Motor Disorders Flashcards
Where is the cerebellum located within the cranial cavity?
posterior cranial fossa
What separates the occipital and parietal lobes from the cerebellum?
tentorium cerebelli
How is the cerebellum attached to the brainstem?
Superior Cerebella Peduncle (midbrain)
Middle Cerebellar Peduncle (pons)
Inferior Cerebellar Peduncle (medulla)
Does pathology originating in the cerebellum present with ipsilateral or contra-lateral signs?
Ipsilateral
How do the areas of the body innervated by the cerebellum differ between the vermis and latral hemispheres?
Lateral Hemispheres
distal structures (e.g. limbs)
Vermis
trunk musculature
Why can cerebellar pathology potentially lead to hydrocephalus?
cerebellum located posterior to the 4th ventricle, compression by a mass may occlude CSF flow
What symptoms may a patient with cerebellar disease present with?
“DANISH”
- D - dysdiadocokinesis
- A - ataxia
- N - nystagmus
- I - intention tremor
- S - slurred speech
- H - hypotonia
What is the basal ganglia?
an areas of the basal forebrain and midbrain known to be involved in the control of movement
Which structures from the lentiform nucleus?
Putamen
Globus Pallidus Interna
Globus Pallidus Externa
When considering the basal ganglia, which structures form the striatum?
Putamen
Caudate Nucleus
Identify these important structures in the basal ganglia
Caudate Nucleus
Putamen
Globus Pallius (int/ext)
Substantia Nigra (pc/pr)
Subthalamic Nucleus
Within which area of the substantia nigra are the dopaminergic neurones located?
in the substantia nigra pars compacta
(dorsally)
Is dopamine and inhibitory or excitatory neurotransmitter in the brain?
can be either depending upon the receptor it is acting
Using the diagram as a point of reference, outline what happens when the cortex is stimulated to initiate movement via the direct pathway
- cortex stimulates basal ganglia and putamen
- substandia nigra (pars, com.) release dopamine
- putamen is stimulated to inhibit the globus pallidus (int.)
- globus pallidus (int.) no longer able to inhibit thalamus (brakes removed)
- thalamus then releases excitatory glutamate to stimulate cortex
What is the overall effect of the direct pathway in the basal ganglia on the thalamus and cortex (excluding the substantia nigra)?
&
How is that affected by the addition of dopamine from the SNc?
excitatory
dopamine encourages stimulation of the cortex