Neurology

Question 1

What is an astrocytoma.

Answer 1

Intracranial tumours that are derived from astrocytes.

Question 2

Describe the demographics of an astrocytoma.

Answer 2

They may occur at any age,although they are more common in males.

Question 3

How can astrocytomas be classified?

Answer 3

• Low grade: Grade I and II, more common in children

- High grade: Grade III and IV, more common in adults

Question 4

Describe the presentation of grade I astrocytomas.

Answer 4

Grade I astrocytomas are often found within the cerebellum and as such tend to present with symptoms relating to balance and coordination.

Typically benign in nature.

Question 5

Describe the presentation of grade II astrocytomas.

Answer 5

Grade II tumours often present with seizures and have the potential to become malignant.

Question 6

Describe the pathology behind MS.

Answer 6

The Oligodendrocytes degenerate for an unknown reason.

It is an acquired, chronic autoimmune disorder affecting the CNS. It results in demyelination, gliosis and neuronal damage.

Question 7

Describe how a patient with MS would present.

Answer 7

Either sensory or motor symptoms as the conduction of signals along a neurone slows down.

Symptoms involve multiple branches of the nervous system, such as vision problems, weakness, pains, tingling and numbness.

Question 8

Describe the pathology behind Alzheimer’s disease.

Answer 8

Mass degeneration occurs, commonly targeting the temporal and parietal lobes which cause a wide range of symptoms.

Question 9

Describe the three disease patterns of MS.

Answer 9

1. Relapsing-remitting: Patients face episodes of remission (during which no symptoms are present) and exacerbations of the disease.
2. Primary progressive: After onset of disease there is steady progression and worsening of the disease.
3. Secondary Progressive: Initially the MS is of relapsing-remitting pattern however at some point the disease course changes and the neurological function gradually worsens.

Question 10

Give an example of a therapy that has proven useful in terms of managing acute exacerbations of MS.

Answer 10

High dose IV corticosteroids

Question 11

Describe the pathology behind Guillain-Barré Syndrome.

Answer 11

A rapid onset of muscle weakness caused by autoimmune damage to the peripheral nervous system.

The cause is unknown, but the underlying mechanism is damage to the myelin sheath of peripheral nerves by the body’s immune system.

Question 12

Describe how a patient with Guillain-Barré Syndrome would present.

Answer 12

Initial symptoms usually include changes to sensation or pain and muscle weakness. These begin distally in the feet and hands and then typically spreads proximally to the arms and upper body.

Question 13

Describe why Guillain-Barré Syndrome can be life threatening in the acute phase.

Answer 13

If the respiratory muscles are affected – this requires mechanical ventilation.

Question 14

Describe the treatment options for Guillain-Barré Syndrome.

Answer 14

• Supportive care
• Plasmapheresis
• Intravenous immunoglobulins.

Question 15

Name three conditions that Acetylcholinesterase Inhibitors can be used in the treatment of.

Answer 15

1. Myasthenia gravis
2. Alzheimer’s disease
3. Glaucoma

Question 16

Name some side effects of Acetylcholinesterase Inhibitors.

Answer 16

• Bradycardia
• Hypotension
• Diarrhoea
• Excessive salivation
• Muscle spasm

Question 17

What does the dorsal column-medial lemniscal pathway (DCML) carry?

Answer 17

The sensory modalities of fine touch (tactile sensation), vibration and proprioception

Question 18

What does the anterior spinothalamic tract carry?

Answer 18

The sensory modalities of crude touch and pressure.

Question 19

What does the lateral spinothalamic tract carry?

Answer 19

The sensory modalities of pain and temperature.

Question 20

What do the spinocerebellar tracts carry?

Answer 20

Unconscious proprioceptive information

Question 21

Describe how patient with an injury to the DCML pathway would present.

Answer 21

Loss of proprioception and fine touch. However, a small number of tactile fibres travel within the anterolateral system, and so the patient is still able to perform tasks requiring tactile information processing.

If the lesion occurs in the spinal cord (which is most common), the sensory loss will be ipsilateral – decussation occurs in the medulla oblongata.

Question 22

Name some conditions that would result in a DCML lesion.

Answer 22

• Vitamin B12 deficiency

- Tabes dorsalis (a complication of syphilis).

Question 23

Describe how patient with an injury to the anterolateral system would present.

Answer 23

Injury to the anterolateral system will produce an impairment of pain and temperature sensation.

This sensory loss will be contralateral (the spinothalamic tracts decussate within the spinal cord).

Question 24

Describe how a patient with Brown-Séquard syndrome would present.

Answer 24

• DCML pathway: ipsilateral loss of touch, vibration and proprioception.
• Anterolateral system: contralateral loss of pain and temperature sensation.

NOTE: It will also involve the descending motor tracts, causing an ipsilateral hemiparesis.

Question 25

Describe how a patient with a lesions of the spinocerebellar tract would present.

Answer 25

Ipsilateral loss of muscle co-ordination.

NOTE: The spinocerebellar pathways are unlikely to be damaged in isolation – there is likely to be additional injury to the descending motor tracts. This will cause muscle weakness or paralysis, and usually masks the loss of muscle co-ordination.

Question 26

Name a common site of cerebrovascular accidents (CVA).

Answer 26

The internal capsule.

NOTE: The pyramidal tracts travel through here are therefore are susceptible to damage

Question 27

Name 5 signs of an upper motor neurone lesion.

Answer 27

1. Hypertonia – an increased muscle tone
2. Hyperreflexia – increased muscle reflexes
3. Clonus – involuntary, rhythmic muscle contractions
4. Babinski sign – extension of the hallux in response to blunt stimulation of the sole of the foot
5. Muscle weakness

Question 28

Describe how a patient with an upper motor neurones for CN XII will present.

Answer 28

A lesion to the upper motor neurones for CN XII will result in spastic paralysis of the contralateral genioglossus. This will result in the deviation of the tongue to the contralateral side.

NOTE: this is in contrast to a lower motor neurone lesion, where the tongue deviates towards the damaged side.

Question 29

Describe how a patient with an upper motor neurones for CN VII will present.

Answer 29

A lesion to the upper motor neurones for CN VII will result in spastic paralysis of the muscles in the contralateral lower quadrant of the face.