the pyramidal system

Question 1

characteristics of pyramidal lesions

Answer 1

1. Pyramidal drift of an upper limb 2. Weakness with characteristic distribution 3. Increase in tone and spasticity 4. hyperreflexia 5. extensor plantar response 6. no muscle wasting

Question 2

lesion prior to the decussation at the pyramids

Answer 2

1. contralateral hemiplegia

Question 3

lesion just beyond the decussation at the pyramids prior to spinal chord entry

Answer 3

1. Quadriplegia

Question 4

Pyramidal drift of the upper limb

Answer 4

1. an upper motor neurone sign 2. Eyes closed + both arms held out with palms facing up 3. affected limb drifts downwards and pronates

Question 5

weakness and loss of skilled movement

Answer 5

1. unilateral pyramidal lesion above the decussation in the medulla causes weakness of opposite limbs 2. Upper limb - flexors remain stronger than extensors 3. Lower limb - extensors remain stronger than flexors 4. no wasting

Question 6

Increase in tone + spasticity

Answer 6

1. increase in tone due to loss of inhibitory effects of the corticospinal tract and increase in spinal reflex activity 2. increase in tone/spasticity - characterised by sudden change in resistance to rapid passive movements 3. tendon reflexes become exaggerated due to increased tone

Question 7

patterns of upper motor neurone disorders

Answer 7

1. Hemiparesis - weakness of limbs on one side 2. Paraparesis - weakness of both lower limbs 3. Tetraparesis/quadriparesis - weakness of four limbs

Question 8

Spastic paraparesis causes

Answer 8

Paraparesis indicates bilateral damage to corticospinal pathways causing weakness and spasticity

Question 9

Hemiparesis causes

Answer 9

1. Motor cortex - weakness or loss of skilled movements confined to contralateral limb 2. Internal capsule 3. Pontine lesion - adjacent structures VIth/VIIth nuclei are involved - diplopia + facial weakness tends to occur 4. Spinal chord - isolated lesion of one lateral corticospinal tract causes ipsilateral UMN lesion

Question 10

Hemiparesis causes ( lesions in which locations?)

Answer 10

1. Motor cortex - weakness or loss of skilled movements confined to contralateral limb 2. Internal capsule 3. Pontine lesion - adjacent structures VIth/VIIth nuclei are involved - diplopia + facial weakness tends to occur 4. Spinal chord - isolated lesion of one lateral corticospinal tract causes ipsilateral UMN lesion

Question 11

describe the corticospinal tract pathway

Answer 11