Parkinson disease affects movement
(motor symptoms). Typical other
symptoms include disorders of mood,
behavior, thinking, and sensation
(non-motor symptoms). Individual
patients' symptoms may be quite
dissimilar and progression of the
disease is also distinctly
individual.
Motor symptoms
The cardinal
symptoms are:
- tremor: normally 4-7 Hz
tremor, maximal when the limb is at
rest, and decreased with voluntary
movement. It is typically
unilateral at onset. This is the
most apparent and well-known
symptom, though an estimated 30% of
patients have little perceptible
tremor; these are classified as
akinetic-rigid.
- rigidity: stiffness; increased
muscle tone. In combination with a
resting tremor, this produces a
ratchety, "cogwheel" rigidity when
the limb is passively moved.
- bradykinesia/akinesia:
respectively, slowness or absence
of movement. Rapid, repetitive
movements produce a dysrhythmic and
decremental loss of amplitude. Also
"dysdiadokinesia", which is the
loss of ability to perform rapid
alternating movements
- postural instability:
failure of postural reflexes, which
leads to impaired balance and
falls.
Other motor symptoms
include:
- Gait and posture
disturbances:
- Shuffling: gait is
characterized by short steps, with
feet barely leaving the ground,
producing an audible shuffling
noise. Small obstacles tend to trip
the patient
- Decreased arm swing: a
form of bradykinesia
- Turning "en bloc":
rather than the usual twisting of
the neck and trunk and pivoting on
the toes, PD patients keep their
neck and trunk rigid, requiring
multiple small steps to accomplish
a turn.
- Stooped, forward-flexed
posture. In severe forms, the
head and upper shoulders may be
bent at a right angle relative to
the trunk (camptocormia) [5].
- Festination: a
combination of stooped posture,
imbalance, and short steps. It
leads to a gait that gets
progressively faster and faster,
often ending in a fall.
- Gait freezing:
"freezing" is another word for
akinesia, the inability to move.
Gait freezing is characterized by
inability to move the feet,
especially in tight, cluttered
spaces or when initiating
gait.
- Dystonia (in about 20%
of cases): abnormal, sustained,
painful twisting muscle
contractions, usually affecting the
foot and ankle, characterized by
toe flexion and foot inversion,
interfering with gait. However,
dystonia can be quite generalized,
involving a majority of skeletal
muscles; such episodes are acutely
painful and completely
disabling.
- Speech and swallowing
disturbances
- Hypophonia: soft speech.
Speech quality tends to be soft,
hoarse, and monotonous. Some people
with Parkinson's disease claim that
their tongue is "heavy".
- Festinating speech:
excessively rapid, soft,
poorly-intelligible speech.
- Drooling: most likely
caused by a weak, infrequent
swallow and stooped posture.
- Non-motor causes of
speech/language disturbance in
both expressive and receptive
language: these include decreased
verbal fluency and cognitive
disturbance especially related to
comprehension of emotional content
of speech and of facial
expression
- Dysphagia: impaired
ability to swallow. Can lead to
aspiration, pneumonia.
• Other motor
symptoms:
- fatigue (up to 50% of
cases);
- masked faces (a
mask-like face also known as
hypomimia), with infrequent
blinking;
- difficulty rolling in bed or
rising from a seated
position;
- micrographia (small,
cramped handwriting);
- impaired fine motor
dexterity and motor
coordination;
- impaired gross motor
coordination;
- Poverty of movement:
overall loss of accessory
movements, such as decreased arm
swing when walking, as well as
spontaneous movement.
Non-motor symptoms
Mood
disturbances
- Estimated prevalence rates of
depression vary widely
according to the population sampled
and methodology used. Reviews of
depression estimate its occurrence
in anywhere from 20-80% of cases.
Estimates from community samples
tend to find lower rates than from
specialist centres. Most studies
use self-report questionnaires such
as the Beck Depression Inventory,
which may overinflate scores due to
physical symptoms. Studies using
diagnostic interviews by trained
psychiatrists also report lower
rates of depression.
- More generally, there is an
increased risk for any individual
with depression to go on to develop
Parkinson's disease at a later
date.
- 70% of individuals with
Parkinson's disease diagnosed with
pre-existing depression go on to
develop anxiety. 90% of
Parkinson's disease patients with
pre-existing anxiety subsequently
develop depression; apathy or
abulia.
- Cognitive
disturbances
- slowed reaction time;
both voluntary and involuntary
motor responses are significantly
slowed.
- executive dysfunction,
characterized by difficulties in:
differential allocation of
attention, impulse control, set
shifting, prioritizing, evaluating
the salience of ambient data,
interpreting social cues, and
subjective time awareness. This
complex is present to some degree
in most Parkinson's patients; it
may progress to:
- dementia: a later
development in approximately 20-40%
of all patients, typically starting
with slowing of thought and
progressing to difficulties with
abstract thought, memory, and
behavioral regulation.
Hallucinations, delusions and
paranoia may develop.
- short term memory loss;
procedural memory is more impaired
than declarative memory. Prompting
elicits improved recall.
- medication effects: some
of the above cognitive disturbances
are improved by dopaminergic
medications, while others are
actually worsened.[10]
Sleep disturbances
- Excessive daytime
somnolence
- Initial, intermediate, and
terminal insomnia
- Disturbances in REM
sleep: disturbingly vivid
dreams, and REM Sleep Disorder,
characterized by acting out of
dream content - can occur years
prior to diagnosis
Sensation disturbances
- impaired visual contrast
sensitivity, spatial reasoning,
colour discrimination, convergence
insufficiency (characterized by
double vision) and oculomotor
control
- dizziness and fainting;
usually attributable orthostatic
hypotension, a failure of the
autonomous nervous system to adjust
blood pressure in response to
changes in body position
- impaired proprioception
(the awareness of bodily position
in three-dimensional space)
- reduction or loss of sense
of smell (microsmia or anosmia)
- can occur years prior to
diagnosis,
- pain: neuropathic, muscle,
joints, and tendons,
attributable to tension, dystonia,
rigidity, joint stiffness, and
injuries associated with attempts
at accommodation
Autonomic disturbances
- oily skin and seborrheic
dermatitis
- urinary incontinence,
typically in later disease
progression
- nocturia (getting up in
the night to pass urine) - up to
60% of cases
- constipation and gastric
dysmotility that is severe
enough to endanger comfort and even
health
- altered sexual function:
characterized by profound
impairment of sexual arousal,
behavior, orgasm, and drive is
found in mid and late Parkinson
disease. Current data addresses
male sexual function almost
exclusively
- weight loss, which is
significant over a period of ten
years - 8% of body weight lost
compared with 1% in a control
group.
