[A case of acute bilateral blindness presumably caused by reversible cerebral vasoconstriction syndrome after traumatic brain injury].

A 62-year-old man was admitted to our hospital for acute bilateral blindness two days after a head injury. Hemorrhagic cerebellar infarction was found on the initial MRI, and peripheral arteries were poorly visualized on MRA. On the follow-up MRA nine days later, peripheral arteries were clearly depicted. These imaging findings suggested reversible cerebral vasoconstriction syndrome (RCVS). We started steroid pulse therapy for suspected optic neuritis with no clear response. The initial fundoscopic examination revealed no abnormalities in the optic disc, but optic nerve atrophy developed one month later. Based on the course of events, we diagnosed the patient with posterior ischemic optic neuropathy triggered by RCVS.

An adult case of cerebral malakoplakia successfully cured by treatment with antibiotics, bethanechol and ascorbic acid.

Cerebral malakoplakia is a very rare chronic inflammatory disease. We herein report the case of a 49-year-old female who presented with a slowly progressive speech disturbance and right hemiparesis. Computed tomography and magnetic resonance imaging showed irregular enhanced mass lesions with numerous scattered areas of calcification in the left insula, thalamus and basal ganglia. Histopathologically, the biopsy specimen showed basophilic laminated inclusion bodies and intracellular and extracellular calculospherules, usually with a typical targetoid appearance (Michaelis-Gutmann bodies). Treatment with antibiotics, bethanechol and ascorbic acid improved her symptoms in association with a decrease in the abnormal calcification and enhancement. The cerebral malakoplakia mimicked a brain tumor in terms of the patient's clinical course and neuroradiological image findings; however, it was successfully cured with medical treatment. This case provides evidence that the pathogenesis of cerebral malakoplakia is deeply tied to bacterial infection and that medical treatment is effective in cases of this disease.

Venous air embolism (VAE) associated with stereotactic biopsies.

BACKGROUND: Venous air embolism (VAE) is a serious potential complication of neurosurgical procedures. Stereotactic biopsies can also cause VAE; therefore, we evaluated VAE patients to call attention to the risk of VAE associated with stereotactic biopsies. METHODS: In this report, symptomatic VAE was defined as paroxysmal coughing with associated symptoms. Air in the dural sinus, cortical vein and/or pterygoid plexus on postoperative computed tomography (CT) scans was considered to be a radiographic VAE. RESULTS: Three patients developed symptomatic VAE following 36 stereotactic biopsies, and the incidence of symptomatic VAE was 8.3 % (3/36). There were five patients with evidence of radiographic VAE on postoperative CT scans, with an incidence of 13.8 % (5/36). A high angle of the head seemed to be associated with VAE, allowing air to flow into the central venous system. CONCLUSIONS: The present report emphasizes that VAE should be recognized as an important adverse effect of stereotactic biopsies because VAE occasionally requires additional treatment and/or termination of surgery. Surgeons must be aware of the possibility of VAE, especially when it is necessary to position the patient's head at a high angle.

Repeated cyst formation in a patient with leukoencephalopathy, cerebral calcifications, and cysts: effectiveness of stereotactic aspiration with Ommaya reservoir placement.

The combination of leukoencephalopathy, cerebral calcifications, and cysts (LCC) constitutes a rare cerebral disorder characterized by distinctive neuroradiological and clinical findings. Twenty-eight cases of LCC have been reported. Surgery is usually required to treat progressively expanding cysts, but surgical strategies have been varied. The authors present the case of a patient who underwent 4 surgical procedures for repeated cyst formation. The first operation was performed for the removal of a cyst and to make a histopathological diagnosis. The second and third operations were performed to treat de novo cysts. The fourth operation was performed to treat a recurrence. This is the first reported case of LCC in which it was necessary to perform surgery 4 times, in large part due to de novo cyst formation. It provides evidence that multiple cysts may develop in these patients and that several surgical operations may be needed to treat LCC. Stereotactic aspiration with Ommaya reservoir placement is an appropriate procedure for this condition because it is less invasive and more repeatable than open surgery.

Stereotactic biopsy with electrical monitoring for deep-seated brain tumors.

OBJECTIVE: The stereotactic biopsy is widely integrated into clinical practice as an efficient and safe procedure for histologic diagnoses. However, the surgical risk increases when the lesions are close to the eloquence of the adjacent brain. The present report describes two patients with deep-seated brain tumors who underwent a stereotactic biopsy with electrical monitoring and demonstrates the importance of this technique. METHODS: The tentative target and trajectory were determined on a stereotactic map from the Schaltenbrand and Wahren atlas. A Cosman-Roberts-Wells stereotactic frame was applied to the patient. Electrical recording along a single trajectory was used to identify the circumscribed neuronal structures, and electrical simulation was administered to the target. The biopsy point was decided when no adverse events were observed with a low electric current level. RESULTS: A 34-year-old male patient with anaplastic astrocytoma in the putamen and thalamus and an 81-year-old female patient with malignant lymphoma in the midbrain underwent stereotactic biopsies with electrical monitoring. The biopsies were successfully performed without any resulting neurologic deficits. CONCLUSIONS: This report describes two patients with deep-seated brain tumors who underwent stereotactic biopsies with electrical recording and stimulation. The electrical monitoring appears to be a useful technique to complement the ordinary image-guided biopsy.

Short latency afferent inhibition associated with cortical compression and memory impairment in patients with chronic subdural hematoma.

OBJECTIVE: To evaluate the cortical excitability in patients with mild cortical compression. METHODS: The present study used short interval intracortical inhibition (SICI), intracortical facilitation (ICF), and short latency afferent inhibition (SAI) to evaluate motor cortex excitability in 16 chronic subdural hematoma (CSDH) patients with memory impairment and compared the data with those of 16 healthy controls. RESULTS: SAI was reduced in patients compared with controls (99±14 vs. 47±11% of the test size; p<0.0001, unpaired t-test). CSDH patients tended to have a high resting motor threshold and less pronounced SICI and ICF than controls, but these differences were not significant. Treatment of hematoma improved memory impairment and SAI in CSDH patients with wide individual variations that ranged from an increase of 74% to 17% of test size. CONCLUSION: These findings suggest that measuring SAI may provide a means of probing the integrity of cortical cholinergic networks in a compressed human brain.

Cognitive alteration after carotid revascularization is correlated with cortical GABA(B)-ergic modulations.

The present study evaluates the hypotheses that a GABAergic mechanism underlies neurobehavioral sequelae of carotid stenosis and that it can be reversed by carotid revascularization. We used the Rivermead Behavioural Memory Test (RBMT), short interval intracortical inhibition (SICI), intracortical facilitation (ICF), long interval intracortical inhibition (LICI), and cortical silent period (CSP) to evaluate cognitive function and cerebral cortical excitability in 16 carotid artery stenosis patients with cognitive impairment before carotid arterial stenting (CAS) and 1 month later. We compared the pre- and post-CAS results and those of 16 healthy controls. CSP was prolonged in patients compared with controls (195.8±18ms vs. 157.8±13.9ms; p<0.0001, unpaired t-test). Patients tended to a have high resting motor threshold and less pronounced SICI and ICF than controls, but differences were not significant. Decreased RBMT score was correlated with hyperperfusion and CSP increase after CAS. RBMT score increase was correlated with CSP normalization. LICI showed positive correlation with CSP. CSP may provide a means of probing the integrity of GABA(B)-ergic networks in an ischemic human brain. CSP and LICI are potential tools to explore neuronal function for improvement as well as impairment after carotid revascularization.

Increasing high-frequency oscillations (HFOs) in patients with brain tumours: implication for increasing amplitude of N20.

OBJECTIVE: The N20 and high-frequency oscillations (HFOs) of somatosensory evoked potentials (SEPs) were recorded in patients with brain tumours. This study sought to estimate how a brain tumour could increase the peak amplitude of N20, while also illustrating the clinical significance of this condition. METHODS: Median nerve SEPs were recorded in 34 conscious patients, who were admitted to the hospital owing to the presence of a circumscribed unilateral brain tumour. Eleven patients showed an increasing peak amplitude of N20 on the affected side (AS). HFOs were used to analyse the underlying mechanism. RESULTS: While the amplitude of N20 in AS was higher than that on the normal side (NS), the latency of N20 showed no difference on either side. The amplitude of the early components of HFOs on the AS was higher than that on the NS (p=0.015), but the latency was not significantly different. The amplitude of late HFOs on the AS was also higher than on the NS (p=0.041), and the latency was also not significantly different. Our findings proved an increasing amplitude of HFOs to be a discrete character in AS>NS group, thereby indicating that a sensory disturbance was not commonly expressed in AS>NS groups. CONCLUSIONS: These results suggested that the hyperexcitability in the thalamocortical pathway were responsible for this condition. Hyperexcitability was presumably caused by the influence of the corticothalamic feedback and the neural interactions between the relay neurons and the reticular neurons. The clinically significant finding was that an increasing amplitude of N20 thus indicated the presence of a sub-clinical change. SIGNIFICANCE: A brain tumour could increase the amplitude of N20 due to the hyperexcitability in the thalamocortical pathway. An increasing amplitude of N20 thus indicated the presence of a sub-clinical change in the thalamocortical pathway on the side of the tumour.

Malignant fibrous histiocytosis after high-dose proton radiation therapy for anaplastic astrocytoma.

This report presents a 70-year-old male who presented with a rare malignant fibrous histiocytosis after high-dose proton radiation therapy for anaplastic astrocytoma. To our knowledge, malignant fibrous histiocytosis caused by proton therapy has not been reported, therefore the clinical features of this complication are described and previous cases are reviewed.

Functional motor recovery of an infant after a huge ependymoma resection.

Huge supratentorial ependymomas are rarely encountered tumors, even in the infant population. A recovery from complete hemiplegia following a tumor resection including the primary motor cortex was observed. A 5-month-old girl presented with a conjugate deviation to the right and a head circumference that had gradually expanded since birth. Magnetic resonance imaging (MRI) demonstrated a well-enhanced huge mass extending into the right hemisphere. A subtotal removal with the primary motor cortex was performed. However, a regrowth of the residual tumor was observed and, thereafter, the patient underwent a subsequent surgical intervention 5 months later. The histological findings demonstrated an ependymoma. Her motor function was dramatically improved after rehabilitation and no tumor recurrence was detected for 10 years. A diffusion tensor imaging study showed that the motor fibers arose from the residual frontal lobe. The successful surgical management of ependymoma may depend on a total microscopic resection. In a case demonstrating a huge ependymoma, we had to remove a very thin motor cortex with the tumor. However, the motor function recovered completely. The motor damage inflicted at an early developmental age may be fully compensated due to the neuroplasticity of the residual brain.

Edaravone, a free radical scavenger, retards the development of amygdala kindling in rats.

This study evaluated the antiepileptogenic effects of edaravone, a newly developed radical scavenger, on the amygdala kindling rats. The afterdischarge duration (ADD), AD threshold (ADT), and seizure severity in animals were measured to study the anticonvulsant effects of edaravone (2mg/kg or 20mg/kg i.p. for 7 days) on fully kindled seizures. Furthermore, for the study of antiepileptogenesis effects of the drug (2mg/kg or 20mg/kg i.p. for 7 days), not only ADD and seizure severity during kindling but also both the pre- and post-kindling ADT were measured. Edaravone neither induces nor inhibits fully kindled seizures regardless of the dose; however high-dose edaravone (20mg/kg) retarded kindling development together with shortened ADD and elevated ADT. The present data suggest that high-dose edaravone has an antiepileptogenic drug effect for the prevention of epilepsy. However, other chronic models and clinical trials are needed to confirm the effects of edaravone on the prevention of human epilepsy.

Unique infiltrating morphology of a meningioma-a case report.

BACKGROUND: We report on the case of a patient with meningioma that was correctly identified through biopsy. CASE DESCRIPTION: A 69-year-old woman presented with slight headache and was then examined at our hospital. Neurologic and physical examinations found no abnormality. Magnetic resonance imaging demonstrated a well-enhanced huge, dural-based, and plaque-like mass extending throughout the parietooccipital convexity and the posterior fossa. Tumors pressed the adjacent brain cortex while extending along the Virchow-Robin space. A CT scan also showed hyperostosis on the parietooccipital bone. Angiography demonstrated a vascular blush that appeared to be of a tumor-like shape. A biopsy was performed to confirm the diagnosis. The histologic findings demonstrated meningothelial meningioma with infiltration into the Virchow-Robin space. CONCLUSIONS: Many radiographic patterns of meningioma have been reported, but the present case is quite rare. The radiographic and pathologic findings in our patient are discussed.

Intracranial atypical fibromuscular dysplasia with ruptured aneurysm--case report.

A 53-year-old woman was admitted with severe subarachnoid hemorrhage due to rupture of an aneurysm associated with atypical intracranial fibromuscular dysplasia (FMD). Angiography demonstrated the aneurysm and very irregular form of the left internal carotid artery (ICA), the right ICA, and right proximal middle cerebral artery (MCA). Other arteries showed signs of atherosclerosis. The aneurysm was treated by embolization, but she subsequently died of shock of unknown cause. Detailed examination of serial angiograms detected enlargement of the aneurysm and progression of the irregular appearance of the ICA. FMD is a non-inflammatory and non-atheromatous arteriopathy that commonly affects the cervical ICA and sometimes the intracranial ICA. The association with saccular aneurysm is widely known and the prevalence of incidental aneurysms is higher than that in the general population. The common "string of beads" finding is easily distinguished from other vascular diseases, but non-specific findings such as "tubular stenosis" and "diverticular-like outpouching" are harder to differentiate. FMD is associated with various complications and appropriate periodic follow-up examination is required. Detailed analysis of serial angiograms may facilitate diagnosis of this condition.

Chronic intraventricular encapsulated hematoma presenting unique radiological features: a case report.

BACKGROUND: Chronic encapsulated hematoma is relatively rare and the exact mechanisms of this condition remain uncertain. In this report, we present a case of chronic encapsulated hematoma in the lateral ventricle and discuss the pathophysiology of this condition. CASE DESCRIPTION: A 68-year-old-woman presented with progressive gait disturbance. Magnetic resonance imaging (MRI) showed a dumbbell-shaped mass arising from the wall of the right lateral ventricle. The mass connecting to the ventricle wall mimicked a hemorrhagic tumor and the other part mimicked a cystic mass. Cerebral angiography demonstrated arteriovenous shunt in the right lateral ventricle wall. The operative findings revealed that the part arising from the ventricle wall contained hematoma showing various stages of coagulation and that the cystic mass visible on MRI was a granulomatous solid mass. Histologic examination revealed that the capsules of both were compatible with chronic encapsulated intracerebral hematomas. CONCLUSION: In the present case, one part of the mass contained only granulomatous tissue, indicating the possibility that the mass was undergoing spontaneous resolution. This fact might indicate that the presence of neo-vascularization in the capsule is not the sole factor in the expansion of hematoma.