Single small enhancing CT lesion in Thai patients with acute symptomatic seizures: a clinico-radiological study
OBJECTIVE To identify the frequency of single small enhancing CT lesion cases (SSECTL) in a provincial hospital in Thailand and verify a set of clinico-radiological criteria for the diagnosis of benign SSECTL.
METHODS All patients who fulfilled the following criteria were recruited: acute symptomatic focal seizures with or without secondary generalization; minimal or no neurological deficit; no evidence of raised intracranial pressure; no evidence of systemic disease; CT scan showing SSECTL of < 20 mm diameter. After recruitment, patients received antiepileptic drugs and other symptomatic treatment. A CT scan of the brain was repeated every 2 weeks until the lesion had significantly resolved, which was defined as a 50% decrease in size. A CT scan was then taken every 4 weeks until the lesion had completely disappeared or turned into a calcified spot. The data from all other patients presenting with seizures and solitary enhancing lesion on the CT scan who did not fulfil the inclusion criteria were also reviewed.
RESULTS 972 patients with seizure disorder were recruited. 110 patients (11.3%) presented with seizure and solitary enhancing lesion on the CT scan, 22 of whom (20%) fulfilled the inclusion criteria. 20 of the 22 patients had SSECTL with a spontaneous resolution: 14 (70%) within 4 weeks and 18 (90%) within 8 weeks. Two patients had a progressive course. One patient with a solitary enhancing CT lesion > 20 mm had spontaneous resolution. 87 patients had another diagnoses. The diagnostic criteria for benign SSECTL were 95.23% sensitive, 97.75% specific, had a positive predictive value of 90.91% and a negative predictive value of 98.86%.
CONCLUSION SSECTL is not uncommon in our provincial hospital. The clinico-radiological criteria proposed by Rajshekhar (1991) are valid and reliable in predicting a benign outcome. CT follow-up within the first 4 weeks is critical.
Document Type: Research Article
Publication date: April 1, 2000