Transcript 17Movementdisorders

Movement Disorders
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Types of Disorders
1. Hypokinetic: reduced amount of intentional
motor activity
 Apraxias
 Parkinson’s
2. Hyperkinetic: increased amount of unintentional
motor activity (plus reduced intentional activity)
 Huntington's
 Tourette’s
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Movement Disorders
 Typically seen by neurologists
 May initially be seen by neuropsychiatrist or
neuropsychologist if there is some psychological
concern
e.g. psychomotor slowing in Parkinson’s
e.g. mood in both Parkinson’s and Huntington’s
 Clinical interventions are therefore multifactor in
nature.
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Prevalence Estimates
 Age-dependent prevalence (APA, 2004)
• More common after age 55 - roughly 0.1-5% of the
population
• Increases to 10-25% after age 80
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Hypokinetic
Disorders
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Apraxias
 Inability to properly execute a learned skilled
movement
 Caused by damage to corpus callosum, premotor
area, prefrontal or parietal cortex.
 4 types:
• oral apraxia, apraxic agraphia
• limb apraxia
• constructional apraxia
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Etiology: Apraxia
1. Strokes - lesions to the parietal lobes are some
of the most common
2. Severe seizure activity
3. Traumatic brain injury
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Limb Apraxia
 Caused by lesions to the corpus callosum, or the
(usually left) parietal lobe
1. movement of the wrong part of the limb
2. incorrect movement of the correct part
3. correct movements but in the incorrect sequence
 Assessed by asking people to perform
movements e.g. use a key to open a door or
pretend to brush your teeth
• Objects are not given - must imagine using object
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Constructional Apraxia
 Lesions of (usually right) parietal lobe
 No trouble using objects, imitating use, or
making skilled movements
 Difficulty drawing or assembling objects
 Unable to express holistic or geometrical relations
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Constructional Apraxia
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Rey-Osterrieth Complex Figure.
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Rey-Osterrieth Complex Figure.
Vargha-Khadem et al, 1997
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Parkinson’s Disease
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1.
2.
3.
4.

Symptoms:
muscular rigidity
slowness of movement
postural instability
resting tremor
Problems with walking, reaching for things (often
a delay to start), writing, balance
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Parkinson’s Disease
 Damage to basal ganglia is the neurobiological
basis for the disorder
 Not enough DA in the nigrostriatal system
(Poizner et al., 2000)
• connections from the substantia nigra to the basal
ganglia)
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Parkinson’s Disease

1.
2.
3.
4.
5.
Etiology:
Idiopathic - no known cause in most cases
Free radicals and oxidative stress
Accelerated aging
Environmental toxins
Genetic predisposition (10- 20% of patients)
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Basal Ganglia
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Rigidity, Tremor
Gait, Posture
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Hyperkinetic
Disorders
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Huntington’s Disease
 Hereditary - dominant gene on Chromosome 4
 Causes a degeneration of the caudate nucleus
and putamen (basil ganglia)
 GABA and Ach neuron loss
 Uncontrollable movements, usually jerky limbs
 Progressive, leading to death (due to
complications from immobility)
 Symptoms start in 30s-40s
 No treatment for the disorder
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Tourette’s Syndrome
 Tics: involuntary, rapid, sudden movements or
vocalizations that occur repeatedly in the same way.
• May occur together
 The occurrence of tics many times a day (usually in
bouts) nearly every day
 Symptoms can disappear for weeks or months at a time.
 Basal ganglia and frontal areas appear to be affected
• Lack of “executive control”
• Systemic disruption, multiple transmitter systems
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Tourette’s Syndrome
 Most people with TS do have some control over the
symptoms.
 Control may only last seconds to hours at a time and
may merely postpone more severe outbursts of
symptoms.
 Tics usually increase in the presence of stress.
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