congenital cranial dysinnervation disorders Flashcards
what is ccdd
Subgroup of strabismus classified by being congenital, non-progressive ophthalmoplegia with restriction of globe movement in one of more fields of gaze
Previously called “congenital fibrosis syndromes” as initially thought to be caused by fibrosis of the extraocular muscles
Since electromyography and genetic studies, this is now consider to be secondary change due to abnormal or absent innervation from 3rd, 4th or 6th Cranial Nerve
what are examples of congenital cranial dysinnervation disorders
Congenital Fibrosis of the Extraocular Muscles (CFEOM)
Duane Syndrome
Strabismus Fixus
Brown Syndrome
Congenital Ptosis
Congenital Ophthalmoplegia
Congenital Strabismus
Horizontal gaze palsy
Marcus Gunn Syndrome
Moebius syndrome
Double Elevator Palsy
what is a subtype of congenital cranial dysinnervation disorder
Congenital Fibrosis of Extraocular Muscles
First described by Baumgarten (1840)
Noted to have a familial component
Brown (1950) classified these conditions as “generalized fibrosis syndrome”
what are the types of congenital fibrosis of the extraocular muscles
3 types cfeom 1 , 2 and 3
Inheritance
CFEOM1 & CFEOM3 are autosomal dominant
CFEOM2 is autosomal recessive
Sporadic (less common)
Affects males and females equally
what are the characteristics of cfeom
Characteristics
Non-progressive disorder
Fibrosis of muscles innervated by the 3rd, 4th and 6th cranial nerves
Restrictive ophthalmoplegia and ptosis
Fibrosis of all extraocular muscles
Fibrosis of Tenon’s capsule
Adhesions between muscles, Tenon’s capsule and globe
Inelasticity of conjunctiva
what are the characteristics of cfeom 1
cfeom 1 is the most common
Bilateral ptosis
Severe restriction on upgaze (neither eye can reach midline). Downgaze and horizontal movement variable restricted.
Large hypotropia, exotropia or esotropia.
Misdirected eye movements common, incl. bilat conv on attempted up gaze.
AHP – Chin up
Dominant Inheritance
KIF21A
cfeom 2 and cfeom 3
CFEOM2 – Recessive Inheritance (PHOX2A)
Bilateral ptosis and absent adduction, upgaze, and downgaze, appearance like bilateral 3rd Nerve palsies. Abduction present but can be incomplete.
Pupils often small and nonreactive to light
Neuroimaging shows 3rd nerve are absent bilaterally
CFEOM3 – Dominant Inheritance (TUBB3)
Similar to CFEOM1 except can be more variable, and may have the ability to evelate eyes above midline
Can have associated facial palsy, peripherial neuropathy, wrist and finger contractures, intellectual, social and behavioural impairments.
what is tukel syndrome
Recessive Inheritance
Gene location 21q22 - TUKLS
Same features as CFEOM3 but mainly unilateral
bilateral postaxial oligodactyly or oligosyndactyly of hands
Absent/Fused carpel bones
what management options for cfeom
Amblyopia Treatment
Surgery
Aim
Clear pupillary axis in primary gaze
Alleviate head posture
Align eyes in primary position
MRI scan recommended
FDT +ve
Options
Weakening procedures to overcome/↓ size of hypotropia
Large IR recessions with conjunctival recessions
Disinsertion of the IR with temporary elevation of globe with fixation sutures
Ptosis surgery - brow suspension
Aim: lift lids only to upper border of pupil and take care to avoid corneal exposure due to the absent Bell’s phenomenon.
what surgeries can be performed on a patient with cfeom
Stepwise surgical approach
FDT +ve for tight LIR muscle
Adhesions and fibrosis bands released
Large LIR recession (12mm) on adjustables
Adjustment performed within 1 week
See Heidary G et al (2019) for further discussion.
what is hcgpps
Horizontal Gaze Palsy with progressive scoliosis
Rare recessive CCDD
Two reported types
Only a several dozen known cases – consanguineous families
Differentiate from: Duanes syndrome type 3 or HGP with facial weakness (Moebius syndrome)
what are the subtypes of hhgps
there are two subtypes type 1 and type 2
Type 1
ROBO3 gene – 11q24.2
Horizontal gaze palsy
Progressive external Ophthalmoplegia (onset at birth)
Progressive Scoliosis (onset from as young as 2yrs)
Pontine and cerebellar hypoplasia
type 2
DCC gene 18q21.2
Horizontal gaze palsy
Progressive Scoliosis
Hypotonia muscles
Delayed psychomotor development
Intellectual disability
Hypoplastic pons and midbrain
Decreased axonal integrity and myelination
describe congenital ptosis
subtype of congenital cranial dysinnervation disorder
PTOS1 gene
Dominant inheritance pattern
Isolated congenital ptosis
Size variable
Unilateral or bilateral
Frequently require surgery to elevate eyelids (see ptosis lecture)
An x-linked type has been described but no gene found
