The following symptoms can occur In
Parkinson's disease. Which of these symptoms that do occur vary from person to
person, over time, and in their severity
Tremor : Tremor can occur in the fingers, hands, arms, legs, chin, tongue, lips,
eyelids, and the head. It is most commonly in the hand and fingers because of
the large size of the colony of pyramidal tract cells concerned with hand and
finger movement. It often ceases during sleep only to return again on waking. As
rigidity becomes increasingly severe, tremor may diminish because the sustained
discharges of motor units which cause rigidity inhibit their rhythmical
interruptions, which are the physiological basis for tremor. tremor: normally
4-7Hz 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. However, an estimated 30% of patients have little
perceptible tremor as one of their symptoms. These are classified as akinetic-rigid.
Rigidity : Rigidity and stiffness occurs in the muscles as a primary symptom, because of their constant
muscle contraction. This can lead to pain in rigid areas. Limbs can consequently resist
passive movement. This may be exacerbated by mental concentration or active
movement in another limb. It may be diminished by relaxation, which may
completely abolish rigidity. In
combination with a resting tremor, this produces a ratchety, "cogwheel" rigidity
when the limb is passively moved.
Hypokinesia : Hypokinesia, which is a poverty of movement of muscles goes
through three stages. Firstly, there is hypokinesia, which is impaired movement
without any obvious disturbance of power or of coordination. Movement tends to
be interrupted by pauses. There can also be difficulty with small movements.
Secondly, there is bradykinesia, which is when voluntary movements can be
performed, but slowly. Thirdly, there is akinesia, which is a loss of physical
movement, which can begin with brief periods of complete immobility called
akinetic attacks. Rapid, repetitive movements produce a dysrhythmic and decremental loss
Mouth : There is loss of control of the movements of the mouth and of the
muscles of the larynx and pharynx. Speech demands precise control of these
muscles, so the voice becomes softer and loses volume. This is called hypophonia. A loss of voice
inflections can make the voice sound monotonous. A loss of articulation can lead to
slurring. Festinating speech is a group of symptoms in which there is
excessively rapid, soft, poorly-intelligible speech. Immobility of the mouth, tongue, palatal and pharyngeal musculature
causes excessive salivation, leading to drooling, as there is no intermittent
spontaneous and subconscious swallowing movements to dispose of saliva. This can
lead to drooling, which is most likely caused by weak, infrequent
swallowing. Dysphagia is the impaired ability to swallow. This can lead to aspiration, pneumonia, and
Head and neck : There is a reduction and slowness of the emotional facial
movements. This gives the appearance of a mask like face. There can also be a
loss of movement and flexion of the neck. masked facies (a mask-like face also
known as hypomimia), with infrequent blinking.
Eyes : A reduction in eye movement leads to the staring appearance of the eyes
and a poverty of blinking. More sustained contraction of the orbicularis oculi
firmly closes the eyes. Eye movements may be disturbed due to the weakness of
their convergence. This causes defects in near vision such as seeing double
because of the misalignment of the eyes. Vertical gaze is more affected than
horizontal eye movements which are normally preserved. Loss of control of the
eye muscles causes slow voluntary movements of the eyes to be Impaired, and fast
voluntary movements of the eyes to be in small jumps. In severe cases there can
be lengthy episodes of involuntary deviation of the eyes.
Trunk : A mild degree of flexion of the trunk Is common. Posture and balance are
disturbed. There is an impairment of righting reflexes, and difficulty in moving
the body. The muscles that control respiration are defective and lead to a
reduction in breathing capacity. The muscles around the stomach, small gut and
oesophagus are also affected so that there is reduced motility of them, and
spasms in the oesophagus. The contraction of the muscles of the anal region
leads to constipation. Contraction or loss of control of the muscles of the
urogenital region can lead to urinary retention, incontinence and sexual
incompetence. Stooped, forward-flexed posture. In severe forms, the head and
upper shoulders may be bent at a right angle relative to the trunk (camptocormia).
difficulty rolling in bed or rising from a seated position;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.
Urinary symptoms : urinary incontinence, typically in later disease progression.
Alimentary symptoms : constipation and gastricdysmotility, severe enough to endanger
comfort and even health.
Reproductive symptoms : 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.
Upper limb : Hypokinesia leads to a loss of arm movements, so that the arms do
not swing whilst walking. There can be a flexion and loss of movement of the
arms and wrists. The loss of hand movement can lead to the inability to carry
out all normal manual functions. Decreased arm swing: a form of bradykinesia.
micrographia (small, cramped handwriting); impaired fine motor dexterity and
coordination. Poverty of movement: overall loss of accessory movements, such as
decreased arm swing when walking, as well as spontaneous movement.
Lower limb : The rigidity and loss of movement in the legs causes difficulty in
walking and running. This is especially difficult in the first few steps. At
first walking is slower, steps become shorter, feet are often dragged. This can
develop into shuffling, or a complete inability to walk or stand without
assistance. Flexion can occur In the knees, toes, and also the ankles, which can
become inverted. 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. 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. Postural instability : failure of postural
reflexes, which leads to impaired balance and falls.
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
Visual symptoms : impaired visual contrast sensitivity, spatial reasoning, colour
discrimination, convergence insufficiency (characterized by double vision) and oculomotor control.
Olfactory symptoms : loss of sense of smell (anosmia).
Cellular effects : L-Tyrosine and molecular oxygen do not completely form
L-Dopa, so the toxic partial reduction product of oxygen, the superoxide anion O2 can be formed. This can destroy the dopaminergic neurons, which. makes the
disorder even worse, as there would be fewer dopaminergic neurons available to
produce dopamine. When L-Dopa is unable to form dopamine, it may Instead lead to
the formation and accumulation of neuromelanin, which is similar to the'pignent
melanin found in skin. It can do this via the enzyme peroxidase, instead of the
enzyme tyrosinase, which Is usually responsible for melanin production, which
does not occur in the dopaminergic neurons.
There are other medical disorders that often occur simultaneously with
Parkinson's Disease. However, they are not actually Parkinson's Disease itself :
Depression : Estimated prevalance rates of symptoms 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. Seventy percent of
individuals with Parkinson's disease diagnosed with pre-existing depression go
on to develop anxiety. Ninety percent of Parkinson's disease patients with
pre-existing anxiety subsequently develop depression, apathy or abulia.
Cognitive symptoms : 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.
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 behavioural regulation. Procedural
memory is more impaired than declarative memory. Prompting elicits improved
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.
Autonomic disturbances : oily skin and seborrheic dermatitis;dizziness and
fainting; usually attributable orthostatic hypotension, a failure of the
autonomous nervous system to adjust blood pressure in response to changes in
Dystonia : abnormal, sustained, painful twisting muscle contractions, usually
affecting the foot and ankle in Parkinson's Disease patients. This causes toe flexion and foot
inversion, interfering with gait.
Pain : neuropathic, muscle, joints, and tendons, attributable to tension,
dystonia, rigidity, joint stiffness, and injuries associated with attempts at