What is peripheral neuropathy? An expert neurologist explains - Online Interview

0:08 as a neurologist you divide the nervous system into the central nervous system by which i mean the brain and the spinal cord and the peripheral nervous system are the nerves which come out from the spinal cord they become nerve roots then they form a collection of nerves in the armpit or the the pelvis called the plexi and then they come out into the arms and legs and what you have in the peripheral nerve are nerves which supply sensation but also motor function by which it enables you to move your arms and legs and peripheral nerve disorders in a broad sense are diseases or processes which affect the nerve roots the collection of nerves or plexuses or

0:53 the nerves which are in the hands and feet and that is the label we give the disorders affecting this anatomical area of the nervous system the number of causes of neuropathy are as long as my arm you know if you look at the textbooks there'll be two big volumes that cause neuropathy but in a very broad sense the commonest cause of neuropathy in the world is diabetes or pre-diabetes and in some parts of the world the other common cause is in fact hiv infection but then the other causes that one always has to think about are inflammation of nerves because that is potentially a very treatable cause of peripheral neuropathy you can have neuropathy if there's an

1:39 underlying cancer in the body what we call paraneoplastic drugs medications very important cause of neuropathy and as a neurologist you have to be up to date about all the new drugs what causes neuropathy because otherwise you may miss the diagnosis people can have neuropathy because of lack of vitamins so vegetarians for example are very predisposed to having neuropathy due to vitamin b12 deficiency people drink too much alcohol and don't eat good food thiamin deficiencies gives you a painful neuropathy you can also get neuropathy due to mechanical causes so for example if you have a nerve in your wrist which is being trapped carpal tunnel that'll give you a neuropathy affecting one particular nerve

2:25 as i've said infections hiv worldwide especially in tropical countries leprosy is an important uh cause of neuropathy which is very treatable you also get neuropathies due to genetic conditions so there are genes which are passed down in the families the common is called chakra mary tooth but perhaps importantly and what's changed in my career span is that we have a genetic neuropathy now which is treatable due to amyloid ttr neuropathy which is unheard of when i qualified you wouldn't dream that you could treat a genetic neuropathy but now you can so those are the sort of main is that when i see patients that are going through your mind trying to work out what the diagnosis is there's a list that you're just going through to sift

3:10 through and try and work out what the answer is sensory nerves are the ones which transmit sensation from the hands and feet to the brain and if they're damaged what people experience is either numbness which is a lack of sensation but interestingly you can also get pins and needles or you get pain or you get what's called halodynia so somebody touches the hands causes pain which is very abnormal because when damaged nerves fire away electrically they cause these painful symptoms so numbness and pain and pins and needles and sometimes it comes all together because the motor nerves can be affected you can get weakness so people for

3:56 example may have foot drop so that when they walk they trip you can have weakness in the hands you can't open bottle tops or you can't use a computer pad properly opening the key in the door is difficult so you get weakness but also you get these sensory symptoms together or sometimes separately those are the main symptoms that people will be presenting with to to me a very important example where this can happen very acutely and people need to know about this is called gain barrier syndrome where they get paralysis very quickly within hours or days and it's a medical emergency it's triggered off by infections generally including alcovid so those are the symptoms that uh you get with peripheral neuropathy and very acutely you need to

4:42 worry about this condition called gain barrier syndrome again very treatable so the treatment really depends on the diagnosis and apart from the history and examination we use electrical tests to diagnose peripheral neuropathy we use a range of blood tests we may end up doing a lumbar puncture test and in about 30 percent when we have no answers from those tests we do a nerve biopsy or a skin biopsy and really the treatable causes are inflammation which we can treat with steroids or intravenous immunoglobulin if you have vitamin deficiencies or if you have an infection so the bottom line is that you treat the underlying cause and then with time you can expect some degree of regeneration

5:27 to come through our treatments do not cause regeneration of nerves you have to stop the process damaging the nerves and give time before you get regeneration of nerves so if it's diabetes you must control the diabetes as tightly as possible as an example so like in medicine generally the earlier you make a diagnosis of neuropathy as you would make of for example cancer then the chances of early treatment stopping the process causing the damage is better and you get more chance of recovery but there are certain conditions where once damage is done you're left with that fixed damage and you can't repair it yet but i think with

6:12 time we will have new treatments for nerve regeneration but that's all in the future you