Dural Arteriovenous Fistula-Derived Parkinsonism Symptoms: A Case Report with Literature Review.

Objective: Parkinsonism caused by dural arteriovenous fistula (DAVF) is very rare, however, it is reversible by endovascular treatment. We herein report a case of parkinsonism caused by DAVF with review of previous literature. Case Presentation: An 87-year-old woman with parkinsonism and dementia was admitted to our hospital with disturbance of consciousness and aggravated parkinsonism symptoms. Plain CT revealed low-density areas in the brainstem and left cerebellar peduncle. Magnetic resonance images revealed hyperintense lesions on FLAIR, which had elevated apparent diffusion coefficient (ADC) values, in the same lesion of plain CT. However, no edematous change was detected. CT angiograms revealed obstruction of the left transverse and sigmoid sinuses. Dilations of the left superior petrosal sinus, left petrosal vein, and pontine veins were also noted. A low-density area on plain CT had a contrast effect. Cerebral angiography revealed a DAVF involving the left transverse sinus and fed by the left occipital and left middle meningeal arteries. Transarterial embolization (TAE) with Onyx obliterated the DAVF, and parkinsonism symptoms gradually improved. We reviewed 21 DAVF-derived parkinsonism cases, most of which were treated by TAE. Recent cases were treated with Onyx. In many cases, parkinsonism improved after endovascular treatment. Conclusion: DAVF-derived parkinsonism is rare but treatable by endovascular therapy. DAVF should be one of the differential diagnosis of the parkinsonisms.

Advantage of high b value diffusion-weighted imaging for differentiation of common pediatric brain tumors in posterior fossa.

PURPOSE: The pediatric posterior fossa (PF) brain tumors with higher frequencies are embryonal tumors (ET), ependymal tumors (EPN) and pilocytic astrocytomas (PA), however, it is often difficult to make a differential diagnosis among them with conventional MRI. The ADC calculated from DWI could be beneficial for diagnostic work up. METHOD: We acquired DWI at b = 1000 and 4000(s/mm2). The relationship between ADC and the three types of brain tumors was evaluated with Mann-Whitney U test. We also performed simple linear regression analysis to evaluate the relationship between ADC and cellularity, and implemented receiver operating characteristic curve (ROC curve) to test the diagnostic performance among tumors. RESULTS: The highest ADC (b1000/b4000 × 10-3 mm2/s) was observed in PA (1.02-1.91/0.73-1.28), followed by PF-EPN (0.83-1.28/0.60-0.79) and the lowest was ET (0.41-0.75/0.29-0.47). There was significant difference among the groups in both ADC value (b-1000/b-4000: ET vs. PF-EPN p < 0.0001/0.0001, ET vs. PA p < 0.0001/0.0001, PF-EPN vs. PA p < 0.0001/0.0001). ROC analysis revealed that ADC in both b-values showed complete separation between ET and PF-EPN. And it also revealed that ADC at b-4000 could differentiate PF-EPN and PA (96.0%) better than ADC at b-1000 (90.1%). The stronger negative correlation was observed between the ADC and cellularity at b-4000 than at b-1000 (R2  = 0.7415 vs.0.7070) CONCLUSIONS: ADC of ET was significantly lower than the other two groups, and ADC of PA was significantly higher than the other two groups in both b-1000 and b-4000. Our results showed that ADC at b-4000 was more useful than ADC at b-1000 especially for differentiation between PF-EPN and PA.