Tentorial Dural Arteriovenous Fistulas as a Cause of Thalamic Edema: 2 Cases of an Important Differential Diagnosis to Consider

Dural Arteriovenous Fistulas Presenting as Symmetric Lesions in the Internal Capsule on Imaging Studies: A Case Report and Literature Review

BACKGROUND

Dural arteriovenous fistulas (DAVFs) leading to oedema, primarily in the internal capsule, are extremely rare and, to our knowledge, have never been reported. We reported a case of DAVFs with oedema in bilateral internal capsule oedema and reviewed the literature.

METHODS

The report describes a unique imaging presentation of cases of DAVFs as symmetric lesions, mainly in the bilateral internal capsule. It also reviews the literature for symmetric lesions in the internal capsule and central grey matter caused by DAVFs to further characterize this rare entity and differential diagnosis through imaging features.

RESULTS

In cases of symmetric oedema caused by DAVFs, the most common artery involved in arterial supply was the middle meningeal artery (13/24; 54%). The main vein involved in the drainage was the Galen vein (18/29; 62%). Most cases were treated with transarterial embolization (23/29; 79%), and the probability of effective treatment or complete cure is 100%. On imaging, the vasogenic oedema signal caused by DAVFs is a symmetrical lesion of the bilateral internal capsule, that is, DWI MRI shows a high signal in the unrestricted diffusion area on the apparent diffusion coefficient map.

CONCLUSIONS

MR has good diagnostic value in abnormal basal ganglia symmetric signals caused by DAVFs, and can quickly identify DAVFs early.

Bithalamic infarction in a tentorial dural artero-venous fistula and thalamic dementia: a case report and systematic review

PURPOSE

To report a case of bilateral thalamic infarction (BTI) presenting as progressive thalamic dementia due to a midline tentorial dAVF (TdAVF) and to provide a systematic review of the literature.

METHODS

We performed a systematic literature review of previously reported cases of bi-thalamic signal changes due to dAVF considering population characteristics, clinical presentation, imaging findings, treatments, and outcomes.

RESULTS

We found 29 papers from 1985 until 2021 describing 35 cases of BTI dAVF-related. We analysed 36 cases comprehensive of our case report. The mean age was 58.7 years (range 38-79), 91.6% were males (n=33). Most cases presented with a subacute syndrome. In 86.1% (n=31) of cases a TdAVF was found; 58.3% (n=21) were type 2 Borden-Shucart fistulas, the remaining were mostly type 3. In 80.5% (n=29), a thrombosed sinus was identified. 33.3% of cases (n=12) had bi-thalamic haemorrhages. Endovascular treatment was performed in 83.3% of cases (n=30). A total of 75% (n=27) of cases had a good recovery.

CONCLUSIONS

BTIs due to dAVFs may present with subacute symptoms overlapping with several differential diagnoses. Prompt identification at MRI, before venous drainage failure and bleeding, is crucial for a good prognosis.

Medial tentorial dural arteriovenous fistula: A rare cause of bithalamic oedema

A 39-year-old man was admitted after 1 week of headaches and cognitive changes. CT scan showed bithalamic hypodensities, corresponding to bithalamic vasogenic oedema. Punctuate hemorrhage was present, with foci of thalamic enhancement. CT angiography raised the suspicion of arteriovenous shunt. Digital subtraction angiography confirmed a medial falcotentorial dural arteriovenous fistula. Complete embolization was performed using liquid embolic agent. Although tentorial dural fistulas have already been described as a cause of bithalamic oedema and subacute dementia, they are not generally included in pathologies implied in this radiologic pattern.