Diagnosing both Parkinson’s and ET requires
taking a very detailed personal and family history and careful clinical
examination.
It is important to know what medications the
individual has taken, or is taking.
Often medications such as Stemetil (prochlorperazine) that are used for
dizziness or as tonics are forgotten, yet they can have dramatic effects on the
nervous system, in extremes causing tremor.
A good
history and examination should allow the physician to establish whether the
individual has either Parkinson’s and/or ET.
It is important that the individual is assessed by a specialist with expertise in the
field of movement disorder, usually a
neurologist. It must be remembered that
various disorders of the nervous system can produce tremors and usually the
diagnosis is reached by considering the associated symptoms and signs which
occur with the tremor (clinical appraisal).
However, there are some people who present with
tremor, in whom it is impossible to decide whether they have or have not got
Parkinson’s or ET. Previously it has
been normal to observe the individual over time so other features of Parkinsonism
will become evident and normally make the diagnosis straight forward. But these days it is possible to measure the dopamine in the striatum by means of a
DaTSCAN. Depleted dopamine in the striatum is a hallmark
of Parkinson’s.
Even with such technologies, tremulous disorders
can be difficult to diagnose and anyone with tremor should be reviewed by a
specialist in movement disorders at least once.
This is the recommendation incorporated into the World Charter on
Parkinson's and is also the strong recommendation of the National TremorFoundation (UK). The reason for insisting
on this is that, although ostensibly the two conditions should be separable on
clinical grounds, mistakes are commonly made confusing the two conditions and
there have been a number of studies to confirm this.
