Studies of bubbles formed on decompression in diving have demonstrated the importance of pulmonary filtration in the protection of the nervous system and that filtration is size dependant, as small bubbles may escape entrapment. Fluid and even small solid emboli, arresting in or passing through the cerebral circulation, do not cause infarction, but disturb the blood-brain barrier inducing what has been termed the 'perivenous syndrome'. The nutrition of areas of the white matter of both the cerebral medulla and the spinal cord depends on long draining veins which have been shown to have surrounding capillary free zones. Because of the high oxygen extraction in the microcirculation of the gray matter of the central nervous system, the venous blood has low oxygen content. When this is reduced further by embolic events, tissue oxygenation may fall to critically low levels, leading to blood-brain barrier dysfunction, inflammation, demyelination and eventually, axonal damage.
cleareaching wrote:However, when diving, the veins that bring the blood to the area carry not only oxygen but nitrogen as well. And there is a strong possibility that this nitrogen, which arrives at increased numbers at the points of inflammation in the brain and the grey matter, will activate symptoms.
cleareaching wrote:I've just concluded a round with doctors on this same topic. I've always wanted to dive, but when I was very young I didn't have the money, then I got married and became a mum and I've just waited for my son to grow up and take him go diving together. In the meantime, I was diagnosed with MS (four and a half years ago, one episode, symptom-free ever since) but this summer, that my son was old enough to go diving, I took him and myself to a scuba diving school where I had to fill in this form and there is this question about neurological problems - I'm an honest person, so I explained my condition and they asked me for a doctor's certification to let me dive.
So I went to my neurologist first. He sent me for another round of MRIs etc. but the truth is he didn't have any clue whatsoever. He only said that he was afraid of underwater pressures.
Then I found out there was this medical center exclusively for divers with doctors specialising in HBO (hyperbaric oxygen) and diving. So I went there and I saw this doctor who is also head of the naval hospital's diving department. What he told me was that it is dangerous for me to go diving and he explained: MS causes these demyelinating foci (which in reality are inflammations) here and there in the brain and grey matter. What the organism does wherever there is inflammation is to send more oxygen at the point, because that's what it does to help it heal. This translates into more blood flowing to the area.
However, when diving, the veins that bring the blood to the area carry not only oxygen but nitrogen as well. And there is a strong possibility that this nitrogen, which arrives at increased numbers at the points of inflammation in the brain and the grey matter, will activate symptoms.
So, scuba diving is not advisable for people with MS who want to learn how to dive, because they run higher risk than any person without MS. If someone used to be a diver, however, and would like to continue, there is always the NitroX method, that causes lower nitrogen concentration in the body during diving. That's what the doctor said to me just yesterday and I wanted to share this with you. I hope you'll excuse my slips in English, as I'm not a native speaker.
I won't get at all into how I felt when the doctor offered me his hand and told me "I'm sorry"...
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