Cerebrovascular Accident (CVA) or Stroke: This is the most likely diagnosis due to the patient's age and the high incidence of stroke in the elderly population. Seizures can occur as a complication of stroke, especially in the acute phase.

Metabolic Disorders: Electrolyte imbalances (e.g., hyponatremia, hypocalcemia), hypoglycemia, or hyperglycemia can cause seizures in elderly patients. Age-related declines in renal function and other metabolic changes increase the risk of these conditions.
Infections: Meningitis or encephalitis, though less common, can cause seizures in this age group, especially if there are underlying health conditions that predispose to infections.
Brain Tumors: Primary or metastatic brain tumors can present with seizures, especially in older adults, due to the increased incidence of cancer with age.
Alzheimer's Disease: Seizures can occur in patients with Alzheimer's disease, particularly in the later stages.

Subarachnoid Hemorrhage: Although less common, subarachnoid hemorrhage is a medical emergency that can present with a seizure and requires immediate attention.
Central Nervous System (CNS) Vasculitis: This is a rare but potentially treatable condition that can cause seizures among other neurological symptoms.
Reversible Posterior Leukoencephalopathy Syndrome (PRES): Associated with hypertension, certain medications, and other factors, PRES can cause seizures and requires prompt recognition and treatment.

Paraneoplastic Syndromes: These are rare disorders caused by an immune response to a cancer, not due to direct local effects of the tumor cells. They can cause a variety of neurological symptoms, including seizures.
Creutzfeldt-Jakob Disease: A rare, degenerative, fatal brain disorder that can cause seizures among its wide range of neurological symptoms.
Hashimoto's Encephalopathy: A rare condition associated with Hashimoto's thyroiditis, characterized by encephalopathy and seizures, which is reversible with treatment of the underlying condition.