Hearing tests can fail to diagnose hearing loss: study

April 21, 2017

Washington, Apr 21: A team of US researchers has revealed that the traditional clinical hearing tests often fail to diagnose patients with a common form of inner ear damage, which otherwise might be detected by some behavioural tests.

HearingAccording to researchers, the reason why some forms of hearing loss may go un-recognised in the clinic is that hearing involves a complex partnership between the ear and the brain and the central auditory system can compensate for significant damage to the inner ear by turning up its volume control, partially overcoming the deficiency.

This type of "hidden hearing loss" paradoxically presents itself as essentially normal hearing in the clinic, where audiograms -- the gold-standard for measuring hearing thresholds -- are typically conducted in a quiet room.

"You can have tremendous damage to inner hair cells in the ear that transmit information to the brain and still have a normal audiogram," said lead study author Richard Salvi from University at Buffalo.

"But people with this type of damage have difficulty in hearing in certain situations, like hearing speech in a noisy room. Their thresholds appears normal," Salvi added. About 95 percent of sound input to the brain comes from the ear's inner hair cells.

"Ear damage reduces the signal that goes the brain and it results trouble in hearing, but that's not what's happening here, because the brain "has a central gain control, like a radio, the listener can turn up the volume control to better hear a distant station." Salvi stated.

The sound is converted to neural activity by the inner hair cells in the auditory part of the ear, called the cochlea.

Sound-evoked neural activity then travels from the cochlea to the auditory nerve and into the central auditory pathway of the brain. For people with inner hair cell loss, sound is less faithfully converted to neural activity in the cochlea.

It is not clear how many people might have this type of hearing loss, but Salvi noted in the journal Frontiers in Neuroscience that it is a common complaint to have difficulty hearing in noisy environments as people get older.

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Agencies
June 17,2020

Leading physicians are celebrating a small dose of good news that arrived Tuesday about dexamethasone, a cheap and widely used steroid shown to be able to save lives among COVID-19 patients, but also cautioning against releasing study results by press release during a global health emergency, like in the case of the latest dexamethasone study by University of Oxford.

"It will be great news if dexamethasone, a cheap steroid, really does cut deaths by one-third in ventilated patients with COVID19, but after all the retractions and walk backs, it is unacceptable to tout study results by press release without releasing the paper", Atul Gawande, surgeon and CEO of Haven Healthcare, tweeted.

"Bottom line is, good news," Dr. Fauci, America's foremost infectious diseases expert told a US newswire on Tuesday, soon after the dexamethasone results were announced in the UK.

Fauci, who has long championed the therapeutics-first view said that dexamethasone is a "significant improvement" in the available therapeutic options currently available.

On Medical Twitter and Facebook, doctors broadly agree that dexamethasone use aligns well with the way COVID19 attacks the body's immune system. Fauci said the results in the Oxford study make "perfect sense" in that context.

"We should see the number of people who actually survive go up, if the study holds up," virologist and epidemiologist Dr. Joseph Fair told a television network.

Global coronavirus cases crossed 8 million on Tuesday. In the US, Texas and Florida are facing a new wave of cases after lifting lockdown orders earlier than medical experts recommended. Amidst the relentless graph upwards, the dexamethasone study results injected hope for better survival rates among those most seriously ill.

World Health Organization chief scientist Soumya Swaminathan welcomed the results from the randomised control trial.

Dr Eugene Gu, Founder and CEO of CoolQuit tweeted that he is "genuinely impressed" with the UK dexamethasone trial. This may be a "game changer", he wrote.

"There's no conflict of interest as dexamethasone is a generic steroid. The mechanism of action makes sense because steroids can reduce cytokine storms and overactive immune systems that makes COVID-19 so deadly. The number needed to treat is 8 ventilated patients which is great."

The Oxford study found that dexamethasone reduced deaths by 35 percent in patients who needed treatment with breathing machines and by 20 percent in those only needing supplemental oxygen. Dexamethasone was one of 5 drugs studied in a large clinical trial in the United Kingdom named RECOVERY, short for Randomised Evaluation of COVID-19 Therapy.

Peter Horby, chief investigator of the University of Oxford clinical trial, said dexamethasone is the first drug to be shown to improve survival in COVID-19. Details of the study have not been released. The trial organisers said they made their announcement via a news release because of "the public health importance of these results." According to Horby's public comments, there was a lot of initial resistance to studying steroids.

During the study, 2,104 patients were randomly selected to be given 6 milligrams of dexamethasone once a day (either by mouth or by intravenous injection) for 10 days. That group was compared with 4,321 patients who received the usual care alone.

Researchers estimated that dexamethasone would prevent one death for every eight patients treated while on ventilators and one for every 25 patients on extra oxygen alone.

UK experts have called the study results a breakthrough in the fight against the virus. The researchers have promised they would publish the results soon.

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April 17,2020

Washington DC, Apr 17: In recent research, scientists have linked the emotional, social and psychiatric problems in children and adolescents with higher levels of genetic vulnerability for adult depression. The study implies that the genetics passed from parents may be linked with psychiatric problems in children and adolescents and may also leading to depression in adults.

University of Queensland scientists made the finding while analysing the genetic data of more than 42,000 children and adolescents from seven cohorts across Finland, the Netherlands, Norway, Sweden and the UK.

Professor Christel Middeldorp said that researchers have also found a link with a higher genetic vulnerability for insomnia, neuroticism and body mass index.

"By contrast, study participants with higher genetic scores for educational attainment and emotional well-being were found to have reduced childhood problems," Professor Middeldorp said.

"We calculated a person's level of genetic vulnerability by adding up the number of risk genes they had for a specific disorder or trait and then made adjustments based on the level of importance of each gene We found the relationship was mostly similar across ages," Middeldorp added.

The results indicate there are shared genetic factors that affect a range of psychiatric and related traits across a person's lifespan.

Middeldorp said that around 50 per cent of children and adolescents with psychiatric problems, such as attention deficit hyperactivity disorder (ADHD), continue to experience mental disorders as adults, and are at risk of disengaging with their school community among other social and emotional problems.

"Our findings are important as they suggest this continuity between childhood and adult traits is partly explained by genetic risk," the Professor said.

"Individuals at risk of being affected should be the focus of attention and targeted treatment," Middeldorp continued.

"Although the genetic vulnerability is not accurate enough at this stage to make individual predictions about how a person's symptoms will develop over time, it may become so in the future, in combination with other risk factors. And, this may support precision medicine by providing targeted treatments to children at the highest risk of persistent emotional and social problems," Middeldorp added.

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Agencies
March 27,2020

New Delhi, Mar 27: The Centre has restricted sale and distribution of "hydroxychloroquine" declaring it as an essential drug to treat the COVID-19 patients and meet the requirements of emergency arising due to the pandemic.

The Ministry of Health and Family Welfare on Thursday made the announcement making it clear that the order "shall come into force on the date of its publication in the official Gazette".

In the order, the government declared that the Central government is "satisfied that the drug hydroxychloroquine is essential to meet the requirements of emergency arising due to pandemic COVID-19 and in the public interest, it is necessary and expedient to regulate and restrict the sale and distribution of the drug 'hydroxychloroquine' and preparation based thereon for preventing their misuse".

"Now, therefore, in exercise of the powers conferred by Section 26B of the Drugs and Cosmetics Act, 1940 (23 of 1940), the Central government hereby directs that sale by retail of any preparation containing the drug Hydroxychloroquine shall be in accordance with the conditions for sale of drugs specified in Schedule H1 to the Drugs and Cosmetics Rules, 1945."

The order came at a time when the novel coronavirus claimed 16 lives and infected over 600 people across India.

The announcement regarding ban of sale and distribution of the drug was made by the government earlier but it issued an official Gazette notification on Thursday signalling that hydroxychloroquine -- an anti-Malaria drug -- will work as a medicine for treating coronavirus infected patients as well.

Recently, the national task force for COVID-19 constituted by Indian Council for Medical Research (ICMR) has recommended hydroxy-chloroquine as a preventive medication.

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