As mentioned on our initial study, in order to have a positive control for our case of meningovascular neuroborreliosis, we have used the brain of a patient with clinically and neuropathologically confirmed general paresis, with slowly progressive dementia.  That spirochetes persist in the brain in general paresis is well known from the discoveries of Noguchi and Moore (1913). When using silver techniques for the detection of spirochetes, in the brain of this patient suffering from general paresis, innumerable spirochetes in colonies and diffusely disseminated in the cerebral cortex were observed. The accumulation of spirochetes in colonies was morphologically indistinguishable from senile plaques. At higher magnification, the regular spiral form of many Treponema spirochetes was well recognized, indicating, that the plaques were indeed made up by spirochetes. This observation raised the hypothesis that in an analogous way to Treponema pallidum, various other types of spirochetes, including Borrelia burgdorferi, periodontal pathogen spirochetes, intestinal and various other spirochetes may also invade the brain and cause dementia and that these various types of spirochetes may be involved in Alzheimer's disease. 

In an initial study presented before in detail we have analyzed spirochetes in the blood, CSF and brains of Alzheimer's patients using well established, neutral techniques, which are able to recognize all types of spirochetes. This was the way that the hypothesis "Alzheimer's disease - A spirochetosis?" was born. This title was chosen for our first manuscript to clearly express that several types of spirochetes may be involved in AD.  We have chosen the term "spirochetosis" at the place of "neurospirochetosis" as we have also anticipated that in addition to the brain, several other organs might also be involved, as these microorganisms reach various organs via hematogen dissemination (Miklossy, 1993).

We expected that in the historic literature we may find illustrations and observations
showing that indeed Treponema pallidum can reproduce the pathological hallmarks of Alzheiumer's disease in patients with generalé paresis suffering from dementia

Indeed, hundreds of publications illlustrate or describe the accumulation of spirochetes in the brain. Between many other authors Pacheco e Silva  and Rizzo described that in the atrophic form of general paresis spirochetes accumulate in the brain and form masses, balls, plaques or colonies and/or diffusely dissemimate in the cerebral cortex, which are identical to senile plaques and curly fibers. The accumulation and proliferation of spirochetes is restricted to the cerebral cortex.

These observations indicated that as in the cortical sections of our positive control case, spirochetes are able to reproduce the pathological hallmarks of Alzheimer's disease. This is an important point as the definite diagnosis of Alzheimer's disease is based on the presence of an identical pathology.

Therefore to continue investigations to answer the quation whether various spirochetes are implicated in Alzheimer's disease was important.