Contralateral hearing loss after acoustic neuroma surgery.

A 74-year-old man suffered contralateral hearing loss after left acoustic neuroma surgery. Steroid therapy was administered, but no improvement was observed. Contralateral hearing loss is an extremely rare and distressing complication that can occur following acoustic neuroma surgery. Although the mechanism of this rare phenomenon remains unclear, we speculate that in this patient the loss of cerebrospinal fluid or internal auditory artery thrombosis may be involved.

[Pure motor monoparesis of a lower limb due to head injury: a case report].

A 70-year-old woman sustained a head injury after a motor vehicle accident. Physical examination conducted on admission revealed pure motor monoparesis (PMM) and pathological reflexes in the right lower extremity. Her left lower extremity and upper extremities were intact. Computed tomography showed a spotty high-density lesion in the left precentral gyrus and a subgaleal hematoma in the left occipital region. Magnetic resonance imaging was performed on the next day. Fluid-attenuated inversion recovery (FLAIR) imaging demonstrated a high-intensity lesion in the left precentral gyrus, and T2 imaging revealed a low-intensity lesion suggesting a small hemorrhage in the same area. The small hemorrhage and perifocal edema were identified on diffusion-weighted images in which low- and high-intensity lesions were observed in the anterior and posterior left precentral gyrus, respectively. Subsequent neurological examinations over 2 weeks showed improvement. We discuss the clinical presentation, diagnosis, and treatment of PMM due to head injury. We concluded that FLAIR and T2 and diffusion-weighted imaging may be useful techniques for diagnosing PMM due to head injury.

Hyperperfusion syndrome after neck clipping of a ruptured aneurysm on a dolichoectatic middle cerebral artery.

A 40-year-old female presented with sudden onset of severe headache and vomiting due to subarachnoid hemorrhage. Angiography demonstrated a saccular aneurysm on a dolichoectatic left middle cerebral artery (MCA) and delayed filling of the MCA. Magnetic resonance imaging showed a partially thrombosed giant aneurysm on the dolichoectatic MCA. An intentionally delayed operation was performed, during which the neck of the aneurysm was successfully clipped. The patient exhibited aphasia 48 hours after surgery. Single-photon emission computed tomography revealed hyperperfusion in the territory of the left MCA. The patient's blood pressure was maintained normotensively, and her symptoms gradually improved. She returned to work 1 month after surgery. The saccular aneurysm was formed on the dolichoectatic MCA, presumably due to an abnormal arterial wall and hemodynamic stress. The preoperative hypoperfusion might have been caused not only by the giant aneurysm, but also to some degree by the dolichoectatic MCA. After neck clipping, the increase in blood flow might have caused hyperperfusion.

[Case of infected subdural hematoma diagnosed by diffusion-weighted imaging].

An 80-year-old man who had undergone total gastrectomy and splenectomy for gastric cancer 13 years ago presented with headache, drowsiness, and high fever 1 month after a traffic accident. Brain CT scans revealed bilateral subdural fluid collections. Diffusion-weighted imaging (DWI) showed mixed high and low signal intensities in the left subdural fluid, and contrast-enhanced MR imaging revealed capsule enhancement of the left subdural fluid collection. The patient was diagnosed with left subdural empyema, and 2 burr-holes were drilled for drainage and irrigation. Operative findings revealed a neomembrane underneath the dura mater. Old hematoma and yellowish-white purulent fluid were present within the neomembrane. This confirmed the diagnosis of infected subdural hematoma (ISH). Abscess culture results were positive for Escherichia coli. The patient's symptoms resolved postoperatively with subsequent antibiotic therapy. However, 4 months after the operation, he suddenly died of severe sepsis and disseminated intravascular coagulation following cholecystitis, which was possibly associated with splenectomy. The clinical presentation, diagnosis, and treatment of an unusual case of ISH have been discussed. We emphasize that DWI and enhanced MR imaging may be useful for diagnosing ISH, and serial DWI evaluations may help in monitoring the therapeutic response in ISH.

Primary cystic germinoma originating from the midbrain.

A primary intracranial germinoma that involves the midbrain is rare. We describe an unusual case of primary cystic germinoma originating from the midbrain. A 29-year-old man presented with diplopia, and his MRI showed a cystic, ring-like enhanced lesion in the thalamo-mesencephalic junction. Open biopsy was performed and the diagnosis of germinoma was based upon the histopathological findings. Following chemotherapy and radiotherapy, the symptoms improved and the tumor disappeared. We propose that primary intracranial germinoma should be included in the differential diagnosis of midbrain tumors, because early diagnosis and appropriate treatment for midbrain germinoma improves clinical outcome.

Prolonged somatic survival of clinically brain-dead adult patient.

A 43-year-old woman suffered clinical brain death after severe head injury. The patient met the criteria for the diagnosis of clinical brain death on Day 3. Aggressive hemodynamic and respiratory managements coupled with triple hormone therapy were performed at the family's request, resulting in continued cardiac activity for a prolonged period. Spinal reflexes and automatisms were observed until cardiac arrest. Ventilatory support was discontinued on Day 168, when cardiac death was confirmed, and her kidneys and eyeballs were removed for transplantation. The patient survived for 165 days after the diagnosis of clinical brain death, which is an extremely prolonged period of somatic support for an adult patient after brain death. An extensive and informed discussion on the end-of-life treatment of clinically brain-dead patients is urgently required in Japan to establish treatment guidelines for such patients.

Meningeal hemangiopericytoma manifesting as massive intracranial hemorrhage--two case reports.

Meningeal hemangiopericytoma is rare, and only seven cases have manifested as intracranial hemorrhage. We treated two patients with meningeal hemangiopericytoma manifesting as life-threatening massive intracerebral hemorrhage. Case 1: A 66-year-old woman presented with consciousness disturbance and left hemiparesis. Computed tomography showed a mass lesion in the right frontal parasagittal region and massive hematoma in the brain tissue at the medial border of the lesion. Immediate evacuation of the hematoma was performed. Postoperative magnetic resonance imaging revealed a well-enhanced mass lesion with small intratumoral hemorrhage. The tumor was removed totally through a bilateral frontal craniotomy. The postoperative course was uneventful. The histological diagnosis was meningeal hemangiopericytoma. Radiotherapy was not performed. Case 2: A 59-year-old man presented with consciousness disturbance. Computed tomography showed a mass lesion in the right frontotemporal convexity region and massive hematoma in the brain tissue at the medial border of the lesion. His neurological condition was refractory to any treatment and the clinical diagnosis of brain death was confirmed. Autopsy was performed and the histological diagnosis was meningeal hemangiopericytoma. Meningeal hemangiopericytoma manifesting as intracranial hemorrhage is quite rare, but carries the risk of life-threatening massive bleeding from the tumor.

[A case of cystic cavernous angioma accompanied by a fluid-fluid level on magnetic resonance imaging].

We describe the case of a patient with cavernous angioma (CA). A 44-year-old woman complained of numbness on the left side of the body as an initial symptom of the disease. The initial magnetic resonance (MR) imaging revealed a cystic mass with a fluid-fluid level without perifocal edema in the right thalamus on the T 2-weighted image (T 2WI) and T2*-weighted image (T2*WI). Her symptoms were self-controllable; therefore we decided to observe her natural course only with serial MR imaging. The cystic mass was not enhanced by gadolinium on T1-weighted images, although, we suspected the tumor was complicated by vascular malformation. Therefore, we performed cranial angiography to eliminate the possibility of bleeding from the vascular malformation. Angiography did not demonstrate tumor staining nor vascular malformation. Longitudinally, the tumor demonstrated mosaic signal intensities on each sequence with perifocal edema. Moreover, the tumor exhibited hypointensities on T2* WIs without perifocal edema. The natural history of the tumor on MR imaging exhibited a typical case of CA. Some previous reports described cystic CA with perifocal edema and vascular malformation. In our present case, we clinically diagnosed CA on the basis of the final MR imaging together with previous reports. An intra-axial fluid-fluid level is a very rare finding of MR imaging. Here, we report the case of a patient with cystic CA accompanied by a fluid-fluid level. This finding is not a pathognomonic sign of CA; although, we consider that it is very important to follow up carefully the natural history of such cases.