Part of the show Brainwashing and the Science of Pain
Wynn, in Northampton asked:
How does meningitis affect the brain? I had it when I was younger and I think it might have affected my ability to remember things.
There are a couple of issues with this. Meningitis comes in two flavours or two forms. There's a viral flavour and a bacterial flavour and by far and away the most serious form of meningitis is the bacterial form.
This is because, in this instance, you have bacteria physically growing and multiplying in the fluid that surrounds the brain. When they do that they secrete lots of factors that promote intense inflammation and can damage the underlying brain.
One of the other things they do is cause inflammation around the nerves that flow through the infected area; these include the auditory nerve that supplies your ears and connects your ears to the brain.
If you have a lot of inflammation around these nerve roots, it can unfortunately pinch them off and cause permanent deafness.
There are also other problems of course. If people aren't treated in time with meningitis it can be very serious and can result in people dying. Fortunately we now have vaccines that have been introduced and this has brought the mortality right down. In the UK, for instance, in young children, there was a type of meningitis caused by meningitis strain C and that was introduced as a vaccine about five years ago.
Since then there's been a dramatic reduction in the number of cases. Among UK adults the most common form is strain B and this still remains a major problem and there is no consistent vaccine for this, so you should be on the look out for signs and symptoms.
These include a non-specific feeling grotty for a few days first, and then you start to get a headache. Then you can start to feel quite sick and get scared of the light and your neck can become very very stiff. Then people start to develop a rash which is non-blanching. In other words if you press on the rash with a wine glass or something and look through the glass, the rash doesn't go away.
If you have those signs and symptoms, you ought to get checked out by a doctor.
The other flavour of meningitis is viral meningitis and this isn't necessarily so bad. This is when a virus infects the membranes that surround the brain and it causes many of the same symptoms but usually these cases are self-limiting, which means they just go away and get better of their own accord.
But, if it's caused by the herpes virus (HSV-2, usually) which is the same virus that can cause genital herpes, then you might need to go into hospital for a while and have a drug called aciclovir, which knocks the virus on the head.
Thankfully, though, most viral menigitis cases don't have long term sequelae, unlike the bacterial form...