Movement Disorders Flashcards
Movement disorders
group of diseases that primarily involve subcortical brain structures that are part of the extrapyramidal motor system, including the basal ganglia (caudate, putamen, and globus pallidus), thalamic and subthalamic nucleus, and substantia nigra, and their interconnections to each other and cortex
extrapyramidal motor system regulates movement and maintains muscle tone and posture.
Three primary neurotransmitters of the basal ganglia that contribute to symptomatology of movement disorders
Dopamine (inhibitory)
acetylcholine (excitatory)
gamma-aminobutyric acid (GABA; inhibitory)
Parkinson’s Disease
neurodegenerative disorder characterized by:
parkinsonism (rest tremors-most common and generally asymmetrical, slowness/bradykinesia, rigidity)
neuronal loss in the substantia nigra,
dopamine depletion in the striatum (and a clear and dramatic beneficial response to dopaminergic therapy)
frontal subcortical circuitry dysfunction.
Risk factors for Parkinson’s Disease
viral encephalitis,
drugs with dopamine antagonistic properties (neuroleptics),
toxic substances, exposure to herbicides, pesticides, and heavy metals drinking of contaminated well water
Medication for Parkinson’s Disease
levodopa, dopamine agonists, and
MAO-B inhibitors.
Nonpharmacological Interventions for Parkinson’s disease
Physical exercise (especially exercises designed to improve balance,
flexibility, and strength),
cued exercises with visual (mirror),
voice therapy,
speech/swallowing therapy,
Deep brain stimulation (DBS) -
Best candidates have severe motor symptoms in the off-medication condition; targets include subthalamic nucleus or globus pallidus as the most common sites, although
ventrointermedius (VIM) thalamic nucleus has clear effect on tremor; dementia is usually a
contraindication for DBS.
neuropsychological expectations for Parkinson’s disease
Impaired: complex attention, working memory, processing speed/EF, initial memory
Language: dysarthria and reduced speech output; comprehension, syntax, and grammar intact
Visuospatial: micrographia, difficulties with constructional praxis
Depression and anxiety common
Huntington’s Disease
fatal autosomal dominant neurodegenerative disorder
CAG repeats on chromosome 4 - can be diagnosed by genetic testing
Symptoms: chorea (jerky involuntary movements), dystonia, tic, incoordination, hypokinesia, saccades
Mean age at onset between 30–50
apathy
Disease duration is 15–20 years. Causes of death include pneumonia (related to dysphagia), heart disease, and suicide
Neuropathology of Huntington’s disease
loss of cells caudate nucleus and putamen.
As the disease progresses, further degeneration is observed in erebral cortex, thalamus, pallidum, brainstem, and cerebellum.
Medication for Huntington’s disease
Chorea may be treated with tetrabenazine (TBZ), a dopamine-depleting agent.
botulinum toxin injections for muscle spasms/spasticity in later stage of HD
SSRIs may be helpful for depression and anxiety but increase for suicide
Huntington’s disease neuropsychological outcomes
Impaired early:
visual attention,
processing speed,
visuospatial integration,
deficits in learning but recognition intact until middle/late stages,
working memory/EF severely impaired
Depression, anxiety, psychosis, OCD
Lewy body disease (LBD)
progressive neurodegenerative disorder that is characterized by parkinsonism and cognitive decline/dementia.
Mean age of onset 50s-80s
Responsible for 20% or more of all dementias, second to AD.
Lewy body disease (LBD) neuropathology
Lewy bodies - abnormal aggregates of protein that form within nerve cells and displace other cell components;
alpha-synuclein is the primary component)
Lewy neuritis (LN; alpha-synuclein cytoplasmic inclusion
bodies) in the cortex and brainstem
Medication for Lewy body disease (LBD)
- Treatment of motor symptoms with levodopa can aggravate hallucinations.
- Treatment with dopamine agonists can result in compulsive behaviors
Lewy body disease/dementia course
slow progression, but with frequent fluctuations whereby the patient may have episodes of marked confusion/attention/alertness interspersed with periods of complete lucidity.
Lewy body disease/dementia neuropsychological expectations
Impaired early: attention, processing speed, EF, migrographia
marked impairment in visuospatial and constructional abilities
Well-formed visual hallucinations, delusions (e.g., Capgras syndrome)
Progressive Supranuclear Palsy
progressive neurodegenerative disorder that represents the most common Parkinson’s plus syndrome
- Onset typically in the 60s, can occur in 40s.
- Dementia occurs in 50–80% of cases.
involves erosion of subcortical structures, as well as of subcortical-cortical connections (primarily to the prefrontal cortex) leading to:
** vertical gaze palsy (particularly downward gaze)** (hallmark)
* axial rigidity (neck and trunk - this is different from Parkinsons that affects limbs)
* postural instability with falls (often backward)
* wide-eye stare
other common symptoms:
- dysarthria
- dysphagia
- bradykinesia
- gait disorder (apraxia)
- cognitive impairment
- behavioral changes (apathy, depression, anxiety, pseudobulbar affect, neurobehavioral symptoms)
Neuropathology of Progressive Supranuclear Palsy
- tau protein deposits.
- Dopamine depletion in the substantia nigra, caudate, and putamen.
- Neuronal loss and gliosis in the globus pallidus, subthalamic nuclei, red nuclei, dentate nucleus, superior colliculi, and periaqueductal gray matter.
- Neurofibrillary tangles and neuropil threads in the basal ganglia, brainstem
Progressive Supranuclear Palsy neuropsychological outcomes
Impairment early:
attention, processing speed, EF, word list generation
depression, anxiety, pseudobulbar affect, wide-eye stare
Tourette Syndrome
characterized by repetitive, stereotyped involuntary movements and vocalizations called tics, generally proceeded by a premonitory urge or sensation.
Age of onset is usually between 5 to 7 years, with symptoms peaking around 10–12 years of age
prevalence three to four times higher in males than females.
Tics usually progress from simple to complex and worsen during the teenage years, followed by improvement in adulthood,
Tics are thought to be a disorder of the basal ganglia/cortical brain circuitry, though the exact pathophysiology is unknown.
Torette’s syndrome comorbidities
ADHD
learning disabilities
obsessive-compulsive disorder
rage attacks
depression
generalized anxiety
panic attacks
sleep disorders
migraines
Onset of Parkinsonism and cognitive dysfunction in close proximity occurs in which disorder?
Lewy body dementia
Co-occurring (within 1 year) cognitive and motor symptoms are most common in LBD and are, in fact, part of the diagnostic criteria. Dementia is inevitable in LBD.
What is a core psychiatric symptom in individuals with Huntington’s disease?
Apathy is the most prevalent neuropsychiatric feature of HD, and is primarily associated frontal- striatal circuit damage.
Cognitive dysfunction in Parkinson’s disease tends to be higher in individuals who
do not have tremor at initial presentation
Older age of onset and initial symptoms other than tremor are risk factors for dementia in PD
