Emergency Medical Technician (EMT) Intermediate Practice Exam

When considering the conditions that can cause a partial seizure in a patient who does not have a history of seizures, idiopathic epilepsy is the least likely among the options provided. Idiopathic epilepsy typically implies a recurring seizure disorder with no identifiable cause and often presents in individuals with a known history of seizures.

In contrast, a brain tumor can create localized irritation in the brain, leading to seizures, especially in someone who has not previously experienced them. Similarly, a cerebrovascular accident, or stroke, can disrupt normal brain activity and provoke seizures, particularly when it affects areas of the brain that regulate electrical signals. Hypoglycemia, or low blood sugar, can also lead to seizures due to the brain's dependency on glucose for proper function, and it may present acutely even in individuals without a seizure history.

Thus, idiopathic epilepsy, which suggests a chronic and recurring seizure pattern, stands out as the least likely cause of a first-time partial seizure event.