Motor Disorders

Question 1

The motor cortex

Answer 1

Issues defending motor commands for muscle activation
Regulates activity levels in spinal cord circuits
Where the upper motor neuron begins
Damage
-Impaired movement
- Poor high level coordination
-Weakness of movement

Question 2

Cerebral palsy

Answer 2

A result of damage to motor control structure of the brain- usuals the motor cortex
The injury often occurs pre- or peri- natally
50% of cases associated with premature birth
Stiffness and weakness of muscles
Motor cortex isn’t able to regulate reflexes properly

Question 3

Stroke

Answer 3

Interruption of blood supply
Upper motor neurone affected
Symptoms depend on extent and location but usually typical of motor cortex damage
Causes:
Cerebral haemorrhage- leakage of blood- blood is toxic to neural tissue
Often results from an aneurism- blood vessel bursting
If an aneurism is spotted before rupture, it can sometimes be treated- by clipping the blood vessel
Prevention of bursting- maintain low blood pressure/ avoid strenuous activity

Cerebral ischaemia- loss of blood supply
Cause by an interruption of the blood supply to part of the brain die to blockage of a blood vessel
Blockages can be cause by specific plugs (thrombus or emboli) or cardiovascular disease
Goal of treatment after stroke is to rescue the penumbra by reopening the blocked blood vessel
Core- can’t be saved
Penumbra- salvageable

Question 4

Upper motor neuron syndrome

Answer 4

Collection of symptoms that indicate a problem with upper motor neurons or their pathways
Leads to lack of voluntary control of muscles via lower motor neurons, and a lack f regulation of LMNs and spinal reflex circuits

Question 5

Basal ganglia dysfunction

Answer 5

There are diseases that damage the basal ganglia
Parkinsons- stops selecting motor programmes
Innapropriat activation of motor movement- tourettes

Question 6

Parkinson’s

Answer 6

Problem’s initiating movement
The right motor programs are not being selected and the wrong ones are not being deselected
Bradykinesia- slow movements
Akinesia- no movement

Question 7

Dopamine

Answer 7

In order to do stuff you have to activate your motor cortex
It is inhibited all the time by the basal ganglia
When you remove the inhibition it allows the motor program to flow through the cortex, spinal cord, and muscles.
Bursts of dopamine allows this disinhibition to happen
In Parkinson’s, that burst of dopamine isn’t there
Give people L-dopa which makes the brain produce dopamine
Too much dopamine can cause schizophrenia symptoms

Question 8

Deep brain stimulation

Answer 8

Insert electrodes into the global pallidus

Question 9

Alpha-synuclein and Lewy bodies

Question 10

Cerebellum

Answer 10

Knows what it is you’re trying to do and the current position of your limbs
When damaged, the impairment of movement is called ataxia:
Disturbances of posture or gait
Decomposition of movement
Voluntary movement loses fluidity and appears mechanical, slow, and robot like
You have intention tremors
Dysarthria- disruption of fine control and speech