Alois Alzheimer is best known for his description of neurofibrillary changes in brain neurons of a demented patient, identifying a novel disease, soon named after him by Kraepelin. However, the range of his studies was broad, including vascular brain diseases, published between 1894 and 1902. Alzheimer described the clinical picture of Arteriosclerotic atrophy of the brain, differentiating it from other similar disorders. He stated that autopsy allowed pathological distinction between arteriosclerosis and syphilis, thereby achieving some of his objectives of segregating disorders and separating them from syphilis. His studies contributed greatly to establishing the key information on vascular brain diseases, predating the present state of knowledge on the issue, while providing early descriptions of what would be later regarded as the dimensional presentation of the now called "Vascular cognitive impairment", constituted by a spectrum that includes a stage of "Vascular cognitive impairment not dementia" and another of "Vascular dementia".

Alois Alzheimer is best known for his description of the pre-senile neurodegenerative disease named after him. However, his previous interest in vascular brain diseases, underlying cognitive and behavioral changes, was very strong. Besides describing the Arteriosclerotic atrophy of the brain and the arteriosclerotic subtype of Senile dementia which he viewed as main forms of vascular brain diseases, he also identified and described a series of conditions he considered subforms. These may be divided, as suggested by the authors of the present paper, into 3 groups: gliosis and sclerosis, subcortical atrophies, and apoplectic. The subforms of the three groups present characteristic neuropathological features and clinical, cognitive and behavioral manifestations. These provide the basis, together with part of the main forms, for the contemporary condition known as Vascular Cognitive Impairment.

Alois Alzheimer is best known for his description of a novel disease, subsequently named after him. However, his wide range of interests also included vascular brain diseases. He described Senile dementia, a highly heterogeneous condition, and was able not only to distinguish it from syphilitic brain disease, but also to discriminate two clinicopathological subtypes, that may be labeled a "arteriosclerotic subtype", comparable to the present clinicopathological continuum of "Vascular cognitive impairment", and another as a "neurodegenerative subtype", characterized by primary [cortical] ganglion cell [nerve cells] degeneration, possibly foreshadowing a peculiar presenile disease that he was to describe some years later and would carry his name. He also considered the possibility of a senile presentation of this disease subtype, which was described by Oskar Fischer a short time later. Considering the clinicopathological overlapping features of the "arteriosclerotic subtype" of Senile dementia with Arteriosclerotic atrophy of the brain, it might be possible to consider that both represent a single condition.