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Catfish Dive & Safari
Dive Medical questions & answers for common scuba diving conditions and illness provided in conjunction with the doctors at the London Diving Chamber and Midlands Diving Chamber.
All Categories » Central Nervous System » Nerves


Recently while diving, I received a blow to the head during a backward roll entry (buddies 15ltr steel tank), after the dive I started to suffer headaches and trouble focusing while reading.

The local A&E department checked me over and said it was post concussion syndrome, which would improve on its own. After 2 months the headaches were still quite bad so I made an appointment to see the A&E consultant. As a precautionary measure having already had a skull x-ray he arranged for me to have a head scan. The scan showed up what he thought might be an arterial angioma, which would have stopped me diving again. I was then referred to a consultant neurologist as an outpatient, who after checking my scan showed them to a senior consultant neurologist at Atkinson Morley, they both agreed that what I had was a small venous angioma which I'd had from birth and as I'd never suffered from fit or blackout they could see no reason why it should affect me in the future.

The consultant confirmed the post concussion syndrome headache would improve and that I could continue diving (she is willing to confirm this in writing if reqd.) As I am about to do an instructor course, do you see the venous angioma as a problem and would it affect an H.S.E. medical?


I think that if you have 2 consultants from one of the world's top neurological hospitals agreeing that this angioma poses absolutely no risk of causing you any problems, then who am I to argue!

The risk here is obviously that a lesion within the skull cavity could cause you to have a fit. But some are more fit inducing than others, and yours falls into the ultra-low risk category. It seems that the neurologists feel that it had absolutely no causal factor with your headache and was just a benign coincidental finding.

However I would ask you to ask them for the risks that this angioma could increase in size. If it is 0% then you would be OK to instruct, however if there is a chance it could get bigger and pose a fit risk later then you may well need regular MRI if you wanted to continue diving.

Finally it was an interesting diagnosis you had there from A&E. Post Concussion Syndrome when concussion never happened, I assume as you completed the dive. It must have been the August changeover!


I'd like to ask your advice, as an volunteer instructor for Scubatrust (who teach those with disabilities to dive). My 'day job' is being a final yr med student, but I am a long way from having the necessary experience to assess a man I have been asked to see with MND.

He was turned away last spring from an organisation who teach divers with disabilities, on the grounds that he had some airway difficulties during initial pool training. In recent years he has dived (untrained) on holiday in Australia and Egypt.

I sent him for (yet another) medical, which confirmed he was fit to dive. Yet, I have spoken to his previous instructor who says I would be mad to take him in the water. This instructor feels the diver is at risk from his bulbar palsy, while the doctor who examined him does not - but says I should trial the diver in the pool on mask and reg removal.

In the past, this man has had some minor difficulty with swallowing when his disease is very active, but at present his gag reflex is intact. His voice is moderately affected by the effects of the disease.

This man is very determined to dive, and if it is at all possible for him to do so safely I will train him on an IAHD level to dive with 2 trained assistants, but initially I must decide if is safe or not to assess him in the pool.


This is an interesting case where we have to weigh up several issues here. MND or motor neurone disease is a terrible neurological condition where due to degeneration of certain areas of the spinal cord and cells in the nerves that supply the throat, tongue and pharynx, the sufferer can find that they progressively become more disabled but with unaffected mental functioning. Sadly it is a rapidly progressive disease and if there are symptoms of "bulbar palsy" i.e. inability to swallow and problems with speech then death can often be within 2 years. So you can see how determined this man may be to dive right now as the future is bleak.

As he has been passed as fit by a diving doctor, then I would agree with their decision, but I would also add that the best people to assess their bulbar palsy and how much airways protection he has at this stage is a speech therapist.

Because MND can be rapidly progressive, if the speech therapist confirms the doctors findings then its not a situation like other medicals where you are passed as fit for a year or so, I think the assessments should be very frequent if he continues to dive, even weekly.

The real problem with this bulbar palsy is that it affects his ability to protect his airways if he were to swallow or inhale any water. If unaffected people get water in their mouth and throat, then the epiglottis comes down over the upper airways to stop it running down to the lungs. This may not be the case with your diver and it would obviously put him at risk underwater, however as you know most competent divers don't need this function as they never lose a reg or let water get in the mouth during a dive.

So my suggestion is that you get him checked and teach him to dive only if his airways protection is up to it and get it checked frequently as there will come a point where it is not good enough to dive and that could come rapidly, but again he has a terrible disease with a poor prognosis and a good doctor would understand this and try to help all they could to make his remaining time as fulfilling as possible.


I have been on long sick leave since the beginning of July 1999, with Post Viral Fatigue and trigeminal neuralgia. With the Fatigue Syndrome I sometimes feel perfectly OK, but some days I feel totally drained sleeping for periods varying between four and forty hours. There is no way of predicting when the good or bad days are going to be , but they are each unmistakable. With the neuralgia I have a permanent numbness on the right side of my skull. I also experience various aches and pains in the right side of my face, jaw, neck and shoulder, which mainly occur in the morning. I occasionally take Diclofenac to ease the pain. As a 54 year old safety conscious PADI Advanced diver, I would appreciate your opinion to whether there is any reason why I should not carry on with my beloved hobby.


Your diagnosis of Post Viral Fatigue syndrome is not a bar to diving in itself but there are a few issues surrounding the problem that you should be aware of. When you get your phases of extreme tiredness you can see the problems that would ensue if you were to dive. You may well be in a situation where your buddy needs your physical assistance, so if you were too weak or unable to help this could be disastrous. You say you cannot predict when the bad days are going to be so what would happen if you had planned on diving on a certain day and this fatigue were to set in. Well, I think that you would have to cancel the planned diving as your fatigue would endanger both yourself and your buddy.

Other issues are brought up with your problem of trigeminal neuralgia. This is a condition where the trigeminal nerve, which supplies the sensation to large parts of the face, can cause extreme pain to the area where it causes sensation. The fact that you have numbness there makes me suspect a different diagnosis and it would be a good idea to see a neurologist to confirm that it is what you think it is.

You also have a range of other symptoms in your shoulder and jaw, and what I always suggest is that you see a diving doctor in your area to get a good map of the numbness and where exactly the aches are. The reason for this is that if you ever had a problem dive that could cause a bend, such as an uncontrolled ascent, then your pre-existing problems could easily be construed as the signs of decompression sickness. But if you were to be able to tell the examining doctor what you had before then this wouldn't be mistaken for an episode of neurological DCS. The other point is that in many dive centres over the world will make you fill in the Health Declaration Form before they let you dive with them. You are obviously going to have to tick the Yes box to a few of the questions, and it is always easier to have a Fit to Dive Certificate with you then as they are well within their rights to ask you to see a local doctor, who may be hard to track down, to pass you as fit if you don't have this certification.

Finally, one of the treatments that is often offered to people with trigeminal neuralgia is a drug called carbamezepine. But this medication cannot be taken if you want to stay diving, due to its effects underwater. It can cause narcosis at far shallower depths than usual and so can affect judgement and ability at a depth where you may have to be more alert due to deco stops, so stay with a simpler pain killer.


My girlfriend has passed her PADI Open water diver, she now discovers she has Multiple Sclerosis (relapse and remitting) she has no symptoms and has had a diving medical. Should she go on to do her advanced open water diver.

Also can you dive with silicone implants?


The current regulations are that anyone who has MS and dives should stay out of the water for 1 year after a relapse of the problem, and in that year should not experience any symptoms of the problem or worsening of the condition.

So if your girlfriend has been free of the problem for 12 months then she is OK to go in again. As for an advanced course... MS can easily mimic DCS, and I would advise that she stays out of the deep and just depth limits to 20m and preferably use nitrox as it is safer if used with air tables. This is because if she surfaces after a deep dive and has any sort of neurological symptom, then it will always have to be assumed to be a bend, rather than a slight problem with her existing MS. This may lead to unnecessary recompressions in a chamber.

Before each diving season I would also recommend a full neurological assessment to map what problems she has prediving, such as any weakness or sensory loss as again this could be misconstrued as a bend too.

As for silicone, I have spoken to a couple of plastic surgeons, and they both say that the modern gel type implants are completely safe, however the old style implants which are silicone bags filled with fluid may have a very small chance of leakage if pressures are extreme.

However I assume she is not diving to the bottom of the Marianas trench, then the only extreme pressure she will get is from a drysuit squeeze... or hands. The former is more likely at the bottom of Stoney Cove, the latter in the bacon sandwich queue.


Sorry to trouble you but I have a friend due to travel to Cyprus soon and she had every intention of learning to dive whilst there. About 6 weeks ago she contracted Bell's Palsy. There has to date been no real improvement although she is fine in herself. Should she continue with her plans or shelve them until there is either a full or significant improvement in the condition? Or would this be something that would need to be assessed by a diving doctor?

The implications I can think of are the fact that her left eye will not close at the moment and she is obviously now a bit "saggy" around her mouth!

Will she be okay to learn to dive?


Imagine waking up one morning, tottering downstairs for that half asleep bowl of cereal, and the milk won’t stay in – it keeps pouring out of your mouth. Something similar happened to George Clooney when he was a boy, and an astute physician diagnosed him with Bell’s Palsy. It was during his first year in high school too – not a good time to have half of your face paralysed, although it doesn’t seem to have done his career much harm.

Named after Charles Bell, the Scot who first described it, it is a peculiar disease of a single nerve (the facial nerve) which controls the muscles of facial expression. Only one side of the face is affected, so sufferers develop a sort of Billy Idol sneer when they smile, and cannot wrinkle one side of their forehead when they frown. It’s most often impossible to find a cause although some cases occur after shingles and it is more common during pregnancy. Interestingly there are some cases that have been caused by diving; air expanding in the middle ear on ascent can exert pressure on the facial nerve (which passes close by), causing a reversible Bell’s Palsy, much like the temporary pins and needles you get when you bang your unaptly named “funny bone”. There is no reliable treatment but most cases resolve on their own in 2 to 3 weeks, and almost all within a few months.

As far as your friend’s diving goes, the implications are several: the ones you mention are significant, in that an eye that does not shut properly is susceptible to injury or infection if her mask comes off. Trying to hold a regulator in a saggy mouth is a bit haphazard also, and might expose her to an increased risk of salt water inhalation or free flows. To dive or not? That would depend on the severity of the symptoms but she would be best off being assessed by a dive doc. I suggest it would be better to wait until all the symptoms have cleared up before learning to dive.


I am 63 years of age, have been diving since 1994, am qualified to Advanced Open Water with PADI and have completed about 80 recreational dives always in warm climates, e.g. Red Sea, Great Barrier Reef, British Virgin Islands, etc. I was diagnosed some time ago with Peripheral Neuropathy which was mild then but has increased in severity over the years. Luckily I only have problems with my toes/feet, e.g. numbness, pins and needles, burning sensations, occasional cramps, all the usual PN stuff. I take no medication for this but take Lansoprazole (15mg) for Barrett's Oesophagus. Otherwise I am reasonablyfit for my age and take 30 mins of fairly testing cross-country machine training 5 times a week.

Do you perceive any problems related to the PN with me continuing scuba diving on a strictly recreational basis?


Not really with the peripheral neuropathy. This illness where nerves in the periphery stop doing what they are supposed to do can be a real pain, as I am sure you know. But the deal with diving is that as long as you have sufficient strength there to fin, haul out a buddy or get back on the boat then that should be OK. It is worth seeing a dive doc to get passed as fit, as well as getting a neurological mapping of your deficit. Numbness and pins and needles are classic bends symptoms, so you need to have a good idea of what's going on baseline, as it could save 5 hours in a chamber if you had a problematic ascent and an over zealous doctor.

The Barrett's though is an issue. This is caused by hyperacidity in the oesophagus, and needs the antacids to prevent pain and burning in this tube. As long as it does not affect your diving, causing reflux or pain when you are horizontal, then cool. If you are a gastric belchy sort of diver then there could be a risk of an acid vomit on a dive, so get that all checked out when the doc is stroking your tootsies with cotton wool before jabbing a pin into big toe.


I hope you will be able to give me some information about my current situation regarding diving. At the beginning of December last year I fell through a glass window. I severed the main artery and median nerve in my left upper arm. The scars have now healed and my strength is coming back. However my hand is still numb and I am only able to move the base joints in my thumb and index finger due to the severed nerve. I have been told that the nerve will have to fully grow back before all the symptoms disappear. What impact does this have on being declared fit to dive, as my self declaration is due at the beginning of May and will need to have a medical?


In these sort of cases, it's not so much the injury, but the level of recovery, and how it specifically relates to diving and your responsibilities as a good buddy.

My first thought is that is your trigger finger for your inflator hose. It is also the hand you may need to grab your buddies occy if you have an out of air situation.

Likewise if you are having to lift a diver up from the deep and keep their reg in their mouth, you are going to need both hands functioning.

So, from this logic, I would say wait until the power has increased in these digits. Work on the physiotherapy to get full power and function too.

When it is strong enough to do all the above, you may have a bit of sensation loss still. Get this mapped by a dive doctor, as you don't want it to be mistaken for a cardinal sign of a bend if ever you have a rapid ascent. 5 unnecessary hours in a pot could be avoided.


I am writing to you following a referral from Phil Howard from London/Surrey Scuba. I spent the weekend attending the PADI Open Water Referral Course, but unfortunately did not complete the full set of confined dives.

While underwater, I experienced a strange pins and needles sensation in my finger tips, on the outer sides of my hands and lower arms. I sometimes have a swollen feeling in my fingers when I am out running and mentioned this to Phil. He felt, given these experiences it would be a good idea to mail you for advice before continuing with my confined dives, and eventually the open water ones. While the pins and needles feeling subsided a short while after I left the pool, and though this may not be anything to worry about, I just wanted to double check to be sure.


You should be fine. For starters, this has nothing to do with nitrogen, bends or whatever. DCS does not come on under water and go when you get to the surface. With tingling, pins and needles, or paraesthesia as we docs call it to seem intelligent, it might have more to do with the nerves in your arm. A BCD can cut up into your armpits, crunching a nerve and cause these symptoms. Over breathing due to anxiety can also cause these symptoms. So can a borrowed wetsuit tight around certain body parts.

I don't know what's going on with your hands when you jog. Perhaps God's punishment for being so fit. A herring with a pinkish tint methinks.

So do not worry, get back in the water, get a loose BCD, custom wettie and if it does continue, go see a neurologist.


Hi... I was diagnosed with multiple sclerosis (MS) in 2000 and whilst I have the odd niggle, relapses are happening at about 3 - 4 year intervals. These are not major as such and thus far I have always recovered pretty much 100% with rest. So far, I know when I am overdoing things and heading for a problem, which when I back off and rest, usually averts any major or long lasting.

I qualified OW in October, and to be honest, as I wasn't taking any medication (never have before) I didn't actually think about a dive medical as I have been fit and well, doing a full time active job etc. However, over Christmas, I have had some problems with my right arm (usual place it affects) with the pins and needles, numbness, nerve pain etc., waking me at night and some loss of grip to the right hand. It has settled fairly well now but I am still taking the diclofenac sodium 3 times a day, the tramadol only when the pain wakes me at night as these space me out too much. I would never consider diving if I didn't feel 100% okay on the day but will I be okay to dive whilst taking diclofenac? My husband has just presented me with the flight tickets etc., for a diving trip to Dahab this Thursday!


A nice surprise to be sure. I can reassure you on that point immediately – there are no problems taking diclofenac on a dive.

MS though is worth a bit of didactic discussion though. It's a neurological illness involving the central nervous system (brain, spinal cord and optic nerves). The CNS nerve fibres are surrounded by an insulating fatty sheath composed of myelin, which aids in the transmission of electrical impulses. In MS, myelin is lost and replaced by areas of scarring, termed sclerosis – often in multiple disparate areas, hence the disease's name. As a result, conduction in the nerves is disrupted, giving rise to a broad range of symptoms – cognitive impairment (memory difficulties, attention and concentration deficits), sensory manifestations (pins and needles, numbness), bowel or bladder disturbances, and visual problems to name the more common. Anyone with a passing knowledge of DCI will perhaps recognise all of these as possible symptoms, and historically this has been a major issue – diagnostic confusion between MS and DCI. Although a delay is possible, precautions such as keeping an up to date record of a MS diver's neurological deficits should allow a clued-up doc to distinguish the two. There's no evidence that diving has any detrimental effect on the disease process, but sometimes MS relapses can be triggered by over-exertion or extremes of temperature. These factors should be borne in mind when considering dive trips and evaluating conditions on the day.

Some drugs used to treat MS and its symptoms might also have an impact on in-water safety, so best discuss any new medications with a dive doc before jetting off. Have a great trip.

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