Aims and objectives
Spinal arachnoid web (SAW) is a rare entity characterized by a pathological thickening of intradural arachnoid tissue.
It is a relatively recent description and frequently underdiagnosed.
It have an unclear etiology but it´s thought to be caused in many cases by subarachnoid bleeding after spinal trauma or surgery.
The evolution of intrathecal spinal hematoma to haemosiderin and its derivatives may be the cause of arachnoiditis and arachnoid web formation.
Pathologically,
these are one or multiple,
intradural,
extramedullary bands that extend from the posterior pial surface...
Methods and materials
We retrospectively review the last cases of spinal cord deformities done at our institution from August 2014 through September 2018.
The spinal MRI protocol benefits from high field equipment,
to guarantee the highest resolution.
So,
all MRI studies were performed on a new generation 3T MRI scanner (Table1).
Eighteen patients,
including both symptomatics and asymptomatics,
were examined using anatomic sequences consisted of sagittal T1-weighted,
sagittal and axial T2-weighted turbo spin-echo (TSE),
and STIR sequences to rule out myelopathy.
We also performed a morphological study of...
Results
The details of the 18 cases are summarized in Fig.6.
In our series,
the median age was 58 years (range 6–74 years),
and there were 7 women and 11 men.
The most common symptom was neck pain,
presented in seven patients.
Back pain was presented in five patients.
Four patients presented lower extremity weakness.
Less common symptoms were lower extremity paresthesias (three patients),
upper extremity weakness (two patients),
and shoulder pain (only one case).
Prior to the diagnosis,
there were no patients with history of...
Conclusion
The "scalpel sign" suggests the existence of a dorsal arachnoid web but high resolution T2WI sequencesnot always allow usthe direct visualization of the dural webs.
The combination of these high-resolution morphological-anatomical MRI sequences and dynamic sequences sensitive to cerebrospinal fluid flow (PC-MRI or cine TRUE FISH) make it possible to establish the diagnosis and plan the best surgical strategy.
For that reason,
it is mandatory to carry out a specific advanced spinal MRI protocol thatencreasesour diagnostic confidence,
locating with accuracy the point of insertion of...
References
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Dorsal thoracic arachnoid web and the "scalpel sign": a distinct clinical-radiologic entity.
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Dua SG,
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Scalpel sign of dorsal arachnoid web.
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