Nerve Palsies

Question 1

what are the 3 types of lesions involved in Horner’s syndrome

Answer 1

1st Order Neuron Central lesions Pre-ganglionic lesions

Post-ganglionic lesions

Question 2

what anhidrosis is present in Horner’s syndrome caused by 1st order neuron central lesions?

Answer 2

Anhidrosis of the face, arm and trunk

Question 3

what anhidrosis is present in Horner’s syndrome caused by pre-ganglionic lesions?

Answer 3

Anhidrosis of the face

Question 4

what anhidrosis is present in Horner’s syndrome caused by post-ganglionic lesions?

Answer 4

No anhidrosis

Question 5

what are the causes of 1st order neuron central lesions in Horner’s syndrome?

Answer 5

Stroke
Syringomyelia
Multiple sclerosis
Tumour
Encephalitis

Question 6

what are the causes of pre-ganglionic lesions in Horner’s syndrome?

Answer 6

Pancoast’s tumour
Thyroidectomy
Trauma
Cervical rib

Question 7

what are the causes of post-ganglionic lesions in Horner’s syndrome?

Answer 7

Carotid artery dissection
Carotid aneurysm
Cavernous sinus thrombosis
Cluster headache

Question 8

what are the clinical features of Horners syndrome?

Answer 8

• Miosis (small pupil)
• Ptosis
• Anhidrosis (loss of sweating one side)
• Enopthalmos (sunken eye)

Question 9

how is Horner’s syndrome diagnosed?

Answer 9

• Cocaine drop test
• Paredrine – localise the cause of the miosis
• Dilation lag test

Question 10

what is the underlying mechanism of Horner’s Syndrome?

Answer 10

interruption of the sympathetic pathway

Question 11

what is the mechanism behind the clinical features of Horners syndrome?

Answer 11

• A small pupil on the affected side due to loss of the dilator function.
• A slight ptosis on the affected side, due to denervation of Muller’s muscle

Question 12

when is the face affected in Horners syndrome?

Answer 12

If sympathetic pathway is affected proximal to the base of the skull. This catches fibres travelling with the branches of the external carotid, which innervate the skin of the face

Question 13

What are the causes of CN III nerve palsy?

Answer 13

PCA ANEURYSM
Microvascular – DM, vasculitis
Congenital, MS

Question 14

What are the causes of CN IV nerve palsy?

Answer 14

CONGENITAL, microvascular – hypertension, DM

Tumour, TRAUMA

Question 15

What are the causes of CN VI nerve palsy?

Answer 15

PAPILLOEDEMA

Microvascular, tumour, meningitis, idiopathic, congenital

Question 16

what are the clinical features of CN III palsy?

Answer 16

Eye is down and out
Ptosis
Pupil may be dilated

Question 17

what are the clinical features of CN IV palsy?

Answer 17

Symptoms worse reading or walking
Vertical double vision
Fundus torsion
Eye is up and in

Question 18

what are the clinical features of CN VI palsy?

Answer 18

Lateral gaze palsy
Horzitonal double vision
Eye is stuck laterally (towards nose)

Question 19

how are nerve palsies investigated?

Answer 19

Bloods – glucose, cholesterol, CRP

Imaging – CT, MRI

Question 20

what is the management of CN III nerve palsies?

Answer 20

Microvascular – usually resolves in 6 months, >6 surgery

Question 21

what is the management of CN IV nerve palsies?

Answer 21

Prisms in glasses
Surgery
Muscle weakening

Question 22

what is the management of CN VI nerve palsies?

Answer 22

Conservatively
Prism, botox
Muscle resection