Objective: To determine the main etiological mechanisms of symptomatic epilepsy and its frequency according to age.
Patients and methods: We made a retrospective analysis of 208 patients admitted during a period of four and a half years, studying the variables: age, sex and type of seizures: simple partial, secondarily generalized partial, complex partial, tonic-clonic, generalized tonic, and also EEG and neuroimaging.
Results: The main etiological mechanisms found were: vascular (31.25%), alcoholic (12.01%), intracranial disorders (9.61%), traumatic (5.28%), degenerative (5.28%), infectious (2.88%) and cryptogenic (33.65%). In the last group there was an outstandingly large proportion of patients with silent infarcts. When considering vascular epilepsy, those seizures occurring during the acute phase of the stroke (24/65) are differentiated from those of late onset (41/65). In the latter there was a marked predominance of ischemic etiology (48.78% corresponded to extensive infarcts in the territory of the middle cerebral artery; 36.58% were associated with partial infarcts) probably because of the greater frequency of ischemic stroke as compared with hemorrhagic stroke. After the acute phase, the latency was of 10.68 +/- 0.43 months and the most frequent seizures were tonic-clonic (48.78%).
Conclusion: In persons under 30 years of age, etiology is multifactorial; between 30 and 50 years of age alcoholic epilepsy (39.53%) and traumatic epilepsy (11.62%) predominate; over the age of 50 years the cause was vascular in 43.5%. In the latter age group there was a high proportion of patients with heraldic seizures.