06.1 Basal Ganglia and Cerebellum Flashcards
What are the anatomical lobes of the cerebellum?
Anterior lobe
Posterior lobe
Flocculonodular lobe
What are the functional zones of the cerebellum are what are their functions?
Vestibulocerebellum - balance
Spinicerebellum - error correction
Cerebrocerebellum - planning + motor learning
What is the arterial supply to the cerebellum?
Superior cerebellar artery
Anterior inferior cerebellar artery
Posterior inferior cerebellar artery
How does the cerebellum connect to the rest of the CNS?
Via peduncles to the midbrain, pons and medulla
What can cause cerebellar damage?
Stroke Hydrocephalus Tumour Infection (bacterial, viral, parasitic, prion) Drugs (alcohol, barbiturates, phenytoin) Multiple sclerosis Congenital
What are some signs of cerebellar damage?
Dysdiadochokinesia Ataxia Nystagmus Intention tremor Slurred speech Hypotonia
What is the main function of the basal ganglia?
Provide a feedback mechanism to the cerebral cortex for initiation and control of motor responses.
What is the direct pathway?
Neostriatum inhibits globus pallidus internal
Globus pallidus internal usually inhibits thalamus
Thalamus excites the cerebral cortex
(overall effect is releasing the thalamus to allow movement)
What is the indirect pathway?
Neostriatum inhibits globus pallidus external
Globus pallidus external usually inhibits subthalamic nucleus
Subthalamic nucleus now excites the globus pallidus internal
Globus pallidus internal inhibits the thalamus
Thalamus usually excites the cortex
(overall effect is inhibiting the cortex)
What is Parkinson’s disease?
Progressive degeneration of the dopaminergic neurones of the substantia nigra.
Leads to reduces direct pathway and an increase in indirect pathway
What are the cardinal signs of Parkinson’s?
Bradykinesia
Resting Tremor
Hypertonia
Postural instability
What are some other signs of Parkinson’s?
Micrographia
Mask face
Monotonous speech
Akinesia
What is Huntington’s disease?
Autosomal dominant inherited condition that causes degeneration of GABA neurones in the neostriatum of the indirect path. This causes excessive thalamus excitation and unwanted movements.
