Several
neurological conditions may appear to be idiopathic (without known cause) PD at
first, but they eventually trace back to known causes, progress differently,
and respond differently to therapy. These other conditions include the
following:
Essential
tremor (ET) is
perhaps the most common type of tremor, affecting as many as five million
Americans. ET differs from the tremor in idiopathic PD in several ways: ET
occurs when the hand is active (as in eating, grasping, writing, and such). It
may also occur in the face, voice, and arms. The renowned actress, Katherine
Hepburn, had ET, not PD. Differentiating ET from PD is very important because
each condition responds to completely different sets of medications.
Parkinson-plus
syndromes may
initially have the same symptoms as PD. But these syndromes also cause early
and severe problems with balance, blood pressure, vision, and cognition and
usually have a much faster progression compared to PD.
Secondary
parkinsonism can
result from head trauma or from damage to the brain due to multiple small
strokes (atherosclerotic or vascular parkinsonism). Both forms can be ruled out
through scans (CTs or MRIs) that produce images of the brain.
Pseudoparkinsonism can appear to be PD when in fact
the person has another condition (such as depression) that can mimic the
inexpressive face of PWP.
Drug
- or toxin-induced parkinsonism
can occur from taking antipsychotic medications (drug-induced) or from exposure
to toxins such as carbon monoxide and manganese dust (toxin-induced).
Drug-induced symptoms are usually (but not always) reversible; toxin-induced
symptoms usually aren’t.
The
subtleties of diagnosing idiopathic PD may lead your family doctor to send you
to a neurologist, a specialist in the treatment of neurological conditions. If
that happens, don’t panic. Getting the correct diagnosis is the first step
toward figuring out what comes next for you.
