Chiari malformations (I-IV) are congenital hindbrain abnormalities affects cerebellum, brainstem, cervical cord, and cranial base structures.
Cleland identified Chiari malformation in 1883 thus it is named after Austrian pathologist Hans Chiari.
The four Chiari malformation types may not represent a single disease continuum. Types III and IV have distinct pathogenesis and share little beyond their names.
Chiari type I malformation is the most common and the least severe of the spectrum while Chiari type II malformation is less common and more severe.
Conservative treatment is possible for asymptomatic Chiari I malformation patients. MRI is the best imaging study for Chiari malformation.
Other useful tests include myelography for MRI-ineligible patients, and CT or X-rays of the neck and head for bony defects.
Surgical treatment aims to decompress cervicomedullary junction and restore normal CSF flow.
Chiari decompression complications include pseudo meningocele, CSF leakage, and higher concussion risk for patients.
Epidemiology
Chiari malformation type I occurs in 1 in 1000 births. Chiari malformations are found incidentally during unrelated imaging tests.
Chiari II commonly linked to myelomeningocele and neural tube defects.
Chiari malformation is increasingly identified with prevalence rates of 0.1-0.5% and female predominance.
In a 14-year study in USA, 34% of Chiari I decompression surgeries were conducted on patients under 20 years old.
Decompression surgery rates rose 51% in younger patients and 28% in adults during the study period.
Anatomy
Pathophysiology
Symptoms of Chiari I arise from three consequences: medulla and spinal cord compression, cerebellum compression, and disrupted CSF flow through the foramen magnum.
Cord compression causes myelopathy and dysfunction of lower cranial nerves.
Disordered CSF flow at foramen magnum may cause syringomyelia and central cord symptoms.
Symptoms are asymmetrical as a syrinx tends to develop on the spinal cord side affected by tonsillar ectopia.
Chiari II symptoms worsen with shunt malfunction due to exacerbated hydrocephalus and nerve stretching.
Etiology
Chiari type I is hypothesized to originate from para-axial mesoderm forms a small posterior fossa.
Cerebellum development causes posterior fossa overcrowding, cerebellar tonsil herniation, and foramen magnum impaction.
Chiari II malformation linked to myelomeningocele in embryogenesis theories.
Fluid escape through the open placode in myelomeningocele may impair skull base mesenchymal condensation.
Fluid loss causes ventricular system to collapse agenesis of corpus callosum and massa intermedia enlargement.
Genetics
Prognostic Factors
Earlier onset in infants may causes severe symptoms, while late-onset cases have better outcomes.
Severe headaches, syringomyelia, balance issues, or neurological deficits signal a worse prognosis than mild symptoms.
Surgical intervention usually enhances recovery, but individual outcomes and prognosis can differ significantly.
Greater tonsillar herniation correlates with severity and poorer outcomes.
Clinical History
Collect details including initial symptoms, mechanism of injury, and medical history to understand clinical history of patient.
Physical Examination
Neurological Examination
Spine Examination
Respiratory Assessment
Cerebellar Function
Age group
Associated comorbidity
Associated activity
Acuity of presentation
Acute symptoms are:
Acute dysphagia, dysarthria, difficulty breathing, severe headache, nausea, vomiting, lethargy
Chronic symptoms are:
Paresthesias, loss of pain, weakness in the upper limbs, ataxia, gait disturbance, progressive clumsiness
Differential Diagnoses
Hydrocephalus
Dandy-Walker Malformation
Intracranial Hypotension
Multiple Sclerosis
Occipital Neuralgia
Laboratory Studies
Imaging Studies
Procedures
Histologic Findings
Staging
Treatment Paradigm
A review of symptomatic patients showed headache and nausea improved, while ataxia and sensory disturbances did not improve.
Surgical treatment aims to decompress cervicomedullary junction and restore normal CSF flow.
Clinical series support extensive posterior fossa craniectomy, suboccipital craniectomy, C1 posterior arch removal, and duraplasty for cerebellar decompression.
During follow-up, 20 of 48 nonsurgical and 18 of 24 surgical symptomatic patients improved symptomatically.
Two conservative group patients with syrinx showed no resolution, while 14 of 16 surgically treated patients demonstrated improvement or complete resolution.
Use lumbar-support chairs and adjust desk height for neck and back strain relief.
Position screens at eye level and take short breaks to prevent pain and stiffness.
Use orthopedic mattresses and pillows for better breathing and spinal alignment.
Install in showers and near toilets to prevent falls from dizziness.
Proper awareness about Chiari malformation should be provided and its related causes with management strategies.
Appointments with a surgeon and preventing recurrence of disorder is an ongoing life-long effort.
Use of Non-Steroidal Anti-Inflammatory Drugs
Ibuprofen:
It inhibits prostaglandin synthesis to block COX-1 and COX-2 enzymes.
Use of Beta Blockers
Propranolol:
It is nonselective beta-adrenergic receptor helps to decrease heart rate.
Use of Triptans
Sumatriptan:
It is associated with antidromic neuronal transmission to relief migraine headache.
Clinical series recommend posterior fossa craniectomy including suboccipital craniectomy and C1 posterior arch removal for cerebellar decompression and duraplasty.
use-of-phases-in-managing-chiari-malformation
In the acute diagnosis phase, evaluate the severity and nature of headaches, neurological deficits, and other associated symptoms.
Pharmacologic therapy is effective in the treatment phase as it includes the use of NSAID’S, beta blockers, and triptans.
In supportive care and management phase, patients should receive required attention such as lifestyle modification and surgical interventional therapies.
The regular follow-up visits with the surgeon are scheduled to check the improvement of patients along with treatment response.
Chiari malformations (I-IV) are congenital hindbrain abnormalities affects cerebellum, brainstem, cervical cord, and cranial base structures.
Cleland identified Chiari malformation in 1883 thus it is named after Austrian pathologist Hans Chiari.
The four Chiari malformation types may not represent a single disease continuum. Types III and IV have distinct pathogenesis and share little beyond their names.
Chiari type I malformation is the most common and the least severe of the spectrum while Chiari type II malformation is less common and more severe.
Conservative treatment is possible for asymptomatic Chiari I malformation patients. MRI is the best imaging study for Chiari malformation.
Other useful tests include myelography for MRI-ineligible patients, and CT or X-rays of the neck and head for bony defects.
Surgical treatment aims to decompress cervicomedullary junction and restore normal CSF flow.
Chiari decompression complications include pseudo meningocele, CSF leakage, and higher concussion risk for patients.
Chiari malformation type I occurs in 1 in 1000 births. Chiari malformations are found incidentally during unrelated imaging tests.
Chiari II commonly linked to myelomeningocele and neural tube defects.
Chiari malformation is increasingly identified with prevalence rates of 0.1-0.5% and female predominance.
In a 14-year study in USA, 34% of Chiari I decompression surgeries were conducted on patients under 20 years old.
Decompression surgery rates rose 51% in younger patients and 28% in adults during the study period.
Symptoms of Chiari I arise from three consequences: medulla and spinal cord compression, cerebellum compression, and disrupted CSF flow through the foramen magnum.
Cord compression causes myelopathy and dysfunction of lower cranial nerves.
Disordered CSF flow at foramen magnum may cause syringomyelia and central cord symptoms.
Symptoms are asymmetrical as a syrinx tends to develop on the spinal cord side affected by tonsillar ectopia.
Chiari II symptoms worsen with shunt malfunction due to exacerbated hydrocephalus and nerve stretching.
Chiari type I is hypothesized to originate from para-axial mesoderm forms a small posterior fossa.
Cerebellum development causes posterior fossa overcrowding, cerebellar tonsil herniation, and foramen magnum impaction.
Chiari II malformation linked to myelomeningocele in embryogenesis theories.
Fluid escape through the open placode in myelomeningocele may impair skull base mesenchymal condensation.
Fluid loss causes ventricular system to collapse agenesis of corpus callosum and massa intermedia enlargement.
Earlier onset in infants may causes severe symptoms, while late-onset cases have better outcomes.
Severe headaches, syringomyelia, balance issues, or neurological deficits signal a worse prognosis than mild symptoms.
Surgical intervention usually enhances recovery, but individual outcomes and prognosis can differ significantly.
Greater tonsillar herniation correlates with severity and poorer outcomes.
Collect details including initial symptoms, mechanism of injury, and medical history to understand clinical history of patient.
Neurological Examination
Spine Examination
Respiratory Assessment
Cerebellar Function
Acute symptoms are:
Acute dysphagia, dysarthria, difficulty breathing, severe headache, nausea, vomiting, lethargy
Chronic symptoms are:
Paresthesias, loss of pain, weakness in the upper limbs, ataxia, gait disturbance, progressive clumsiness
Hydrocephalus
Dandy-Walker Malformation
Intracranial Hypotension
Multiple Sclerosis
Occipital Neuralgia
A review of symptomatic patients showed headache and nausea improved, while ataxia and sensory disturbances did not improve.
Surgical treatment aims to decompress cervicomedullary junction and restore normal CSF flow.
Clinical series support extensive posterior fossa craniectomy, suboccipital craniectomy, C1 posterior arch removal, and duraplasty for cerebellar decompression.
During follow-up, 20 of 48 nonsurgical and 18 of 24 surgical symptomatic patients improved symptomatically.
Two conservative group patients with syrinx showed no resolution, while 14 of 16 surgically treated patients demonstrated improvement or complete resolution.
Neurosurgery
Use lumbar-support chairs and adjust desk height for neck and back strain relief.
Position screens at eye level and take short breaks to prevent pain and stiffness.
Use orthopedic mattresses and pillows for better breathing and spinal alignment.
Install in showers and near toilets to prevent falls from dizziness.
Proper awareness about Chiari malformation should be provided and its related causes with management strategies.
Appointments with a surgeon and preventing recurrence of disorder is an ongoing life-long effort.
Neurosurgery
Ibuprofen:
It inhibits prostaglandin synthesis to block COX-1 and COX-2 enzymes.
Neurosurgery
Propranolol:
It is nonselective beta-adrenergic receptor helps to decrease heart rate.
Neurosurgery
Sumatriptan:
It is associated with antidromic neuronal transmission to relief migraine headache.
Neurosurgery
Clinical series recommend posterior fossa craniectomy including suboccipital craniectomy and C1 posterior arch removal for cerebellar decompression and duraplasty.
Neurosurgery
In the acute diagnosis phase, evaluate the severity and nature of headaches, neurological deficits, and other associated symptoms.
Pharmacologic therapy is effective in the treatment phase as it includes the use of NSAID’S, beta blockers, and triptans.
In supportive care and management phase, patients should receive required attention such as lifestyle modification and surgical interventional therapies.
The regular follow-up visits with the surgeon are scheduled to check the improvement of patients along with treatment response.
Chiari malformations (I-IV) are congenital hindbrain abnormalities affects cerebellum, brainstem, cervical cord, and cranial base structures.
Cleland identified Chiari malformation in 1883 thus it is named after Austrian pathologist Hans Chiari.
The four Chiari malformation types may not represent a single disease continuum. Types III and IV have distinct pathogenesis and share little beyond their names.
Chiari type I malformation is the most common and the least severe of the spectrum while Chiari type II malformation is less common and more severe.
Conservative treatment is possible for asymptomatic Chiari I malformation patients. MRI is the best imaging study for Chiari malformation.
Other useful tests include myelography for MRI-ineligible patients, and CT or X-rays of the neck and head for bony defects.
Surgical treatment aims to decompress cervicomedullary junction and restore normal CSF flow.
Chiari decompression complications include pseudo meningocele, CSF leakage, and higher concussion risk for patients.
Chiari malformation type I occurs in 1 in 1000 births. Chiari malformations are found incidentally during unrelated imaging tests.
Chiari II commonly linked to myelomeningocele and neural tube defects.
Chiari malformation is increasingly identified with prevalence rates of 0.1-0.5% and female predominance.
In a 14-year study in USA, 34% of Chiari I decompression surgeries were conducted on patients under 20 years old.
Decompression surgery rates rose 51% in younger patients and 28% in adults during the study period.
Symptoms of Chiari I arise from three consequences: medulla and spinal cord compression, cerebellum compression, and disrupted CSF flow through the foramen magnum.
Cord compression causes myelopathy and dysfunction of lower cranial nerves.
Disordered CSF flow at foramen magnum may cause syringomyelia and central cord symptoms.
Symptoms are asymmetrical as a syrinx tends to develop on the spinal cord side affected by tonsillar ectopia.
Chiari II symptoms worsen with shunt malfunction due to exacerbated hydrocephalus and nerve stretching.
Chiari type I is hypothesized to originate from para-axial mesoderm forms a small posterior fossa.
Cerebellum development causes posterior fossa overcrowding, cerebellar tonsil herniation, and foramen magnum impaction.
Chiari II malformation linked to myelomeningocele in embryogenesis theories.
Fluid escape through the open placode in myelomeningocele may impair skull base mesenchymal condensation.
Fluid loss causes ventricular system to collapse agenesis of corpus callosum and massa intermedia enlargement.
Earlier onset in infants may causes severe symptoms, while late-onset cases have better outcomes.
Severe headaches, syringomyelia, balance issues, or neurological deficits signal a worse prognosis than mild symptoms.
Surgical intervention usually enhances recovery, but individual outcomes and prognosis can differ significantly.
Greater tonsillar herniation correlates with severity and poorer outcomes.
Collect details including initial symptoms, mechanism of injury, and medical history to understand clinical history of patient.
Neurological Examination
Spine Examination
Respiratory Assessment
Cerebellar Function
Acute symptoms are:
Acute dysphagia, dysarthria, difficulty breathing, severe headache, nausea, vomiting, lethargy
Chronic symptoms are:
Paresthesias, loss of pain, weakness in the upper limbs, ataxia, gait disturbance, progressive clumsiness
Hydrocephalus
Dandy-Walker Malformation
Intracranial Hypotension
Multiple Sclerosis
Occipital Neuralgia
A review of symptomatic patients showed headache and nausea improved, while ataxia and sensory disturbances did not improve.
Surgical treatment aims to decompress cervicomedullary junction and restore normal CSF flow.
Clinical series support extensive posterior fossa craniectomy, suboccipital craniectomy, C1 posterior arch removal, and duraplasty for cerebellar decompression.
During follow-up, 20 of 48 nonsurgical and 18 of 24 surgical symptomatic patients improved symptomatically.
Two conservative group patients with syrinx showed no resolution, while 14 of 16 surgically treated patients demonstrated improvement or complete resolution.
Neurosurgery
Use lumbar-support chairs and adjust desk height for neck and back strain relief.
Position screens at eye level and take short breaks to prevent pain and stiffness.
Use orthopedic mattresses and pillows for better breathing and spinal alignment.
Install in showers and near toilets to prevent falls from dizziness.
Proper awareness about Chiari malformation should be provided and its related causes with management strategies.
Appointments with a surgeon and preventing recurrence of disorder is an ongoing life-long effort.
Neurosurgery
Ibuprofen:
It inhibits prostaglandin synthesis to block COX-1 and COX-2 enzymes.
Neurosurgery
Propranolol:
It is nonselective beta-adrenergic receptor helps to decrease heart rate.
Neurosurgery
Sumatriptan:
It is associated with antidromic neuronal transmission to relief migraine headache.
Neurosurgery
Clinical series recommend posterior fossa craniectomy including suboccipital craniectomy and C1 posterior arch removal for cerebellar decompression and duraplasty.
Neurosurgery
In the acute diagnosis phase, evaluate the severity and nature of headaches, neurological deficits, and other associated symptoms.
Pharmacologic therapy is effective in the treatment phase as it includes the use of NSAID’S, beta blockers, and triptans.
In supportive care and management phase, patients should receive required attention such as lifestyle modification and surgical interventional therapies.
The regular follow-up visits with the surgeon are scheduled to check the improvement of patients along with treatment response.
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