COMMON CONGENITALNEUROSURGICAL DISEASES

Essam Elgamal

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428 surgery team

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OutlineOutlineApproach to Congenital Neurosurgical Approach to Congenital Neurosurgical

DiseasesDiseasesDevelopment of the Nervous SystemDevelopment of the Nervous SystemCongenital MalformationsCongenital MalformationsNeural Tube DefectNeural Tube DefectCongenital HydrocephalusCongenital HydrocephalusArnold Chiari MalformationArnold Chiari MalformationDandy-Walker CystDandy-Walker CystArachnoid CystArachnoid CystCraniosynostosisCraniosynostosisNeurocutaneous SyndromesNeurocutaneous Syndromes2

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What can go wrong with the What can go wrong with the brain?brain?

Abnormal Abnormal developmentdevelopment

Pernatal EventsPernatal Events

Abnormal functioningAbnormal functioning

Abnormal Abnormal programmingprogramming

Neural Tube DefectsNeural Tube Defects Neuromigrational DisordersNeuromigrational Disorders

Cerebral palsyCerebral palsy

Seizures & EpilepsySeizures & Epilepsy HydrocephalusHydrocephalus

NeurofibromatosisNeurofibromatosis Tuberous SclerosisTuberous Sclerosis Sturge-Weber SyndromeSturge-Weber Syndrome Mitochondrial DisordersMitochondrial Disorders

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Development of the Nervous Development of the Nervous SystemSystem

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Gross DevelopmentGross DevelopmentEctodermEctoderm

Will form nervous system and outer skinWill form nervous system and outer skin

EndodermEndoderm Will form skeletal system and voluntary Will form skeletal system and voluntary

musclemuscle

MesodermMesoderm Will form gut and digestive organsWill form gut and digestive organs

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Developmental SequenceDevelopmental SequenceNeural plate invaginates Neural plate invaginates

as neural folds push upas neural folds push up

Neural folds eventually Neural folds eventually form neural grooveform neural groove

Cells of neural fold Cells of neural fold eventuall meeteventuall meet

Form the neural tubeForm the neural tube

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Developmental SequenceDevelopmental Sequence

Neural tube runs anterior – posterior along Neural tube runs anterior – posterior along embryoembryo

Surrounding ectoderm eventually encloses Surrounding ectoderm eventually encloses neural tubeneural tube

When neural tube closes off brain and spinal When neural tube closes off brain and spinal cord are formedcord are formed

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Human EmbryoHuman EmbryoPrimitive brain Primitive brain

consists of 3 cavities consists of 3 cavities that will form that will form ventriclesventricles

Brain’s gross features Brain’s gross features are then formed are then formed through a series of through a series of bendsbends

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Human EmbryoHuman EmbryoDeveloping embryoDeveloping embryoGoes through a series Goes through a series

of folds or “flexures”of folds or “flexures”Gives rise to the Gives rise to the

compact structure of compact structure of the brainthe brain

BrainBrain

DiencephalonDiencephalon

MidbrainMidbrain

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Congenital MalformationsCongenital MalformationsNeural Tube Defects (Neural Tube Defects (the most the most

common defectcommon defect))(Dysraphism)(Dysraphism)

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PathophysiologyPathophysiology

Spina bifida occulta (Spina bifida occulta (closedclosed))

5-10% of population 5-10% of population 1/1000 in US, 2/1000 in 1/1000 in US, 2/1000 in ksa ksa

not clinically significantnot clinically significant tuft of hair, dimple sinus or port wine staintuft of hair, dimple sinus or port wine stain high incidence of underlying defecthigh incidence of underlying defect no treatment required no treatment required just to cover itjust to cover it, U/S or , U/S or

MRMR

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PathophysiologyPathophysiology

The openings at each end are termed the rostral The openings at each end are termed the rostral and caudal neuropores, and close at around the and caudal neuropores, and close at around the 2424thth and 27 and 27thth days respectively days respectively

If the neural folds do not fuse at the rostral end, If the neural folds do not fuse at the rostral end, anencephalyanencephaly results results

If the neural folds do not fuse at the caudal end, If the neural folds do not fuse at the caudal end, myeloschisismyeloschisis (cleft spinal cord) results (the (cleft spinal cord) results (the most most severesevere form of form of spina bifidaspina bifida) ) treated as an treated as an emergency case, just few hour after delivery emergency case, just few hour after delivery

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If it doesn’t get closed = myeloschisimyeloschisiss

anencephalyanencephaly

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•Failure of vertebral Failure of vertebral arch bony growth arch bony growth and fusion.and fusion.

•Neurologic Neurologic symptoms are symptoms are usually absent, usually absent, although problems although problems may occur during may occur during growth owing to growth owing to "tethering" of the "tethering" of the spinal cord. spinal cord.

•Skin anomalies Skin anomalies frequently overlie frequently overlie the defect, including the defect, including a hairy patch, a hairy patch, hemangioma, or hemangioma, or dermal sinus dermal sinus

Meninges Meninges with with CSF CSF bulge bulge

through the through the defectdefect coverd coverd

by skinby skin

Same as B Same as B ++Spinal cord and Spinal cord and its nerves enter its nerves enter

the defect the defect

Neural tissue Neural tissue is directly is directly exposedexposed

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Multiple factors implicated: Multiple factors implicated: not well understoodnot well understood

Folate deficiency (most common cause)Folate deficiency (most common cause)(there is no benefit to give folic acid after 24(there is no benefit to give folic acid after 24thth-27-27thth

day) day) Radiation & chemicalsRadiation & chemicals DrugsDrugs MalnutritionMalnutrition Genetic determinants (mutations in folate-Genetic determinants (mutations in folate-

responsive or folate-dependent pathways)responsive or folate-dependent pathways)

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DiagnosisDiagnosis Maternal Alpha FetoproteinMaternal Alpha Fetoprotein

AFP leaks into amniotic fluid, and then into maternal blood AFP leaks into amniotic fluid, and then into maternal blood in case of open spina in case of open spina

bifidabifida

Blood level taken 13-16 weeks gestation is used as a screening test; Blood level taken 13-16 weeks gestation is used as a screening test;

Amniocentesis Amniocentesis at around 18 weeks, allows detection of over 99 percent of fetuses with neural at around 18 weeks, allows detection of over 99 percent of fetuses with neural

tube defectstube defects

UltrasoundUltrasound

MRIMRI U.S is the first way to detect neural tube defect

M.R.I is the confirmatory method to detect neural tube defect

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Associated anomaliesAssociated anomaliesAssess for presence & severity ofAssess for presence & severity of

Chiari MalformationChiari Malformation HydrocephalusHydrocephalus Associated brain malformationsAssociated brain malformations Extremity deformities: contracturesExtremity deformities: contractures Congenital kyphosis and/or scoliosisCongenital kyphosis and/or scoliosis Other abnormalities (renal, bowel, bladder, Other abnormalities (renal, bowel, bladder,

cardiac)cardiac)

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Chiari II MalformationChiari II Malformation•Cerebellar Cerebellar tonsiltonsil Herniation Herniation plus Medulla distortion and plus Medulla distortion and dysplasiadysplasia

• Seen in >50% of children Seen in >50% of children with with lumbar lumbar myelomeningocoelesmyelomeningocoeles

•Hydrocephalus results from Hydrocephalus results from aqueduct stenosis or an aqueduct stenosis or an obstruction of outflow of CSF obstruction of outflow of CSF from 4from 4thth ventricle secondary to ventricle secondary to herniationherniation

•Symptoms of raised ICP, Symptoms of raised ICP, oropharyngeal dysfunction, oropharyngeal dysfunction, cranial nerve palsies, cranial nerve palsies, cardiorespiratory failurecardiorespiratory failure

•Dx by Dx by MRIMRI•Rx by Rx by Posterior fossa Posterior fossa decompression & VP shuntdecompression & VP shuntChiari I MalformationChiari I Malformation

•Cerebellar herniation through Cerebellar herniation through foramen magnumforamen magnum

•Incidental finding: headache; Incidental finding: headache; neck pain; oropharyngeal neck pain; oropharyngeal dysfunctiondysfunction

•Diagnosed in adulthoodDiagnosed in adulthood

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Further AssessmentFurther Assessment Latex Allergy (Latex Allergy (glovesgloves) () (all children with spina bifida are all children with spina bifida are

considered to have allergy to latex till prove otherwise considered to have allergy to latex till prove otherwise ) )

SeizuresSeizures

Nutrition: obesity or malnutritionNutrition: obesity or malnutrition

VP shunt dysfunctionVP shunt dysfunction

Psychosocial developmentPsychosocial development

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Clinical Clinical manifestationsmanifestations

Sacral and Low Lumbar (L4, L5) Sacral and Low Lumbar (L4, L5) most common most common site site Ambulate into adulthoodAmbulate into adulthood Ankle/Foot orthoses (Ankle/Foot orthoses (device to support limb functiondevice to support limb function))

Mid-lumbar (L3, L4)Mid-lumbar (L3, L4) Difficulties with ambulation into adulthoodDifficulties with ambulation into adulthood As above plus crutches/walkerAs above plus crutches/walker Wheelchair for distancesWheelchair for distances

High lumbar & Thoracic (L2 & above)High lumbar & Thoracic (L2 & above) May be trained to ambulate in early childhoodMay be trained to ambulate in early childhood Hip-knee-ankle orthosesHip-knee-ankle orthoses Walker or crutches but most wheelchair-boundWalker or crutches but most wheelchair-bound

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EncephaloceleEncephalocele Encephalocele Encephalocele = A sac with a part of brain but this part = A sac with a part of brain but this part doesn’t workdoesn’t work Usually occipitalUsually occipital may contain occipital lobe, or cerebellummay contain occipital lobe, or cerebellum often associated with hydrocephalusoften associated with hydrocephalus Immediate treatment if ruptured Immediate treatment if ruptured to prevent infectionto prevent infection outcome depends upon contentsoutcome depends upon contents Meningeocele in skull = A sac in the skull with no brainMeningeocele in skull = A sac in the skull with no brain

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Congenital HydrocephalusCongenital Hydrocephalus

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Enlargement of brain ventricles (internal hydrocephalus) and/or subarachnoid spaces (external hydrocephalus), associated with increased ICP.

The incidence 0.9 and 1.8/1000 live births.

DefinitionDefinition

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RATIONALECSF secretion is an active process.

70% by ventricular choroid plexuses,

30% by extrachoroid sources capillary ultrafiltrate, ependyma, metabolic water production

rate of production is 0.35 ml/min or 500 ml/day.

350ml/day reabsorbed 27

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CSF is passively absorbed by:

arachnoid villi into venous dural sinuses

other pathways of absorption: spine venous plexuses.perivascular and the perineural sheaths.

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PATHOPHYSIOLOGY

1. CSF overproduction: hypervitaminosis A, choroid plexus tumors.

2. Obstruction to CSF flow. ventricular dilatation generates mechanical damages to the parenchyma.

3- decreased absorption by adhesion (N:B:

adhesion occur in case of trauma, infection,& hemorrhage )

4- DVT in dural veinous sinusis 31

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Clinical manifestations depends on age

Infants & young children: 1. Increasing head circumference.2. Irritability, lethargy, poor feeding, and vomiting.3. Bulging anterior fontanelle.4. Widened cranial sutures.5. McEwen's cracked pot sign with cranial percussion. (palpable separation of cranial suture,

percussion of the skull evokes a 'jagged' sound)6. Scalp vein dilation (increased collateral venous drainage).7. Sunset sign (forced downward deviation of the eyes, a neurologic sign almost unique with hydrocephalus).8. Epidsodic bradycardia and apnea & HTN . Occur later in life

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TreatmentEndoscopic third ventriculostomy

CSF diversion:V-P shuntV-A shuntV-Plural shuntV-sinus shunt

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are needed to see this picture.

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Chiari malformation

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type II chiari malformation associated with lumbar myelomeningocoeles lumbar myelomeningocoeles and may be ended and may be ended up with up with hydrocephalus hydrocephalus

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Dandy-Walker cystCyst in cerebellar area no cerebellum =

cerebellar agenisis

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Arachnoid cystIncidentally Dx, conservative Rx

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Craniosynostosiss

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Neurocutaneous Neurocutaneous SyndromesSyndromes

Tuberous SclerosisTuberous Sclerosis

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Neurocutaneous Neurocutaneous SyndromesSyndromes

Neurofibromatosis Type 1Neurofibromatosis Type 1

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Lisch noduleLisch nodule

Café au lait spotCafé au lait spotNeufibromasNeufibromas

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Optic gliomaOptic glioma

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Thank you Thank you abo-7medabo-7med

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