Movement Disorders

Movement Disorders Movement Disorders

Types of Disorders • 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 Movement Disorders

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. Movement Disorders

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 Movement Disorders

HypokineticDisorders Movement Disorders

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 Movement Disorders

Etiology: Apraxia • Strokes - lesions to the parietal lobes are some of the most common • Severe seizure activity • Traumatic brain injury Movement Disorders

Limb Apraxia • Caused by lesions to the corpus callosum, or the (usually left) parietal lobe • movement of the wrong part of the limb • incorrect movement of the correct part • 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 Movement Disorders

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 Movement Disorders

Constructional Apraxia Movement Disorders

Rey-Osterrieth Complex Figure. Movement Disorders

Rey-Osterrieth Complex Figure. Vargha-Khadem et al, 1997 Movement Disorders

Parkinson’s Disease • Symptoms: • muscular rigidity • slowness of movement • postural instability • resting tremor • Problems with walking, reaching for things (often a delay to start), writing, balance Movement Disorders

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) Movement Disorders

Parkinson’s Disease • Etiology: • Idiopathic - no known cause in most cases • Free radicals and oxidative stress • Accelerated aging • Environmental toxins • Genetic predisposition (10- 20% of patients) Movement Disorders

Basal Ganglia Movement Disorders

Movement Disorders

Rigidity, Tremor Gait, Posture Movement Disorders

HyperkineticDisorders Movement Disorders

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 Movement Disorders

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 Movement Disorders

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. Movement Disorders

Movement Disorders

Movement Disorders