Upper and Lower Motor Lesions (Task 4)

Question 1

Location of UMN cell bodies

Answer 1

Primary Motor Cortex

Question 2

Location of sensory nerve cell bodies

Answer 2

First Order - Dorsal root ganglia
Second Order - Spine or Brainstem
Third Order - Ventral Posterolateral Nuclei of Thalamus

Question 3

Synapse site for UMNs

Answer 3

Ventral Horn

Question 4

UMN lesion features

Answer 4

Hyper Reflexia
Spastic Paralysis
No wasting of muscles

Question 5

LMN lesion features

Answer 5

Hypo Reflexia
Hypotonia
Flaccid Paralysis
Muscle Wasting

Question 6

Features of a unilateral spine lesion:

Answer 6

Mainly IPSILATERAL motor symptoms such as spastic paralysis and hypertonia below the lesion

Some motor fibres decussate AFTER synapsing with lower motor neuron so some motor symptoms will be CONTRALATERAL

Ipsilateral loss of proprioception, fine touch and vibration as lesion is below where DCML tracts decussate

Contralateral loss of crude touch, temp, pain and pressure as lesion is above where anterolateraal tracts decussate

Question 7

Muscular control of diaphragm which may be compromised in cervical spine lesions

Answer 7

Phrenic Nerve (C3-C5)