7) Movement Disorders Flashcards
What is the function of the Basal Ganglia ?
Group structures involved in the control and coordination of motor function. BUT they do not produce motor function.
They communicate with each other and the Thalamus and the Cortex to allow movement
Describe the anatomy of the Basal Ganglia
> Lentiform Nucleus = Putamen + Globus Pallidus
> Striatum = Putamen + Caudate Nucleus
> Substantia Nigra (Pars Compacta and Reticularis region)
Subthalamic Nucleus
What type of neurones make up the Pars Compacta of the Substantia Nigra and what does it allow ?
Dopaminergic Neurones which allow for inhibitory and excitatory control of movement
Describe the function of Direct Pathway
> Allows movement
> Excitatory
What receptors are activated in the presence of Dopamine ?
D1 Receptors (Direct) D2 Receptors (Indirect)
Describe the function of the Indirect pathway
> Inhibits movement
> Inhibitory without Dopamine
Which side does disorder to the Basal Ganglia Present ?
Contralateral
What is Parkinson’s Disease
> Pathophysiology
> Features
Progressive Disorder Due to the degeneration of the Substantia Nigra => Loss of Dopamine
- Less Stimulation of Putamen therefore GPi is inhibited less and so activity increases, this results in inhibition of the thalamus leading to reduced cortex stimulation
- Both Direct and Indirect Pathway affected
Features: > Resting Tremor > Bradykinesia > Hypertonia > Shuffling Gait > Lead Pipe Rigidity > Depression > Hypophonia - Quiet speaking
What is Huntington’s Disease
> Pathophysiology
> Features
Autosomal dominant progressive neuro degenerative disorder due to loss of cell in Straitum
- Indirect Pathway is switched off meaning there is constant stimulation of the motor cortex
Features: > Chorea - Abnormal Jerky Movements > Dystonia - Abnormal movements due to repetitive cramping of the muscle > Incoordination > Cognitive Decline
What is Hemiballismus ?
Damage to the Subthalamic Nuclei resulting abnormal unilateral movement.
Typically due to a Sub Cortical Stroke - Indirect Pathway is affected
Describe the anatomy of the Cerebellum
> Located in posterior cranial fossa
Consists of Midline Vermis and 2 hemispheres
- Vermis deals with the trunk
- Hemispheres deal with the corresponding body
> x3 Peduncles
- Superior => Attaches to Midbrain
- Middle => Attaches to Pons
- Inferior => Attaches to the Medulla
What is the function of Cerebellum ?
Role in Motor Control and Coordination
Work with Basal Ganglia
What pathology can affect the Cerebellum
> Tumour > Stroke > MS > Alcohol > Epilepsy Medication (Carbamazepine)
How can Hydrocephalus arise in Cerebellar Pathology ?
Lesion extending from Vermis can compress the 4th ventricle
What are the common presentation of Cerebellar Disease ?
Dysdiadochokinesis - Ability to perform rapid alternating movements
Ataxia - Incoordination of voluntary movement
Nystagmus - Eyes make repetitive uncontrolled movements
Intention Tremor
Slurred Speech
Hypotonia
