These falls/attacks are called cryptogenic drop attacks. References:[5][12] The differential diagnoses listed here are not exhaustive.
[amboss.com]
Autonomic failure 8.1.2 Epilepsy and ictal asystole 8.1.3 Cerebrovascular disorders 8.1.4 Migraine 8.1.5 Cataplexy 8.1.6 Drop attacks 8.2 Neurological tests 8.2.1 Electroencephalography
[escardio.org]
[…] tool=bestpractice.com It has many causes, and is distinct from vertigo, seizures, coma, falls, psychogenic pseudosyncope, drop attacks, transient ischaemic attacks, and states
[bestpractice.bmj.com]