Acute symptomatic seizures — incidence and etiological spectrum: a hospital-based study from South India

We analysed the incidence and etiological spectrum of acute symptomatic seizures in 2531 patients with seizure disorder, both in-patients and out-patients, seen in a university hospital in South India. Seizure(s) occurred in close temporal association with an acute systemic, metabolic, or toxic insult or in association with an acute central nervous system (CNS) insult in 22.5% of patients. Of the 572 patients, 8% could be grouped under the International League Against Epilepsy (ILAE) category 4.1 and 92% under category 1.2. The seizure type was generalized in all the patients included in category 4.1 and 78% of patients grouped in category 2.1 had simple or complex partial seizure(s) with or without secondary generalization. Sixteen (3%) patients developed status epilepticus during the acute phase of illness and 7% of patients had only single seizure. Infections of the central nervous system (CNS) and single CT enhancing lesions (SCTEL) together accounted for 77% of the provoking factors in patients grouped under category 2.1. These two etiological factors together accounted for 95% of etiologies in patients aged under 16 years. SCTEL and neurocysticercosis together accounted for 67% of the provoking factors. In 14% of patients cerebrovascular diseases were the etiological factors and 60% of the patients were aged over 40 years. In patients with cerebrovascular diseases, aged under 40 years, cortical sinovenous thrombosis accounted for 37%. SCTEL was the provoking factor in 61% of patients with isolated seizure. Infections of CNS and SCTEL together accounted for 62.5% of etiological factors for status epilepticus. This study illustrates that the etiological spectrum of acute symptomatic seizures in this part of the world is different from that described from developed countries and CNS infections account for a significant number of cases.