Cranial Syndromes and anomalies Flashcards
What is Apert syndrome?
AKA type 1 acrocephalosyndactyly.
- Brachycephaly
- Syndactyly
- Maxillary hypoplasia
Predominantly skull and limb malformations. Congenital cardiac anomalies 10%. Congenital genourinary anomalies. Symphalangism.
1/800000 pregnancies. Older paternal age.
What malformation show *enlarged posterior fossa, *hypoplasia or agenesis of vermis and *cystic dilatation of the fourth ventricle. The fourth ventricle is also distorted and enchased by NEUROGLIAL VASCULAR membrane?
Dandy Walker malformation
Cardinal symptoms in Syringomyelia?
- Bilateral UE impaired ability for pain sensation.
- Bilateral UE impaired temperature sensation
- Spastic paraparesis.
Where are arachnoidal cyst most commonly found?
- middle fossa
- CPA
- Suprasellar region
- posterior fossa
Recommendation for incidental findings of arachnoidal cysts?
Follow up after 6-8mo. then only if symtomatic
When does the few arachnoidal cysts that become symtomatic usually become symtomatic?
In early childhood.
When a suture ossifies, normal growth changes. How?
The growth 90 degrees to the suture terminates and instead it proceeds parallel to the suture. ( så om coronarsuturen sluter blir huvudet långsmalt )
What sydrome is associated to higher PATERNAL age?
Apert syndrome.
Dandy Walker malformation is often associated to something else. WHat?
Hcph.
Name 5 differential diagnostics to Dandy Walker malformation
- Dandy Walker variant
- Persistent Blakes pouch cyst
- Retrocerebellar arachnoid cyst
*Joubert syndrome - Enlarged cisterna magna
What is Joubert syndrome?
Abscence or underdevelopment of cerebellar vermis
What is amblyopia?
Poor vision in only one eye caused by abnormal visual development. The “lazy” eye often wander inwards.
Which tyoe of craniosynostosis might cause Amblyopia?
coronal
Name two syndromes/malformations in which vermis is underdeveloped/hypoplastic or agenesis of vermis is shown?
- Joubert syndrome - unerdeveloped
- Dandy Walker - hypoplastic or agenesis
Another name for enlarged cisterna magna?
Mega cisterna magna.
How does the posterior fossa look in “Mega cisterna magna”?
The whole posterior fossa is enlarged due to the enlarged cistern. Normal vermis, normal 4th v, no mass effect.
What can happen with retrocerebellar arachnoid cyst that does not occur in cisterna magna?
The arachnoid cyst may anteriorly displace the 4th ventricle and cerebellum, causing a significant mass effect. Vermis is intact in both situations.
What is a Dandy walker variant?
When not all of the (3) Dandy Walker criteria are fullfilled;
* Vermian hypoplasia/agenesis
* Enlarged 4th ventricle
* Enlarged posterior fossa.
What more is seen in Crouzons syndrome?
hypoplasia of the midface.
What more is seen in Apert syndrome?
Syndactyly
What deformity is seen by unilateral coronal craiosynostosis?
Anterior PLAGIOcephaly
What is plagiosephaly?
Flattened or concave forehead on the affected side and compensatory prominence of the contralateral forehead.
TYPISK TENTAFRÅGA
Bilateral coronal craniosynostosis is seen in Aperts syndrome. What is it called and how does it look?
ACROcephaly.
Broad flattened forehead.
How many craniophasial dysmorphic syndromes hae been described?
Over 50.
What is the most common differential diagnostic?
Flattened head by positioning.
What is Apert syndrome?
AKA type 1 acrocephalosyndactyly.
- Brachycephaly
- Syndactyly
- Maxillary hypoplasia
Predominantly skull and limb malformations. Congenital cardiac anomalies 10%. Congenital genourinary anomalies. Symphalangism.
1/800000 pregnancies. Older paternal age.
What may be the diagnosis if you see a tetraventricular hcph and a communicating 4th ventricle and posterior fossa cyst? Vermis and medial parts of cerebellum hemispheres might also look hypoplastic.
That is probably a persistent Blakes pouch cyst.
What is the treatment of a Blakes cyst (persistent)?
Shunting. Shunting might also change the appearance as the vermis and cerebellum hemispheres expand (if not atrophy)
What are the two most difficult differential diagnostics regarding cysts in the 4th ventricle?
To differentiate between Dandy Walker, a Dandy walker variant and a persistent Blakes pouch cyst. The difference should be a tetraventricular hcph in Blakes pouch. Hcph is common in Dandy Walker too, but then there is an enlarged posterior fossa present.
It is possible to look for positioning of the choroid plexus of the fourth ventricle when differentiating between arachnoidal cyst, Blakes pouch and Dandy walker/dandy walker variant.
What differs in the Choroid plexus?
- Choroid plexus of the fourth ventricle does not exist in Dandy Walker malformations.
- The position of the Choroid plexus is normal in case of an arachnoidal cysts.
- The Choroid plexus is DISPLACED in a Blakes pouch cyst.
Where is the fourth ventricle choroid plexus situated in a Dandy Walker malformation?
It does not exist.
Does a mega cisterna magna communicate with the ventricles?
Yes, and if needed that can be shown with a iodine instillation via an EVD. NB obs some arachnoidal cysts do also communicate w the ventricles.
How common is hcph in Dandy walker malformation?
70-90%
Where is the choroid plexus of the 4th ventricle normally situated?
What other CNS abnormalities are associated to Dandy Walker malformation?
- CC agenesis 17%
- hcph 70-90%
- Occipital enphalocele 7%
+ Most have enlarged posterior fossa with elevation of torcular herophilli.
OTHERS: heterotopias, spina bifida, syringomyelia, microcephaly, dermoid cysts, porencephaly, Klippel-Feil deformity.
What is PHASES syndrome?
What important non- neuro deformities might be associated to Dandy Walker deformities and important to remember in case of surgery?
- Facial abnormalities (many kinds eg cleft palpate)
- Ocular deformities
CARDIOVASCULAR deformities*
What is Klippel-Feil deformity?
How common is corpus callosum agenesis on radiological examinations?
1:2000-3000
From what structure does Corpus Callosum form?
From the genu of splenium.
What is the normal part missing in agenesis of CC?
A posterior segment of CC missing.
What does abscence of anterior CC with precence of some posterior CCindicate?
Some form of holoproencephaly.
Agenesis of CC is associated to A NUMBER of neuropathologic findings. Name a few.
- Porencephaly
- Microgyria
- Lipomas (interhemispheric or CC)
- Arhinencephaly
- optic atrophy
- Colobomas
- Hypoplasia of the limbic system
- Bundles of Probst
- Loss of horizontal orientation of cingulate gyrus
- Schizencephaly
- Total or partial absence of anterior and hippocampal comissures
- Hcph
- Cyst in CC region
- Spina Bifida w/W/O myelomeningocele
- Abscence of septum pellucidum
What is Aicardi syndrome?
- Agenesis of CC
- Seizures
- Retardation
- Patches of retinal pigmentation
Is disconnection syndrome common in congenital CC defects?
NO, that is usually from aquired CC defects.
Name the three most common presentations where CC is found with clinical significance - usually its only incidental.
- Hcph
- Microcephaly
- Precocious puberty
(Seizures are rare and dissconnection syndorme usually associated to aquired)
Etiologies in abscence of septum pellucidum
- Holoproencephaly
- Schizencephaly
- Agenesis of CC
- Chiari type 2
- Basal encephalocele
- Porencephaly/hydranencephaly
- Due to necrosis from severe hcph
- Septo-optic dysplasia
Why are intracranial lipomas brought up in the “anomalies” chapter of greenberg?
They are “FELT to be” of maldevelopmental origin.
Incidence of lipomas in autopsies?
8:10.000
Where are lipomas usually found intracranially?
Near the midsagittal plane.
Particularly over CC and often associated to agenesis of CC.
Other locations where IC lipomas may be found than CC?
- CP angle
- cerebellar vermis
- tuber cinerum
- quadrigeminal plate
What is a hypothalamic hamartoma?
A non-neoplastic congenital malformation.
Where are hypothalamic hamartomas usually situated?
At tuber cinerum
How does hypothalamic hamartomas usually present?
- Precocious puberty
- Seizures
- Developmental delay
- Aggressive behavoiur/rage attacks.
Hypothalamic hamartomas are associated with a very special form of seizures. What is it called?
Gelastic seizures.
How are gelastic seizures usually presenting?
Brief unprovoked laughter.
Why does hypothalamic hamartoma patients get precocious puberty?
Due to GnRH release from hamartoma cells.
This is the most common tumouros change to cause precocious puberty.
Where is tuber cinerum situated?
In the floor of the third ventricle, between the infundibular stak and the mammillary bodies.
Apert syndrome and Crouzon syndrome are similar. WHat differs?
In apert syndrome, cleft palpate, complex syndactyli and mental retardation is seen, whereas all this is normal in Crouzon.
