Which cause should be considered for seizures that first manifest in early to middle adult life?

Seizures that first appear in early to middle adult life can often be attributed to structural causes, making the presence of a tumor a significant consideration. Tumors can disrupt normal brain function, leading to various neurological symptoms, including seizures. In adults, especially those over the age of 20, intracranial tumors such as gliomas, meningiomas, or metastases from other cancers are common causes of newly developed seizures.

While cerebrovascular disease, encephalitis, and idiopathic epilepsy may also cause seizures, their typical presentation and demographic factors differ. Cerebrovascular disease tends to manifest with acute neurological deficits rather than isolated seizures. Encephalitis is typically associated with systemic symptoms or recent viral infections and can occur at any age, but it often presents more acutely rather than as a new onset in adulthood without prior history. Idiopathic epilepsy is generally considered when no identifiable cause is found, and it typically presents earlier in life rather than in mid-adulthood.

Thus, the presence of a tumor should be considered as a primary cause for seizures that start in early to middle adult life, emphasizing the need for thorough imaging and evaluation in such cases.