Neurological diseases in the aged

In this paper, I described clinical and basic problems on neurology of the aged patients. These studies have been done in various institutions with many co-workers. 1) A PET study revealed some age differences on CBF, CMRO2, or CMRgl. But these results are not so rigid in which much of individual variations should be considered in interpretation. Calendar age is not always compatible to biological age. 2) Saccular aneurysms in the brain artery were found in 7.3% of 1200 routine autopsy series of the aged subjects. Aneurysms with external diameter exceeding 6 mm had been fatally ruptured in 14 (78%) of 18 subjects. 3) Variations of the pyramidal crossing are found responsible for bizarre clinical manifestations. Non-crossing component was more prominent in the right pyramidal tract; consequently, right pyramidal tracts including ventral and lateral one seemed to have more extensive representation in the spinal cord level. 4) I123-IMP SPECT study showed a reduced uptake in the area 4 or area 4-6 of the ALS patients. 5) I introduced a new simplified Wartenberg's maneuver, which is useful for detection of subtle pyramidal dysfunctions. 6) Cases with central pontine myelinolysis and those of paraneoplastic syndrome were presented with an emphasis on their patho-chemical mechanisms. 7) Lewis-Sumner syndrome showing multifocal persistent conduction block is not rare in the aged, in which we have already had some useful therapeutic methods. 8) Dementia complicated with neurodegenerative disease was discussed on its clinical and chemical features of mental disturbances. In ALS-dementia, CSF-homovanilic acid reduced significantly than in the control and L-dopa was effective in some patients. 9) Vascular and Alzheimer-type dementias were presented and discussed on their pathogenetic mechanism according to our recent studies with review of literature.