Control CS4 somatosensory disorders

Question 1

How can you tell if there is inflammation in the spinal cord on x-ray?

Answer 1

Spinal cord should look black on x-ray but if inflamed will appear white

Question 2

How can you remember where dorsal is?

Answer 2

Think dorsal fin on sharks and dolphins - is the fin on their back thus the dorsal tract is towards your back/ the posterior spinal cord.

Question 3

How do the somatosensory pathways travel in the spinal cord?

Answer 3

Spinothalamic tract sensations (crude sensation, pain and temperature) travel contralaterally
Dorsal column medial lemiscus pathway sensations (discrete touch, proprioception and vibration) travel ipsilaterally

Question 4

What is brown-sequard syndrome?

Answer 4

A hemi-cord lesion

Question 5

What is a common cause of hemi cord lesions?

Answer 5

Inflammation of the spinal cord aka myelitis can be due to virus or MS

Question 6

What sensory loss is a hemi-cord lesion/brown-sequard syndrome and example of?

Answer 6

Dissociated sensory loss

Question 7

What CN have somatic sensory nuclei in the brain stem?

Question 8

What CN have taste/baroreceptors sensory nuclei in the brain stem

Question 9

What CN have special sense nuclei in the brain stem?

Question 10

What CN have somatic motor nuclei in the brainstem?

Question 11

What CN have parasympathetic motor nuclei in the brainstem?

Question 12

What CN have branchiomotor motor nuclei in the brainstem?

Question 13

Is vertigo a symptom or a diagnosis?

Answer 13

Symptom

Question 14

What is lateral medullary syndrome/Wallenbergs syndrome?

Question 15

What can cause lateral medullary syndrome/ Wallenbergs syndrome?

Answer 15

A stroke due to occlusion of PICA or a vertebral artery dissection

Question 16

Why are the dorsal columns not affected by an occlusion in the anterior spinal artery?

Answer 16

As they have collateral blood supply from the posterior spinal artery

Question 17

What is anterior spinal syndrome?

Answer 17

When occlusion of anterior spinal artery causes loss of blood supply leading to infarction and loss of sensation and motor supply in the anterior 2/3 of the spinal cord so only proprioception and vibration sensations can be felt in the affected spinal nerves (as dorsal columns not affected)

Question 18

What is a good way to think of the thalamus?

Answer 18

As a relay station (containing synapse) between the cortex and the spinal cord/brainstem

Question 19

What is a lacunar stroke?

Answer 19

A non-cortical infarct due to an occlusion in a single perforating branch of a large cerebral artery

Question 20

What are risk factors for a lacunar stroke?

Answer 20

Smoking
Hypertension
Diabetes

Question 21

What is syringomyelia?

Answer 21

Expansion of central canal of the spinal cord (which is filled with CSF)

Question 22

What fibres are affected first by syringomelia?

Answer 22

Crossing fibres - i.e. the fibres in the spinothalamic pathway which provide pain and temperature sensation

Question 23

What are later consequences/ damage caused by syringomyelia if untreated?

Answer 23

Paraparesis and root lesions

Question 24

How is syringomyelia treated?

Answer 24

Surgically

Question 25

Why can sensory loss begin as a symmetrical glove and stocking distribution?

Answer 25

Longest nerves have highest metabolic demands so loss of sensation begins in these nerves at the distal ends

Question 26

How are reflexes affected by upper motor neuron vs lower motor neuron lesions?

Answer 26

Upper motor neuron = Hyper reflexive reflexes Lower motor neuron = absence of reflexes

Question 27

What are risk factors of peripheral neuropathy?

Answer 27

Diabetes mellitus Toxic drugs e.g. chemotherapy drugs Autoimmune disease e.g. Gillian-barre, CIPD, vasculitis etc.. Vitamin deficiency Pare neoplastic causes Chronic kidney or liver disease Inherited e.g. Charcot-Marie-tooth diesease

Question 28

How can patients with subacute combined degeneration present?

Answer 28

Gradual onset of numb feet Potentially with vitiligo Unsteady +/- falling on uneven ground or in the dark With anaemia and high mean cell volume Loss of vibration up to the waist Loss of proprioception in the feet Normal strength Intact spinothalamic pathway e.g. normal temperature and pain perception A sensory ataxic gait

Question 29

What causes subacute combined degeneration?

Answer 29

B12 deficiency Anti-parietal cell antibodies Nitrous oxide use - laughing gas/balloons

Question 30

What can subacute combined degeneration lead to?

Answer 30

Peripheral neuropathy Dementia

Question 31

What part of the spinal cord is damaged by subacute combined degeneration?

Answer 31

The dorsal columns

Question 32

What is the distribution of peripheral neuropathy upon onset?

Answer 32

Glove and stocking