Riku Mihara
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Riku Mihara has a total of 11 co-authors. Here are the top co-authors by number of shared publications:
- Akio Morita
Department of Neurological Surgery, Nippon Medical School, Tokyo, Japan
1 shared publication - Fumihiro Matano
Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
1 shared publication Kenta Koketsu
Department of Neurological Surgery, Chiba Hokusoh Hospital, Nippon Medical School
1 shared publicationKyongsong Kim
Department of Neurological Surgery, Chiba Hokusoh Hospital, Nippon Medical School
1 shared publicationMinoru Ideguchi
Department of Neurological Surgery, Chiba Hokusoh Hospital, Nippon Medical School
1 shared publicationNobuaki Kobayashi
Cardiovascular Center, Chiba Hokusoh Hospital, Nippon Medical School
1 shared publication
Latest Publications
- Open Access
- 31 December 2026
- Published by Japan Neurosurgical Society in NMC Case Report Journal
- Vol. 13, 175-180
Cerebral Infarction Diagnosed as Isolated Cardiac Sarcoidosis
Cardiac sarcoidosis elicits cardiac disorders due to granuloma formation in cardiac tissue; it can lead to cerebral infarcts. We encountered a 72-year-old Japanese male with isolated cardiac sarcoidosis diagnosed after a cardiogenic cerebral infarction. He suffered a sudden-onset disturbance of consciousness, aphasia, and right hemiparesis. His National Institutes of Health Stroke Scale score was 17. The diagnosis was left middle cerebral artery occlusion due to cardiogenic embolism. Percutaneous thrombectomy achieved thrombolysis and recanalization of the cerebral infarction; his National Institutes of Health Stroke Scale score improved to 0. Cardiac ultrasonography revealed an enlarged left atrial diameter, a thinned inferior ventricular wall, a ventricular aneurysm, and left ventricular systolic dysfunction. During the clinical course, ventricular tachycardia was noted; sarcoidosis was suspected as the underlying disease. As no definitive diagnosis could be made, he was discharged on the 54th day of hospitalization. 18F-fluorodeoxyglucose positron emission tomography in the outpatient department showed localized abnormal accumulation in the left ventricle, and he was diagnosed with isolated cardiac sarcoidosis. Steroid treatment was added to anticoagulation therapy. There have been no recurrent cerebral infarctions or lesions in other organs. Cardiac sarcoidosis can be 1 cause of cardiogenic cerebral infarction.
- 31 December 2026
- Published by Japan Neurosurgical Society in NMC Case Report Journal
- Vol. 13, 175-180
Open AccessCerebral Infarction Diagnosed as Isolated Cardiac Sarcoidosis
Cardiac sarcoidosis elicits cardiac disorders due to granuloma formation in cardiac tissue; it can lead to cerebral infarcts. We encountered a 72-year-old Japanese male with isolated cardiac sarcoidosis diagnosed after a cardiogenic cerebral infarction. He suffered a sudden-onset disturbance of consciousness, aphasia, and right hemiparesis. His National Institutes of Health Stroke Scale score was 17. The diagnosis was left middle cerebral artery occlusion due to cardiogenic embolism. Percutaneous thrombectomy achieved thrombolysis and recanalization of the cerebral infarction; his National Institutes of Health Stroke Scale score improved to 0. Cardiac ultrasonography revealed an enlarged left atrial diameter, a thinned inferior ventricular wall, a ventricular aneurysm, and left ventricular systolic dysfunction. During the clinical course, ventricular tachycardia was noted; sarcoidosis was suspected as the underlying disease. As no definitive diagnosis could be made, he was discharged on the 54th day of hospitalization. 18F-fluorodeoxyglucose positron emission tomography in the outpatient department showed localized abnormal accumulation in the left ventricle, and he was diagnosed with isolated cardiac sarcoidosis. Steroid treatment was added to anticoagulation therapy. There have been no recurrent cerebral infarctions or lesions in other organs. Cardiac sarcoidosis can be 1 cause of cardiogenic cerebral infarction.
- Open Access
Subcutaneous Emphysema of the Orbit after Nose-Blowing
Orbital emphysema after nose-blowing is an uncommon condition and can appear without a trigger. Herein, we reported a case of orbital emphysema after nose-blowing and performed a literature review. A 68-year-old man fell and sustained an injury near his left orbit. No symptoms were noted. He noticed a left periorbital swelling after blowing his nose. Through computed tomography examination, he was diagnosed with subcutaneous emphysema. There are no previous reports that have reviewed the clinical features, need for surgery, and severity of symptoms of subcutaneous emphysema after nasal swallowing due to different factors. We retrospectively analyzed a cohort of 48 cases by searching PubMed to clarify these issues. Regarding the emphysema trigger, 21 cases had an injury or had previously undergone surgery. In 34 cases, conservative treatment was required, while surgery was selected in the acute phase in 6 cases and after the acute phase as a radical cure in 8 cases. Reduced visual acuity, diplopia, exophthalmos, facial hypoesthesia, and color disorders were noted and were more common among surgical cases. The literature review revealed no association between fracture location and the need for surgery; furthermore, surgery was less required in non-trauma cases, excluding osteoma, than in trauma cases (p = 0.0169). Our study reveals that a strict follow-up examination of visual symptoms is necessary for the first 2 days in cases of subcutaneous emphysema caused by nose blowing after facial trauma.
Open AccessSubcutaneous Emphysema of the Orbit after Nose-Blowing
Orbital emphysema after nose-blowing is an uncommon condition and can appear without a trigger. Herein, we reported a case of orbital emphysema after nose-blowing and performed a literature review. A 68-year-old man fell and sustained an injury near his left orbit. No symptoms were noted. He noticed a left periorbital swelling after blowing his nose. Through computed tomography examination, he was diagnosed with subcutaneous emphysema. There are no previous reports that have reviewed the clinical features, need for surgery, and severity of symptoms of subcutaneous emphysema after nasal swallowing due to different factors. We retrospectively analyzed a cohort of 48 cases by searching PubMed to clarify these issues. Regarding the emphysema trigger, 21 cases had an injury or had previously undergone surgery. In 34 cases, conservative treatment was required, while surgery was selected in the acute phase in 6 cases and after the acute phase as a radical cure in 8 cases. Reduced visual acuity, diplopia, exophthalmos, facial hypoesthesia, and color disorders were noted and were more common among surgical cases. The literature review revealed no association between fracture location and the need for surgery; furthermore, surgery was less required in non-trauma cases, excluding osteoma, than in trauma cases (p = 0.0169). Our study reveals that a strict follow-up examination of visual symptoms is necessary for the first 2 days in cases of subcutaneous emphysema caused by nose blowing after facial trauma.