A Case of Vestibular Schwannoma with Deafness Showing Remarkable Hearing Recovery Following Hearing-Preserving Surgery.

Surgery for vestibular schwannoma can be divided into hearing-preserving and nonhearing-preserving surgeries. Hearing-preserving surgery is usually not considered in patients with deafness due to vestibular schwannoma, because hearing is unlikely to improve, and surgery aims to maximize the tumor resection at the expense of hearing. We report an extremely rare case of a 46-year-old man with unilateral profound hearing loss due to a vestibular schwannoma with marked cystic degeneration in the left cistern, which significantly recovered to near-normal hearing levels after hearing-preserving surgery. Hearing loss gradually worsened, and preoperative pure-tone evaluation showed complete hearing loss in the left ear. However, the response to the distortion product otoacoustic emission was preserved, and hearing loss was considered to be retrocochlear. Tumor resection was performed using the retrolabyrinthine approach with continuous monitoring using dorsal cochlear nucleus action potential, auditory brainstem response, and facial nerve function muscle action potential. The cistern portion of the tumor was almost completely resected along with the wall. Postoperatively, the pure-tone threshold on the left side markedly improved. The present case clearly demonstrates the possibility of hearing recovery in patients with retrocochlear hearing loss. We should consider expanding the indications for hearing-preserving surgery.

Effects of the Loss of Binocular and Motion Parallax on Static Postural Stability.

Depth information is important for postural stability and is generated by two visual systems: binocular and motion parallax. The effect of each type of parallax on postural stability remains unclear. We investigated the effects of binocular and motion parallax loss on static postural stability using a virtual reality (VR) system with a head-mounted display (HMD). A total of 24 healthy young adults were asked to stand still on a foam surface fixed on a force plate. They wore an HMD and faced a visual background in the VR system under four visual test conditions: normal vision (Control), absence of motion parallax (Non-MP)/binocular parallax (Non-BP), and absence of both motion and binocular parallax (Non-P). The sway area and velocity in the anteroposterior and mediolateral directions of the center-of-pressure displacements were measured. All postural stability measurements were significantly higher under the Non-MP and Non-P conditions than those under the Control and Non-BP conditions, with no significant differences in the postural stability measurements between the Control and Non-BP conditions. In conclusion, motion parallax has a more prominent effect on static postural stability than binocular parallax, which clarifies the underlying mechanisms of postural instability and informs the development of rehabilitation methods for people with visual impairments.

T2*-Weighted MRI Detected Dilated Cerebral Veins in a Patient with Acute-Phase Cerebral Venous Sinus Thrombosis-A Case Report.

We describe a 45-year-old man who presented with nausea, vomiting, and strong occipital headache on the right side. Although no abnormalities on neurological examination or computed tomography imaging were found on admission, peripheral blood cell counts showed polycythemia (hemoglobin 20.6 g/dL) and electrocardiography demonstrated atrial fibrillation. Therefore, anticoagulant treatment with heparin was started immediately. On the following day, the occipital headache continued. Brain T2*-weighted (T2*WI) magnetic resonance imaging (MRI) and, to a lesser extent, susceptibility-weighted imaging showed dilation of numerous cortical veins, suggesting the possibility of cerebral venous thrombosis (CVT). MR venography (MRV) showed a deficit of the right transverse sinus. Contrast-enhanced MRI revealed partial defects of the right transverse sinus, and led to the definite diagnosis of CVT, and the anticoagulation therapy was continued. On day 7 the headache disappeared, and MRV on day 16 showed the recanalization of the right transverse sinus. There were no complications subsequent to the CVT. On day 25, the patient was discharged with no after-effect. We speculate that the dilation of cortical veins on T2*WI is a helpful sign in detecting acute-phase CVT.

Reversible cerebral vasoconstriction complicated with brain infarction immediately after carotid artery stenting.

Reversible cerebral vasoconstriction is a very rare complication after carotid artery stenting (CAS). It has been reported to occur more than several hours after CAS and to have a good clinical course. A 73-year-old man underwent CAS for a high-grade symptomatic stenosis of his left carotid artery. Immediately after CAS, he had consciousness disturbance and right hemiparesis. We first suspected hyperperfusion syndrome, but antihypertensive therapy exacerbated his symptoms. On repeated postoperative angiography, the middle cerebral artery (MCA) appeared to become progressively narrower. Perfusion computed tomography indicated hypoperfusion in the left MCA territory, so we diagnosed the patient with ischemic symptoms due to hypoperfusion associated with MCA vasoconstriction. Although these findings were temporary, right weakness and cognitive dysfunction lingered and caused severe disability. As vasoconstriction after CAS may result in a poor outcome, it must be promptly distinguished and treated accordingly.

Diagnosis and follow-up of posterior inferior cerebellar artery dissection complicated with ischemic stroke assisted by T1-VISTA: a report of two cases.

BACKGROUND: Volume isotropic turbo spin-echo acquisition (VISTA) is a new method similar to the 3D black-blood imaging method that enables visualization of a intramural hematoma. T1-VISTA has recently been applied in the diagnosis of intracranial arterial dissection. However, the identification of an intramural hematoma in posterior inferior cerebellar dissection (PICA-D) by T1-VISTA has only rarely been reported. CASE PRESENTATION: We herein report two patients who suffered from PICA-D complicated with ischemic stroke. Initial magnetic resonance arteriography was not informative, however, T1-VISTA depicted high-intensity signal areas suggesting an intramural hematoma of PICA-D in both cases. The high-intensity signal areas gradually reduced and finally disappeared at 4 months and 5 months after the onset, respectively. CONCLUSION: Our cases demonstrate that T1-VISTA was able to assist in the diagnosis and follow-up of PICA-D.