Yuichi Kawabata

Arterial spin-labeling magnetic resonance imaging for diagnosis of early seizure after stroke

BACKGROUND AND PURPOSE Arterial spin labeling (ASL) is a non-invasive modality of magnetic resonance imaging (MRI) used to evaluate cerebral perfusion without a contrast agent. The usefulness of ASL for diagnosis in the acute phase of late seizure after stroke was evaluated. METHODS Twelve consecutive patients diagnosed with late seizure after stroke were enrolled in this study. MRI including ASL was performed for each patient at the time of the emergency department visit. Eight of the patients underwent electroencephalography (EEG). RESULTS All patients showed hyperperfusion around the stroke lesion on ASL. Only 6 patients showed high signal intensity along the cerebral cortex around the stroke lesion on diffusion-weighted imaging. The patients who underwent EEG showed slow activity, but paroxysmal discharges such as spikes or sharp waves were not observed. CONCLUSIONS ASL was able to reveal hyperperfusion and was of great diagnostic value in the peri-ictal phase of late seizure after stroke.

Cavernous Sinus Dural Arteriovenous Fistula Patients Presenting With Headache as an Initial Symptom

Cavernous sinus (CS) dural arteriovenous fistula (dAVF) patients presenting with only headache as an initial symptom are not common. Patients with CS-dAVF commonly present with symptoms related to their eyes. In all three patients, headache was the initial symptom. Other symptoms related to the eyes developed 1 - 7 months after headache. In one patient, headache was controlled by sumatriptan succinate, but not diclofenac sodium or loxoprofen sodium. In another patient, headache was controlled by loxoprofen sodium. In the third patient, headache was improved by stellate ganglion block. In all patients, magnetic resonance angiography (MRA) in the early stage of the clinical course showed abnormal blood flow in the CS. However, reflux to the superior ophthalmic vein (SOV) was not detected. As treatment, transarterial and transvenous embolizations were necessary for one patient, and transvenous embolization was performed for another patient with significant blood flow to the SOV and cortical veins. On the other hand, manual compression of the bilateral carotid arteries at the neck resulted in disappearance of the fistula in the third patient. In all patients, the symptoms improved after the disappearance of blood reflux to the CS. The refluxed blood to the CS might cause elevation of the CS pressure and stimulate the trigeminal nerve in the dural membrane, resulting in headache before developing reflux in an anterior direction. CS-dAVF could induce both migraine and common headache. In cases with blood reflux to the CS on magnetic resonance imaging and/or MRA even without eye symptoms, a differential diagnosis of CS-dAVF should be taken into consideration.

High-resolution magnetic resonance imaging findings of basilar artery plaque in a patient with branch atheromatous disease: a case report.

IntroductionIntracranial branch atheromatous disease is a type of ischemic stroke that is caused by narrowing or occlusion of the orifice of the penetrating artery by atheromatous plaque. Pontine branch atheromatous disease is usually diagnosed using indirect findings such as the extension of a lesion to the basal surface of the pons because of the difficulty of demonstrating plaque in the basilar artery.Case presentationA 72-year-old Japanese man developed sudden dysarthria and left hemiparesis, and his symptoms deteriorated thereafter. Brain magnetic resonance imaging revealed an acute infarction in the territory of the right paramedian pontine artery extending to the basal surface. Non-contrast-enhanced three-dimensional fast spin-echo T1 imaging with variable flip angles and three-dimensional fast imaging with steady-state acquisition revealed a plaque in the dorsal wall of the basilar artery that spread to the origin of the paramedian pontine artery that branched toward the infarction. Although antithrombotic agents were started, the left hemiparesis got worse and became flaccid on the following day.ConclusionsThis is the first report to confirm the pathological basis of branch atheromatous disease by three-dimensional images using the new modalities of 3-Tesla magnetic resonance imaging. The use of these techniques will foster better understanding of the clinicopathological mechanisms of branch atheromatous disease.

Pseudoaneurysm formation due to rupture of intracranial aneurysms: Case series and literature review.

Background Intracranial pseudoaneurysm formation due to a ruptured non-traumatic aneurysm is extremely rare. We describe the radiological findings and management of pseudoaneurysms due to ruptured cerebral aneurysms in our case series and previously reported cases. Patients and methods Four additional and 20 reported patients presenting with subarachnoid hemorrhage (SAH) are included. Radiological findings and clinical features of these patients were reviewed. Results In our series, three-dimensional computed tomographic angiography (3D-CTA) and/or angiography showed an irregular- or snowman-shaped cavity extending from the parent artery. The radiological examination additionally revealed delayed filling and retention of contrast medium. These findings were the same as previously reported cases. One patient underwent direct clipping of the true aneurysm. For the other three patients with aneurysms at the basilar and anterior communicating arteries, the true portion of the aneurysm was embolized with platinum coils. During the procedures, care was taken not to insert the coils into the distal pseudoaneurysm portion to prevent rupture. The review of 24 cases revealed that the location of the aneurysms was most frequent in the anterior communicating artery (41.7%), and 86.7% of patients were in a severe stage of SAH (>Grade 3 in WFNS or Hunt & Kosnik grading) implying abundant SAH. Conclusions Pseudoaneurysm formation in SAH after non-traumatic aneurysm rupture is rare. However, in cases with an irregular-shaped aneurysm cavity, pseudoaneurysm formation should be taken into consideration.

Agenesis of the Left Internal Carotid Artery Associated with Dolichoectatic Intracranial Arteries

A 28-year-old man without a significant medical history visited our hospital complaining of a headache. Computed tomography (CT) demonstrated thick, calcified vertebral artery (VA) and basilar artery (BA), despite the patient being young. Magnetic resonance angiography demonstrated the absence of the left internal carotid artery (ICA). The right ICA, the bilateral VA, and the BA were well developed and dolichoectatic. CT revealed the absence of the carotid canal on the left side. The condition was diagnosed as congenital agenesis of the left ICA with dolichoectatic changes in 3 other arteries. In a young patient with thick, calcified intracranial arteries, close examination is necessary, because vascular anomalies such as ICA agenesis may exist.

Late Seizures after Stroke in Clinical Practice: The Prevalence of Non-convulsive Seizures

Objective The prevalence of the non-convulsive type of late seizure after stroke is unknown. The aim of the present study was to clarify the characteristics of late seizure in clinical practice, mainly focusing on the prevalence of non-convulsive seizure. Methods A total of 178 consecutive patients who were admitted and diagnosed with late seizure after stroke were retrospectively enrolled, and the data of 127 patients for whom the complete seizure was observed by a bystander were analyzed. Clinical information was obtained from the medical records and nursing notes. Results A non-convulsive seizure was observed in 37 patients (29%). A focal seizure and its secondary generalization accounted for 79% of the seizure types. Status epilepticus was observed in 60 patients (47%), including 11 patients (9%) without convulsion. The patients with non-convulsive seizures were significantly younger than those with convulsive seizures, but there were no other significant differences between the two groups with respect to sex, classification or the lesion of stroke. Conclusion There was a high rate of non-convulsive seizures in patients with late seizure after stroke. A non-convulsive seizure may be caused by any type or location of preceding stroke. More attention is needed in the differential diagnosis of neurological deterioration after stroke.

Bedside evaluation of smooth pursuit eye movements in acute sensory stroke patients

BACKGROUND AND PURPOSE Unilateral saccadic pursuit is reported to be suggestive of a pontine lesion in sensory stroke patients. We attempted to verify this eye sign in just-hospitalized pontine sensory stroke patients. METHODS Horizontal smooth pursuit eye movements were evaluated upon hospital arrival in 4 pontine sensory stroke patients and were compared with those in 6 thalamic sensory stroke patients. Eye movements were evaluated with the patient lying down on the emergency room or stroke care unit bed by means of a newly developed video-oculography-based eye movement recording system equipped to project a moving laser pointer onto the ceiling. RESULTS Laterality of horizontal smooth pursuit gain in pontine sensory stroke patients was evident upon arrival; in thalamic sensory stroke patients, horizontal smooth pursuit gain was equal in both directions. These characteristics were easily detected at bedside. CONCLUSION Unilateral saccadic pursuit in pontine sensory stroke patients may be a practical diagnostic sign that can be detected even in the emergency room. The video-oculography-based recording system equipped to project a moving laser pointer onto the ceiling may be useful for detecting this eye sign.

Dissection of anterior cerebral artery presenting with cerebral infarction in contralateral frontal lobe

Although diagnosis of dissection in the anterior cerebral artery (ACA) has increased, cerebral infarction in frontal lobe due to contralateral ACA dissection is rare. A 52‐year‐old woman developed headache and motor weakness in the left hemibody. Magnetic resonance images demonstrated a fresh cerebral infarction in the right frontal lobe and thin right ACA. The initial diagnosis was a cerebral infarction in the right frontal lobe due to right ACA stenosis. Angiography performed nine days after onset showed dilatation and stenosis of the left ACA, and a small diameter of the right ACA. An intramural thrombus in the left ACA was demonstrated on MRI. The diagnosis was a cerebral infarction in the right frontal lobe due to dissection of the contralateral left A2 and A3 of ACA. There is a possibility that cerebral infarction in frontal lobe is induced by the contralateral ACA abnormality in a case with bihemispheric ACA.

Duplicated middle cerebral artery associated with aneurysm at M1/M2 bifurcation: a case report

BackgroundA duplicated middle cerebral artery arises from the internal carotid artery and supplies blood to the middle cerebral artery territory. A duplicated middle cerebral artery is sometimes associated with an intracranial aneurysm. Most aneurysms associated with duplicated middle cerebral artery are located at the origin of the duplicated middle cerebral artery. An aneurysm located at the distal middle cerebral artery is not common.Case presentationWe encountered a 62-year-old Asian man with duplicated middle cerebral artery associated with aneurysms at the M1/M2 junction of the duplicated middle cerebral artery and top of the internal carotid artery.ConclusionsIn cases of duplicated middle cerebral artery, association with a distal aneurysm on the duplicated middle cerebral artery is rare. However, the aneurysm may be formed on the thicker middle cerebral artery due to hemodynamic stress.

Superficial Temporal Artery-Middle Cerebral Artery Bypass Using a Thick STA after Endarterectomy: A Rescue Technique

Background and Objective Superficial temporal artery (STA)‐middle cerebral artery (MCA) bypass is a procedure to reconstruct cerebral blood flow in the MCA territory. In some cases, the STA wall is thickened and the size discrepancy between STA and MCA is apparent. In such a situation, STA‐MCA bypass is challenging. We present two patients who underwent STA‐MCA bypass using STA in which a thickened intima was removed. We discuss the usefulness of this rescue technique. Patients and Results A patient with an atherosclerotic MCA occlusion and another with an occluded internal carotid artery are included. Endarterectomy of STA was performed before or during anastomosis, and the intima‐resected STA was anastomosed to MCA. In both cases, the STA was thick and hard, and it was difficult to anastomose the STA as it was to the MCA. Patency of the bypass was confirmed by postoperative angiography. Conclusion Endarterectomy of a thickened STA might be an effective rescue technique in cases with severely atherosclerotic STA in STA‐MCA bypass.