Amyotrophic lateral sclerosis (ALS)--also termed "motor neuron disease" or "Lou Gehrig's disease"--is a common disorder and a number of texts have appeared over the last several years regarding either its clinical or biological characteristics. However, there are no existing texts that discuss the clinical, neuroimaging, neuropathological and neurochemical characteristics of dementia in ALS. This is in spite of the increasing evidence that dementias occur in ALS and that they share many features in common with a frontotemporal lobar degeneration. The importance of this is highlighted by the...