Original Chiari III description: Upper cervical dysraphism with protruding encephalocele containing herniated hindbrain
Sincipital/Frontoethmoidal: 15% (↑ in southeast Asia)
Nasoethmoidal: Most common form; defect between nasal bone & nasal cartilage
Nasofrontal: Defect between frontal & nasal bones
Nasoorbital: Least common form; defect at junction of maxilla (anterior) & lacrimal bone with lamina papyracea of ethmoid bone (posterior)
Parietal: 10% (↑ in Japan at 38%)
Atretic parietal cephaloceles most common
Midline posterior parietal scalp mass over small bony defect; triangular elevation of falx/tentorial junction; persistent falcine venous sinus; fibrous tract splits superior sagittal sinus
Majority have benign clinical course
Parietal meningoencephaloceles uncommon
Usually associated with significant brain anomalies → poor prognosis
Basal/Nasopharyngeal: Up to 10% of cases
Transethmoidal
Transsphenoidal/sphenopharyngeal
Sphenoethmoidal
Sphenomaxillary
Frontosphenoidal/sphenoorbital
Remaining calvarium: Rare
Interfrontal
Interparietal
Anterior fontanelle
Posterior fontanelle
Temporal (lateral)
Mastoid &/or petrous temporal bone: Rare
Cavum trigeminale: Rare
IMAGING
General Features
CT Findings
MR Findings
Ultrasonographic Findings
Imaging Recommendations
DIFFERENTIAL DIAGNOSIS
PATHOLOGY
General Features
Gross Pathologic & Surgical Features
CLINICAL ISSUES
Presentation
Demographics
Natural History & Prognosis
Treatment
DIAGNOSTIC CHECKLIST
Consider
Reporting Tips
Selected References
Boppel T et al: Excavating Meckel's cave: Cavum-trigeminale-cephaloceles (CTCs). J Neuroradiol. 42(3):156-61, 2015
Morone PJ et al: Temporal lobe encephaloceles: a potentially Curable Cause of Seizures. Otol Neurotol. 36(8):1439-42, 2015
Copp AJ et al: Neural tube defects: recent advances, unsolved questions, and controversies. Lancet Neurol. 12(8):799-810, 2013
Tirumandas M et al: Nasal encephaloceles: a review of etiology, pathophysiology, clinical presentations, diagnosis, treatment, and complications. Childs Nerv Syst. 29(5):739-44, 2013
Barkovich et al:a Pediatric Neuroimaging: 5th edition. Lippincott Williams & Wilkins: Philadelphia. 501-21, 2012
Bui CJ et al: Institutional experience with cranial vault encephaloceles. J Neurosurg. 107(1 Suppl):22-5, 2007
Original Chiari III description: Upper cervical dysraphism with protruding encephalocele containing herniated hindbrain
Sincipital/Frontoethmoidal: 15% (↑ in southeast Asia)
Nasoethmoidal: Most common form; defect between nasal bone & nasal cartilage
Nasofrontal: Defect between frontal & nasal bones
Nasoorbital: Least common form; defect at junction of maxilla (anterior) & lacrimal bone with lamina papyracea of ethmoid bone (posterior)
Parietal: 10% (↑ in Japan at 38%)
Atretic parietal cephaloceles most common
Midline posterior parietal scalp mass over small bony defect; triangular elevation of falx/tentorial junction; persistent falcine venous sinus; fibrous tract splits superior sagittal sinus
Majority have benign clinical course
Parietal meningoencephaloceles uncommon
Usually associated with significant brain anomalies → poor prognosis
Basal/Nasopharyngeal: Up to 10% of cases
Transethmoidal
Transsphenoidal/sphenopharyngeal
Sphenoethmoidal
Sphenomaxillary
Frontosphenoidal/sphenoorbital
Remaining calvarium: Rare
Interfrontal
Interparietal
Anterior fontanelle
Posterior fontanelle
Temporal (lateral)
Mastoid &/or petrous temporal bone: Rare
Cavum trigeminale: Rare
IMAGING
General Features
CT Findings
MR Findings
Ultrasonographic Findings
Imaging Recommendations
DIFFERENTIAL DIAGNOSIS
PATHOLOGY
General Features
Gross Pathologic & Surgical Features
CLINICAL ISSUES
Presentation
Demographics
Natural History & Prognosis
Treatment
DIAGNOSTIC CHECKLIST
Consider
Reporting Tips
Selected References
Boppel T et al: Excavating Meckel's cave: Cavum-trigeminale-cephaloceles (CTCs). J Neuroradiol. 42(3):156-61, 2015
Morone PJ et al: Temporal lobe encephaloceles: a potentially Curable Cause of Seizures. Otol Neurotol. 36(8):1439-42, 2015
Copp AJ et al: Neural tube defects: recent advances, unsolved questions, and controversies. Lancet Neurol. 12(8):799-810, 2013
Tirumandas M et al: Nasal encephaloceles: a review of etiology, pathophysiology, clinical presentations, diagnosis, treatment, and complications. Childs Nerv Syst. 29(5):739-44, 2013
Barkovich et al:a Pediatric Neuroimaging: 5th edition. Lippincott Williams & Wilkins: Philadelphia. 501-21, 2012
Bui CJ et al: Institutional experience with cranial vault encephaloceles. J Neurosurg. 107(1 Suppl):22-5, 2007