By Dawn M. Richardson, MD, FACEP
Dear Doctor Richardson,
I am a 50-year-old former racer who has been riding for more than 20 years. I still ride between 8 and 10 hours a week. I had even planned to race this year but due to work conflicts I didn’t manage to pull it off. Nonetheless, I had been training and in hopes of competing later this year… that is until last week.
My wife and I were on vacation and on the last day of our trip, I went for a 2.5-hour ride. I went early in the morning to beat the heat of the day. It was extremely humid, but the temperature was in the upper 60’s when I left and may have been in the lower 80’s when I returned at 10:30. I am used to these conditions as I live in north Alabama where hot and humid weather is the norm during the summer and early fall.
However, I ran out of fluids during the ride and not being familiar with the area, arrived back at my hotel before I found a place to get water. Thinking I was dehydrated, I drank a bottle of water and 2 bottles of Gatorade. I had ridden fairly hard, but did not feel unusual given the circumstances. Two hours later my wife and I stopped for lunch on our way back home. As I got out of the car, I began to feel light headed (similar to the way you feel when you stand up quickly). About five minutes later I had a seizure in the lobby of the restaurant.
This is a first for me. I was out for about 10-15 minutes and it took me about an hour to totally regain my memory. Luckily, my wife is a nurse and a passer-by who also happened to be a retired nurse had dealt with people with seizures during her career. This happened five days ago and I still feel groggy and tried and I have been sleeping a lot since. I saw my doctor the morning after the seizure and he scheduled me for an EEG and MRI later this week. Do you know what might have triggered the problem and if this groggy feeling will ever pass?
Your question brings up a couple of issues. First is the long list of possible causes of a seizure. New onset seizures in a 50-year-old is cause for concern. I’m glad you’re looking into the possible causes with diagnostic testing such as EEG and MRI. I wish you had been checked immediately after the event for possible metabolic causes that might have corrected themselves before you saw your doctor the next day. Examples of metabolic causes of sizure that might correct overnight include heat stroke, low blood sugar, low blood calcium and low blood sodium (See “Askthe Doctor: The dangers of drinking“). It’s especially curious that you say you ran out of fluids during your ride. Is it that you didn’t bring enough fluids or that you drank too much too soon? I’d be interested to know how many ounces of Gatorade and water were in the three drinks you consumed right after the ride. Even so, I doubt hyponatremia as the cause of the seizure because I would think you would have had your seizure within minutes of the fluid binge. We’ll never know without a blood test for electrolytes shortly after the seizure.
More worrisome causes for new onset seizure are space occupying lesions (such as cancer or a buildup of blood between the brain and skull) and stroke. Drug and alcohol withdrawal are also possible causes but unlikely with your health habits.
I’m not sure what kind of seizure you had based on your description, but let’s say it was a classic grand mal seizure. The lightheaded feeling you had was your “aura,” the premonition that you were about to have a seizure. If that aura were to ever happen again, don’t fight it and get to the ground so you don’t fall like a statue if a seizure does actually occur. After a seizure there is a “post-ictal” phase in which there is a period of lethargy and gradually declining levels of confusion and fatigue. This generally lasts minutes to hours but it doesn’t surprise me that you still feel groggy several days later. A seizure is quite an insult to the brain and it may take days to feel back to normal. You didn’t mention whether your doctor had started any medication to try to prevent another seizure. If so, the medication may likely be the cause of feeling so drowsy.
The best possible ultimate diagnosis for your seizure is “idiopathic seizure,” translated into English that simply means “We looked hard for a reason why and we couldn’t find one.” While it may be frustrating never to find the cause, this is the best-case scenario and obviously much better news than a stroke, brain tumor, meningitis, etc. Speak with your doctor about how soon it is okay to drive or ride outdoors safely. Good luck and let me know how things turn out.
On a further note, I received a letter from Gatorade in response to the The dangers of drinking article-they are marketing a new product called Gatorade Endurance Formula with higher sodium and potassium content to address the needs of endurance athletes. Just note that it’s still not a substitute for conditioning and picking the right competitive distance for your ability level.
Dawn Richardson retired from the women’s peloton as a category 2 on the Verizon Wireless-Cervelo Women’s Cycling Team at the end of 2002 after 13 racing seasons. She is a board-certified emergency medicine physician practicing at Roger Williams Medical Center in Providence, Rhode Island, and is a clinical instructor in emergency medicine at Brown Medical School. Send your questions to her email@example.com.Important note
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