Fatigue is one of the most common symptoms experienced by people with
Parkinson’s. Various studies have indicated
that at least 50% of people with Parkinson’s are affected by fatigue, and it is
frequently one of the most disabling symptoms.
Fatigue does not correlate with the severity of Parkinson’s, or how
long a person has had the condition. But
it does correlate with depression, and depression itself invariably causes
fatigue. However, in Parkinson’s the
effective treatment of depression often does not relieve fatigue. As such, for people with Parkinson’s, fatigue
and depression are considered independent of each other.
Although fatigue tends to be a neglected Parkinson’s symptom, with few
studies on this aspect of the condition, there are two significant, long-term
reports:
One study1 observed people with Parkinson’s over nine years
and found that the majority of those who experienced fatigue at their first
assessment still had it at the end of the nine year period. By contrast, the study showed that those who
were not fatigued at their first assessment were unlikely to become fatigued
later. The study also revealed that fatigue
tended to be persistent and often worsened over time in people who experienced
the symptom in the early stages of their Parkinson’s.
In another study2, 230 people with Parkinson’s were observed
for eight years, and it was found that the fatigue became more prevalent over
that period, with 36% affected initially, 43% after five years, and 56% after
eight years. The people who experienced
fatigue generally complained of persistent fatigue, but at least 44% said that
fatigue fluctuated or varied over time.
Doctors often describe more than one type of fatigue in Parkinson’s:
- muscle or peripheral fatigue
- the loss of strength with repeated muscle contraction or activity. This type of fatigue is frequently reported
as a sense of weakness, and probably earned the disease its original name
“paralysis agitans” (‘paralysis’ referring to weakness and ‘agitans’ referring
to the associated tremor). Muscle
fatigue is usually called ‘peripheral fatigue’ by specialists and some studies
have shown that people with Parkinson’s who experience it noticed an
improvement when taking levodopa
or other dopaminergic medications
-
central fatigue - this
involves an inability to cope with physical and mental tasks which require self
motivation. This type of fatigue does
not seem to respond as well to levodopa and dopaminergic medications as
peripheral fatigue
-
mental fatigue – a
difficulty in initiating and sustaining mental tasks of any type
-
physical fatigue – a
difficulty in carrying out physical activities.
The effect of fatigue on quality of life is usually clear to see:
- mental and physical fatigue can affect
psychological and emotional wellbeing
- the person who is fatigued may become less active
and unable to pursue hobbies and interests
- social activity requires energy, so a person with
fatigue will have a greater tendency to become withdrawn
- a reduced inclination to engage in activities is
likely to bring with it reduced stamina, reduced fitness and further muscle
weakness.
For all these reasons it is important for people with fatigue to try
and keep as active as possible. One
leading neurologist advises that anyone newly diagnosed with Parkinson’s that
they have no restrictions and should encourage their relatives to prevent them
from becoming less active to reduce the risk of experiencing fatigue and other
symptoms.
