Basal Ganglia Flashcards
Lesions of the basal ganglia result in ___________ and characterized by what?
“movement disorders” characterized by specific dyskinesias
Slowed movements
Bradykinesia
decreased amount of movements
hypokinesia
absence of movement
akinesia
twisting movements of the limb, face, and trunk
Athetosis
Huntington’s Disease is associated with what 2 movement disorders?
Athetosis
Chorea
What types of medications can cause athetosis/chorea?
antipsychotic and anitemetic medications
Continuous involuntary movements, fluid or jerky quality “break dancing”
Chorea
movements of proximal limb muscles with larger-amplitude and more flinging quality (usually unilateral due to lesion in contralateral subthalamic nucleus)
Ballismus
Rhythmic or semirhythmic oscillating movements
Tremor
Increased resistance to passive movement of a limb
Rigidity
Sustained assumption of abnormal, often distorted, positions of the limbs trunk or face.
Dystonia
4 cardinal features of Parkinson’s Disease
- Tremor
- Rigidity
- Bradykinesia
- Postural Instability
Difference between lead pipe rigidity and cog-wheel rigidity
lead pipe - uniform rigidity throughout range of motion
cog wheel - rigidity is interrupted by series of brief relaxations
7 possible causes of PD
- idiopathic
- Encephalitis lethargica
- MPTP (contaminant in heroin)
- Head trauma
- Antipsychotic drugs
- Poisoning with manganese or carbon monoxide
- Pesticides
6 treatments for PD
- Monoamine oxidase inhibitors (prevent dopamine breakdown)
- Dopamine agonist drugs (mimic dopamine)
- non-steroidal anti-inflammatory agents
- Levodopa L-DOPA (dopamine precursor)
- Deep Brain Stimulations
- Surgical Lesions - Ablations
Combination drug used with L-DOPA
Sinemet
Sign that L-DOPA is failing
dyskinesia (head bobbing, lip smacking, tongue thrusting, leg writhing, hand clasping, trunk twisting)
What does DBS do?
Continuous stimulus that reduces the discharge of action potentials of cells to rebalance control messages
Where may the electrode of DBS be placed?
- thalamus to treat disabling tremor
- globus pallidus to treat disabling dyskinesias and tremor
- Subthalamic nucleus to treat bradykinesia, tremor, rigidity
2 Types of surgical lesions for PD
- Thalamotomy ( destorys a small part to treat tremors)
2. Pallidotomy ( destroys a small part to treat akinesia)
2 causes of Huntington’s Disease?
- Loss of cholinergic and GABA-ergic neurons in the striatum - thought to cause choreiform movements
- Loss of cortical cells thought to cause impaired cognitive functions and dementia
Extrapyramidal motor disorder characterized by violent flinging of one extremity or both?
Hemiballism or Ballism
What causes Ballism/hemiballism?
Vascular infarct, hemorrhage or tumor of the subthalamic nucleus
