November 13, 2006

Frontotemporal Dementia

Alois Alzheimer famously described a case of a 51-year-old female with delusions and memory impairment in a 1907 paper. His observations were coupled with his neuropathological findings of neuritic plaques and neurofibrillary tangles, the pathologic hallmarks of the disease. Originally used to describe a rare form of pre-senile dementia, those who suffer from Alzheimer's Disease are mainly elderly patients with functional decline in memory, language, visuospatial function, and executive function.

Frontotemporal Dementias affect less patients but the results are equally if not more devastating. Age of onset is usually around 50 to 60. The causes are heterogeneous. As the name suggests, frontotemporal dementias are marked by a preponderance of atrophy in the frontal and temporal lobes. Bifrontal atrophy leads to disinhibition and socially inappropriate behavior. Depending on the location of atrophy, varying degrees of aphasia, semantic dementia, prosopagnosia, and limb apraxia can be seen. FTD can present as a progressive behavioral disturbance or a progressive language disturbance. Among those exhibiting the latter, disinhibition, overactivity, and restlessness are associated with prominent orbitofrontal involvement. Loss of motivation is associated with dorsolateral frontal involvement.

A female with a psychiatric history was admitted from an outside hospital. Her illness began when she was 53: she was hospitalized in a psychiatric hospital for frank delusions. She is now 61 with marked dementia. She cannot form new memories; she exhibits diffuse hyperreflexia with upgoing toes bilaterally; she has a tendency to retropulse; she perseverates and cannot be redirected easily. Her age and severe cognitive impairment together with long-tract signs suggest FTD, although the length of her course argues against it. She is no longer in contact with her family and her caretaker is no longer able to manage her at home.

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