By Martha Kerr
NEW YORK (Reuters Health) - Dementia in patients who are
younger than 45 years of age is often caused by
degenerative, metabolic or autoimmune diseases, Dr.
Brendan Kelley, of the Mayo Clinic in Rochester,
Minnesota, told attendees at the 60th annual meeting of
the American Academy of Neurology, being held this week
Kelley and colleagues searched the Mayo Clinic
database for patients who began to develop dementia
between 17 and 45 years that was not related to trauma,
brain infections or mental retardation. They identified
235 such patients receiving care between 1996 and 2006.
The average age at dementia onset was 34.7 years.
Neurodegenerative causes accounted for dementia in
29.8 percent of the group, frontotemporal dementia
occurred in 13.2 percent and Alzheimer's disease was
seen in less than 1 percent," data presented by Kelley
Autoimmune-inflammatory causes, including multiple
sclerosis, accounted for 21.2 percent. Inborn errors of
metabolism were identified in 10.6 percent.
At the last evaluation, the cause of dementia was
still unknown in 44 patients (18.7 percent) despite
exhaustive evaluations, Kelley reported.
Inborn errors of metabolism were more common in
individuals with symptoms appearing before age 30.
Neurodegenerative causes were more common in dementias
occurring after age 35.
"Some of the important causes, such as lupus,
metabolic disorders, Huntington chorea, among others,
can occur in very young children," Kelley told Reuters
Health. "Only 4 of the 235 cases in our series resembled
Alzheimer's type dementia."
"It is important to increase awareness that dementia
can and does occur in young patients," Kelley continued.
"This is important for social services and other
aid-giving organizations to know."
"Symptoms in younger patients
have more of a neuropsychiatric
focus, with a lot of psychiatric
features," he said. These
patients can be misdiagnosed
with psychiatric disorders, such
The causes of young-onset
dementia are more often
hereditary or genetic than they
are in older patients with
"We are now looking to
determine which clinical
features are more
features to focus on," Kelley
said. "This is a single disorder
with multiple underlying causes.
Treating the causes may correct
to some extent the disorder."