Thalamic involvement of status epilepticus: diffusion-weighted image of MRI in two cases of status epilepticus

Status epilepticus (SE) is prolonged and repetitive epileptic seizure. SE is associated with widespread neuronal necrosis in vulnerable regions of the brain. We obtained diffusion-weighted image of magnetic resonance imaging (DWI-MRI) from two cases with SE. Case 1 is a 55-year-old man who showed repetitive tonic seizures on his left side evolving to generalized tonic seizure. Seizure occurred every 20 min at maximum rate. Todd's palsy was seen on his left side. Electroencephalogram (EEG) showed repetitive high-amplitude sharp waves over the right front-central region, which continued 10 days with diminishing repetitive rate of sharp waves. DWI-MRI showed high signal intensity at the right frontal cortex and dorsomedial portion of the thalamus. Apparent diffusion coefficient (ADC) was low at the same area. Case 2 is a 37-year-old woman. She initially stopped speech evolving to generalized tonic seizure. The seizure disappeared 30 min later. Todd's palsy appeared on her right side. EEG showed repetitive spikes, polyspikes and slow waves with high amplitude over the left centro-parieto-tempolo-occipital region, which disappeared next day. DWI-MRI showed high signal intensity at the left parieto-tempolo-occipital lobes without the thalamic involvement. ADC was low at the same area. Thalamus was involved in case 1, but not in case 2. The fact may depend on the intensity of epileptic activity of neocortex.