Arachnoscopy: a special application of spinal intradural endoscopy

Object The microsurgical removal of obstructions to CSF flow is the treatment of choice in the surgical management of intradural arachnoid cysts. Cardiac-gated phase-contrast MR imaging is an effective tool for the primary diagnosis and localization of arachnoid cysts. Microsurgery, however, does not lend itself to assessments of further adhesions beyond the borders of the exposed area. The use of a thin endoscope allows surgeons to assess intraoperatively whether the exposure is wide enough. Methods Between 2006 and 2010, a single neurosurgeon performed 31 consecutive microsurgical procedures with endoscopic assistance in 28 patients with spinal arachnoid adhesions. A MurphyScope endoscope was used for this purpose. The CSF flow was studied before and after surgery in all patients by using phase-contrast MR imaging in the region of the craniocervical junction, the cervical spine, the thoracic spine, and the lumbar spine. Results In all 31 procedures, CSF flow obstructions were detected at the level identified by phase-contrast MR imaging. In 29 procedures, image quality was sufficient for an inspection of the adjacent subarachnoid space. In 6 cases, the surgeon detected further adhesions that obstructed CSF flow in the adjacent subarachnoid space that were not visualized with the microscope. In all cases, these adhesions were identified and removed during microsurgery. Conclusions Arachnoscopy is a helpful adjunct to microsurgery and can be performed safely and easily. It allows the surgeon to detect further adhesions in the subarachnoid space that would remain undetected by microscopy alone.

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Surgical outcome of primary intradural spinal arachnoid cysts: a series of 10 cases

The Egyptian Journal of Neurology Psychiatry and Neurosurgery ◽

10.1186/s41983-021-00290-8 ◽

2021 ◽

Vol 57 (1) ◽

Author(s):

Essam Abdelhameed ◽

Ahmed Ali Morsy

Keyword(s):

Tertiary Care ◽

Outer Wall ◽

Arachnoid Cysts ◽

Neurophysiological Monitoring ◽

Japanese Orthopedic Association ◽

Common Location ◽

Before And After ◽

Microsurgical Resection ◽

Tertiary Care Centers ◽

Intradural Arachnoid Cysts

Abstract Background Primary intradural spinal arachnoid cysts are rare pathologies of uncertain etiology and variable presentation from no symptoms to myelopathy or radiculopathy according to cord or root compression. MRI with diffusion and contrast differentiates them from many pathologies. There is a lot of debate regarding when to treat and how to treat such rare pathologies. Objective We present a series of 10 primary intradural arachnoid cysts and evaluate outcome after surgery. Methods This retrospective study includes patients having primary intradural spinal arachnoid cysts operated in two tertiary care centers from October 2012 till October 2019. Symptomatic cysts were subjected to microsurgical resection or outer wall excision and inner wall marsupialization under neurophysiological monitoring. The Japanese Orthopedic Association Score was used for clinical evaluation while MRI with contrast and diffusion was used for radiological evaluation before and after surgery. Results This series included 10 patients, 4 males and 6 females, with mean age of 40 years. Pain was the most common presentation. The most common location was dorsal thoracic region. Total excision was achieved in 2 cases and marsupialization in 8 cases. All symptoms improved either completely or partially after surgery. No neurological deterioration or recurrence was reported during the follow-up period in this series. Conclusion Treatment of symptomatic primary intradural spinal arachnoid cysts should be microsurgical resection, when the cyst is adherent to the cord, microscopic fenestration can be safe and effective.

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Standard and cardiac-gated phase-contrast magnetic resonance imaging in the clinical course of patients with Chiari malformation Type I

Neurosurgical FOCUS ◽

10.3171/2011.7.focus11105 ◽

2011 ◽

Vol 31 (3) ◽

pp. E5 ◽

Cited By ~ 19

Author(s):

Uwe Max Mauer ◽

Andreas Gottschalk ◽

Carolin Mueller ◽

Linda Weselek ◽

Ulrich Kunz ◽

...

Keyword(s):

Mr Imaging ◽

Chiari Malformation ◽

Phase Contrast ◽

Foramen Magnum ◽

Central Canal ◽

Type I ◽

Csf Flow ◽

Chiari Malformation Type I ◽

Cerebrospinal Fluid Flow ◽

Contrast Magnetic Resonance

Object The causal treatment of Chiari malformation Type I (CM-I) consists of removing the obstruction of CSF flow at the level of the foramen magnum. Cerebrospinal fluid flow can be visualized using dynamic phase-contrast MR imaging. Because there is only a paucity of studies evaluating CSF dynamics in the region of the spinal canal on the basis of preoperative and postoperative measurements, the authors investigated the clinical usefulness of cardiacgated phase-contrast MR imaging in patients with CM-I. Methods Ninety patients with CM-I underwent preoperative MR imaging of CSF pulsation. Syringomyelia was present in 59 patients and absent in 31 patients. Phase-contrast MR imaging of the entire CNS was used to investigate 22 patients with CM-I before surgery and after a mean postoperative period of 12 months (median 12 months, range 3–33 months). In addition to the dynamic studies, absolute flow velocities, the extension of the syrinx, and tonsillar descent were also measured. Results The changes in pulsation were highly significant in the region of the (enlarged) cistern (p = 0.0005). Maximum and minimum velocities (the pulsation amplitude) increased considerably in the region where the syrinx was largest in diameter. The changes of pulsation in these patients were significant in the subarachnoid space in all spinal segments but not in the syrinx itself and in the central canal. Conclusions The demonstration of CSF flow pulsation can contribute to assessments of surgical outcomes. The results presented here, however, raise doubts about current theories on the pathogenesis of syringomyelia.

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Analysis of aqueductal cerebrospinal fluid flow after endoscopic aqueductoplasty by using cine phase-contrast magnetic resonance imaging

Journal of Neurosurgery ◽

10.3171/jns.2000.93.2.0237 ◽

2000 ◽

Vol 93 (2) ◽

pp. 237-244 ◽

Cited By ~ 82

Author(s):

Henry W. S. Schroeder ◽

Christiane Schweim ◽

Klaus H. Schweim ◽

Michael R. Gaab

Keyword(s):

Cerebrospinal Fluid ◽

Magnetic Resonance ◽

Mr Imaging ◽

Healthy Volunteers ◽

Phase Contrast ◽

Aqueductal Stenosis ◽

Csf Flow ◽

Content Type ◽

Endoscopic Aqueductoplasty ◽

Fine Print

Object. The purpose of this prospective study was to evaluate aqueductal cerebrospinal fluid (CSF) flow after endoscopic aqueductoplasty. In all patients, preoperative magnetic resonance (MR) imaging revealed hydrocephalus caused by aqueductal stenosis and lack of aqueductal CSF flow.Methods. In 14 healthy volunteers and in eight patients with aqueductal stenosis who had undergone endoscopic aqueductoplasty, aqueductal CSF flow was investigated using cine cardiac-gated phase-contrast MR imaging. For qualitative evaluation of CSF flow, the authors used an in-plane phase-contrast sequence in the midsagittal plane. The MR images were displayed in a closed-loop cine format. Quantitative through-plane measurements were performed in the axial plane perpendicular to the aqueduct. Evaluation revealed no significant difference in aqueductal CSF flow between healthy volunteers and patients with regard to temporal parameters, CSF peak and mean velocities, mean flow, and stroke volume. All restored aqueducts have remained patent 7 to 31 months after surgery.Conclusions. Aqueductal CSF flow after endoscopic aqueductoplasty is similar to aqueductal CSF flow in healthy volunteers. The data indicate that endoscopic aqueductoplasty seems to restore physiological aqueductal CSF flow.

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Phase-contrast MR Studies of CSF Flow Rate in the Cerebral Aqueduct and Cervical Subarachnoid Space with Correlation-based Segmentation

Magnetic Resonance in Medical Sciences ◽

10.2463/mrms.8.91 ◽

2009 ◽

Vol 8 (3) ◽

pp. 91-100 ◽

Cited By ~ 23

Author(s):

Keita YOSHIDA ◽

Hiroto TAKAHASHI ◽

Masaki SAIJO ◽

Takashi UEGUCHI ◽

Hisashi TANAKA ◽

...

Keyword(s):

Flow Rate ◽

Subarachnoid Space ◽

Phase Contrast ◽

Mr Studies ◽

Cerebral Aqueduct ◽

Csf Flow

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Phase-Contrast Cine Mr Imaging of Normal Aqueductal CSF Flow

Acta Radiologica ◽

10.1177/028418519403500204 ◽

1994 ◽

Vol 35 (2) ◽

pp. 123-130 ◽

Cited By ~ 51

Author(s):

F. Barkhof ◽

M. Kouwenhoven ◽

P. Scheltens ◽

M. Sprenger ◽

P. Algra ◽

...

Keyword(s):

Mr Imaging ◽

Phase Contrast ◽

Volume Averaging ◽

Cortical Atrophy ◽

Csf Flow ◽

Caudal Direction ◽

Cine Mr ◽

Flow Void ◽

Phantom Studies ◽

Cine Phase Contrast

Cine phase-contrast MR imaging was used to study pulsatile CSF flow in the aqueduct in 11 young controls (mean age 30 years) and 9 old controls (mean age 69 years). A high-resolution gradient echo technique and an oblique imaging plane, perpendicular to the aqueduct, was used to avoid volume averaging. Phantom studies confirmed that the technique was accurate. Aqueductal velocity and flux in old controls was higher than in young controls, but the differences were not significant. For all controls together, the averaged peak velocity was 4.2 ± 1.5 cm/s in rostral and −7.8 ± 4.9 cm/s in caudal direction; for the flux it was 0.16 ± 0.10 cm3/s in rostral and −0.29 ± 0.19 cm3/s in caudal direction. Phase-contrast measurements were significantly related to flow-void on modulus MR images, but not with ventricular size or cortical atrophy. The present technique avoids underestimation of aqueductal flow, and therefore reveals higher aqueductal velocity and flux values than previous studies. Factors other than age or atrophy seem to determine aqueductal CSF flow.

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Phase-contrast cine MR imaging of normal aqueductal CSF flow

Acta Radiologica ◽

10.3109/02841859409172348 ◽

1994 ◽

Vol 35 (2) ◽

pp. 123-130 ◽

Cited By ~ 6

Author(s):

Frederik Barkhof ◽

M. Kouwenhoven ◽

P. Scheltens ◽

M. Sprenger ◽

P. Algra ◽

...

Keyword(s):

Mr Imaging ◽

Phase Contrast ◽

Csf Flow ◽

Cine Mr

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Measurement of Cerebrospinal Fluid Flow: Technique Validation in a Patient with Idiopathic Normal Pressure Hydrocephalus

Rivista di Neuroradiologia ◽

10.1177/197140090501800104 ◽

2005 ◽

Vol 18 (1) ◽

pp. 34-36

Author(s):

A. Romano ◽

A. Bozzao ◽

G. Trillò ◽

M. Bonamini ◽

F. Fasoli ◽

...

Keyword(s):

Normal Pressure Hydrocephalus ◽

Phase Contrast ◽

Normal Pressure ◽

Third Ventriculostomy ◽

Csf Flow ◽

Flow Measurements ◽

Cerebrospinal Fluid Flow ◽

Functional Changes ◽

Before And After ◽

Long Term Follow Up

This study aimed to assess anatomical and functional changes disclosed by magnetic resonance imaging in a patient with suspect normal pressure hydrocephalus following surgical third ventriculostomy with placement of a ventriculoperitoneal shunt. The patient was investigated by phase contrast sequences to calculate CSF flow in the Sylvian aqueduct before and after the two surgical procedures. In addition, T1-weighted volumetric MPRAGE images were acquired using voxel-based morphometry to study any changes in size of the ventricular system and CSF in the subarachnoid spaces before and after surgery. CSF flow measurements were closely correlated with the patient's clinical course, increased CSF flow coinciding with worsening symptoms, and a decrease in flow noted after surgery. There were no significant changes in the CSF volumes analyzed. Phase contrast technique proved reliable and effective for the purposes of diagnosis and long-term follow-up in patients with suspect normal pressure hydrocephalus eligible for surgery

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The “presyrinx” state: is there a reversible myelopathic condition that may precede syringomyelia?

Neurosurgical FOCUS ◽

10.3171/foc.2000.8.3.4 ◽

2000 ◽

Vol 8 (3) ◽

pp. 1-13 ◽

Cited By ~ 23

Author(s):

Nancy J. Fischbein ◽

William P. Dillon ◽

Charles Cobbs ◽

Philip R. Weinstein

Keyword(s):

Spinal Cord ◽

Mr Imaging ◽

Clinical Evidence ◽

Cervical Spinal Cord ◽

Central Canal ◽

Intramedullary Tumor ◽

Csf Flow ◽

Before And After ◽

Late Evolution ◽

History Of

Object Alteration of cerebrospinal fluid (CSF) flow has been proposed as an important mechanism leading to the development of syringomyelia. We hypothesize that a “presyrinx” condition due to potentially reversible alteration in normal CSF flow exists and that its appearance may be due to variations in the competence of the central canal of the spinal cord. Methods Five patients with clinical evidence of myelopathy, no history of spinal cord trauma, enlargement of the cervical spinal cord with T1 and T2 prolongation but no cavitation, evidence for altered or obstructed CSF flow, and no evidence of intramedullary tumor or a spinal vascular event underwent MR imaging before and after intervention that alleviated obstruction to CSF flow. Results Preoperatively, all patients demonstrated enlarged spinal cords and parenchymal T1 and T2 prolongation without cavitation. Results of magnetic resonance (MR) imaging examinations following intervention in all patients showed resolution of cord enlargement and normalization or improvement of cord signal abnormalities. In one patient with severe arachnoid adhesions who initially improved following decompression, late evolution into syringomyelia occurred in association with continued CSF obstruction. Conclusion Nontraumatic obstruction of the CSF pathways in the spine may result in spinal cord parenchymal T2 prolongation that is reversible following restoration of patency of CSF pathways. We refer to this MR appearance as the “presyrinx” state and stress the importance of timely intervention to limit progression to syringomyelia.

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Active spontaneous decompression of a suprasellar-prepontine arachnoid cyst detected with routine magnetic resonance imaging

Journal of Neurosurgery Pediatrics ◽

10.3171/2008.10.peds0869 ◽

2009 ◽

Vol 3 (1) ◽

pp. 70-72 ◽

Cited By ~ 11

Author(s):

Bradley P. Thomas ◽

Matthew M. Pearson ◽

Curtis A. Wushensky

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Mr Imaging ◽

Arachnoid Cyst ◽

Male Infant ◽

Ventricular System ◽

Arachnoid Cysts ◽

Resonance Imaging ◽

Csf Flow ◽

Routine Magnetic Resonance Imaging

Arachnoid cysts are congenital CSF collections that arise adjacent to arachnoid cisterns. These lesions can be incidental neuroimaging findings but may also cause symptoms and necessitate treatment, particularly in children. The authors present their experience with a male infant harboring a large suprasellar-prepontine arachnoid cyst who underwent spontaneous decompression into the ventricular system, as evidenced by a visualized CSF flow jet observed on routine MR imaging.

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