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Hyperglycemia-induced hemichorea can show T1 hyperintensity of the contralateral striatum on MRI. This is thought to be due to petechial hemorrhages or gemistocytic astrocyte accumulation. This study explores the utility of susceptibility-weighted imaging (SWI) and diffusionweighted imaging (DWI) in identifying the nature of these lesions. Three patients underwent MR imaging of the brain with SE T1, F SE T2, DWI, and SWI. T1 images showed hyperintensity predominantly involving the contralateral striatum, where mild (two cases) to moderate (one case) restricted diffusion (low apparent diffusion coefficient [ADC]) was detected on DWI. SWI demonstrated bilateral symmetrical hypointensities in the first two cases, suggesting age associated mineralization. In addition, increased susceptibility change (hypointensity) was also noted in the right putamen in the first and the third cases, suggesting paramagnetic mineral deposition. T1 hyperintensity may be from the protein hydration layer inside the cytoplasm of swollen gemistocytes appearing after an acute cerebral injury. These astrocytes also express metallothionein with zinc, which is thought to be the cause of asymmetric hypointensity of the posterior putamen on SWI. ADC values were thought to be useful for prognostication; however, they should be interpreted cautiously in the presence of susceptibility changes.

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ObjectiveTo study the long-term outcome following seizure recurrence on antiepileptic drug (AED) withdrawal after anterior temporal lobectomy for mesial temporal lobe epilepsy.MethodsWe retrospectively studied the AED profile of patients who had a minimum of 5 years of postoperative follow-up after anterior temporal lobectomy for mesial temporal lobe epilepsy. Only those patients with hippocampal sclerosis or normal MRI were included. AED withdrawal was initiated at 3 months in patients on ≥2 drugs and at 1 year for patients on a single drug.ResultsThree hundred eighty-four patients with median postoperative follow-up of 12 years (range, 7–17 years) were included. Of them, 316 patients (82.3%) were seizure-free during the terminal 1 year. AED withdrawal was attempted in 326 patients (84.9%). At last follow-up, AEDs were discontinued in 207 patients (53.9%). Seizure recurrence occurred in 92 patients (28.2%) on attempted withdrawal. After a median postrecurrence follow-up of 7 years, 79 (86%) of them were seizure-free during the terminal 2 years. AEDs could be stopped in 17 patients (18.5%) and doses were reduced in another 57 patients (62%). Patients with febrile seizures, normal postoperative EEG at 1 year, and duration of epilepsy of <20 years (FND20 score) had 17% risk of seizure recurrence on attempted AED withdrawal. We also formulated a score to predict the chances of AED freedom for the whole cohort.ConclusionPatients with seizure recurrence on AED withdrawal have good outcome with 86% becoming seizure-free and 18% becoming drug-free after initial recurrence. A FND20 score helps in predicting recurrence on AED withdrawal.