Symptoms may include a decline in social behavior (including disinhibition, tactlessness, and breaches of interpersonal etiquette), emotional blunting, apathy, changes in eating habits (including increased appetite, weight gain, and increased preference for sweets), attention problems, decreased insight, speech and language problems (including reduced speech ability, repetition of phrases heard, reduced use of nouns, difficulty naming objects, loss of word meaning, diminished writing ability, and mutism), and difficulty recognizing faces. Though Alzheimer's disease and other forms of dementia can sometimes cause similar symptoms, Pick's disease is more likely to cause certain deficits in behavior and speech (such as disinhibition or loss of nouns), while memory and visuospatial function (which are frequently affected by Alzheimer's Disease) tend to be relatively spared. Also, the onset of Pick's Disease (usually between the ages of 45 and 65) is earlier than is normally seen in Alzheimer's disease.
The clinical syndrome of FTLD can also result from dementia lacking distinctive histology (DLDH). Because DLDH and Pick's disease cannot be separated clinically, it is currently not possible to make a final diagnosis of Pick's disease until autopsy. At autopsy, Pick's disease is diagnosed by the presence of cortical Pick bodies, which are silver-staining, spherical aggregations of tau protein in neurons.
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