Deep Dive
Yes. Seizures can disturb breathing even when there is no obvious convulsion, and in some focal seizures the respiratory change may be one of the earliest or least visible signs.
What can change?
Reported peri-ictal respiratory changes include central or obstructive apnoea, slowed breathing, rapid breathing, hypoventilation and oxygen desaturation. These changes are not limited to bilateral tonic-clonic seizures.
Why focal seizures can affect breathing
Seizure activity can involve networks that help regulate breathing and autonomic function. Research using intracranial recordings and stimulation has particularly implicated mesial temporal structures and the amygdala in some cases of ictal central apnoea.
Why witnesses may miss it
A person may not dramatically gasp or turn blue. A short pause, shallow breathing or subtle change can be difficult to recognise without respiratory monitoring. In some focal seizures, the person may be unaware that breathing changed at all.
What this does not mean
Not every breathing change is a seizure, and not every seizure causes apnoea. Breathing symptoms need to be interpreted with the rest of the event, and persistent or dangerous breathing difficulty requires urgent medical attention.
Sources
Micalizzi et al. — Seizures and breathing: lessons from peri-ictal respiratory disturbances
Ochoa-Urrea et al. — Electrical stimulation-induced seizures and breathing dysfunction
Breathing and Seizures