Pathophysiology and long-term outcome of reversible tumor-like lesions induced by presenting status epilepticus

J Neuroimaging. 2010 Apr;20(2):169-74. doi: 10.1111/j.1552-6569.2008.00334.x. Epub 2009 May 18.


Background and purpose: Within the spectrum of reversible neuroimaging abnormalities induced by status epilepticus (SE) tumor-like lesions (TLL) have been rarely described. Their etiology, pathophysiology, and long-term outcome remain uncertain. These issues could be clarified by long-term magnetic resonance imaging (MRI) studies in TLL induced by presenting SE.

Methods: Prospective multi-sequence MRI and clinical and electroencephalographic long-term (18 to 60 months) follow-up studies were performed in 3 patients with reversible TLL induced by presenting SE.

Results: In the peri-ictal MRI, TLL are hypointense in T1-weighted, hyperintense in T2-weighted, and fluid-attenuated inversion recovery images with a marked subcortical component and sulci effacement. The diffusion and MR-spectroscopy studies disclosed intermixed areas of increased/decreased diffusivity associated with a lactate peak and a decreased N-acetylaspartate. At long-term follow-up, none of the patients had seizure recurrence or electroencephalographic epileptiform abnormalities; MRI showed residual focal atrophy and gliosis associated with neuronal loss/dysfunction.

Conclusions: SE per se may induce TLL. MRI multi-sequence studies disclosed that they are mainly formed by focal vasogenic and cytotoxic edema resulting from the hypermetabolism associated with seizure activity. In spite of a clinical favorable long-term outcome, the demonstration of irreversible brain damage argues in favor of immediate treatment of SE.

MeSH terms

  • Aged
  • Brain Neoplasms / complications*
  • Brain Neoplasms / diagnosis*
  • Electrocardiography / methods*
  • Female
  • Humans
  • Longitudinal Studies
  • Magnetic Resonance Imaging / methods*
  • Middle Aged
  • Status Epilepticus / complications*
  • Status Epilepticus / diagnosis*
  • Young Adult