How do I differentiate between a seizure and other conditions that may mimic seizure activity in primary care?

To differentiate between a seizure and other conditions that mimic seizure activity in primary care, a detailed clinical history and eyewitness accounts are essential. Key features suggestive of epileptic seizures include a bitten tongue (especially the side), head-turning to one side during the event, absence of memory of abnormal behaviour before, during, or after the event as reported by witnesses, unusual posturing, prolonged limb jerking, confusion following the event, and prodromal phenomena such as déjà vu or jamais vu. These features warrant urgent specialist referral within two weeks for epilepsy assessment ¹.

In contrast, syncope (fainting) often has prodromal symptoms such as sweating, feeling warm, pallor, and is typically provoked by prolonged standing or specific triggers like pain or medical procedures. Syncope may also be associated with rapid recovery and brief seizure-like activity that is not diagnostic of epilepsy. Situational syncope is provoked by straining actions like coughing or micturition. Postural hypotension should be suspected if symptoms occur on standing and blood pressure measurements support this ¹.

Observing the event or obtaining video recordings from family or friends can be very helpful in distinguishing epileptic seizures from non-epileptic events, as behavioural analysis can clarify the diagnosis (SIGN, 2018). The presence of tonic-clonic movements lasting more than 5 minutes or multiple seizures in a short period also supports a diagnosis of epilepsy and requires urgent management ².

Other mimics include transient loss of consciousness due to cardiac causes, which should be suspected if there is a history or signs of heart failure, exertional syncope, family history of sudden cardiac death under 40 years, or a heart murmur. Such cases require urgent cardiovascular assessment ¹.

In children, seizure mimics vary by age and include non-epileptic paroxysmal events; an age-based approach to history taking is recommended to differentiate these (Stainman and Kossoff, 2020). Overall, prospective recording of events, including detailed written descriptions and video, combined with a thorough history and examination, is critical to differentiate seizures from mimics in primary care ¹,²[(Stainman and Kossoff, 2020)].