Hippocampal sclerosis is evaluated unilaterally in a coronal section of the mid hippocampus at the level of the lateral geniculate body and graded as absent or present based on severe neuronal loss and gliosis in CA1 and/or subiculum. The following regions are assessed:

Neuronal loss and gliosis in each region ranges from 0-5, with higher values indicating more severe neuronal loss (0 = none, 1 = mild, 2 = mild to moderate, 3 = moderate, 4 = moderate to severe, 5 = severe). Hippocampal sclerosis is recognized if it is graded 5 = severe.

Notes on missing data: Hippocampal sclerosis grade may be missing for certain cases (e.g., the mid hippocampus are not assessed due to damage from infarct).

This variable replaces "hip_scl_3reg_yn" as the measure of hippocampal sclerosis.