF ganglion cells during retinal degeneration can also be exploited by photoswitches to restore light sensitivity to degenerated retinae. Finally, our work has also considered how P2X7 expression by innate immune cells, and its role as a scavenger receptor, contributes to age-related macular degeneration (AMD). Our results show that loss of P2X7 function is associated with thickening of Bruch's membrane as well as increased risk of advanced disease in people with AMD. Overall, our work over the last 20 years highlights the importance of purinergic signalling in normal retinal function and retinal disease and suggest that developing therapies that target P2X7 function could be of benefit for these diseases.     

Vestibular dysfunction in patients with auditory neuropathy detected by vestibular evoked myogenic potentials

ObjectivesThis study aimed to determine vestibular involvement in patients with auditory neuropathy (AN) using ocular vestibular evoked myogenic potential (oVEMP), cervical vestibular evoked myogenic potential (cVEMP), caloric tests, video Head Impulse Tests (vHIT), and Suppression Head Impulse Paradigm (SHIMP) tests.MethodsTwenty-two patients with AN (study group) and 50 age-and-gender-matched healthy subjects (control group) were enrolled. All patients underwent air-conducted sound oVEMP and cVEMP tests. In the study group, 20 patients underwent a caloric test, 10 patients underwent a video Head Impulse Test (vHIT), and nine patients underwent the Suppression Head Impulse Paradigm (SHIMP) test.ResultsSignificant differences in VEMP abnormalities were found between the two groups. Most AN patients showed no VEMP response, while only a few patients showed VEMP responses with normal parameters. Some AN patients presented abnormal VEMP parameters, including thresholds, latencies, and amplitudes. The abnormal rate (including no response and abnormal parameters) was 91% in the cVEMP test and 86% in the oVEMP test. No significant difference was found between oVEMP and cVEMP abnormalities. AN patients exhibited a 70% abnormal rate in the caloric test. Most AN patients showed normal VOR gains. Most patients showed no overt corrective saccades in vHIT, and exhibited normal anticompensatory saccades in the SHIMP test.ConclusionMany AN patients experience vestibular dysfunction, which may be detected by using a vestibular functional test battery.SignificanceVEMP abnormalities might reflect the status and degree of vestibular involvement in AN.     

An unusual case of cutaneous Waldenström macroglobulinemia with the MYD88 L265P mutation

Waldenström macroglobulinemia is a lymphoplasmacytic lymphoma with bone marrow involvement and a monoclonal IgM gammopathy. Infiltration of the skin by neoplastic cells is very rare, and it can be difficult to distinguish from marginal zone lymphoma. The MYD88 L265P mutation is strongly associated with Waldenström macroglobulinemia, and it may be helpful in differentiating the two disorders, although the presence of this mutation is not specific, and other factors must be considered when making the final diagnosis. We present a diagnostically challenging case of cutaneous Waldenström macroglobulinemia in which the MYD88 L265P mutation was identified in the skin but not in the bone marrow, due to a low tumor burden.