Orbital meninges-encephalocele
Introduction
Eyelid meninges - brain swelling Orbitalmeningoencephalocele is a congenital abnormality caused by intracranial structure through the bone defect into the sputum. The simple meningeal sputum contains cerebrospinal fluid and forms a cystic mass called meningocele. The meninges are accompanied by the brain membrane-brain bulging of brain tissue. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: eyeballs
Cause
Eyelid meninges - the cause of brain swelling
(1) Causes of the disease
The defect of the tibia caused by various reasons, the meninges of the eyelids and the bulging of the brain are a congenital malformation of the failure of the formation of the iliac crest during the embryonic period. How the bone defect is formed is not consistent. Pollock is a comprehensive hypothesis:
1 The closure of the sieve plate around the olfactory nerve failed;
2 increased ventricular pressure during embryonic period, driving brain tissue to bulge;
3 neuroectodermal leaves are incompletely separated;
4 residual craniopharynx, sphenoid dysplasia;
5 skeletal ossification center development failure, etc., in which the neuroectodermal leaf insufficiency and ossification failure are accepted by most scholars, in addition, intracranial or intraorbital inflammation and tumor erosion, trauma and surgery caused by the loss of the tibia can also continue Meninges - brain swelling.
(two) pathogenesis
In the early stage of normal embryos, the neuroectodermal leaves are separated from the surface ectoderm and finally developed into the nervous system. If the adhesion is incomplete due to adhesion, the bone formation between the two occurs, and the residual bone hole, intracranial and extracranial brain tissue passes through the hole. Connected, in this case, the brain bulges in the front, the bone hole is formed in the posterior, and the ossification is thought to be in the late stage of the embryo. For some reason, the ossification or bone fusion is incomplete, and the hole of the orbital eyelid is cracked (optical nerve hole, sacral Fissure, posterior stenosis, etc.) enlargement, or sacral wall dysplasia, due to higher intracranial pressure, driving the meninges, brain tissue into the sputum, in this case the bone defect is in front, the brain bulges in the posterior, from the clinical perspective The anterior cerebral bulge is suitable for the neuroectodermal detachment theory, and the posterior bulge is suitable for the ossification failure theory.
Prevention
Eyelid meninges - brain swelling prevention
Give your child adequate nutrition and pay more attention to your child's living habits.
Complication
Eyelid meninges - cerebral bulging complications Complications
Congenital meninges-brain bulging can be associated with other developmental abnormalities.
Symptom
Eyelid meninges - brain swelling symptoms common symptoms
Meningeal-brain bulging has formed during the embryonic period and often manifests symptoms and signs during childhood or youth.
Anterior type: also known as nasal type, skull defect or unclosed part between the frontal bone, ethmoid bone, lacrimal bone and maxilla, ie the front part of the inner wall of the iliac crest, the bulge is derived from the meninges of the anterior cranial fossa and Brain tissue, which appears in the internal iliac crest, can develop into large masses.
Posterior type: also known as pterygium type, skull defect or unclosed part in the optic nerve hole or sacral fissure, bulge from the middle cranial fossa, appearing in the sputum, due to eyeball limitation, generally not large, but can produce Pulsatile eyeballs stand out.
There are 3 different degrees of bulging, the lighter only the meninges and their middle cerebrospinal fluid, called meningocele; the heavier brain tissue also bulges together, called meningeal bulging; the heaviest ventricle anterior horn also bulges Extracranial, called ventricle-brain bulging, the outer layer of the anterior tibial type is the skin, followed by the subcutaneous tissue, the dura mater, containing the cerebrospinal fluid, and the posterior tibial layer is the dura mater, embedded in the fat of the sputum. Histopathological examination revealed that the bulged brain tissue is mature, and there is a thin layer of meninges. There is a cystic space between the brain tissue and the meninges. After long-term lesions, the brain tissue is variably, and the meninges covering it are reduced. A string of compressed tissue with a small calcium ball.
Examine
Eyelid meninges - examination of brain swelling
No special laboratory tests.
1. The X-ray of the anterior bulge of the X-ray is generally difficult to show. When the outer wall of the iliac crest and the dome are missing, the X-ray of the orbital ridge is a low-density or "cavity sign".
2. Ultrasound ultrasound generally can not show the intracranial condition due to the attenuation of the acoustic energy of the dura mater. It can only show the soft tissue deformation (B-ultrasound) and the posterior high-reflection (A-super) after the ball, and the real-time scan can show the ball. Tissue pulsation, due to the significant attenuation of sound energy by brain tissue, ultrasound can show multiple repetitive waves after the ball.
3.CT Due to the CT volume problem, the horizontal axis CT is difficult to display the location of the bone loss. Unless the bone loss is large, the coronary CT generally shows good, and the large area of the sphenoid horn has a good CT and X-ray. It can be seen that the brain tissue is invaded into the iliac crest. Because the degree of dysplasia of the apex and the outer wall is different, especially when the area is large, the coronary CT can show similar lesions in the anterior segment during the anterior scan, which is easy to be misdiagnosed.
4. MRI showed that the bulged brain tissue was continuous with the intracranial brain tissue. The intrathoracic cerebrospinal fluid T1WI was low signal and T2WI was high signal.
Diagnosis
Diagnosis of eyelid meninges-brain bulging
1. Typical clinical signs and symptoms.
2. Auxiliary examination performance X-ray examination in the anterior meninges-brain bulging, the photographic position using the mouth position 45 ° anterior position, can be found in the sieve plate bone defect, the posterior bulge in the anterior X-ray film after 20 °, visible The anterior cranial fossa is small, the cranial fossa is large, the sphenoid bone is large, the small wing bone is missing or the bone tube, the bone hole, the bone fracture is enlarged, the ultrasound examination shows the pulsatile cystic mass, compressible, and the CT scan shows the bone loss and lower Or high-density block shadow, suction can extract clear liquid, routine and biochemical analysis confirmed cerebrospinal fluid, lumbar puncture injection pigmentation, intracerebral spinal fluid staining in the mass, gas injection into the orbital mass, X-ray plain film visible intracranial air bubbles, above All examinations indicated the intratumoral mass and intracranial communication.
The anterior meningeal bulge needs to be differentiated from the lacrimal sac cyst: the former spontaneously vibrates and has a positionality, and the bone hole can be found by X-ray and CT.
