Seizure threshold

A seizure threshold is the balance between excitatory and inhibitory forces in the brain which affects how susceptible one is to seizures. Those diagnosed with epilepsy or certain other neurological conditions are vulnerable to sudden new seizures if the threshold is upset.

Prescription drug effects
Those using prescription drugs must be especially careful and compliant with their therapeutic drug regimen. Drugs such as the anticonvulsants, antidepressants and nicotinic antagonist bupropion (Wellbutrin, Zyban) and the analgesic tramadol (Ultram, Ultram ER, Ultracet) can lower the seizure threshold.

Other factors
So can other factors, including, among many others: exposure to neon or laser flashing lights, lengthy periods of fasting, malnutrition, starvation, lengthy periods of high stress and/or fear, fatigue and exhaustion (i.e., sleep deprivation and/or rest), uncontrolled diabetes, other endocrine and/or metabolic disorders (like electrolyte or hormonal imbalances), cancer, and certain disorders of the nervous, cardiovascular, and gastrointestinal systems.