A review of brain imaging and occupation data from 588 patients diagnosed with frontotemporal dementia has found that among the dementias affecting those 65 years and younger, FTD is as common as Alzheimer's disease. The study also found that the side of the brain first attacked (unlike Alzheimer’s, FTD typically begins with tissue loss in one hemisphere) is influenced by the person’s occupation.
Using occupation scores that reflect the type of skills emphasized, they found that patients with professions rated highly for verbal skills, such as school principals, had greater tissue loss on the right side of the brain, whereas those rated low for verbal skills, such as flight engineers, had greater tissue loss on the left side of the brain. This effect was expressed most clearly in the temporal lobes of the brain. In other words, the side of the brain least used in the patient's professional life was apparently the first attacked.
These findings are in keeping with the theory of cognitive reserve, but may be due to some asymmetry in the brain that both inclines them to a particular occupational path and renders the relatively deficient hemisphere more vulnerable in later life.
(2010). Occupation attributes relate to location of atrophy in frontotemporal lobar degeneration.
Neuropsychologia. 48(12), 3634 - 3641.