Tramadol Abuse-associated Seizure: An Epidemiological and Electroencephalographic Study

Background: Seizure is one of the most severe side effects of tramadol abuse that can be irreversible. Objectives: This study aimed to investigate the frequency of tramadol abuse-associated seizure and electroencephalogram findings in patients with seizures. Patients and Methods: This cross-sectional study was conducted on patients with generalized tonic-clonic seizures caused by tramadol abuse. After history examination and systemic and neurologic evaluation, patients with abnormality in the neurological examination, metabolic evaluation, or non-contrast CT scan were excluded. Electroencephalography was performed between the third and fifth day. Demographic data and electroencephalographic findings were recorded and analyzed. Results: A total of 356 patients with seizures was enrolled, and tramadol abuse-associated seizure was the initial diagnosis in 12.9% of the patients. Among them, 9.3% had tramadol abuse seizures, which followed the study protocol completely. Abnormal electroencephalography was found in 48.5% of the patients, and epileptic discharges were observed in 21.2% of them. The consumed amount of tramadol, the duration of consumption, and the time interval between the consumption of tramadol and the onset of seizure were associated with electroencephalogram abnormality. Conclusions: Tramadol abuse-associated seizures occurred in a significant number of patients. Half of the patients had electroencephalogram abnormalities.