Sensory deficits

Question 1

Consequence of a lesion in the cortex?

Answer 1

o Often follows a stroke

o Affects the contralateral side including the face

Question 2

Consequences of a lesion in the thalamus

Answer 2

o Affects the contralateral side

o Including the face

Question 3

Conseuqces of a lesion between the medulla and pons

Answer 3

When the dorsal columns, which decussate in the medulla, and the spinothalamic fibres, which decussate immediately)
o Affects the sensation in the limbs contralaterally
o Does not affect the face – as the trigeminal nerve enters the pons

Question 4

Consequences of transection of spinal cord

Answer 4

Affects all sensation below lesion - both sides

Question 5

Consequences of dorsal root destruction?

Answer 5

Loss of all sensation in particular dermatome

Question 6

Consequence of destruction of 1ON?

Answer 6

Due to peripheral neuropathy - DM, B12 deficiency, Guillian Barre, Hep C

Glove and stocking distribution of sensory loss

Question 7

Consequence of partial transection of spinal cord? What is this called?

Answer 7

o The lesion is below the medulla, so the dorsal columns haven’t yet decussated – ipsilateral loss of fine touch, vibration, proprioception
o The spinothalamic tracts decussate immediately, so loss of pain etc. is contralateral
o This is Brown-Sequard syndrome

Question 8

Consequences of lesions affecting just dorsal columns?

Answer 8

o Lose fine touch, proprioception, vibration, two point discrimination
o Causes include Tabes dorsalis – a late stage of syphilis – and degeneration of the dorsal columns in B12 deficiency
o It causes sensory ataxia, positive Rombergs sign

Question 9

Consequence sof lesions affecting the spinothalamic tracts?

Answer 9

o Causes include syringomyelia (formation of cavity around central canal which expands, can compress the spinothalamic tract as it decussates in the midline)
o Bilateral loss of pain, crude touch and temperature sensation
o Vulnerable to tissue damage