Western countries appear to be affected by a ‘hidden' epidemic of neurological disease, and it is not just ageing that is to blame, a new study suggests.

According to UK researchers, environmental factors ‘must play a major part', such is the increase in these diseases.

They analysed data from 21 Western countries that covered the period 1989 to 2010. They found that overall, dementias are starting in adults a decade earlier than they used to.

Meanwhile, deaths from neurological diseases in people aged between 55 and 74 have increased significantly, while in people over the age of 75, the rate of death from neurological conditions has practically doubled in every Western country over the last two decades.

"The rate of increase in such a short time suggests a silent or even a ‘hidden' epidemic, in which environmental factors must play a major part, not just ageing. Modern living produces multi-interactional environmental pollution but the changes in human morbidity, including neurological disease, is remarkable and points to environmental influences," commented lead researcher, Prof Colin Pritchard, of Bournemouth University.

Environmental changes over the last 20 years have resulted in much more air transport, motor vehicles, insecticides and electro-magnetic fields, which can be generated by sources ranging from X-rays to electricity pylons.

Prof Pritchard noted that some of the results can be put down to the fact that there are now more effective treatments for cancer and heart disease, ‘while there have been less advances in the treatment of neurological conditions'.

However, he believes that environmental changes are key.

"These results will not be welcome news as there are many with short-term vested interests that will want to ignore them. It is not that we want to stop the modern world but rather make it safer. Essentially, it is time for us to wake up and realise that a major problem we now face is unprecedented levels of neurological disease," he said.

He added that this increase in neurological diseases is having a major impact on patients, their families and carers, and health services which are becoming ‘swamped' with cases.

Details of these findings are published in the journal, Surgical Neurology International.