Reflexes of cranial nerves

Question 1

Pupillary light reflex- afferent

Answer 1

Optic Nerve

Question 2

Pupillary light reflex- efferent

Answer 2

Oculomotor

Question 3

Corneal reflex- afferent

Answer 3

Ophthalmic (CN V1)

Question 4

Corneal reflex- efferent

Answer 4

Facial nerve

Question 5

Lacrimation reflex- afferent

Answer 5

Ophthalmic (CN V1)

Question 6

Lacrimation reflex- efferent

Answer 6

Facial

Question 7

Jaw jerk- afferent

Answer 7

Mandibular nerve (CNV3)

Question 8

Gag- afferent

Answer 8

Glosso

Question 9

Gag- efferent

Answer 9

Vagus

Question 10

Carotid sinus- afferent

Answer 10

Glosso

Question 11

Carotid sinus- efferent

Answer 11

Vagus

Question 12

Horner’s syndrome

Answer 12

Ptosis
Miosis
Anhidrosis 
Aniscoria
Worse in the dark

Question 13

Holmes-Adie pupo;

Answer 13

Dilated pupil (Mydriasis) due to parasympathetic loss
Benign condition more common in women
Unilateral 80%

Question 14

Argyll-Robertson pupil

Answer 14

Small miotic pupils associated with neurosyphilis

Accommodation reflex intact but pupillary light reflex absent

Question 15

Sensory loss V1

Answer 15

Herpes or cavernous sinus thrombosis

Question 16

Sensory loss V2

Answer 16

Trauma

Question 17

Sensory loss V3

Answer 17

Basal tumour or meningitis

Question 18

Sensory loss in all trigeminal branches

Answer 18

Geniculate ganglion, sensory root or nucleus lesion (basilar meningitis or pontine lesion

Question 19

Sensory loss around mouth

Answer 19

Syringomyelia

Question 20

Bell’s Palsy

Answer 20

LMN facial nerve palsy with forehead affected

Question 21

Bell’s palsy presentation

Answer 21

Unilateral facial paralysis
Sudden onset
May also experience- post-auricular pain, altered taste, dry eyes, hyperacusis

Question 22

Conductive deafness

Answer 22

Otosclerosis
Otitis media with effusion
Impacted ear wax

Question 23

Sensorineural deafness

Answer 23

Presbycusis
Meniere's 
Drug ototoxicity
Noise damage
Acoustic neuroma

Question 24

Otosclerosis

Answer 24

Autosomal dominant (positive FHx)
Replacement of normal bone by vascular spongy bone
Onset 20-40yo
Tinnitus

Question 25

Otitis media with effusion (glue ear)

Answer 25

Peaks at 2yo | May be secondary problems such as speech and language delay, behavioural and balance problems

Question 26

Impacted ear wax

Answer 26

Usually visible on otoscopy

Question 27

Presbycusis

Answer 27

``` Age related hearing loss Often bilateral (therefore normal R + W tests) ```

Question 28

Menieres

Answer 28

``` Middle aged adults Vertigo Tinnitus Hearing loss Episodes lasting minutes-hours Can also have nystagmus and positive Rombergs ```

Question 29

Drug otoxicity

Answer 29

Aminoglycosides (gentamicin, vancomycin) Furosemide Aspirin Cytotoxics

Question 30

Noise damage

Answer 30

Typically bilateral

Question 31

Acoustic neuroma

Answer 31

Features depending on CN affected (V, VII or VIII) | seen bilaterally in neurofibromatosis type 2

Question 32

Vertigo causes

Answer 32

``` Viral labyrinthitis Vestibular neuronitis BPPV Vertebrobasilar insufficiency Acoustic neuroma Menieres Posterior circulation stroke Trauma MS Ototoxicity ```

Question 33

Viral labyrinthitis

Answer 33

Recent viral infection Sudden onset N+V Hearing may be affected

Question 34

Vestibular neuronitis

Answer 34

Recent viral infection Recurrent vertigo attacks lasting hours- days No hearing loss

Question 35

BPPV

Answer 35

``` Gradual onset Triggered by change in head position Each episode lasts 10-20s Perform Dix-Hallpike to confirm Epley to treat ```

Question 36

Vertebrobasilar insufficiency

Answer 36

Often elderly patients | Dizziness on extension of neck