I was somewhat surprised to learn that although the majority of technical divers believe in the value of the simple neurological exam — taught to students during decompression courses to identify signs of potential DCS — few carry a printed copy (or pdf on their phone or tablet) with them on their dives.
What follows is ONE of several versions that exist. I use it because it seems the most comprehensive and straightforward. Regardless of if you opt to use this or another, remember to record the results, and in particular to note any abnormalities. If a dive buddy is evacuated for evaluation at a hyperbaric facility or even a hospital emergency department, sending a notarized copy of this with them may help them get treated more rapidly.
There are NINE test categories… # 1, 7 and 9 are key.
1. Orientation (these may sound facile but they may indicate real confusion in a otherwise normal-looking victim… do not omit them).
- Ask diver for full name and age
- Ask diver to state present location
- Ask diver what time it is, what day of the week, the date and month
2. Eyes / Vision
- Ask diver to count the number of fingers you display (do this several times using different numbers)
- Check eyes together and then separately
- Ask the diver to describe a distant object… something several metres (yards) away at least
- Have diver follow your clenched fist with his/her eyes as you move it up, down, left and right in front of their face. Have them hold their head still and check that their eyes follow your movements smoothly
- Check both pupils are equal in size
3. Face (muscles and nerves)
- Ask the diver to smile and check there is symmetry in their expression
- Have the diver whistle. Watch the “pucker”. Note any drooping of lips.
- Have the diver close their mouth tightly and feel that their jaw muscles are equally tight
- With their eyes closed, stroke the diver’s face, forehead and neck and ask them to describe the sensation. It should be similar
- Check hearing by rubbing your thumb and forefinger together with the diver’s eyes closed. See how close the fingers have to be to be audible.
Note: If the surroundings are noisy, ask bystanders to be quiet and have noisy machinery turned off if possible.
5. Swallowing Reflex
- Have the diver take a sip of water and watch their “Adam’s apple” as they swallow to be sure it moves up and down
- Have the diver stick out their tongue. Note if it droops, moves to one side or other abnormal movements.
7. Muscle Strength
- Place your hands firmly on the diver’s shoulders, have them “shrug”. Note if there is any difference in strength
- Have the diver squeeze your fingers with both hands at the same time, notice any difference in strength. Have the diver hold his hands together at chest level and elbows high. Gently push and pull the elbows while the diver resists the movement. Notice any difference in strength
- Check leg strength by having the diver lie flat and raise and lower the legs while you resist the movement
8. Sensory Perception
- Check the diver’s ability to feel you touching them lightly starting at their shoulders and working down to cover their entire body. Compare degree of response on each side. The diver’s eyes should be closed while this is done.
9. Balance and Coordination
Note: Be prepared to protect the diver from injury when performing this test.
- If possible, have the diver walk heel to toe and check balance and coordination. Make sure the diver does not fall!
- Have the diver stand with feet together and eyes closed. Ask them to hold their arms straight out, and hold that position for half a minute at least. Be ready to catch them if they lose their balance or fall.
After the exam…
The diver’s condition or the environment may prevent you conducting one or more of these tests. Record any omitted test and the reason.
A cycle of tests should be repeated at 30- to 60-minute intervals while awaiting assistance in order to determine if any change occurs. Report the results to the emergency medical personnel responding to the call.
If there is a delay getting to a suitable recompression facility, repeat the test hourly.