Showing posts with label Spinal Dural AF Fistula. Show all posts
Showing posts with label Spinal Dural AF Fistula. Show all posts

Friday, 10 August 2012

Spinal Epidural Hematoma MRI

A 26 yo male with sudden onset backache and chest pain for last 2 days. An associated bilateral upper limb tingling numbness. Both lower limb weakness is of sudden onset and non progressive.
Power: Rt arm 4-5, Lt arm 4-5, Rt leg 0, Lt leg 0.
No history of trauma or any heavy weight lifting. 
BT CT PT and other related caugulation profile normal.
On admission MRI dorsal region spine done with contrast. 
MRI Findings: 

A focal posterior epidural lentiform shaped collection extending from C6-7 to D2-3 disc level
Collection is hypo intense on sagittal T2 images with low signal intensity 'blooming'on GRE. No significant enhancement within the collection on post contrast T1 and fat sat T1. Thin enhancement noted along the normal dura.
Significant cord compression with focal cord edema.

Imaging wise Diagnosis: Possible DDs given were as Epidural Hematoma more likely than Abscess.

Post operative findings:

Operated with C6-D3 Laminectomy, posterior epidural hematoma / blood clot evacuated with coagulation of dural AV fistula along left D2 root.

Final Diagnosis : Posterior epidural hematoma secondary to Spinal Dural AV Fistula - Malformation.

Discussion:
In this case possibility of Epidural hematoma is more likely due to sudden onset of symptoms clinically, low signal intensity of collection on T2w and T2*GRE, iso to hyper intensity on T1w images, non enhancing on post contrast on imaging, thought there no history of history of trauma and normal coagulation profile. So one should entertain a possibility of Hematoma for a spinal Epidural lesion as Epidural Hematoma can present without history of trauma and moreover blood has variable signal and enhancement pattern on MRI.

Spinal Epidural hematoma (EDH)

Extra vasation of blood into the epidural space of spine.

Imaging
MRI is best.
Typically lentiform shaped long segmental extra axial collection mass encasing or displacing cord or cauda equina.
Location anywhere along spinal canal, commonly in dorsal region. 
vertical extent variable depending upon severity of bleed, often multi segmental,rarely focal when associated with an adjacent fracture.
On CT, density on CT varies with age of hematoma high density in acute stage to low density in chronic. 
On MRI 
TIWI: Hypo-, iso- or hyperintense (depending on age)
T2WI: Inhomogeneous low (if acute), or high signal (if subacute) intensity.
T2* GRE: low signal.
T1 C+: None to marginal enhancement along the dural outling of collection. Avid enhancement if bleeding is active. 
DSA
Often negative. Rarely, may show AVM or vascular tumor as Source of bleeding. 

DDs
Epidural abscess: Usually vivid enhancement, associated osteomyelitis or paraspinous infection, constitutional signs like fever, pain, chills.
Epidural tumor: Typically quite focal, adjacent bone often involved, Lymphoma may simulate EDH, enhances vividly. 

Etiology
o Spontaneous in 1/3
• Pressure elevation in vertebral venous plexus due to minor exertion, like sit-ups with Valsalva.
• Chiropractic manipulation
o Therapeutic anticoagulation
• Coumadin
• Anti platelet agents
o Instrumentation
• Epidural anesthetic
• Nerve block
• Facet joint injection
• Lumbar puncture
o Vascular malformation

Clinical Presentation
Most common signs/symptoms are intense, knife-like pain.
Associated extremity weakness, sphincter disturbance
Age: 35-70 Gender: Male > Female

Treatment
o Surgical for significant cord compression is decompressive Laminectomy and evacuation of hematoma. 
o Non-surgical for minor neurological signs.

Sunday, 10 June 2012

Spinal AV Malformation- Spinal Dural AV Fistula

MRI Sagittal and Axial T2 images at the level of conus shows peri medullary T2 flow voids suggestive of Vascular malformation. 
Vascular malformations of Spinal cord represent a heterogeneous group consists of spinal arteriovenous malformations (AVMs), dural arteriovenous fistulas (AVF), spinal hemangiomas, cavernous angiomas, and aneurysms.
Among these AVMs and AVFs are most prevalent spinal vascular malformations.

Spinal AV malformations can be classified in a number of ways;
The most simple classification is extramedullary (80%) or intramedullary.
In 1992, Anson and Spetzler classified spinal cord AV malformations into the following 4 categories as;
Type 1: These are Dural AVF, the most common type of malformation, accounting for 70% of all spinal vascular malformations. Here radiculomeningeal artery feeds directly into a radicular vein, usually near the spinal nerve root.  The AVF creates venous congestion and hypertension, resulting in hypoperfusion, hypoxia, and edema of the spinal cord. Due to the slow flow nature of type 1 AVFs, hemorrhage rarely occurs. Exact etiology of its development is still unknown. Most frequently found in men between the fifth and eighth decades of life. Most commonly found in the thoracolumbar region.
Type 2: Referred to as a Glomus AVM, consist of a focal tightly compacted group of arterial and venous vessels (nidus) inside a short segment of the spinal cord. Multiple feeding vessels from the anterior spinal artery and/or the posterior spinal circulation typically supply these AVMs. The abnormal vessels are intramedullary in location, may reach surface and sometimes subarachnoid space if extensive. Are the most commonly encountered intramedullary vascular malformations, representing about 20% of all spinal vascular malformations. Usually present in younger patients with acute neurologic deterioration hemorrhage. The rebleed rate is 10% within the first month and 40% within the first year.
Type 3: Referred to as Juvenilte AVM, are extensive lesions with abnormal vessels that can be both intramedullary and extramedullary in location. Typically found in young adults and children.
Type 4: Also known as pial AVFs, these malformations are intradural extramedullary AVFs on the surface of the cord that result from a direct communication between a spinal artery and a spinal vein without an interposed vascular network. Usually seen in patients of third to sixth decade of life.

References: 
Anson JA, Spetzler RF. Interventional neuroradiology for spinal pathology. Clin Neurosurg. 1992;39:388-417.
Krings T. Vascular Malformations of the Spine and Spinal Cord : Anatomy, Classification, Treatment. Klin Neuroradiol. Feb 28 2010;