Successful endovascular treatment of a ruptured bihemispheric posterior inferior cerebellar artery aneurysm: illustrative case.

BACKGROUND: Normal posterior inferior cerebellar artery (PICA) anatomy is highly variable, but bihemispheric PICA crossing the midline to supply the vascular territory of bilateral cerebellar hemisphere is rare. Herein, the authors reported a rare case of ruptured aneurysm that was associated with bihemispheric PICA and successfully treated endovascularly. OBSERVATIONS: A 46-year-old woman presented with sudden headache and loss of consciousness because of an intraventricular hemorrhage due to a ruptured aneurysm that was associated with the bihemispheric PICA. Angiography revealed that the aneurysm was located at the bifurcation between the bihemispheric PICA and the bilateral distal PICA. The ruptured aneurysm was successfully occluded using coil embolization, which preserved the parent artery with no procedural-related complication. LESSONS: To the best of the authors' knowledge, this was the first report of a ruptured aneurysm associated with bihemispheric PICA being successfully treated endovascularly. Aneurysm formation may be accelerated by hemodynamic stress and vascular fragility. For neurosurgeons and neurointerventionalists, it is important to understand the anatomical variation of PICA, especially bihemispheric PICA, which is a potential risk factor for a fatal stroke.

The Usefulness of CT-Diffusion Weighted Image Mismatch in Patients with Mild to Moderate Traumatic Brain Injury.

Traumatic brain injury (TBI) has a complex and heterogeneous pathology. It is frequently difficult to predict the neurological deterioration of patients with TBI, and unpredictable change may occur even when TBI is mild to moderate. When computed tomography (CT) findings are considered to be inconsistent with the traumatic origin or with the neurological deterioration of patients observed on admission, magnetic resonance imaging (MRI) is employed based on the standards of our ethical committee. In this retrospective study, we compared CT and diffusion weighted imaging (DWI) of patients with mild to moderate TBI in the very acute phase. When the high-intensity lesions on DWI are larger than the high-density lesions on CT images, we defined the imaging finding as a 'CT-DWI mismatch'. Between January 2010 and December 2013, 92 patients were inspected using both CT and MRI at admission, and we detected a CT-DWI mismatch in 35 patients. CT-DWI mismatch was 92.6% (95% confidence interval 79.8-97.9) sensitive and 84.6% (95% confidence interval 79.3-86.3) specific for the prediction of enlargement of the hemorrhagic lesions on repeat CT. CT-DWI mismatch is considered to be useful as one of the predictors of the enlargement of hemorrhagic lesions in patients with mild to moderate TBI.

[A Case of Transorbital Penetrating Brain Injury Caused by a Steel Wire Entirely Embedded in the Brain Parenchyma].

Penetrating brain injury(PBI)is very rare in Japan. Because there is a very wide variety of pathological condition of PBI, the guideline for the treatment of PBI has not been established yet. We report the unique case of PBI caused by a steel wire piece completely embedded in the brain parenchyma. A 75-year-old man was brought to the emergency department due to ocular injury caused by a steel wire piece. Neurological examination revealed only left visual disturbance. CT scan revealed a steel wire piece located intraparenchymally between the left frontal lobe and the ventricles, but digital subtraction angiography showed no significant vascular injury in the surrounding structures. We performed an open surgery and removed the steel wire piece. Because the steel wire piece was completely embedded in the brain, we used intraoperative X-ray fluoroscopy to choose a less invasive approach for the brain. The patient suffered no additional neurological deficit and no sign of cerebral infection or seizure after surgery. He was discharged after a 4-week administration of antibiotics. In most cases of PBI caused by low velocity injury, foreign bodies are not completely embedded in the brain except for remnants after surgical removal. This is the first report of low velocity PBI caused by a foreign body completely embedded in the brain.