YOUNG - ONSET PARKINSON'S
DISEASE

Parkinson's
disease (PD) is typically thought to be a disorder
of the elderly. The average age of onset for Parkinson's
disease (PD) is approximately 58 years in the
U.S. and elsewhere. However, the first symptoms
(such as tremor, slowed movement, or decreased
dexterity) can arise much earlier in life; some
cases of PD have clearly developed up to three
decades earlier than its typical age of onset.
Most estimates indicate that no more than 5-10%
of PD cases begin under the age of fifty. When
patients develop PD in this age range (sometimes
as early as in their twenties or thirties), this
is generally referred to as "young-onset
PD". Though distinguished by its age of onset,
this disorder appears in most respects to be identical
to PD beginning at an older age. The clinical
features and response to medications do not differentiate
it from development of PD in the elderly. The
loss of nerve cell generating dopamine in the
brain is the same for both younger- and older-onset
PD. There are some differentiating characteristics,
however. PD beginning under the age of 50 has
less of a tendency to develop concomitant cognitive
impairments or dementia than when the disorder
begins in older years. There may be an increased
tendency for the chronic use of levodopa to result
in involuntary movements (dyskinesias) in the
young-onset patient.
The
disabilities of young-onset PD differ from problems
experienced from the same disorder beginning later
in life. The impact of young-onset PD affects
a patient's livelihood, family roles, friendships,
and enjoyment of life in sometimes a more extreme
manner than for an older person, who might be
retired from work and unburdened with young children.
It is obvious from discussions at support groups
involving young-onset patients that their daily
struggle with PD is often quite different from
that experienced by older subjects. Sometimes
the need for a patient to inform his or her young
children, employers, and peers about this uncommon
occurrence of PD is very challenging. Even for
patients affected with relatively mild forms of
it, PD has the "persona" of exaggerated
aging and physical deterioration. As a result,
sometimes work or other activities are unfairly
restricted as a result. The tremors often associated
with PD can be misinterpreted by others as either
anxiety or physical frailty. Difficulties that
PD can cause for the ease of communication by
voice or handwriting can only add to the "cosmetic"
stigma of PD.
Fortunately,
the same drugs and other treatment options useful
in older patients can be highly effective in young-onset
PD. Those making use of medications needs to give
consideration to the risk for long-term outcomes
such as dyskinesias. For this reason, many clinicians
believe that levodopa use should either be restricted
(if possible) or that a dopaminergic agonist be
used together with it. Young-onset PD has an increased
risk to be a hereditary disorder. If other first-order
family members are also affected with young-onset
PD, a search for the very rare genetically mediated
forms of PD may be warranted. A young onset of
PD also calls for a careful investigation of possible
alternative diagnoses. Since several conditions
can mimic PD, a thorough examination by a neurological
specialist is warranted. This evaluation sometimes
uses testing such as an MRI scan of the brain
to make a correct diagnosis. Fortunately, most
persons even at a young age with Parkinsonism
have nothing more than PD. Since many (if not
most) people with PD continue to respond well
to medications over long periods of time, this
disorder is generally deserving of reassurance
to the patient from the treating physician.

Peter
A. LeWitt, M.D.
Professor of Neurology, Wayne State University
School of Medicine
Clinical Neuroscience Center, Southfield, Michigan
Past Chairman, Professional Advisory Board,
MPF
Past President, Board of Directors, MPF.
Check out our list of Young Onset Support Groups.