The number of deaths due to neurological disorders like Alzheimer's and Parkinson's disease, stroke and epilepsy has increased by 36.7 per cent worldwide between 1990 and 2015, a study says.

In 2015, these diseases comprised of 16.8 per cent of global deaths, according to the report by the Global Burden of Disease (GBD) project published in the journal The Lancet.The number of global disability adjusted life years (DALYs) increased 7.4 per cent over the past 25 years, while in 2015 they accounted for 10.2 per cent of DALYs worldwide."One of the main reasons for the increase in neurological disorders is longer life expectancy," said Vasily Vlassov, Professor at the National Research University Higher School of Economics in Russia."People live longer and, accordingly, suffer dementia more often than several decades ago," Vlassov explained, adding "another reason is a growing population". The most prevalent neurological disorders were tension-type headaches (about 1,500 million cases), migraine (about 1,000 million), medication overuse headaches (about 60 million), and Alzheimer's disease and other dementias (about 46 million cases). 

In addition, the rates of communicable neurological disorders, stroke, and Parkinson's are higher in males than females, and the prevalence was higher particularly in children under five, the report said. The rates of cases per 100,000 was 15.7 per cent higher in Parkinson's, 2.4 per cent in Alzheimer's, 3.1 per cent in motor neuron disease, and 8.9 per cent higher in brain and nervous system cancers.However, the number of deaths and DALYs per 100,000 people caused by stroke and communicable neurological disorders decreased by 26 and 29.7 per cent respectively between 1990 and 2015, the report noted.