Corpus Callosum Anomalies
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Transcript of Corpus Callosum Anomalies
MarwanAlhalabiMDPhDProfessorinReproductiveMedicineFacultyofMedicineDamascusUniversity&ClinicalMedicalDirectorOrientHospitalAssistedReproductionCenterDamascus,Syria.
Inthe18thcentury,thecorpuscallosumwasconsideredthesiteofthesoul(MauricePtito),andintheearly20thitwasassignedthemereroleofpreventing thecerebralhemispheresfromcollapsingontoeachother
Itwasonlyinthe1950'sthatthecorpuscallosum,inthepioneeringworkofMyersandSperry,wasattributedthefunctionoftransferalofinformation betweenthetwohemispheres
Thiswasfollowedbythedevelopment,intheearly1960's,ofasurgicalinterventionaimedatreducingtheinterhemispherictransmissionofabnormalelectricaldischargesinepileptic patients
Underneaththecerebrumatthecenterofthebrain.
Ø Largestconnectivepathway
Ø 200millionnervefibers
Ø Connectsleft&right
hemisphere
Ø “Communication”
l Transfersthefollowing:
l Motorinformation
l Sensoryinformation
l Cognitiveinformation
l “ALLTHROUGHLEFT&RIGHTHEMISPERES!”
1. Splenium
2. Body
3. Genu
4. Rostrum
5.Isthmus
Motor
Somatosensory Auditory
Visual200,000,000Neuronsconnecteach
hemisphere
• Developmentalabsenceofthecorpuscallosum:Agenesis(ACC)• PartialACC
• CompleteACC
• Eachofthesemaybe:• Isolated:ACCwithnootherabnormalities
• Complex:ACCwithotherabnormalities
• Incidence – difficulttoestimate(asymptomaticindividuals)
• Therearenolargestudies• 1.4per10.000livebirths(CaliforniaBirthDefect
MonitoringProgram)• Prevalenceofassociatedbrainabnormalities- 45,8%(posteriorfossa,interhemispheric cystsandneuronalmigrationdisorders)
• Theoverallrateofchromosomal abnormality - 17,8%(consider- chromosomalanalysis,CGH)
• MeasurementofCCsize– recommendedbysomeauthors
Achiron R, Achiron A..Ultrasound Obstet Gynecol 2001; 18: 343–347.
Corpuscallosum• By18-20weeks’gestation– finalshape
Corpuscallosum:• Approach:mid-sagittalormid-coronalplaneofthebrain• Multiplanar sonographyorTVS– useful• Mid-sagittalview– thinanechoicspace• Mid-sagittalview– pericallosal arteryasamarker(especiallyin
resolution-relateddifficulties)
• 3D/4Dreconstruction
Absenceofthecavumsepti pellucidi (CSP)• NotspecifictoACC(holoprosencephaly,hydrocephalus,septo-opticdysplasia,schizencephaly,encephalocele,porencephaly andhydranencephaly).
• InpartialACC- CSPisusuallypresent
FusedfrontalhornsmimicthepresenceofCSP
Abnormalitiesoftheventricles
• Colpocephaly - dilatationoftheatriaandoccipitalhornsofthelateralventricles• ResultoftheabsenceofCCposteriorportion,whichallows
expansionoftheoccipitalhorns.
• Usuallynotassociatedwithprogressiveventriculomegaly
• LateraldisplacementofLateralVentricleoncoronalviews.
• Upwarddisplacementofthethirdventricle,whichreachesthelevelofthelateralventricles
Abnormalcourseofthepericallosal artery• CompleteACC:thesemicircularloopofthepericallosal arteryislost
• PartialACC:thepericallosal arteryfollowstheanteriorpartoftheCCbutthenlosesitsnormalcoursewheretheCCdisappearsposteriorly;
Wideningoftheinterhemispheric fissure
• Increasedseparationofthehemispheres
• 3parallelechogeniclines(themiddle- falx cerebri)
• Thelateralonesrepresentingthemedialbordersoftheseparatedhemispheres
Signsandsymptoms• Varygreatlyamongindividuals
• Somecharacteristicscommoninindividualswithcallosal disordersinclude
1. Poor motor coordination, 2. Delays in motor milestones such as sitting
and walking, 3. Delayed toilet training, 4. Chewing and swallowing difficulties
5. Vision impairments, 6. Hypotonia7. Low perception of pain, .8. sometimes seizures, spasticity, early
feeding difficulties
• Associatedsyndromes• ACCcanoccurasanisolatedconditionorincombinationwithother
cerebralabnormalities,including• Arnold-chiari malformation,• Dandy-walkersyndrome,• Andermann syndrome(motorandsensoryneuropathy)• Schizencephaly (cleftsordeepdivisionsinbraintissue)• Holoprosencephaly(failureoftheforebraintodivideintolobes.)
• Aicardi Syndrome.• Cephalocele.
Cause• Agenesis of the corpus callosum is caused bydisruption to development of the fetal brainbetween the 3rd and 12th weeks of pregnancy.
• In most cases, it is not possible to know whatcaused an individual to have ACC or anothercallosal disorder.
Cause• However,researchsuggeststhatsomepossiblecausesmayinclude
• chromosomeerrors,
• inheritedgeneticfactors,
• prenatalinfectionsorinjuries,• prenataltoxicexposures,
• structuralblockagebycystsorotherbrainabnormalities
• metabolicdisorders.
Treatment• There are currently no specific medical treatments for
callosal disorders, it usually involves management ofsymptomsand seizures if they occur.
• Patients may benefit from a range of
• developmental therapies,
• educational support, and services.
• Dependsoncoexistenceofotherabnormalities
• Associationwithcorticaldisorders– poorprognosis
• Normalorborderlineintellectualdevelopment– incaseofisolated
• Pediatricdatasuggest– morethan90%mentalretardationorsevereabnormalities
Only& The& Rostrum& (1),& Genu& (2)& And& Body& (3)& Are& Visible;& The& Splenium& Is&Missing.&The&Corpus&Callosum&Is&Short&Posteriorly&And&Does&Not&Seem&To&Overlay&The&Quadrigeminal&Plate
Sunday, July 28, 13
• Agenesis of corpus callosum (ACC)
• Cortical heterotopia,• Infantile spasm, • Chorioretinopathy, • Mental retardation with
or without associated vertebral anomalies.
• X Linked Recessive