Alzheimer's disease (AD) is the most common dementia in older people. Therefore, it should be one of the first diseases your doctor considers. Alzheimer's disease usually begins with memory loss while FTD is usually a behavior or language disorder.
People with either disease will show cognitive difficulties and multitask poorly. And at the end stages, AD and FTD look very similar. Doctors use the early symptoms and the brain image, usually done on a MRI (magnetic resonance imaging) scanner, to reach the most appropriate diagnosis.
When behavioral symptoms predominate, FTD patients who become ill in mid-life may be confused with patients who have late life depression, or when the onset is in younger persons, the FTD may be confused with schizophrenia or bipolar disorder. Repetitive compulsive behaviors are very common in bvFTD, and some patients may initially be given the diagnosis of obsessive-compulsive disorder.
Since the history and exam may look very similar for a psychiatric patient and an FTD patient, neuropsychological testing and a brain image will help clarify the picture.
Once other likely diseases have been ruled out, an FTD diagnosis is
made by looking at the data from a neurological exam and personal
history (which may come from the patient, family or other caregiver);
neuropsychological tests that help quantify memory, language and other
cognitive skills; and a brain image - usually a MRI (magnetic resonance
imaging) scan but perhaps a functional scan like PET (positron emission
tomography) which can show increased or lowered brain activity in the
frontal and anterior temporal areas.
An accurate diagnosis made after ruling out other possible explanations is essential for successful treatment or management of any disease. As new medical treatments become available, early intervention will be more and more important. Regardless of medical treatments, the sooner patients and caregivers have an accurate diagnosis, they sooner they can plan for upcoming care. As FTD tends to affect younger people than Alzheimer's or other dementias and lasts for eight years on average, creating a care plan is particularly important for everyone touched by this disease.
Links:
[1] http://memory.ucsf.edu/ftd/ftd/node/21
[2] http://memory.ucsf.edu/ftd/ftd/node/22
[3] http://memory.ucsf.edu/ftd/ftd/node/579
[4] http://memory.ucsf.edu/ftd/ftd/node/258
[5] http://memory.ucsf.edu/ftd/ftd/node/23
[6] http://memory.ucsf.edu/ftd/ftd/node/24