Disorders of the CNS

Question 1

What is brown-sequard syndrome?

Answer 1

A hemi section of the spinal cord = damage to a whole half of the spinal cord

Question 2

Which tracts does Brown-Sequard syndrome affect?

Answer 2

Both ascending and descending tracts

Question 3

If there is loss of sensation which tract has been affected?

Answer 3

Ascending - either dorsal or spinothalamic depending on the type of damage

Question 4

If the tract decussates in the medulla, which side will the lesion / damage affect?

Answer 4

The same side as the lesion

Question 5

If the tract decussates in the spinal cord, which side will the lesion / damage affect?

Answer 5

The other side

Question 6

Loss of motor function of the limbs will be on what side relative to the lesion?

Answer 6

The same side / IPSILATERALLY, as motor function to the limbs is controlled by the lateral corticospinal tract which decussates in the MEDULLA

Question 7

Loss of pain and temperature will be on what side of the body relative to the lesion?

Answer 7

Will be on the opposite / CONTRALATERAL side to the lesion - this is because the spinothalamic tract decussates in the spinal cord, and therefore a lesion will affect the other side

Question 8

If there is loss of proprioception, fine touch and vibration, which side will the lesion be on relative to the site of damage?

Answer 8

The SAME side as these components are part of the DORSAL pathway which decussates in the medulla

Question 9

If a patient experiences abnormal sensations in the left hand what part of the brain is affected and why?

Answer 9

• Right parietal cortex in the primary somatosensory cortex.
• Because this region is responsible for sensory innervation to the contralateral side of the body

Question 10

Why would a stroke patient have jerking movements?

Answer 10

Seizures are formed as a result of tissue damage from the stroke leading to propagation of discharge to the arm area of the motor cortex in the frontal lobe therefore causing jerks

Question 11

What treatments reduces/prevents involuntary jerking movements?

Answer 11

Anticonvulsants

Question 12

What happens if these movements are left untreated

Answer 12

• Seizures could spread to whole motor cortex and/or propagate to other hemispheres of the brain to produce generalised seizures.
• Recurring seizures may contribute to neuronal injury within brain and lead to cognitive decline and reduced quality of life