Arnold-Chiari malformation overview: Difference between revisions
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==Overview== | ==Overview== | ||
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==Historical Perspective== | ==Historical Perspective== | ||
Arnold-Chiari malformation was first described by Cleland in 1883 in a child with [[spina bifida]]. [[Hans Chiari]], an Austrian [[pathologist]] was the first person who described type 2 Arnold-Chiari malformation. [[Hans Chiari]] also described different classification of Arnold-Chiari malformation into 4 groups. | |||
==Classification== | ==Classification== | ||
Arnold chiari malformation may be classified according to [[herniation]] content into 4 subtypes. Type 1 has [[herniation]] of [[Cerebellar tonsil|cerebellar tonsils]]. Type 2 has [[herniation]] of [[Cerebellar tonsil|cerebellar tonsils]] and [[Cerebellar vermis|vermis]]. Type 3 has [[herniation]] of [[cerebellar tonsil]] and [[Cerebellar vermis|vermis]] and lower [[brain stem]]. Type 4 has [[cerebellar hypoplasia]] with [[brain stem]] in [[posterior fossa]]. | |||
==Pathophysiology== | ==Pathophysiology== | ||
The exact [[pathogenesis]] of Arnol-Chiari malformation is not fully understood but It is thought that Arnol-Chiari malformation is the result of [[bone]] [[developmental]] [[abnormalities]] or [[Mesoderm|mesodermal]] [[growth]] and differentiation [[abnormalities]]. [[Gene|Genes]] involved in the [[pathogenesis]] of Arnold-Chiari malformation include [[PAX1]], [[PAX2]], [[PAX3]], [[PAX6]], [[FGF2]], [[TBX6]], HOX [[gene]], [[Noggin (protein)|Noggin]] gene, and EFNB1. Conditions associated with Arnold-Chiari malformation include [[hydrocephalus]], [[Syringomyelia|syringomyelias]],[[Tethered spinal cord syndrome]], [[Neurofibromatosis type I|neurofibromatosis type 1]], [[Noonan syndrome]], [[Pierre Robin syndrome|Pierre Robin sequence]], [[Klippel-Feil syndrome]], [[Albright hereditary osteodystrophy]], x-linked aqueductal stenosis, [[Goldenhar syndrome]], [[Williams syndrome]], [[Shprintzen-Golberg craniosynostosis|Shprintzen- goldberg syndrome]], [[achondroplasia]], familial osteosclerosis, [[velocardiofacial syndrome]], and [[connective tissue disorders]]. | |||
==Causes== | ==Causes== | ||
The cause of Arnold Chiari malformation include [[craniosynostosis]], [[osteopetrosis]], [[vitamin D deficiency]] and [[genetic mutations]]. | |||
==Differentiating Arnold-Chiari malformation from Other Diseases== | ==Differentiating Arnold-Chiari malformation from Other Diseases== | ||
On the basis of [[seizure]], [[visual disturbance]], and constitutional symptoms, Arnold-Chiari malformation must be differentiated from [[astrocytoma]], [[oligodendroglioma]], [[meningioma]], [[hemangioblastoma]], [[pituitary adenoma]], [[schwannoma]], [[Primary central nervous system lymphoma|primary CNS lymphoma]], [[medulloblastoma]], [[ependymoma]], [[craniopharyngioma]], [[pinealoma]], [[Arteriovenous malformation|AV malformation]], [[brain aneurysm]], [[bacterial]] [[brain]] [[abscess]], [[tuberculosis]], [[toxoplasmosis]], [[hydatid cyst]], [[CNS]] [[cryptococcosis]], [[CNS]] [[aspergillosis]], and [[brain metastasis]]. | |||
==Epidemiology and Demographics== | ==Epidemiology and Demographics== | ||
The [[prevalence]] of Arnold Chiari malformation is unknown since most of the cases are accidentally found. The mortality rate of Arnold Chiari malformation depends on the subtype but type 3 has the highest [[mortality rate]] as a result of [[respiratory failure]] in infancy. Arnold Chiari malformation commonly affects [[adolescence]] and adulthood, but also has been seen in younger [[children]]. There is no [[racial]] predilection to Arnold Chiari malformation. | |||
==Risk Factors== | ==Risk Factors== | ||
Common [[Risk factor|risk factors]] in the development of Arnold-Chiari malformation include lumbar-peritoneal shunt and multiple [[lumbar puncture]]. | |||
==Screening== | ==Screening== | ||
There is insufficient evidence to recommend routine [[screening]] for Arnold-Chiari malformation. | |||
==Natural History, Complications, and Prognosis== | ==Natural History, Complications, and Prognosis== | ||
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==Diagnosis== | ==Diagnosis== | ||
===Diagnostic Study of Choice=== | ===Diagnostic Study of Choice=== | ||
[[MRI]] is the [[Gold standard (test)|gold standard]] test for the [[diagnosis]] of Arnold Chiari malformation. [[Cerebellar tonsill herniation|Cerebellar tonsillar herniation]], wedge shaped [[Cerebellar tonsil|tonsils]], syringohydromyelia, small [[posterior fossa]], obstructive [[hydrocephalus]], and [[Brain stem|brainstem]] anomalies. | |||
===History and Symptoms=== | ===History and Symptoms=== | ||
[[Patients]] with Arnold-Chiari malformation may have a positive [[History and Physical examination|history]] of [[lumbar puncture]], lumbar-peritoneal shunt, [[hydrocephalus]], [[Syringomyelia|syringomyelias]],[[Tethered spinal cord syndrome]], [[Neurofibromatosis type I|neurofibromatosis type 1]], [[Noonan syndrome]], [[Pierre Robin syndrome|Pierre Robin sequence]], [[Klippel-Feil syndrome]], [[Albright hereditary osteodystrophy]], x-linked aqueductal stenosis, [[Goldenhar syndrome]], [[Williams syndrome]], [[Shprintzen-Golberg craniosynostosis|Shprintzen- goldberg syndrome]], [[achondroplasia]], familial osteosclerosis, [[velocardiofacial syndrome]], and [[connective tissue disorders]]. The most common [[symptoms]] of Arnold-Chiari malformation is [[headache]], [[arm pain]] and [[weakness]], [[neck pain]], [[nausea and vomiting]], [[Balance disorder|balance problem]], [[dizziness]] and [[ear ringing]]. | |||
===Physical Examination=== | ===Physical Examination=== | ||
[[Patients]] with Arnold Chiari malformation usually appear normal. [[Physical examination]] of [[patients]] with Arnold Chiari malformation is usually remarkable for impaired [[coordination]], [[sensory]]/ [[Motor skill|motor]] deficit, [[Gait abnormality|abnormal gait]], [[nystagmus]], [[scoliosis]], and [[autonomic dysfunction]]. | |||
===Laboratory Findings=== | ===Laboratory Findings=== | ||
There are no diagnostic [[laboratory]] findings associated with Arnold Chiari malformation. | |||
===Electrocardiogram=== | ===Electrocardiogram=== | ||
There are no [[ECG]] findings associated with Arnold Chiari malformation. | |||
===X-ray=== | ===X-ray=== | ||
=== | ===Ultrasound=== | ||
There are no [[ultrasound]] findings associated with Arnold-Chiari malformation. | |||
===CT scan=== | ===CT scan=== | ||
[[CT scan]] may be helpful in the [[diagnosis]] of Arnold Chiari malformation. Findings on [[CT scan]] [[diagnostic]] of Arnold Chiari malformation depends on the subtype and include [[Cerebellar tonsill herniation|herniation of cerebellar tonsils]], [[vermis]], and lower [[brain stem]], underdeveloped [[cerebellum]] and crowded [[foramen magnum]]. | |||
===MRI=== | ===MRI=== | ||
MRI may be helpful in the diagnosis of Arnold-Chiari malformation. Findings on MRI diagnostic of Arnold-Chiari malformation include [[Cerebellar tonsil|cerebellar tonsillar]] [[herniation]], wedge shaped [[Cerebellar tonsil|tonsils]], syringohydromyelia, small [[posterior fossa]], obstructive [[hydrocephalus]], and [[Brain stem|brainstem]] anomalies. | |||
===Other Imaging Findings=== | ===Other Imaging Findings=== | ||
There are no other [[imaging]] findings associated with Arnold-Chiari malformation. | |||
===Other Diagnostic Studies=== | ===Other Diagnostic Studies=== | ||
There are no other [[Diagnosis|diagnostic]] studies associated with Arnold-Chiari malformation. | |||
==Treatment== | ==Treatment== | ||
Revision as of 21:25, 28 September 2019
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Arnold-Chiari malformation Microchapters |
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Differentiating Arnold-Chiari malformation from other Diseases |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Fahimeh Shojaei, M.D.
Overview
Historical Perspective
Arnold-Chiari malformation was first described by Cleland in 1883 in a child with spina bifida. Hans Chiari, an Austrian pathologist was the first person who described type 2 Arnold-Chiari malformation. Hans Chiari also described different classification of Arnold-Chiari malformation into 4 groups.
Classification
Arnold chiari malformation may be classified according to herniation content into 4 subtypes. Type 1 has herniation of cerebellar tonsils. Type 2 has herniation of cerebellar tonsils and vermis. Type 3 has herniation of cerebellar tonsil and vermis and lower brain stem. Type 4 has cerebellar hypoplasia with brain stem in posterior fossa.
Pathophysiology
The exact pathogenesis of Arnol-Chiari malformation is not fully understood but It is thought that Arnol-Chiari malformation is the result of bone developmental abnormalities or mesodermal growth and differentiation abnormalities. Genes involved in the pathogenesis of Arnold-Chiari malformation include PAX1, PAX2, PAX3, PAX6, FGF2, TBX6, HOX gene, Noggin gene, and EFNB1. Conditions associated with Arnold-Chiari malformation include hydrocephalus, syringomyelias,Tethered spinal cord syndrome, neurofibromatosis type 1, Noonan syndrome, Pierre Robin sequence, Klippel-Feil syndrome, Albright hereditary osteodystrophy, x-linked aqueductal stenosis, Goldenhar syndrome, Williams syndrome, Shprintzen- goldberg syndrome, achondroplasia, familial osteosclerosis, velocardiofacial syndrome, and connective tissue disorders.
Causes
The cause of Arnold Chiari malformation include craniosynostosis, osteopetrosis, vitamin D deficiency and genetic mutations.
Differentiating Arnold-Chiari malformation from Other Diseases
On the basis of seizure, visual disturbance, and constitutional symptoms, Arnold-Chiari malformation must be differentiated from astrocytoma, oligodendroglioma, meningioma, hemangioblastoma, pituitary adenoma, schwannoma, primary CNS lymphoma, medulloblastoma, ependymoma, craniopharyngioma, pinealoma, AV malformation, brain aneurysm, bacterial brain abscess, tuberculosis, toxoplasmosis, hydatid cyst, CNS cryptococcosis, CNS aspergillosis, and brain metastasis.
Epidemiology and Demographics
The prevalence of Arnold Chiari malformation is unknown since most of the cases are accidentally found. The mortality rate of Arnold Chiari malformation depends on the subtype but type 3 has the highest mortality rate as a result of respiratory failure in infancy. Arnold Chiari malformation commonly affects adolescence and adulthood, but also has been seen in younger children. There is no racial predilection to Arnold Chiari malformation.
Risk Factors
Common risk factors in the development of Arnold-Chiari malformation include lumbar-peritoneal shunt and multiple lumbar puncture.
Screening
There is insufficient evidence to recommend routine screening for Arnold-Chiari malformation.
Natural History, Complications, and Prognosis
Diagnosis
Diagnostic Study of Choice
MRI is the gold standard test for the diagnosis of Arnold Chiari malformation. Cerebellar tonsillar herniation, wedge shaped tonsils, syringohydromyelia, small posterior fossa, obstructive hydrocephalus, and brainstem anomalies.
History and Symptoms
Patients with Arnold-Chiari malformation may have a positive history of lumbar puncture, lumbar-peritoneal shunt, hydrocephalus, syringomyelias,Tethered spinal cord syndrome, neurofibromatosis type 1, Noonan syndrome, Pierre Robin sequence, Klippel-Feil syndrome, Albright hereditary osteodystrophy, x-linked aqueductal stenosis, Goldenhar syndrome, Williams syndrome, Shprintzen- goldberg syndrome, achondroplasia, familial osteosclerosis, velocardiofacial syndrome, and connective tissue disorders. The most common symptoms of Arnold-Chiari malformation is headache, arm pain and weakness, neck pain, nausea and vomiting, balance problem, dizziness and ear ringing.
Physical Examination
Patients with Arnold Chiari malformation usually appear normal. Physical examination of patients with Arnold Chiari malformation is usually remarkable for impaired coordination, sensory/ motor deficit, abnormal gait, nystagmus, scoliosis, and autonomic dysfunction.
Laboratory Findings
There are no diagnostic laboratory findings associated with Arnold Chiari malformation.
Electrocardiogram
There are no ECG findings associated with Arnold Chiari malformation.
X-ray
Ultrasound
There are no ultrasound findings associated with Arnold-Chiari malformation.
CT scan
CT scan may be helpful in the diagnosis of Arnold Chiari malformation. Findings on CT scan diagnostic of Arnold Chiari malformation depends on the subtype and include herniation of cerebellar tonsils, vermis, and lower brain stem, underdeveloped cerebellum and crowded foramen magnum.
MRI
MRI may be helpful in the diagnosis of Arnold-Chiari malformation. Findings on MRI diagnostic of Arnold-Chiari malformation include cerebellar tonsillar herniation, wedge shaped tonsils, syringohydromyelia, small posterior fossa, obstructive hydrocephalus, and brainstem anomalies.
Other Imaging Findings
There are no other imaging findings associated with Arnold-Chiari malformation.
Other Diagnostic Studies
There are no other diagnostic studies associated with Arnold-Chiari malformation.