sincipital encephaloceles , also called frontal or anterior encephaloceles , are rare neural tube defects and are more common in south and southeast asian populations . in children with sincipital encephaloceles
there are often significant associated intracranial anomalies , including intracranial cysts , complete / partial corpus callosal agenesis , interhemispheric lipomas , facial clefts , and migrational anomalies .
occipital encephaloceles may be associated with chiari or dandy - walker malformations and callosal or migrational anomalies .
it is reported that younger siblings of patients affected with encephaloceles have up to 6% risk of a congenital central nervous system abnormality .
after approval from the institutional ethics review committee , a hospital - based cross - sectional study was conducted over 8 years from june 2007 to may 2015 on 28 patients in the departments of radiodiagnosis and pediatric surgery in a tertiary care hospital . the study comprised of outpatients and in patients , of both sexes presenting with sincipital encephaloceles .
patients were only allowed plain water preceding the imaging so as to keep the patient ready for sedation / anesthesia if needed .
the patients were evaluated by either computed tomography ( ct ) or magnetic resonance imaging ( mri ) whichever was feasible .
the ct scanner used in this study was siemens somatom spirit dual slice ct scanner ( siemens healthcare , erlangen , germany ) .
unenhanced ct scans of head and faciomaxillary region were obtained in all patients . scanning parameters used were spiral mode with slice thickness of 6 mm and collimation 6 mm  2.5 mm , pitch : 1.4 ; kvp : 130 ; mas : 80 .
mri imaging was performed with a 1.5-t superconducting magnet system 1.5 tesla siemens magnetom avanto b15 system ( siemens healthcare , erlangen , germany ) using a transmit / receive body coil with a 15-mt / m gradient .
the imaging parameters were t1 , t2 , and fluid - attenuated inversion recovery ( flair ) sequences obtained in all three planes : axial , coronal and sagittal .
parameters for t1-wi ( t1-weighted image ) : 400600/15 ( repetition time ms / echo time ms ) , 220240-mm field of view , 256  192 matrix , and slice thickness of 5 mm with a gap of 1 mm .
parameters for t2-wi : 3200/428 ( repetition time ms / echo time ms ) , 256-mm field of view , 256  256 matrix , and slice thickness of 5 mm with a gap of 1 mm .
parameters for flair : 10,000/70130 ( repetition time ms / echo time ms ) , 240-mm field of view , 256  192 matrix , and slice thickness of 5 mm with a gap of 1 mm .
the areas of interest in the study were type of encephalocele , its contents , extracranial extension and effect on adjacent structures and to look for associated brain malformations .
after approval from the institutional ethics review committee , a hospital - based cross - sectional study was conducted over 8 years from june 2007 to may 2015 on 28 patients in the departments of radiodiagnosis and pediatric surgery in a tertiary care hospital . the study comprised of outpatients and in patients , of both sexes presenting with sincipital encephaloceles .
patients were only allowed plain water preceding the imaging so as to keep the patient ready for sedation / anesthesia if needed .
the patients were evaluated by either computed tomography ( ct ) or magnetic resonance imaging ( mri ) whichever was feasible .
the ct scanner used in this study was siemens somatom spirit dual slice ct scanner ( siemens healthcare , erlangen , germany ) .
scanning parameters used were spiral mode with slice thickness of 6 mm and collimation 6 mm  2.5 mm , pitch : 1.4 ; kvp : 130 ; mas : 80 .
mri imaging was performed with a 1.5-t superconducting magnet system 1.5 tesla siemens magnetom avanto b15 system ( siemens healthcare , erlangen , germany ) using a transmit / receive body coil with a 15-mt / m gradient .
the imaging parameters were t1 , t2 , and fluid - attenuated inversion recovery ( flair ) sequences obtained in all three planes : axial , coronal and sagittal .
parameters for t1-wi ( t1-weighted image ) : 400600/15 ( repetition time ms / echo time ms ) , 220240-mm field of view , 256  192 matrix , and slice thickness of 5 mm with a gap of 1 mm .
parameters for t2-wi : 3200/428 ( repetition time ms / echo time ms ) , 256-mm field of view , 256  256 matrix , and slice thickness of 5 mm with a gap of 1 mm .
parameters for flair : 10,000/70130 ( repetition time ms / echo time ms ) , 240-mm field of view , 256  192 matrix , and slice thickness of 5 mm with a gap of 1 mm .
the areas of interest in the study were type of encephalocele , its contents , extracranial extension and effect on adjacent structures and to look for associated brain malformations .
fifty percent of the patients presented before the age of 3 years , with the youngest presenting on day 7 .
rest of the patients ( 42% ) presented between 3 and 10 years of age .
our study did not show any gender predominance , with both males and females being affected equally .
nasofrontal encephalocele was the most common type , seen in 13 ( 46.4% ) patients .
the naso - orbital and the combined type were the least common with 4 ( 14.2% ) patients each .
two patients had evidence of herniation of lateral ventricle along with brain tissue through the cranium into the encephalocele sac [ table 1 ] .
type of sincipital encephaloceles corpus callosal agenesis with colpocephaly was the most common associated malformation in our study [ table 2 ] .
6/10 archnoid cysts were hemispheric , 4/10 were inter hemispheric and 2/10 were located in posterior fossa .
associated brain malformations seven patients had evidence of hydrocephalus , of which five cases were due to the obstruction by large arachnoid cysts and two cases were due to aqueduct stenosis .
subdural collection was noted in 6 patients . in 4 patients it was subdural csf collection due to hyperfunctioning of shunts and in 2 patients it was blood due to rupture of bridging cortical veins . of these 6 patients , ventriculoperitoneal ( vp ) shunts
were performed in 2 patients and cystoperitoneal shunt in 2 patients with large interhemispheric cysts causing mass effects .
corpus callosal agenesis with colpocephaly was the most common associated malformation in our study [ table 2 ] .
6/10 archnoid cysts were hemispheric , 4/10 were inter hemispheric and 2/10 were located in posterior fossa .
associated brain malformations seven patients had evidence of hydrocephalus , of which five cases were due to the obstruction by large arachnoid cysts and two cases were due to aqueduct stenosis .
subdural collection was noted in 6 patients . in 4 patients it was subdural csf collection due to hyperfunctioning of shunts and in 2 patients it was blood due to rupture of bridging cortical veins . of these 6 patients , ventriculoperitoneal ( vp ) shunts
were performed in 2 patients and cystoperitoneal shunt in 2 patients with large interhemispheric cysts causing mass effects .
encephaloceles occur due to the failure of surface ectoderm to separate from the neuroectoderm , resulting in a bony defect in the cranial and/or facial bones , which allows herniation of meninges or brain tissue .
encephaloceles occur in one of every 4000 live births and have no sex predilection . according to location , these
are occipital ( 75% of cases ) , sincipital ( 15% ) , or basal ( 10% ) .
sincipital encephaloceles involve the mid - face and occur about the dorsum of the nose , orbits , and forehead .
these sincipital encephaloceles are more common in south and southeast asian populations whereas the occipital encephaloceles are more common in the western population .
the sincipital encephaloceles are further subdivided into nasofrontal , nasoethmoidal , and naso - orbital types . the nomenclature used for encephaloceles
is based on the origin of their roof and floor ; thus , for example , the roof and floor of frontonasal encephaloceles are the frontal and nasal bones , respectively
. nasofrontal encephaloceles result from herniation through both the foramen cecum and the fonticulus frontalis and projecting along the nasal bridge between the nasofrontal sutures into the glabella ( nasofrontal region ) .
nasoethmoidal encephaloceles occur when there is persistent herniation through the foramen cecum into the prenasal space and nasal cavity under the nasal bones and above the nasal septum ( nasoethmoidal region ) . moreover , naso - orbital types occur along the medial orbit at the level of the frontal process of the maxilla and the ethmoid - lacrimal bone junction ( naso - orbital region ) .
affected children may present with nasal obstruction , mass in the frontal region , proptosis , or cerebrospinal fluid ( csf ) leaks from ruptured encephalocele sac with recurrent meningitis .
the prognosis for the sincipital encephalocele patients is generally good and is usually associated with normal intelligence and motor development .
surgery is the best treatment option for encephaloceles , and mri is the choice of imaging modality for defining the contents of an encephalocele prior to surgery .
high - resolution ct may also be used to display the bone anatomy , but the intracranial extension is best defined with mri .
the extent of cerebral tissue in an encephalocele is also better defined with mri , which aids in prognosis and surgical planning .
the aim of the radiologist is to precisely define the type of the encephalocele ; delineate the size , contents , extension ; and identify associated anomalies .
there are often significant associated intracranial anomalies , including intracranial cysts , complete / partial corpus callosal agenesis , interhemispheric lipomas , facial clefts , and migration anomalies .
earlier studies postulated theories such as adhesive theory , which suggest failure of mesodermal migration into midline leading to herniation of the brain matter and resulting failure of closure of anterior neuropore . as corpus callosum forms near the site of final closure of anterior neuropore ,
many of these patients have associated corpus callosal agenesis which was also observed in our series . rapport et al . , postulated that this condition may have several etiological factors because mesodermal abnormalities alone can not account for the observed abnormalities .
lemire et al . , thought that anterior encephaloceles result from abnormal dedifferentiation , whereas some other studies suggest neuroectodermal abnormality . from the array of associated malformations that we have observed in our series
the most common associated malformation with sincipital encephaloceles is the agenesis or hypogenesis of the corpus callosum .
corpus callosum is the largest cerebral commissure connecting neocortical areas and develops between 12 and 20 weeks of gestation .
development occurs from front to back with the exception of the rostrum which develops after the splenium .
imaging by ct and mr in complete callosal agenesis reveals widely separated and nonconverging lateral ventricles , disproportionately enlarged occipital horns ( colpocephaly ) , and an elevated third ventricle which is continuous superiorly with the interhemispheric fissure [ figure 1 ] . in sagittal mr studies , corpus callosum , cingulate gyrus , and sulcus are not seen .
gyri on the medial hemispheric surface radiate outward from the high - riding third ventricle . in partial agenesis of corpus callosum , the splenium and rostrum are absent .
3-year - old male child with a swelling at nasal bridge , ( a ) axial computed tomography scan shows a nasofrontal encephalocele ( * ) , ( b and c ) axial computed tomography sections show corpus callosal agenesis as evidenced by parallel running lateral ventricles with colpocephaly ( arrow  in c ) .
they are congenital lesions that occur as a result of the splitting of the arachnoid membrane .
the cysts are extra - axial fluid - filled sacs , which are sharply marginated somewhat scalloped appearing lesions that parallel the csf intensity on all sequences of mri .
some suprasellar cysts become very large [ figures 2 and 3 ] and cause obstructive hydrocephalus .
the arachnoid cysts , particularly the interhemispheric cysts , are usually associated with corpus callosal agenesis .
2-year - old male child with a forehead swelling , ( a ) axial computed tomography bone window shows nasoethmoidal and naso - orbital type of encephalocele ( * ) .
( b ) axial , ( c ) coronal and ( d ) sagittal computed tomography sections show associated large hemispheric arachnoid cyst ( arrow ) .
( b ) axial ct section also reveals the parallel orientation left lateral ventricle ( upward arrow  ) suggestive of corpus callosal agenesis .
2-year - old female child with swelling at nasal bridge , ( a ) sagittal t1-weighted image shows a large interhemispheric arachnoid cyst ( # ) .
( b ) axial t1-weighted image in another patient with nasoethmoidal encephalocele ( * ) shows an arachnoid cyst in right temporal fossa ( arrow ) . in our series , subdural collection
of the six patients four had subdural csf collection and it was thought to be due to hyperfunctioning of the shunts [ figure 4 ] , ( two had been operated with ventriculo - peritonial shunt for obstructive hydrocephalus and in the other two , ventricular catheter of the shunt was placed in the large interhemispheric cysts i.e. cysto - peritoneal shunt which caused mass effects ) .
other two patients had small subdural hematomas probably due to rupture of bridging cortical veins around the herniation . 2-year - old female child with forehead swelling , ( a ) axial computed tomography section shows left subdural collection ( arrow ) in a patient with ventriculoperitoneal shunt .
( b ) axial computed tomography section in another patient with a large arachnoid cyst showing bilateral frontal subdural collection ( arrow ) with calcification of the arachnoid membrane .
agyria - pachygyria complex is a defect in migration of cerebral neurons , resulting in failure of cortical gyri to develop [ figure 5 ] .
the extent , distribution , and detailed structure of agyria - pachygyria vary widely , and the clinical features are accordingly very diverse . rather than one entity , pachygyric cortical abnormalities form a broad spectrum that raises different clinical and genetic problems
. this complex can be of generalized / bilateral or localized / unilateral gyral malformations .
generalized seizures with increased incidence of spastic quadriparesis and microcephaly are associated with the generalized / bilateral type , whereas partial seizures are more common in localized / unilateral gyral malformations and hemiparesis is the most frequent neurologic deficit .
patients with bilateral or generalized gyral anomalies have poor prognosis for outcome of epilepsy and neurologic disability .
the recognition of these lesions with high - resolution techniques of mri is important for planning proper treatment and genetic counseling .
4-year - old child presented with swelling over the nose and seizure , ( a ) axial computed tomography scan shows nasofrontal type of encephalocele ( * ) with mild orbital extension .
( b ) axial computed tomography section also shows agyria and pachygyria complex involving left parietooccipital lobe ( arrow  ) with corpus callosal agenesis .
( c ) higher axial computed tomography section also shows ventriculoperitoneal shunt ( # ) in interhemispheric fissure with left subdural collection ( arrow ) .
we could not perform mri in many cases , which is the investigation of choice due to cost constraints .
we could not perform mri in many cases , which is the investigation of choice due to cost constraints .
encephaloceles are often associated with significant intracranial anomalies , with agenesis of corpus callosum being the most common .
hence , a precise analysis of each case is necessary to recognize the associated malformations and establish the prognosis and risk of recurrence .
 objective : the aim of this study was to evaluate the associated intracranial malformations in patients with sincipital encephaloceles.materials and methods : a hospital - based cross - sectional study was conducted over 8 years from june 2007 to may 2015 on 28 patients . 
 the patients were evaluated by either computed tomography or magnetic resonance imaging whichever was feasible . 
 encephaloceles were described with respect to their types , contents , and extensions . 
 a note was made on the associated malformations with sincipital encephaloceles.results:fifty percent of the patients presented before the age of 3 years and both the sexes were affected equally . 
 nasofrontal encephalocele was the most common type seen in 13 patients ( 46.4% ) , and corpus callosal agenesis ( 12 patients ) was the most common associated malformation . 
 other malformations noted were arachnoid cyst ( 10 patients ) , hydrocephalus ( 7 patients ) , and agyria - pachygyria complex ( 2 patients).conclusion : capital brain malformations are frequently encountered in children with sincipital encephaloceles . 
 detail radiological evaluation is necessary to plan treatment and also to prognosticate such rare malformations . 
INTRODUCTION
MATERIALS AND METHODS
Study group
Patient preparation
Technique of study
Computed tomography
Magnetic resonance imaging
RESULTS
Associated brain malformations
DISCUSSION
Limitation
CONCLUSION
Financial support and sponsorship
Conflicts of interest