This chapter talks about a 43-year-old male who was referred to a Memory Clinic by a psychiatrist to evaluate the possibility of Frontotemporal Lobar Dementia. Neuropsychological evaluation revealed a general cognitive functioning within normal limits, but weaknesses in some executive functions such as abstraction, attention/concentration, and working memory. The patient was taken out of his job environment. On the follow-up visit 11 months later, he felt improved significantly, but still complained of lack of energy and attention difficulties. When he tried returning to his previous professional duties doing mechanics and paint, he experienced readily mild acute intoxication symptoms. This is probably caused by hypersensitivity to chemicals associated with chronic solvent intoxication. Solvents are widely used in many industrial processes in our society. Since these agents are used to dissolve fatty substances, they easily penetrate cell membranes and they cross the blood-brain barrier.