FRONTAL-LOBE DEGENERATION OF NON-ALZHEIMER TYPE - STRUCTURAL CHARACTERISTICS, DIAGNOSTIC-CRITERIA AND RELATION TO OTHER FRONTOTEMPORAL DEMENTIAS

Frontal lobe degenerative dementias, the second largest degenerative d ementia group after Alzheimer's disease, is dominated by frontal lobe degeneration of non-Alzheimer type. It is classified in a group also c ontaining Pick's disease, progressive aphasia and dementia in motor ne uron disease. Frontal lobe degeneration of non-Alzheimer type is clini cally marked by frontal lobe symptoms and frontotemporal reduction of blood flow. From a histopathological point of view it is characterized by gliosis, microvacuolation, neuronal atrophy-loss and 40-50% loss o f synapses in three superficial cortical laminae of the frontal convex ity and anterior temporal cortex, while the deeper laminae are little or not changed. The structural changes of Alzheimer's disease includin g amyloid, Levy body dementia and Pick's disease are entirely lacking. A strong heredity points to a genetic cause as yet undefined.