Sacral fracture associated with a Tarlov cyst causing an anterior sacral CSF fistula and intraventricular fat emboli - a case report and review of the literature.

BACKGROUND: Sacral fractures are rare and either associated with high-energy trauma or osteoporosis in most cases. A search of the current literature on sacral fractures and cerebrospinal fluid fistula identified only few cases. Pathological fractures are uncommon and exceedingly rare in case of Tarlov cysts. Sacral fractures can be missed in oligosymptomatic patients. However, severe complications may emerge as shown by this case report. METHODS: We present the case of a pathological sacral fracture at the level S2/3 following a low-impact trauma, associated with a Tarlov cyst, which was complicated by an anterior CSF fistula and intraventricular fat emboli. RESULTS: The patient was treated conservatively with strict bedrest and a CT-guided blood patch. Postponed mobilization was successful with decreasing orthostatic symptoms. Follow-up MRI and CT imaging showed a complete resolution of the ventral CSF fistula and ossification of the fracture. The intraventricular fat did not resolve, however, there was no radiological sign of hydrocephalus with excellent clinical outcome at 6-months follow-up. CONCLUSION: Although exceedingly rare, sacral Tarlov cysts may be associated with pathological fractures of the sacrum. Relevant complications can emerge and need to be properly addressed.

Transcallosal, transchoroidal clipping of a hypothalamic collateral vessel aneurysm in Moyamoya disease.

Peripheral collateral vessel aneurysms in Moyamoya disease (MMD) remain difficult to treat due to their deep location, small size, and vascular fragility. We report the case of an aneurysm localized in the hypothalamus, which was rapidly increasing in size with repeated hemorrhage despite revascularization surgery. Aneurysm clipping was performed to prevent further progress and rerupture with favorable outcome. To our best knowledge, this is the first description of a hypothalamic aneurysm in MMD being clipped via a transcallosal, transchoroidal approach through the third ventricle.

Improved visualisation of early cerebral infarctions after endovascular stroke therapy using dual-energy computed tomography oedema maps.

OBJECTIVE: The aim was to investigate whether dual-energy computed tomography (DECT) reconstructions optimised for oedema visualisation (oedema map; EM) facilitate an improved detection of early infarctions after endovascular stroke therapy (EST). METHODS: Forty-six patients (21 women; 25 men; mean age: 63 years; range 24-89 years) were included. The brain window (BW), virtual non-contrast (VNC) and modified VNC series based on a three-material decomposition technique optimised for oedema visualisation (EM) were evaluated. Follow-up imaging was used as the standard for comparison. Contralateral side to infarction differences in density (CIDs) were determined. Infarction detectability was assessed by two blinded readers, as well as image noise and contrast using Likert scales. ROC analyses were performed and the respective Youden indices calculated for cut-off analysis. RESULTS: The highest CIDs were found in the EM series (73.3 ± 49.3 HU), compared with the BW (-1.72 ± 13.29 HU) and the VNC (8.30 ± 4.74 HU) series. The EM was found to have the highest infarction detection rates (area under the curve: 0.97 vs. 0.54 and 0.90, p < 0.01) with a cut-off value of < 50.7 HU, despite slightly more pronounced image noise. The location of the infarction did not affect detectability (p > 0.05 each). CONCLUSIONS: The EM series allows higher contrast and better early infarction detection than the VNC or BW series after EST. KEY POINTS: • Dual-energy CT EM allows better early infarction detection than standard brain window. • Dual-energy CT EM series allow better early infarction detection than VNC series. • Dual-energy CT EM are modified VNC based on water content of tissue.