Masahiro Oomura

Carotid Artery Stenting Successfully Prevents Progressive Stroke Due to Mobile Plaque

We report a case of progressive ischemic stroke due to a mobile plaque, in which carotid artery stenting successfully prevented further infarctions. A 78-year-old man developed acute multiple infarcts in the right hemisphere, and a duplex ultrasound showed a mobile plaque involving the bifurcation of the left common carotid artery. Maximal medical therapy failed to prevent further infarcts, and the number of infarcts increased with his neurological deterioration. Our present case suggests that the deployment of a closed-cell stent is effective to prevent the progression of the ischemic stroke due to the mobile plaque.

Combination of ketogenic diet and stiripentol for super-refractory status epilepticus: A case report

Super-refractory status epilepticus (SRSE) is defined as status epilepticus (SE) that continues for at least 24 h after initiation of general anaesthetic medications, including cases in which SE recurs on reduction or withdrawal of anaesthesia [1]. Given the severity of SRSE, there is a critical need for new therapies to halt ongoing seizure activity. Because neuronal excitation is regulated by energy metabolism, SRSE can be suppressed by inhibiting metabolic pathways. A ketogenic diet (KD) has been proven to be effective in critically ill adults with SRSE [2]; however, the mechanisms by which KD prevents seizures remain unknown. It has recently been found that one of the mechanisms that KD works on is a metabolic pathway via lactate dehydrogenase (LDH) and that LDH may be inhibited by stiripentol (STP) [3]. Here, we report that a combination of KD and STP appeared to constitute effective treatment of a patient with SRSE underlying anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. A 20-year-old Japanese woman presented with a week of headaches followed by impaired consciousness. On admission, she exhibited abnormal behaviours, including altered manner of speaking and shouting loudly. She was unable to follow commands and became unresponsive to external stimuli. An electroencephalogram (EEG) showed generalized rhythmic delta frequency activity at 1 Hz with superimposed, frontally predominant bursts of rhythmic beta frequency activity (extreme delta brushes) (Fig. 1(A-1)). Her cerebrospinal fluid demonstrated mild pleocytosis (74 cells per mm) with a slightly elevated IgG index (1.01). Glucose and protein concentrations were normal. She was diagnosed as having NMDAR encephalitis (positive anti-NMDAR antibody result) with bilateral ovarian teratomas (pelvic CT findings) (Fig. 1(B)). Her symptoms were not alleviated by bilateral ovariectomy and immunotherapy (plasma exchange, intravenous immunoglobulin at 400 mg/kg over 5 days and intravenous methylprednisolone at 1000 mg over 3 days). Additionally, her seizures were unresponsive to conventional antiepileptic drugs (AEDs) such as valproate, carbamazepine, phenytoin, clonazepam, phenobarbital, and levetiracetam. Further, these treatments repeatedly resulted in a generalized rash accompanied by fever, leukopenia, and acute hepatitis and they were accordingly ceased.

Fatal Intraperitoneal Bleeding after Intravenous Administration of Tissue Plasminogen Activator.

We report a case of acute ischemic stroke, which developed fatal intraperitoneal bleeding after intravenous administration of alteplase. An 86-year-old woman developed acute infarction of the right middle cerebral artery during admission for chronic heart failure. Two days before the stroke, liver biopsy was performed; the result was benign. Although rivaroxaban was prescribed for atrial fibrillation, the rivaroxaban had been discontinued for liver biopsy until the time when she developed the stroke. A condition of recent biopsy required careful determination of eligibility of intravenous alteplase; however, we considered that the benefit of intravenous alteplase outweighed the hemorrhagic adverse effects. Alteplase (0.6 mg/kg) was started 2 hours after the stroke onset, however, no clinical improvement was obtained. One hour after the completion of alteplase, she suddenly developed a shock state. Emergent computed tomography disclosed massive intraperitoneal hemorrhage. She died 8 hours after the completion of alteplase. In the present case, mechanical thrombectomy without intravenous alteplase can be an alternative therapeutic option.

Utility of T1- and T2-Weighted High-Resolution Vessel Wall Imaging for the Diagnosis and Follow Up of Isolated Posterior Inferior Cerebellar Artery Dissection with Ischemic Stroke: Report of 4 Cases and Review of the Literature

BACKGROUND An accurate diagnosis of isolated posterior inferior cerebellar artery dissection (iPICA-D) is difficult due to the limitation of spatial resolution on conventional magnetic resonance imaging (MRI) techniques to detect subtle vessel wall abnormalities. The recent development of MRI techniques, including high-resolution vessel wall imaging (HRVWI), has resulted in the improved diagnostic accuracy and efficiency of iPICA-D. In fact, T1-weighted HRVWI, which can reveal intramural hematomas in the posterior inferior cerebellar artery (PICA), is useful for the diagnosis of iPICA-D. However, the utility of T2-weighted HRVWI has not been previously reported. The aim of this study was to investigate the diagnostic utility of T1- and T2-weighted HRVWI for the diagnosis of iPICA-D. METHODS We retrospectively evaluated MRI findings including intramural hematomas, dilations, and chronological changes in 4 patients with iPICA-D admitted to our hospital and related facility from January 2015 to August 2016. In addition to T1-weighted HRVWI, T2-weighted HRVWI was performed on isovoxel three-dimensional (3D) fast spin-echo or 3D sampling perfection with application-optimized contrast using different flip-angle evolution. We also reviewed cases of nonhemorrhagic iPICA-D with ischemic onset in which the MRI findings were described. RESULTS In all 4 patients, in addition to the intramural hematomas on T1-weighted HRVWI, T2-weighted HRVWI clearly showed the fusiform dilation of the external diameter of the PICA. T2-weighted HRVWI was more useful than other techniques, including T1-weighted HRVWI, for the evaluation of arterial shape changes. CONCLUSIONS Like T1-weighted HRVWI, T2-weighted HRVWI is useful for the diagnosis and assessment of chronological changes in vessel wall abnormalities during the follow-up period.

Development of paradoxical cerebral embolism during lymphatic draining massage: A case report

A 62‐year‐old woman presented with left hemiparesis just after finishing lymphatic draining massage involving the four extremities. Diffusion‐weighted magnetic resonance imaging showed an acute infarct in the right precentral gyrus. The diagnosis of paradoxical cerebral embolism was established on the findings of transesophageal echocardiography and detected thrombi in the leg veins. Movement of extant thrombi in the legs to the right atrium, in association with massage, is considered to have contributed to the stroke onset.

Miller Fisher Syndrome Mimicking Tolosa-Hunt Syndrome

We herein report a patient with Miller Fisher syndrome mimicking Tolosa-Hunt syndrome. A 47-year-old man presented with right orbital pain and diplopia. On a neurological examination, he had right oculomotor nerve palsy and diminished deep tendon reflexes. Brain magnetic resonance imaging failed to show any parenchymal lesions; however, the bilateral oculomotor nerves were gadolinium-enhanced. The presence of a triad of orbital pain, ipsilateral oculomotor nerve palsy, and a rapid response to steroid therapy met the diagnostic criteria for Tolosa-Hunt syndrome. After discharge, antibodies against GQ1b and GT1a were reported to be positive only with phosphatidic acid. The present case was ultimately diagnosed as an incomplete phenotype of Miller Fisher syndrome.

Fatal remote cerebral hemorrhage at a site of a microbleed immediately after intravenous thrombolysis

We report a patient with ischemic stroke who was treated with intravenous alteplase and subsequently developed a fatal pontine hemorrhage during cerebral angiography. An 88‐year‐old woman presented with right hemiplegia and aphasia. Magnetic resonance angiography at onset showed occlusion of the left middle cerebral artery. T2*‐weighted magnetic resonance imaging showed a cerebral microbleed in the pons. She was treated with intravenous alteplase followed by cerebral angiography. Left carotid angiography showed recanalization of the left middle cerebral artery, and neurointervention was not carried out. During the angiography, she became comatose. Computed tomography showed a massive pontine hemorrhage. The hemorrhage was considered to be attributable to the microbleed. The variety of time phases of cerebral microbleeds have been elucidated; there are a subset of lesions reflecting acute or subacute microhemorrhages. It is considered that expansion of a pontine microbleed induced by alteplase caused a fatal remote cerebral hemorrhage in the present case.

Hyperdense Vessel Signs Showing Migration of a Thrombus

A 59-year-old man developed right hemiplegia and total aphasia. His National Institute of Health Stroke Scale score was 27. Serial multi-detector row non-contrast computed tomography (CT) with multiple planar reconstruction (MPR) revealed a hyperdense middle cerebral artery (MCA) sign in the left MCA (Picture A and B, arrow), and a diagnosis of acute ischemic stroke was made. Alteplase (0.6 mg/kg, IV) was started 165 minutes after onset. Repeat CT after completion of the alteplase administration revealed resolution of the hyperdense MCA sign but the appearance of an M2 dot sign (Picture C and D, arrowhead). Angiography showed the occlusion of the left MCA M2 segment, corresponding to the M2 dot sign (Picture E, arrowhead). The hyperdense vessel sign (HVS) is typically evaluated on axial CT images (1, 2). The present case demonstrated that serial multi-detector row non-contrast CT with MPR can not only recognize an HVS but also track a migrating thrombus. Early identification of the occlusion site can avoid unnecessary insertion of a large-bore sheath.

Cerebral infarction due to cardiac myxoma developed with the loss of consciousness immediately after defecation-a case report.

A 74-year-old man lost consciousness immediately after defecation. The loss of consciousness lasted for several minutes, and he experienced difficulty in walking when he regained consciousness. He was transferred to our hospital via an ambulance. Upon neurological examination, nystagmus and ataxia in the left arm and leg were noted. An MRI of the brain revealed multiple acute infarcts mainly in the bilateral cerebellum. Intravenous thrombolytic therapy with alteplase was initiated 3 h and 20 min after the onset of symptoms, and an improvement in neurological symptoms was observed. Echocardiography displayed a mobile mass in the left atrium, suggesting myxoma. After 14 days from the onset of symptoms, the tumor was surgically resected, and a pathological diagnosis of myxoma was established. Because of the unique event surrounding the onset in this case, we considered that there was a potential detachment of myxoma and/or thrombi fragments triggered by an increase in intrathoracic pressure induced by the action of defecation. This present case suggests that clinicians should consider cardiac myxoma in patients with cerebral infarction if the stroke is preceded by a Valsalva maneuver-like action and accompanied by the loss of consciousness.