Pick Disease Health Article

Definition

Pick disease is a rare neurodegenerative disorder that affects pre-senile adults. It is characterized by atrophy of the tissues in the frontal and temporal lobes of the brain and by the presence of aggregated tau protein that accumulates in Pick bodies in the neurons of the affected regions. Named for the German physician who studied patients who with the disease, Pick disease is grouped together with other non-Alzheimer's dementias, under the category of frontotemporal dementia (FTD), which is now the preferred term for Pick disease. FTD is classified by the Diagnostic and Statistical Manual of Mental disorders, Fourth Edition (DSM-IV) as a Dementia Due to Other General Medical Conditions.

Description

The disease is named after the German physician, Arnold Pick, but it was not named by him. German psychiatrist and pathologist Alois Alzheimer named the illness in 1923 following post-mortem examinations of Pick's patients. One of these patients was a 71-year old man who died following progressive mental deterioration. His autopsy revealed atrophy of the frontal cortex. This feature is seen nearly universally among patients with FTD. The disease is also referred to as frontotemporal lobar degeneration, progressive aphasia and semantic dementia.

The disease may be inherited through mutations associated with chromosomes 17, 9 and 3, or develop sporadically.

Demographics

Alzheimer's disease and other non-Alzheimer's dementias are much more common than FTD. The average age of onset is 54 years, and most cases arise between the ages of 40 and 60. Few diagnoses are made in individuals older than 75 years of age, but FTD has been diagnosed in people as young as 20.

At autopsy, 8–10% of all cases of pre-senile dementia meet the diagnostic criteria for FTD disease, although some estimates put the incidence of the disease in the United States at as much as 15% of individuals with dementia. Epidemiological studies have estimated that FTD affects as few as one in 100,000 people. The familial incidence of FTD disease may be higher in Europe; a Dutch study indicated a prevalence of 28 per 100,000 individuals. The incidence increases with age, affecting 10.7 per 100,000 in the 50–60-year age range and 28 per 100,000 in the 60–70-year age range. FTDs account for about 3% of dementias. One-fifth to one-half of individuals diagnosed with FTD has a first-degree relative that has also been diagnosed with dementia.

Discrepancies in neuropathological diagnosis have led some groups to suspect that its incidence is much greater than previously indicated. There is some suggestion that as imaging techniques improve the disease is becoming more frequently recognized in younger patients.