Pathoarchitectonic pattern of iso‐ and allocortical lesions in juvenile and adult neuronal ceroid‐lipofuscinosis

Conclusion Juvenile and adult forms of NCL reveal a pronounced and specific involvement of nerve cells generating isocortico‐isocortical projections and isocortico‐entorhinal connections. They also show a specific destruction of the nerve cells generating the perforant path. Additional changes are seen in a deep entorhinal layer receiving a feedback projection from the hippocampus. Within the hippocampal formation, the CA4/CA3 projection cells necessary for intrahippocampal processing of the data are markedly changed. This lesion pattern leads to a partial or complete interruption of the flow of information from the isocortex to the hippocampal formation. It is assumed that the pathoarchitectonic pattern contributes to the development of personality changes and cognitive impairment, both frequently seen even in early stages of NCL.