Presentation
Admitted to emergency departement in status epilepticus with fever.
Patient Data
There is subtle T2 hyperintensity in the right mesial temporal lobe, particularly involving the hippocampus, with corresponding abnormal diffusion restriction. Both T2 hyperintensity and diffuse restriction extends into the right thalamus.
No enhancing cerebral mass lesion. Sulcal and ventricular pattern is within normal limits. No susceptibility blooming. Periventricular and multiple punctate deep white matter T2 hyperintensities, out of keeping in number for patient's age, in keeping with chronic small vessel ischemia.
Conclusion: T2 hyperintensity with diffusion restriction in the right hippocampus and ipsilateral thalamus are likely seizure related.
The differential includes herpes encephalitis, in the context of acute onset symptoms, however the involvement of thalamus is atypical for HSV encephalitis as is the very limited involvement of just the hippocampus.
Case Discussion
The patient had been a heavy alcohol drinker (4-6L wine a day) and recently decided to quit cold turkey, prior to admission.
This patient went on to have a lumbar puncture which was bland with negative HSV PCR.
Thalamic as well as hippocampal high DWI signal is well described in the peri-ictal period in the setting of prolonged seizures.
Limbic (paraneoplastic) encephalitis is also a consideration on imaging, however it is at odds with the acute presentation.