Clinically rare: spontaneous spinal epidural hematoma

Spontaneous spinal epidural hematoma (SSEH) is a condition
of unknown etiology characterized by acute onset of neck or back pain and rapidly progressive nerve root or spinal cord compression.

Clinically rare, with a prevalence of about 1
in 1 million.
However, most patients progress rapidly and sometimes require emergency surgery to decompress
.

Due to the lack of population-based epidemiological survey data on SSEH, clinicians have a serious lack of understanding of the disease, and it is easy to miss the best treatment time, leaving patients with neurological dysfunction that is difficult to recover, such as paralysis
.

Clinical features

SSEH is more common in the cervicothoracic and thoracolumbar segments, and is slightly more common in males than females because the ventral and vertebral bodies of the dura are tight
.
Epidural hematomas mostly occur on the dorsal side, typically manifested as sudden back tingling, with symptoms of spinal cord or nerve compression, followed by varying degrees of motor and/or sensory impairment below the painful site, and severe cases can develop into total paralysis
.
There are also a small number of patients who do not have the typical symptoms described above, such as Brown-Sequard syndrome
.
SSEH generally develops rapidly, with severe spinal cord or neurologic deficits
occurring within hours or days.

Diagnosis

MRI of the spine is
preferred for definitive diagnosis.
MRI sagittal hematomas show crescent-shaped, long-banded, or fusiform abnormal signals
.
The limited ones are convex lens-shaped, with a wide base and a clear
realm.
The transection is crescent-shaped around the dorsal or ventral side of the dura and can involve several vertebral bodies
.
Young people are often located in the cervicothoracic segment; Older people are often located on and below
the lower thoracic segment.

Typical SSEH has the characteristics of various stages of hematoma and is not difficult to
diagnose.
Its signal evolution is roughly divided into 4 stages on MRI:

A small number of cases are mixed because in the hematoma of the same patient, there are different periods of bleeding mixed, often dominated by signals of one stage, mixed with signals of other stages, so that the signals are mixed and difficult to identify
.
On the basis of grasping the characteristics of SSEH hematoma in each stage, combined with the bleeding time of the patient, especially the time of symptom aggravation or recurrence, it is very helpful
to identify mixed signals.

Figure: C5-7 Dorsal dorsal dorsal hematoma (arrowhead)

Figure: C2-L1 dural ventral hematoma

Figure: T8-L5 dorsal dural hematoma (arrowhead)

Figure: C2-T8 ventral hematoma of the dura (arrowhead)

Figure: Dorsal hematoma of the C3-T2 dura
.
E and F are conservative treatment for 1 week, the hematoma is absorbed
.

Figure: C2-C6 dorsal dural hematoma with Brown-Sequard syndrome

In addition, SSEH hematomas are generally unenhanced, which is an important sign
that distinguishes them from tumors.
In the subacute and chronic phases, the hematoma wall may be strengthened in a ring, while the tumor is strengthened
by the entire tumor.

Some scholars suggest that SSEH routinely perform DSA to exclude vascular malformations or hemangiomas, however, the literature on SSEH caused by vascular malformation rupture accounts for less than 7% of all SSEH-related reports, and DSA is an invasive examination, which can also delay the timing
of surgery.
All things considered, this invasive test is only meaningful
if MRI shows a high probability of vascular malformations.

Meta-analysis

Due to the clinical rarity of SSEH, most of the literature at home and abroad appears in the form of case reports, and there is still a lack of analysis of large cases, and it is difficult to systematically summarize its risk factors and prognostic correlation
。 A recent systematic review of inpidual patient data (IPD) meta-analysis found that as of September 1, 2014, excluding cases of pregnancy, hemophilia, and conservative treatment, a total of 487 journal articles reported 741 cases of SSEH alone, and then excluded incomplete cases, and finally 617 surgical SSEH cases were included in the study
.
It is a relatively large sample size and published in the journal Neurology with high impact factors, and the conclusions are relatively reliable
.

It turned out that:

Treatment

At present, most scholars advocate early laminar decompression and hematoma removal in order to obtain neurological recovery
.
Some scholars even believe that surgical treatment is the preferred treatment method
for patients with SSEH.
However, some scholars have successively reported cases of conservative treatment of SSEH, and most of them have obtained satisfactory results
.

The principle of conservative treatment, some cases may have early improvement in nerve function and hematoma absorption
.
Possible mechanisms are "hematoma spread" and "hematoma leakage"
.
The former refers to the spread of the hematoma along the epidural space to "self-decompression", and the latter refers to the hematoma that can partially leak out of the intervertebral foramen, thereby reducing the pressure in the spinal canal and reducing spinal cord and nerve compression
.

Therefore, some scholars have summarized the following situations, which can be treated conservatively:

Conservative treatment strategies include:

Recently, the team of Zhu Tao, Department of Neurosurgery, Tianjin Medical University General Hospital, summarized the case data of 42 SSEH patients (relatively large number of cases) and found that patients with SSEH graded as A, B, C or with progressive neurological dysfunction should be treated with surgery as soon as possible; Conservative treatment
is an option for patients with ASIA grading D or E, or who have a tendency to improve neurological function in the short term.
The higher the preoperative ASIA grade and the shorter the time interval from onset to surgery, the better
the prognosis.
The higher the grade of ASIA before treatment in patients who are treated conservatively, the better the prognosis
.
The conservative treatment group lasted 3~19 days from discovery to complete hematoma absorption, with an average of 13.
3 days
.
At the same time, it is also pointed out that in terms of surgical methods, most scholars currently believe that decompression of the lamina can achieve a good prognosis, but there are different
views on whether the vertebral body is fused and fixed, and whether the lamina is still accepted.