The influence of neuropathology on brain inflammation in human and experimental temporal lobe epilepsy

• HS in TLE patients is not associated with a sustained brain inflammatory response.
• Amygdala kindled seizures are not associated with a sustained inflammatory response.
• Brain inflammation is not necessarily present in temporal lobe epilepsy.

It is unclear to what extent neuropathological changes contribute to brain inflammation observed in temporal lobe epilepsy (TLE). Here, we compared cytokine levels between histopathologically-confirmed sclerotic hippocampi and histopathologically-confirmed normal hippocampi from TLE patients. We analyzed a similar cytokine panel in the hippocampi of amygdala-kindled rats and we evaluated neuropathological changes by immunohistochemistry. In TLE patients, cytokine levels were not significantly different between sclerotic and non-sclerotic hippocampi. Though kindling resulted in increased astrocyte activation, cytokine levels and microglia activation were unchanged. These results suggest that the chronic epileptic state in TLE can also occur in the absence of intracerebral inflammation.Highlights
• HS in TLE patients is not associated with a sustained brain inflammatory response.
• Amygdala kindled seizures are not associated with a sustained inflammatory response.
• Brain inflammation is not necessarily present in temporal lobe epilepsy.