A 44-year-old man with a history of schizophrenia intentionally stabbed himself in the anterior neck and left thorax with a fruit knife. On arrival to our hospital, he was alert and oriented without neurological abnormalities. His vital signs were respiratory rate 14 breaths/min, blood pressure 149/89 mmHg, and heart rate 90 b.p.m. His SpO2 was 97% using 10 L/min O2. Physical examination revealed three stab wounds: one was a neck wound (approximately 4 cm) that penetrated the trachea, and the others were chest wounds (approximately 1.5 cm and 4 cm) that entered the thoracic cavity from the left front chest. Chest radiograph revealed s.c. emphysema. Ultrasonography revealed pleural effusion in the left chest cavity. A left-side chest tube was inserted, and the stab wounds in the left chest were sutured. Contrast-enhanced computed tomography (CT) of the patient's neck and chest showed s.c. emphysema, pneumomediastinum, tracheal injury, right pneumothorax, left hemopneumothorax, and intrapulmonary hemorrhage. The abbreviated severity score of the chest was 3 points. The pulmonary vein and artery ran across the lung consolidation in the vicinity of the penetration route. There were no abnormal findings such as vascular injury or intravascular air shadow on the 3D-CT angiography of the head and neck from the aortic arch. Three hours later ICU admission, another chest tube was inserted in the left thoracic cavity due to progressive aggravation of s.c. emphysema and oxygenation. Despite the chest tubes, pneumothorax and oxygenation gradually worsened (SpO2 78%, using 15 L/min O2). Six hours after hospital admission, endotracheal intubation was carried out to provide positive pressure ventilation (PPV) under sedation and analgesia. On the third day after admission, improved oxygenation allowed for extubation in the absence of persistent air leak from the chest cavity. However, right hemiparesis appeared following weaning from sedation and mechanical ventilation. The manual muscle test grade of the right upper and lower extremities was 1/5. Head CT showed subacute cerebral infarcts in multiple areas of the bifrontal and right temporal lobes. Diffusion weighted imaging (DWI) of the head showed right temporo-occipital and left frontal cortical laminar hyperintensity. Three-dimensional CT angiography of the head and neck showed no evidence of stenosis or occlusion in major cerebral arteries. We did not detect paroxysmal atrial fibrillation on the electrocardiogram monitor. Laboratory analysis did not reveal systemic coagulation disorder or congenital coagulation defects. The presence of foramen ovale could not be determined. Taking into account the imaging findings and the clinical course of the patient, we diagnosed CAE from the penetrating lung injury that had occurred during PPV. Thirty milligrams of edaravone was given twice daily for 14 days. On the 18th day after admission, right hemiparesis improved after rehabilitation; the manual muscle test grade of the right upper extremity was 5/5 and that of the right lower extremity was 4/5. The patient was transferred to another hospital on the 56th day after admission.