CONGENITAL CONGENITAL ANOMALIES OF CNSANOMALIES OF CNS

ETIOLOGYETIOLOGY Hyperthermia Drugs Malnutretion Nutrition: folic acid deficiency Disease: diabetes Toxins: alcohol, smoking Infections: rubella, toxoplasmosis, CMV,

syphilis Radiation Unknown (most cases)

Primary neurolationPrimary neurolation Occur in 3-4 week gestation Neural tube (NT) internally (gives rise to the

CNS above S2 segment), epidermis externally & neural crest (NC) at the junction of NT &

Epidermis mesoderm cells which migrate away from the

neural tube and give rise to the PNS,skull, facial and jaw bones, pigment cells, adrenal medulla

Neural tube closureNeural tube closure Start at the cervical area (cervico-

medularly junction) Extend cranially and caudally Cephalic neuropore close around day

25 Caudal neuropore closes around day

29 and correspond to S2 segment

Disorders of primary Disorders of primary neurolationneurolation

Split cord syndrome Craniorachischisis Neuroenteric cyst Anencephaly Myeloschisis Arnold chiari malformation Meningocele, myelomeningocele Dermal sinus Encephalocele

Dermal sinus Dermal sinus tracttract

result from incomplete disjunction of neuroectoderm from cutaneous ectoderm

The sinus tracts extend deep into the subcutaneous tissues, reaching the spinal canal in one-half to two-thirds of cases.

it may be attached to the dura, causing tenting of the thecal sac.

     

AnencephalyAnencephaly:: Failure of anterior neuropore to close 

Brain and calvarium are absent & Replaced by a cerebrovasculorum - a tangle of glial and connective tissue

Spina Bifida OccultaSpina Bifida OccultaCommon anomaly

Midline defect of vertebral bodies without protrusion of spinal cord or meningesAsymptomaticSpine X RayMRI

Meningocele and Meningocele and myelomeningocelemyelomeningocele

Primary failure of neural tube closure Myelomeningocele Meningocele

Most frequently located in the thoracolumbar area.

MeningoceleMeningoceleMeninges herniate through a defect in the

posterior vertebral arches

Spinal cord is normal

Fluctuant midline mass

Covered with skin

MeningoceleMeningoceleINVESTIGATIONSINVESTIGATIONS::

Plain X RayUltrasonography

MRICT Scan

MyelomeningoceleMyelomeningocele Severe form of neural tube defectSevere form of neural tube defect1/40001/4000

- -Located anywhere esp. lumbosacralLocated anywhere esp. lumbosacral - -Low sacral region: no motor impairment, anesthesia in Low sacral region: no motor impairment, anesthesia in

perineal areaperineal area - -Mid lumbar region: saclike cystic structure covered with thin Mid lumbar region: saclike cystic structure covered with thin

layer of partially epithelialized tissuelayer of partially epithelialized tissue . .

Remnant of neural tissue are visibleRemnant of neural tissue are visibleFlacid paralysisFlacid paralysis

Clinical MinifestaionClinical Minifestaion

EncephaloceleEncephalocele Bony defects in midline Brain tissue can protrude through

hole Most common in occipital region Prognosis depends on quantity of

cerebral tissue that herniates into the defect

Surgical repair is required

CHIARI MALFORMATIONCHIARI MALFORMATIONHerniation of post. Fossa contents through Herniation of post. Fossa contents through foramen magnumforamen magnum..

Normal: upto 5 mm of tonsillar descent Normal: upto 5 mm of tonsillar descent through foramen magnumthrough foramen magnum..

Classified into Chiari I and II based on Classified into Chiari I and II based on amount of descentamount of descent..

CLINICAL FEATURESCLINICAL FEATURES

Presents in infants or young adultsPresents in infants or young adults..

Headache aggravated by coughing or Headache aggravated by coughing or strainingstraining..

Signs of brainstem compressionSigns of brainstem compression

TREATMENTTREATMENT

DECOMPRESSIONDECOMPRESSION

CRANIOSYNOSTOSISCRANIOSYNOSTOSIS

Premature closure of cranial suturesPremature closure of cranial sutures..May affect single or multiple suturesMay affect single or multiple suturesPresent with abnormal head shapePresent with abnormal head shape..Associated with rare genetic Associated with rare genetic abnormalitiesabnormalities..Surgery is required to correct itSurgery is required to correct it..

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