Cholinergic Crisis

A cholinergic crisis (CC) is an over-stimulation at an NMJ due to an excess of acetylcholine (ACh).

In MG, this occurs as a result of excessive inhibition of the acetylcholinesterase (AChE) enzyme, which normally breaks down acetylcholine. This is a consequence of too high a dose of AChE inhibitors.

In CC, respiratory failure may be present alongside other typical cholinergic symptoms e.g. miosis, diarrhoea, urinary incontinence, bradycardia, emesis, increased lacrimation, or hypersalivation. These features may also be present in organophosphate poisoning.

Excessive ACh stimulation of striated muscles at the NMJ produces flaccid muscle paralysis that can be clinically indistinguishable from weakness due to MC [12].