Radiology Chiari Malformation
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Transcript of Radiology Chiari Malformation
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8/17/2019 Radiology Chiari Malformation
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Sagittal and coronal MRI images of Chiari type I malformation. Note descent of cerebellar
tonsils (T) below the level of foramen magnm (white line) down to the level of C! posterior arch
(asteris").
#$ial MRI image at the level of foramen
magnm in Chiari type I malformation. Note crowding
of foramen magnm by the ectopic cerebellar tonsils (T) and the medlla (M). #lso note the absence of
cerebrospinal flid.
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CS% hypotension syndrome& 'ostcontrast MRI before (#) and after () treatment with lmbar epidral
blood patch. Notice the thic" meningeal enhancement (arrows) the relative pacity of CS% in front of thebrainstem and behind the cerebellar tonsils and the engorgement of the pititary gland before treatment
(#). Notice reversal of these abnormalities and ascent of the cerebellar tonsils after treatment (). In this
case an ac*ired Chiari malformation was not present bt in some cases it is.
T+ hyperintense region on MRI (arrow) depicting edema in central cord region of a
patient with Chiari I malformation. ,eft ntreated this patient is li"ely to develop cavitation of the
edematos central cord reslting in syringomyelia.
Gejala Chiari 1 berkembang sebagai hasil dari 3 konsekuensi patofsiologi
anatomi teratur: (1) kompresi medula dan sumsum tulang belakang bagian atas, (2)
kompresi otak kecil, dan (3) gangguan aliran CS melalui !oramen magnum"
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#ompresi tali dan medula dapat men$ebabkan m$elopath$ dan sara! kranial $ang
lebih rendah dan dis!ungsi nuklir" #ompresi otak dapat men$ebabkan ataksia,
d$smetria, nistagmus, dan d$se%uilibrium" Gangguan aliran CS melalui !oramen
magnum mungkin account untuk gejala $ang paling umum, n$eri"
&leh karena itu, sakit kepala dan sakit leher di Chiari Sa$a sering diperburuk
oleh batuk dan 'alsaa manuer" idrose!alus terjadi lebih jarang" Selain itu, aliran
teratur CS melalui !oramen magnum dapat mengakibatkan pembentukan
s$ringom$elia dan kabel pusat gejala seperti kelemahan tangan dan dipisahkan
hilangn$a sensasi" Gejala*gejala ini biasan$a asimetris, karena s$rin+ memiliki
kecenderungan untuk mengembangkan di sisi sumsum tulang belakang $ang lebih
signifkan dipengaruhi oleh ectopia tonsil" -.
/2 0ila$ah hiperintens pada (panah) $ang menggambarkan ed
/2 0ila$ah hiperintens pada (panah) $ang menggambarkan edema di
0ila$ah tali pusat pasien dengan Chiari mal!ormasi " 4iobati, pasien ini mungkin
mengembangkan kaitasi kabel pusat edematous, sehingga s$ringom$elia"
5atofsiologi Chiari lebih kompleks" eskipun mekanisme tekan
kemungkinan memainkan peran, seperti di Chiari , mekanisme tambahan mungkin
operasi di Chiari " 5eregangan berorientasi abnormal sara! kranial di$akini
berperan" Chiari dapat menjadi akut dengan gejala kerusakan shunt, mungkin
karena hidrose!alus kian perpindahan ke ba0ah batang otak dan peregangan sara!
kranial" a telah mengemukakan bah0a iskemia ireersibel batang otak ba0ah
ketegangan mungkin bertanggung ja0ab untuk prognosis $ang lebih buruk dari
Chiari setelah operasi dibandingkan dengan Chiari " Selanjutn$a, kelainan
neuroembr$ological intrinsik di Chiari tersebar luas dan tidak terbatas pada !ossa
posterior (misaln$a, heterotopia, kelainan g$ral, callosal dan kelainan thalamic,
selain hidrose!alus dan m$elomeningocele), lebih rumit patofsiologi gangguan ini"
Characteristic Chiari I Chiari II
Usual age of
diagnosis
Adults and older children Infants and young children
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Clinical findings Headache and neck pain
(worsened by cough or Valsalva
maneuver)
yelopathy
Cerebellar symptoms
!ower brainstem symptoms
(eg" dysarthria" dysphagia" downbeatnystagmus)
Central cord symptoms (eg"
hand weakness" dissociated sensory
loss" cape anesthesia)
In infants" signs of brainstem
dysfunction predominate#
swallowing$feeding difficulties" stridor"
apnea" weak cry" nystagmus
%eakness of e&tremities
'rimary anatomicalabnormalities
Herniation of cerebellar
tonsils through foramen magnum"
producing compression of
cervicomedullary unction
Herniation of lower brainstem
through foramen magnum
Cephalad course of cranial
nerves
inking of cervicomedullary
unction
*+eaking* of tectumUpward herniation of vermis
through incisura
,early vertical tentorium
yelomeningocele ,o Always
Hydrocephalus !ess than -./ of cases Very common
0yringomyelia 1.23./ Common
Associated
abnormalities
Craniocervical hypermobility
syndromes
lippel24eil anomaly
Hereditary connective tissuedisorders and neurofibromatosis type
II
Callosum corpus pellucidum
septum of agenesis
Hypoplasia or
5nlargement of massaintermedia
Heterotopias and gyral
abnormalities
0hared associated
abnormalities
+asilar invagination
6ccipitali7ation of atlas
+ifida of C- posterior arch
4oramen magnum variant
anatomy
+asilar invagination
6ccipitali7ation of atlas
+ifida of C- posterior arch
4oramen magnum variant
anatomy
0U+58 # http#$$emedicine9medscape9com$article$-:;1