I can add another funny stroke mimic to the list of diagnoses that have been thrombolysed: heatstroke. We review what there is to learn about this old and modern disease. Here are some reminders:
- The classic form (toddlers, elderly, nursing home residents, sick people) stems from exhaustion of the sweating mechanism, so the skin is dry while the temperature is up.
- The exertional variant (marathon runners etc.) keeps sweating as much as it can, yet the heat produced is too much (and the behavioural compensation [stop running] is switched off by psychopathology and endorphins).
The latter case is an emergency medicine problem in the field. While it has some differentials, it is vital to
- get a monitor
- get a thermistor probe into the proper hole
- cool as quick and as good as you can – preferentially a cold water tub. It seems that there is an age-old debate whether this is really the best option, because “theoretically” the body could shut down perfusion of the skin – I understand neither the physiology nor the physics of this caveat, so I’d recommend the tub anyway. The goal is to reduce core temperature to 39°C. Remember that the patient probably will not shiver (the thermostat still works).
The damage to the body stems from heat and it affects the brain, the liver, the kidney and the blood first, before destroying anything else. The longer and the higher the temperature is, the worse.
As for references
- the emedicine entry is pretty good
- a review on the neurology of heatstroke in Seminars in Neurology
- and a fervent advocate of cold water immersion