Moebius syndrome

Question 1

what is the ateiology of moebius syndrome

Answer 1

sporadic

maternal thalidomide use

insult at 4-7 weeks gestation

week 6

developmental defect

insult to developing brain (hypoxia, trauma , vascular)

heterogeneous group

ccdd

6th and 7th nerve nuclei

hypoplasia

atrophy

6th and 7th peripheral nerve damage

maldevelopment

developmental disorders of lower brainstem and cerebellum

supranuclear
vascular

Question 2

what are the features of moebius syndrome

Answer 2

spectrum

bilateral 6th and 7th palsies

asymmetrical

bilateral horizontal gaze palsy

Question 3

what are the features of a bilateral 7th nerve palsy if someone with moebius syndrome

Answer 3

facial palsy (partial/ incomplete)

lack of facial expression

poor/absent lid closure

corneal exposure

bells phenomena

open mouth

Question 4

what are the features of someone with moebius syndrome with a bilateral 6th nerve palsy

Answer 4

marked limitation of abduction

marked esotropia

contracted medial rectus

face turn to fix

cross fixation

+ve FDT

V pattern

bilateral horizontal gaze palsy

no deviation in the 1st position

intact vertical gaze

25% may have impaired vertical eye movements

Question 5

what are associated features of moebius syndrome

Answer 5

deafness

low set ears

external ear defects

microstomia (small mouth)

muscle hypolasia
-pectoral muscles
- neck muscles

limb defects

polydactyl
- extra digits

syndadactyl

-webbed fingers/toes

mental retardation

dental defects - because of poor mouth closure

Question 6

Hoare the 9th and 12th cranial nerves affected in moebius syndrome

Answer 6

9th= glossophrngeal N (pharynx)

12th = hypoglossal N (lounge)

bulbar palsy

swallowing difficulties

feeding difficulties

delayed speech development

atrophic tounge

Question 6

how is lid closure and adduction affected

Answer 6

bells phenomena - protect cornea

limited adduction

Question 7

what things are involved in the orthoptic investigation of people with moebius syndrome e

Answer 7

va , ct,

bsv is unlikely

om - check bells , and ocular movement system s

convergence

measurements

refraction

refractive correction - because of the ear defects

amblyopia treatment

strabismus

eye movements

ocular health - cornea

lid taping/lubricants

Question 8

what does moebius syndrome need to be differentially diagnosed from

Answer 8

lack of facial expression

• could be because of mythic dystrophy

fasciocapulohumeral dystrophy

ocular moveements

• 6tth nerve palsy

duanes syndrome

infantile esotropia

nystagmus blockage syndrome

COMA

horizontal gaze palsy

Question 8

what is the management of people with moebius syndrome

Answer 8

corrective refractive error - astigmatism

occlusion - amblyopic

bsv unlikely

ocular care (lubricants, lid taping at night)

strabismus surgery for et and ahp

large bilateral medial rectus recessions

vertical muscle transposition