Objective】：To investigate the diagnosis and surgical treatment of epidural cysts.
METHODS]: We retrospectively analyzed four cases in this group, all of which were treated surgically, and evaluated the clinical results, their clinical manifestations, pathogenesis, imaging data, and surgical points.
Results]: All four patients obtained satisfactory recovery of motor and sensory disorders after surgery without any complications.
Conclusion】：The diagnosis could be confirmed according to clinical manifestations and imaging features combined with postoperative pathological examination, and surgical excision of the cyst was an effective treatment method.
Keywords】：Epidural cyst, diagnosis, surgical procedure
The epidural cyst is a rare clinical intravertebral mass with mild and atypical early symptoms. 4 such patients were admitted to our hospital from February 1996 to May 2005, accounting for 3-4% of the intravertebral tumors treated by surgery during the same period.
1. [Clinical data
1.1 General information
There are 4 cases in this group, 3 male cases and 1 female case, age 15-60 years old, average age 32 years old, disease duration 4 months to 7 years, average 3 years.
The average duration of the disease was 3 years, with 1 case in the thoracic segment, 2 cases in the thoracolumbar segment and 1 case in the sacrococcygeal segment.
1. 2 Clinical manifestations
Among the 4 cases in this group, there were 3 cases of lumbar and leg pain with numbness and weakness of both lower limbs, 1 case of lumbosacral pain, 1 case of urinary and defecation disorder.
2 cases with pathological signs.
1.3 Preoperative examination
X-ray examination was performed in all cases, vertebrogram in 2 cases, and MRIA in 3 cases. Two cases were combined with occult spina bifida.
The MRI examination showed extra-medullary occupying lesions in the spinal canal, and the T1-weighted image was low signal.
The T1-weighted image was low signal, and the T2-weighted image was high signal. The signal and cerebrospinal fluid were similar with clear borders, and the spinal canal of the lesion was enlarged.
1.4 Surgery and results
All four cases were treated surgically, and intraoperative thinning of the vertebral plate, enlargement of the spinal canal and reduction of epidural fat were seen. Thoracic
In the two cases of lumbar segment, the cysts were large, involving three vertebral segments, easily separated from the dura mater, and no obvious spinal fissure was seen.
In one case, the cysts in the thoracic segment were adherent to the dura mater at both ends and were removed completely without
The dural fissure was not found. In one case located in the sacral region, a tubular connection was seen at 1.5 cm from the terminal of the dural sac, which was connected to the subarachnoid space.
In one case located in the sacral region, a tubular connection was found 1.5 cm above the end of the dural sac, which was connected to the subarachnoid space. The postoperative pathological examination showed that the wall of the sac was dense connective tissue, and the sac
In three cases, the protein content of the fluid was high, but the other components were the same as those of cerebrospinal fluid.
All four cases recovered normal sensory and motor disorders without any complications.
2. [Discussion].
Epidural cysts are rare clinically and can occur at any age, with the youngest in the literature being a few months after birth and the oldest at 67 years.
It is common in adolescents aged 11-20 years, accounting for more than 50%, and slightly more in males (1, 2, 3). From the four cases in this group and the relevant literature, the authors
The authors’ experience from this group of 4 cases and the relevant literature is as follows.
The cause of epidural cysts is not yet clear and may be due to congenital spinal diverticula or congenital herniation through the dura
The cause of epidural cysts is not known, but may be due to congenital spinal diverticula or congenital herniation of the arachnoid membrane through a congenital defect in the dura mater, which gradually increases in size under the influence of hydrostatic pressure and cerebrospinal pulsation. In a small number of cases, the herniation is due to trauma.
This is an acquired condition with slow progression, early symptoms and lack of specificity.
This is an acquired condition with slow progression, early symptoms and lack of specific signs and symptoms, which makes it easy to miss and misdiagnose the disease, and the diagnosis rate is very low before MRI is performed(4) .
The clinical manifestations of the disease vary depending on the location of the cyst, while those in the cervicothoracic region may cause spastic paralysis of both lower limbs, and those in the lumbosacral region may present with lower motor neurogenesis.
The clinical manifestations of the disease vary depending on the location of the cyst, with spastic paralysis of both lower limbs in the cervicothoracic region and lower motor neurogenic damage in the lumbosacral region. In general, sensory disturbances, especially superficial sensory disturbances, are mild. Sphincter
The sphincter dysfunction occurs in the later stages.
Imaging: Radiographs often show significant changes, such as unilateral or bilateral atrophy of the vertebral arches. The spacing between the vertebral arches is widened.
MRI can understand the relationship between the cyst and spinal cord and cauda equina in detail, which can help early and
MRI can help to diagnose the disease accurately and make a correct assessment of the extent of spinal cord and cauda equina injury and its healing process, and provide guidance for surgery.
The presentation of MRI is characteristic: an epidural cystic mass in the spinal canal with low signal in T1 and high signal in T2, signal
Similar to cerebrospinal fluid, with clear borders, spinal cord and dural compression, anteriorly or slightly to one side.
The following manifestations suggest the possibility of this disease: adolescents with symptoms of mid-thoracic spinal cord compression, lower extremity motor deficits
The possibility of this disease is often considered through the use of a combination of other congenital deformities, especially thoracic kyphosis.
The possibility of this disease is mostly considered, and the diagnosis can be clarified by MRI examination.
Surgical excision of the cyst is the most effective treatment for epidural cysts, and the tip of the cyst needs to be removed during surgery to avoid recurrence of the cyst.
In a few cases, the cysts are multiple and need to be removed one by one. The authors experienced that, according to the MRIA shown, with
The cyst should be entered at the largest diameter and the lamina should be removed as little as possible to avoid affecting the stability of the spine. The relationship between the cyst and the nerve root and dura mater should be clarified during surgery.
The relationship between the cyst and the nerve root and dura mater should be clarified during surgery, and the cyst should be carefully separated to the neck, ligated at a high level, and the cyst and the tip should be completely removed. If the cyst
If the cyst is tightly adhered to the nerve root or dura mater, it is not necessary to force a complete excision of the cyst, but only to fully excise its back wall to achieve the purpose of treatment.
If the nerve root or cauda equina adhesion in the cyst makes cyst excision difficult, it can be operated under microscope and supplemented with
If the nerve roots inside the cyst or the adhesions with the cauda equina make the cyst removal difficult, the operation can be performed under the microscope and supplemented with neurophysiological monitoring to avoid damaging the nerves and cauda equina. The cyst can also be incised and the cyst wall tightly overlapped and sutured to achieve decompression of the
The nerve root is decompressed. The dura should be sutured strictly, and in case of combined spina bifida and large local defect after cyst excision, the dura may be filled with muscle to reduce the cerebrospinal fluid.
muscle filling to reduce complications such as cerebrospinal fluid leakage and infection. (5) Mik(6) A believes that the disease can generally be cured by surgical treatment
The key to a good postoperative recovery is: early diagnosis, early surgical treatment, and avoidance of irreversible damage to the spinal cord and cauda equina.