Early involvement of the tegmentopontine reticular nucleus during the evolution of Alzheimer's disease-related cytoskeletal pathology

The tegmentopontine reticular nucleus (nucleus of Bechterew) plays a crucia l role in the generation of horizontal saccades and smooth pursuit movement of the eyes. The evolution of Alzheimer's disease-related cytoskeletal pat hology was studied of this nucleus was studied in 27 autopsy cases at diffe rent stages of the cortical neurofibrillary pathology (NFT/NT stages I-VI). The first cytoskeletal changes were seen at stages I and II (preclinical A lzheimer's disease). At stages III and IV (incipient Alzheimer's disease), the nucleus exhibited a marked pathology, and it was severely involved at s tages V and VI (clinically overt Alzheimer's disease). Damage to the tegmen topontine reticular nucleus most probably contributes to the hypometrie of horizontal saccades and the slowing of smooth pursuits that characteristica lly develop in patients suffering from Alzheimer's disease. Given the fact that pathological alterations of the tegmentopontine reticular nucleus begi n early during the evolution of the underlying process, the question arises as to whether dysfunctional horizontal saccades and abnormal smooth pursui ts could be employed as means of screening or diagnosing Alzheimer's patien ts in the very earliest stages of the disease. (C) 2001 Elsevier Science B. V. All rights reserved.