Session 6 - Motor Disorders Flashcards
Where is the cerebellum located?
Posterior cranial fossa at the back of the brain.
The cerebellum is important in what functions?
Motor control
Coordination
What separates the cerebellum from the occipital and parietal lobes?
Tentorium cerebelli
The cerebellum communicates with the brainstem via what?
The cerebellar peduncles.
Superior cerebellar peduncle attaches the cerebellum to the midbrain.
Middle cerebellar peduncle attaches the cerebellum to the pons.
Inferior cerebellar peduncle attaches the cerebellum to the medulla.
The cerebellum communicates with the cortex via what?
The thalamus
The cerebellum is separated from the pons by what?
The fourth ventricle
What does the cerebellum consist of?
Vermis - regulates trunk musculature
Two lateral cerebellar hemispheres - regulate distal structures i.e. limbs
Lesions in the midline (vermis) can result in what?
Truncal ataxia
Abnormal gait
Extension of midline lesions can also cause compression of the fourth ventricle leading to hydrocephalus.
What are the symptoms of cerebellar disease?
Dysdiadochokinesis Ataxia Nystagmus Intention tremor Slurred speech Hypotonia
What is dysdiadochokinesis?
Inability to perform rapid, alternating movements
What is the function of the basal ganglia?
Communicate with the cortex and cerebellum to aid with the initiation of movement.
What are the important structures in the basal ganglia?
Caudate nucleus Putamen Globus pallidus externa Globus pallidus interna Substantia nigra (pars compacta and pars reticularis) Subthalamic nucleus
Which parts of the basal ganglia make up the lentiform nucleus?
Putamen
Globus pallidus externa
Globus pallidus interna
Which parts of the basal ganglia make up the striatum?
Putamen and caudate nucleus
Is dopamine excitatory or inhibitory?
Can be either excitatory or inhibitory depending on the receptors it acts on.
What is the overall net effect of dopamine in the basal ganglia pathways?
Overall net effect of dopamine is motor cortex stimulation via the thalamus.
Parkinson’s disease is characterised by a triad of what symptoms?
Bradykinesia
Tremor
Rigidity
What is the cause of Parkinson’s disease?
Degeneration of the substantia nigra causes deficiency of dopamine
What are the symptoms of Parkinson’s disease?
Cardinal features:
Resting tremor
Bradykinesia
Hypertonia - rigidity
Other associated features: Shuffling gait Hypophonia Reduced facial expression Micrographia Dementia Depression
What sort of disease is Huntington’s disease?
Autosomal-dominant, progressive neurodegenerative disorder
What are the symptoms of Huntington’s disease?
Chorea Dystonia Incoordination Cognitive decline Behavioural difficulties
What is the cause of Huntington’s disease?
Associated with cell loss within the striatum.
What is chorea?
Jerky involuntary movements, especially affecting the shoulders, hip and face.
What is hemiballismus?
Rare movement disorder resulting in unilateral abnormal movement contralateral to subthalamic nuclei damage. Often secondary to sub-cortical stroke.
