Paeds - Neuro Flashcards
Child with demyelination symptoms (ataxia, visual loss etc) with low T1 and high T2 lesions extending bilaterally from occipital lobes towards frontal lobes. Also involvement of corpus callosum
What is diagnosis?
What blood test is elevated?
Adrenoleukodystrophy
Disease of demyelination
-VLCFA very long chain fatty acids are elevated
What is most common BRAIN TUMOUR in children?
Astrocytoma
Posterior fossa cyst with enhancing mural nodule
-some components are isodense to grey matter (this is a good differentiator to medulloblastoma which is hyperdense)
-any solid component will enhance
What is most common POSTERIOR FOSSA tumour?
Medulloblastoma
- Midline mass at roof of 4th ventricle
- Cause mass effect and hydrocephalus
- Vast majority appear hyperdense on CT
- Cysts/Necrosis/Calcification present*
Low T1
Iso/High T2
Hetero enhancement
Multilocular cystic structure at posterior triangle in newborn
What is diagnosis?
Cystic hygroma
Where would second branchial cleft cyst be located?
Between submandibular gland and sternocleidomastoid
What is most common suture to close prematurely?
Saggital suture
Known as Saggital Craniosynostosis
Causes elongation of the skull
What is triad of Tuberous sclerosis?
Disease of multiple hamartomas all over body/organs. Multiple bilateral angiomyolipomas
Clinical Triad
- Facial angiofibroma
- Epilepsy
- Mental retardation
Neuro Features
1. Subependymal grey matter islands (beside ventricles)
- Cortical/subcortical tubers - oddly shaped gyri that can be low attenuation centrally*
- Giant Cell Astrocytomas - found near foramen of munro and can cause hydrocephalus*
All of above give low T1 and high T2
Subependymal hamartomas - SAME as white matter on MR. can protrude into ventricles
Premature closure of metopic suture is called?
Trigonocephaly
Premature closure of saggital suture is called?
Dolichocephaly
or
Scaphcephaly
Premature closure of coronal suture known as?
Brachycephaly
Premature closure of lamboid suture?
Unilateral - Plagiocephaly
Bilateral - Turricephaly
What is a Pott puffy tumour?
Osteomyelitis of frontal bone and subperiosteal collection as a result of acute sinusitis
CT - opacitication of frontal sinus
-defect in bone in anterior frontal sinus
Can extend intracranially also - which can cause seizures
Differentiating intracranial abscess vs met
What is useful?
What is mnemonic for ring enhancing lesions?
Abscess
- central diffusion restriction
- thin smooth rim of enhancement
Metastases
- thick irregular margin
- tend not to restrict diffusion centrally but can in certain cases like neuroblastoma mets
MAGIC DR
- Mets*
- Abscess*
- Glioma*
- Infarction*
- Contusion*
- Demyelination*
- Radiation necrosis*
Large hyperdense mass with homogenous enhancement that sits in trigone of lateral ventricle.
What is it?
Choroid plexus papilloma
iso T1, high T2
- secrete CSF
- cause communicating hydrocephalus
- occur in children
- can occur in adults and then if so they will be in 4th ventricle
What is a DNET?
Dysembryoplastic neuroepithelial tumour
- child with temporal lobe lesion
- lesion will be multicystic or bubbly
-no enhancement or oedema
-refractory epilepsy
What are the features of a juvenile angiofibroma?
Teenage with epistaxis and mass seen
Vascular mass
- Located in sphenopalatine fossa with erosion of medial pterygoid plate
- supplied by internal maxillary artery
-flow void on T2 imaging
What is holoprosencephaly?
Congenital abnormality resulting from incomplete separation of the 2 cerebral hemispheres
IF CORPUS CALLOSUM IS PRESENT - IT IS NOT HOLOPROSENCEPHALY
Three subtypes
Alobar holoprosencephaly = most severe
- thalami are fused
- one large posteriorly located ventricle
- facial abnormalities such as cleft lip
Semilobar holoprosencephaly
- basic structure of lobes are present
- lobes are fused anteriorly and at thalami
- agenesis or hypoplasia of the corpus callosum
Lobar holoprosencephaly = least severe
- mostly normal
- may have a few midline abnormalities
What is schizencephaly?
Where there is a tract leading from the lateral ventricles to the subarachnoid space
Can be:
Open lip - cleft walls are separated and filled with CSF leaving tract
Closed lip - cleft walls are opposed and touching together
Sinus disease
What causes football like apperance in sinus?
Football - Mucus retention cyst
Gyral cortical calcification and leptomeningeal enhancementment is seen in which congential condition?
Sturge Weber syndrome
Gyral cortical calcification = due to venous ischaemia caused by pial angioma
Pial angioma also causes leptomeningeal enhancement due to its vascular nature
What are phakomatoses?
Name the 5 most common phakomatoses?
They are Neurocutaneous syndromes characterised by hamartomatous lesion of the skin, central and peripheral nervous system
- Neurofibromatosis Type 1 & 2
- Ataxic telangiectasia
- Tuberous sclerosis
- Von hippel lindau
- Sturge weber
What is the order of cranial suture closure?
- Metopic
- Coronal
- Lamboid
- Saggital
Early closure is called Synotosis and is associated with syndromes
Trigonocephaly ?
Premature closure of metopic suture
Brachycephaly?
Turricephaly?
Scaphocephaly?
Premature closure of:
- Coronal
- Lamboid
- Saggital
Craniosynostosis summary
Premature closure of coronal and lamboid sutures results in this
Clover leaf skull syndrome (Kleeblattschadel)
Saggital can also close
Head is shaped like a 3 leaf clover***
-Hydrocephalus is common
Associated with:
- Thanatophoric dysplasia
- Apert syndrome
- Crouzon syndrome
What is a copper beaten skull due to ?
What does it look like?
This appearance is seen due to multiple normal gyral impressions on the inner table of the skull - throughout the skull
(Gyral impressions can be normal but only seen in posterior part of skull)
Caused by things that cause increased ICP:
- Craniosynostosis
- Obstructive hydrocephalus
What are Wormian Bones?
Causes?
PORK CHOPS
These are essentially extra bones within the cranial sutures. Can be idiopathic or syndromic associated
It <10 they are IDIOPATHIC
If >10 first think OSTEOGENESIS IMPREFECTA
If >10 and absent clavicle think CLEIDOCRANIAL DYSOSTOSIS
Dermoid & Epidermoid of the Skull - what are their appearances?
Due to the abnormal placement of scap cells into the skull bone
Results in growth of a lump of tissue (keratin/skin etc) within the bone
Has benign sclerotic borders
- Dermoid and Epidermoid have differing appearances*
- Dermoid is associated with Encephaloceles*
Congenital Dermal Sinus of skull
What is it?
Where are 2 most common locations?
Communications between the dura and the skin externally
Seen at:
- Nose
- Occiput
Both are classically midline
Can be associated with a dermoid cysts
- Cysts may NOT have a sinus*
- Sinus may NOT have a cyst*
If you see a midline cyst in occiput or nose - consider these
What are the 3 types of skull haemorrhage in newborns that are a result of delivery?
- Cephalohaematoma
- Deepest. Under periosteum
- Limited by suture lines
- Seen post vacuum or instrument extraction - Subgaleal Haemorrhage
- Can bleed like a pig
- Between periosteum and aponeurosis
- Vacuum extraction - Subcut Haemorrhage (Caput succedaneum)
- Due to prolonged delivery
- Resolves in a few days
What are 3 main skull fracture types seen in kids?
DDD
- Diastatic - along suture lines. Can intersect or be confined to suture itself. >3mm diastasis.
- Depressed fracture - qualifies if there is inward displacement greater than or equal to the thickness of the skull. High morbidity and often require surgery
- Ping pong fracture - a subtype of depressed fracture like a buckle or greenstick
- Tend to have good outcome
- Can occur in setting of birth trauma (a low trauma vs depressed fracture which is usually as a result of high trauma)
- Fractures tend to be hard to see
Sinus pericranii - what is it?
Focal skull defect with vascular malformation (communication between dural venous sinus, usually superior sag and extra cranial vein)
Non-accidental Injury: Head Trauma
Look High
Look Low
Vigorous shaking can lead to tearing of bridging cortical veins = LOOK HIGH for evidence of thrombosed hyperdense vein
Subdural haematomas are more common in NAI = LOOK LOW for retroclival haematoma (sits above tectorial membrane)
An EPIDURAL retroclival haematoma will sit below the tectorial membrane
What is BESSI?
Benign enlargement of the subarachnoid space in infancy
Symmetric enlargement which favours the anterior aspect of the brain
(spaces in posterior brain usually normal)
- Most common cause of macrocephaly
- Presents around month 2 or 3 and resolves without treatment after 2 years
- Increased risk of subdural bleed
- -Very mild communicating hydrocephalus can be seen*
**In Subdural hygroma - cortical veins are DISPLACED AWAY from the inner table due to compression from subdural**
In BESSI cortical veins are as they were, adjacent to inner table
PVL - Periventricular Leukomalacia (Hypoxic ischaemic encephalopathy of the newborn)
What are 2 main risk factors?
Occurs as a result of ischaemia/haemorrhage during birthing
Presentation usually:
- Intellectual disability
- Visual issues
- Cerebral palsy
- 50% develop cerebral palsy
- Premature babies under 1500g are at greatest risk
- Favours periventricular white matter which initially appears bright on US (White matter should always be less bright than choroid plexus)
- ‘Blush’ describes normal brightness of posteriosuperior perventricular white matter, it should be less bright than choroid plexus.*
- ‘Flaring’ describes normal brightness in premature infants white matter - this will normalise within 7 days - this is how you differentiate from true PVL*
Later findings include:
-Periventricular cysts
Note the cysts can take up to 4 weeks to develop so if you seen cysts in a Day1 newborn = the vascular insult must have occured in utero
Germinal Matrix haemorrhage
Who do they occur in?
When do they occur?
Highly vascular structures only present in premature babies
By full term (or around 36 weeks) - the germinal matrix has regressed and disappears
NO such thing as Germinal matrix haemorrhage in full term infant (this is called Choroid Plexus haemorrhage)
- Germinal matrix is highly vascular and can bleed*
- -90% of bleeds occur in first week*
- -Cranial US used to test for it in first week of like in a prem baby*
Identifying bleed on US
Both blood and choroid plexus are ECHOBRIGHT
Choroid plexus should NOT extend anterior to caudothalamic groove
Caudothalamic groove is where Germinal matrix is located
Homocysteinuria vs marfans
Whats the difference?
Biconcave veretebra in homocystinuria
Posterior vertebral scalloping in Marfans
What are features of Leigh Disease?
2 year old
- Ataxia
- Ophthalmoplegia
- Dystonia
Elevated lactate to pyruvate ratio
MRI: high T2 in putamen and periaqueductal grey matter
Kearns sayre features?
Think of this when Droopy eyelids are mentioned
MRI: subcortical calcifications. basal ganglia siderotic deposits
Dandy walker classic vs Dandy walker variant?
