C.N.S. Normal anatomy, congenital anomalies Flashcards
The brain Develops from the _______
neural tube
Brain is Subdivided into:
○_____brain
○______brain
○____brain
Fore
Mid
Hind
Primary brain vesicles
____encephalon (forebrain)
_____encephalon (midbrain)
_________encephalon (hindbrain)
Prosencephalon
Mesencephalon
Rhombencephalon
Secondary brain vesicles
____encephalon
____encephalon
___encephalon
____encephalon
____encephalon
Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon
Prosencephalon gives you _________ secondary vesicle
Mesencephalon gives you _________ secondary vesicle
Rhombencephalon gives you _________ secondary vesicle
Telencephalon; Diencephalon
Mesencephalon
Metencephalon; Myelencephalon
Prosencephalon gives you _________ Adult neural canal regions
Mesencephalon gives you _________ Adult neural canal regions
Rhombencephalon gives you _________ Adult neural canal regions
Lateral ventricles; Third ventricle
Cerebral aqueduct
Fourth ventricle; Central canal
CNS congenital abnormalities
This refers to a morphological abnormality of the CNS that dates to the embryonic or fetal period, regardless of the mechanism of its origin.
_______ are most common
Accounts for between ____ to ——% of cases that occur in Nigeria (studies from Enugu, Jos, Kano, Lagos)
Neural tube defects (NTD)
60 to 90
Neural tube defects
Anencephaly
○Total (____) or partial (____) _______ of the brain with absence of the _________ and _______
holo
mero
absence
cranial vault and covering skin.
Neural tube defects: Anencephaly
○Results from failure of ________________________________
closure of the anterior portion of the embryonic neural tube.
Anencephaly is compatible with life
T/F
F
Stillbirths or die immediately after birth
Aetiology of anencephaly
○_____ and _____ deficiency
○Genetic defects: Inactivation of _____________
○Environmental: ______,________
Folate & Vit B12
NUAK2 kinase (anencephaly)
Maternal smoking, radiation,
Craniorachischisis
○is basically ________ combined with a _________________________________
○Failure of ____________________
Anencephaly
contiguous bony defect of the spine and meninges.
closure of the anterior neuropore.
Craniorachischisis is compatible with life
T/F
F
Stillborn foetus
Neural tube defects: Iniencephaly
○Failure of ___________
○Characterised by ________ defect, _________ of the ______ vertebrae and _______________ on the cervical spine.
closure of neural tube
occipital bone
spinal bifida ; cervical
retroflexion of the head
Neural tube defects: Iniencephaly
Associated with Trisomies ———— as well as lack of ____________, drugs e.g. _______, and ________.
18 & 13
folic acid supplementation
vinblastine; obesity
Iniencephaly is compatible with life
T/F
Results in miscarriage or stillborn
Neural tube defects: Encephalocele
○Characterised by a _______________ or _____________ skin covered lesion protruding through a __________________ as a result of the failure of the ___________________________________
pedunculated or sessile cystic,
defect in the cranium
surface ectoderm to separate from the neuroectoderm.
Encephalocele
May be classified based on content/site
Content:
Meninges (________)
meninges and brain tissue (________)
brain (_________)
Meninges (meningocele)
meninges and brain tissue (meningoencephalocele)
brain (encephalocele)
Encephalocele
May be classified based on content/site
Location: list 6
frontal, nasofrontal, occipital, parietal,orbital, nasal
Encephalocele
Diagnosis:______ (pre- and post-natal)
Treatment:_______.
imaging
surgery
Spina Bifida
Incomplete embryologic closure of the _____________
vertebral arches
Most common NTD is ???
Spina bifida
Spina bifida: Classification
○Anatomical: _______ ,______,_______
Cervical, Thoracic, Lumbosacral
most common Anatomical location for Spina bifida is ??
Lumbosacral
Spina bifida : Severity of defect
Spina bifida ______
Spina bifida _________
___________/_____________
occulta
cystica
Myelocele/syringomyelocele
Spina bifida : Severity of defect
Spina bifida occulta: just a ——————-, ____________________
Spina bifida cystica: ______ of the _____________ and or __________________.
Myelocele/syringomyelocele: defective _____________ leading to ________
vertebral defect; does not affect spinal cord and meninges
herniation; meninges (dura & arachnoid); spinal cord (meningo-/myelomeningocele)
closure of the spinal canal; CSF leakage
Myelomeningocele and myelocele are associated with neurologic deficits including _______,________, and ______
bladder and bowel dysfunction, paraplegia.
__________ and _______ are associated with neurologic deficits including bladder and bowel dysfunction, paraplegia.
Myelomeningocele and myelocele
Spina bifida
Diagnosis is by imaging (may be confused with _________________).
Increased levels of _____ in maternal blood in certain cases
Amenable to _________
sacrococcygeal teratomas
AFP
surgery
Hydrocephalus
The __________ of ________________ in the ventricular system.
accumulation
excessive cerebrospinal fluid
Hydrocephalus
This usually results in the _______ of the ________ and increased ——————
dilatation
ventricles
intracranial pressure.
The incidence of congenital hydrocephalus in the U.S. is ___/1000 live births.
Globally, the incidence is higher in ______ and _______ (145 and 316/100,000 live births). It is lowest in _______ (68/100000 live births)
3
Africa and Latin America
North America
Hydrocephalus (Classification)
________ hydrocephalus
________ hydrocephalus
Primary
Secondary
Hydrocephalus (Classification)
Primary hydrocephalus: characterised by _______________ alongside ___________
increased volume of CSF
increased intracranial pressure.
Hydrocephalus (Classification)
Primary hydrocephalus:
It can be divided into:
○_____________
○________________
Communicating
Non-communicating
Secondary hydrocephalus: caused by _____________ with resultant compensatory ___________. In this case, there is ______________________________
reduction in neural tissue
increase in CSF volume
no increase in intracranial pressure.
CSF production
Produced by the _________ in the ________________
_____ -_______ mls in volume
choroid plexus
lateral, 3rd, 4th ventricles
120 - 150
Primary Hydrocephalus
Aetiology
○________ to CSF flow
○_____________ of CSF
○__________________ of CSF
Obstruction
Increased production
Reduced absorption
Non-communicating Hydrocephalus
Characterised by ———- to CSF flow at the level of the _____________,____________,_____________ or __________________
obstructions
intraventricular foramen, 3rd ventricle, aqueduct of sylvius or the foramen of Lushcka and Magendie.
Non-communicating Hydrocephalus
Aetiology
○ Congenital :
______ of the aqueduct
___________ malformation
Intra-uterine _______
Progressive _______ of the aqueduct and ____________
____________ syndrome
Stenosis
Arnold-Chiari
meningitis
gliosis; arachnoid cysts
Dandy-Walker
Non-communicating Hydrocephalus
Aetiology
○ Acquired:
________
__________
___________________
Tumours
Haemorrhage
Inflammatory lesions
Non-communicating Hydrocephalus
Aetiology
○ Acquired:
Tumours e.g. ____________,_________
Haemorrhage: ————,———-,————-
Inflammatory lesions: _________,_________
choroid plexus papillomas, ependymoma
Epidural, subdural, intraventricular
Meningitis, cerebral abscess
Communicating Hydrocephalus
CSF _________ within the _________ and the ___________.
freely flows
dilated ventricles
spinal canal
Communicating Hydrocephalus
Aetiology:
○Overproduction of CSF e.g. _________
○Impaired reabsorption e.g. following ______,___________ etc
○Congenital absence of _________
choroid plexus papilloma
meningitis, subdural haemorrhage
arachnoid villi
Secondary hydrocephalus
•__________ hydrocephalus
•Hydrocephalus ______
Normal pressure
ex-vacuo
Secondary hydrocephalus
•Normal pressure hydrocephalus:
○(Slow or Rapid?) but persistent increase in CSF.
○The ______ around the ventricles compensate and the fluid pressure in the head _________
Slow
tissues; does not increase.
Secondary hydrocephalus
•Normal pressure hydrocephalus:
○May result from head trauma, infections, post-surgery or be insidious
○Characterised by problems with ________,_________, and —————
walking, bladder control and difficulty with reasoning
Clinical features of hydrocephalus
Infants:
(Small or Large?) head
(slow or rapid?) increase in head size
bulging ________
_________ vomiting
problems with ______
eyes fixed _________ (“________”)
seizures.
Large ; rapid
anterior fontanelle
projectile; feeding
downwards; sun setting
Clinical features of hydrocephalus
Older children/young to middle aged adults:
headache, _________
nausea and vomiting
difficulty in __________
poor —————
loss of ______ control
_______ loss
blurred vision
maintaining balance
coordination
bladder
memory
Clinical features of hydrocephalus
Older adults:
________ problems (____ feeling ____),
——— impairment and _________
loss of _________
poor __________________
Walking; feet; stuck
mental ; dementia
bladder control
coordination and balance
Investigations of hydrocephalus
Imaging: Ultrasound, MRI, CT Scan
○ ______ ventricles, loss of ____________ and sites of obstruction
Neurological examination
Enlarged
sulcal gyral pattern
Treatment of hydrocephalus
Surgery:
○______
○________ ———- _______
○Choroid villi ________
○__________ / removal of tumour
○Shunts
○Endoscopic third ventriculostomy ○Choroid villi cauterisation ○Debulking / removal of tumour
Treatment of hydrocephalus
Drugs: ______ and _______ are useful in reducing CSF production
Physiotherapists, speech therapists etc
furosemide and acetazolamide
____________ is world spina bifida and hydrocephalus day
October 25th
Neural Tube
Begins as neural _____ to neural _____ which “closes” to form neural ____
Process complete by ________ gestation
plate
fold
Tube
28 weeks
Neural Tube
___________ = cranial and caudal open ends of tube
(First or Last?) structures to close
Neuropores
Last
Neural Tube Defects: Risk Factors
Low ———- intake during pregnancy
_________ drugs, Especially _______ and ________
folic acid
Antiepileptic
valproic acid ; carbamazepine
Neural Tube Defects
Risk Factors
Folate in pregnancy
Normal-risk mothers: _____ mcg/day
High-risk mothers: ___mg/day
400
4
ANENCEPHALY
Ultrasound:
____ calvaria
_____-like appearance of fetus
Open
Frog
ANENCEPHALY
Mother will have ______hydramnios
Why?
poly
Baby can’t swallow amniotic fluid normally
Least common neural tube defect is ????
ENCEPHALOCOELE
ENCEPHALOCOELE
Most common site:________ bone
occipital
SPINA BIFIDA: Clinical Features
May damage ____________ nerves
_____/______ dysfunction
_______ symptoms
Treatment: surgery
spinal cord
Motor / sensory
Urologic
Spina Bifida Occulta
Often has skin abnormalities: ____,______
Usually (asymptomatic or symptomatic?)
dimple, tuft of hair
asymptomatic
Least common type of spina bifida is ?????
Meningocele
Meningocele
Usually ( asymptomatic or symptomatic?)
(Good or Bad?) prognosis
asymptomatic
Good
Dandy-Walker Malformation
______ or ———— of the _____________
(Enlarged or Shrunken?) _______ ventricle
Hypoplasia or agenesis; cerebellar vermis
Enlarged; 4th
Dandy-Walker Malformation
______ of ——- ventricle hydrocephalus
Imaging findings:
Small ________
Dilated ________
Cysts; 4th
cerebellum
4th ventricle
Dandy-Walker Malformation
Often detected by _______ in utero
ultrasound
Dandy-Walker Malformation
Many, many associated symptoms/conditions:
____,______, or ______defects
____________________
Heart, facial or limb
Spinal bifida
Dandy-Walker Malformation
Affected children
_________
Delayed ________
________ dysfunction (crawling, walking) Ataxia
Hydrocephalus
development
Motor
NPH(normal pressure hydrocephalus) PATIENTS ARE _______,________, and ————
WET, WOBBLY & WACKY
