The onset of cerebral infarction may be affected by differences in atmospheric pressure distribution patterns.

Background: Some papers have highlighted a possible causal relationship between the onset of ischemic stroke and weather conditions. This study aimed to elucidate the onset mechanism of cerebral infarction from a meteorological approach. We focused on the atmospheric pressure distribution patterns (APDPs). Methods: The subjects are 221 cases diagnosed as cardiogenic cerebral embolism (Group A) and 612 cases diagnosed as atherosclerotic cerebral thrombosis (Group B). We investigated the APDP on the date closest to the date and time of onset of cerebral infarction in each patient on the website and chose the most similar one from the reported 11 APDPs. Groups A and B were compared for clinical characteristics and the appearance rate of each APDP in each group. Results: The clinical characteristics of Groups A and B were consistent with some previously reported clinical characteristics of cerebral embolism and cerebral thrombosis except for smoking. The appearance rate of the other high-pressure type, which cannot be classified as either the anticyclone belt type or the migratory anticyclone type, in Group B was statistically significantly higher than that in Group A, and the appearance rate of the anticyclone belt type in Group A was statistically significantly higher than that in Group B (p < 0.05, Fisher's exact probability method, respectively). Conclusions: Cerebral embolism and cerebral thrombosis exhibited significant differences in APDPs on the day of onset. Dehydration particularly in the other high-pressure type or in the anticyclone belt type should be prevented. Further investigation should focus on the other meteorological factors.

Impact of Coronavirus Disease 2019 on Time Delay and Functional Outcome of Mechanical Thrombectomy in Tokyo, Japan.

OBJECTIVES: An association has been reported between delays in the onset-to-door (O2D) time for mechanical thrombectomy (MT) and outbreaks of coronavirus disease 2019 (COVID-19). However, the association between other MT time courses or functional outcomes and COVID-19 outbreaks remains unclear. We compared the time courses of stroke pathways or functional outcomes in 2020 (the COVID-19 era) with those in 2019 (the pre-COVID-19 era) in Tokyo, Japan. MATERIALS AND METHODS: This retrospective observational study used data from the Tokyo-tama-REgistry of Acute endovascular Thrombectomy (TREAT), a multicenter registry of MT for acute large vessel occlusion in the Tokyo Metropolitan Area. Patients who had undergone acute MT from January 2019 to December 2020 were included. Patients were classified by the year they had undergone MT (2019 or 2020). RESULTS: In total, 477 patients were analyzed. O2D time was significantly longer in 2020 (146.0 min) than in 2019 (105.0 min; p = 0.034). No significant difference in door-to-puncture time (D2P) time or modified Rankin Scale (mRS) score 0-2 at 90 days was seen between 2019 and 2020. In the subgroup analysis, O2D time was significantly longer in the first half of 2020 compared with 2019. Multivariable logistic regression analysis revealed that the year 2020 was a independent predictor of longer O2D time, but not for mRS score 0-2 at 90 days. CONCLUSIONS: Although O2D time was significantly longer in the COVID-19 compared with the pre-COVID-19 era, D2P may not be significantly delayed and functional outcomes may not be different, despite the COVID-19 pandemic.

Simultaneously cooperative, but serially antagonistic: a neuropsychological study of diagonistic dyspraxia in a case of Marchiafava-Bignami disease.

We describe a patient with Marchiafava-Bignami disease who showed, in addition to signs of callosal interruption, a peculiar form of diagonistic dyspraxia. Unlike the typical diagonistic dyspraxia, both of the patient's hands could simultaneously cooperate in a sequence of bimanual actions. More specifically, his right hand could start a commanded action with the cooperation of his left hand. However, once the action was completed, his left hand started an antagonistic action, undoing the result, with the cooperation of his right hand. Once this countermanding action was completed, the original action started again. These antagonistic actions repeated themselves alternately unless he was restrained. The patient's diagonistic dyspraxia was apparent in only some bimanual actions, and he showed no diagonistic dyspraxia when performing voluntary actions; the antagonistic actions occurred in response to oral commands or by imitation. Magnetic resonance imaging showed symmetrical demyelination with partial necrosis in the genu, body, and anterior splenium of the corpus callosum. We speculate that the bimanual coordination is possible because part of the corpus callosum is intact, whereas the antagonistic actions may be caused by conflict between the two hemispheres due to interhemispheric disinhibition elicited by the demyelinated part of the corpus callosum.

Asymptomatic carotid artery dissection caused by blunt trauma.

A 42-year-old man presented with asymptomatic traumatic carotid artery dissection 3 months after sustaining blunt injury with tracheal laceration. Magnetic resonance imaging performed as a screening procedure for asymptomatic carotid artery injury unexpectedly showed dissection of the carotid artery. Angiography confirmed carotid artery dissection with narrowing of the true lumen. Balloon angioplasty and stent placement were carried out to dilate the true lumen and isolate the false lumen from blood flow. Intravascular ultrasonographic virtual histology defined the precise anatomic structure of the lesion and identified the internal flap as fibrotic. Careful clinical assessment of patients with blunt cervical trauma may permit diagnosis of carotid artery dissection and intervention prior to the development of cerebral ischemic symptoms.

External carotid artery aneurysm developing after embolization of a ruptured posterior inferior cerebellar artery aneurysm in a patient with cervicocephalic fibromuscular dysplasia--case report.

A 30-year-old man presented with an aneurysm of the left posterior inferior cerebellar artery manifesting as subarachnoid hemorrhage and cerebellar infarction. Angiography demonstrated string-of-beads sign typical of fibromuscular dysplasia (FMD) in the extracranial carotid and vertebral arteries. The aneurysm and the parent artery were successfully embolized with Guglielmi detachable coils. Severe vasospasm developed 1 week after admission, and was treated several times by selective injection of vasodilator. A new aneurysm of the left external carotid artery became evident 1 month later, whereas only slight dilation had previously been apparent. This angiographic sequence demonstrated a new arterial dissection. Despite the possibility of damage to the artery during multiple catheterizations, arterial wall changes caused by FMD appear to have been primarily responsible. This case emphasizes the need for particular care in performing vascular interventional procedures in the presence of FMD.

Radiation-induced osteosarcoma 16 years after surgery and radiation for glioma--case report.

A 35-year-old man developed osteosarcoma of the left parietal and occipital bones 16 years after radiotherapy for glioma in the right occipital lobe. Radiotherapy of the primary neoplasm used 50 Gy administered to a localized field through two lateral ports. The secondary neoplasm arose contralateral to the primary lesion but within the irradiated field. The tumor had a multilocular cyst with considerable intracranial extension, and symptoms of elevated intracranial pressure were prominent early in the course. After a short-lived initial remission following surgical intervention and chemotherapy, the patient deteriorated because of tumor recurrence and died 18 months after the diagnosis. Radiation-induced osteosarcoma is a well-known but rare complication of radiotherapy for brain neoplasms with a poor prognosis.

[Isolated crossed superior rectus palsy in a midbrain infarction].

A 61-year-old man suddenly heard tinnitus and diplopia at night during watchinng television. A few days later he visited at our hospital. Neurologically he exibited marked isolated right superior rectus palsy which was also indicated by the Hess test. No other neurological abnormalities were found such as other ocular muscle paresis, cranial nerve palsies, hemiparesis, sensory impairement or cerebellar ataxia. MRI showed a left medial thalamic infarction extending to a rostral part of the midbrain anterolateral to the cerebral aqueduct at the superior colliculi level. Unilateral superior rectus palsy can rarely be caused by a contralateral midbrain infarction, because fibers from the subnucleus subserving the superior rectus decussate within the oculomoter nerve complex. In this case the crossing fibers toward the contralateral superior rectus may have been selectively involved by a tinny lesion in the area of the oculomotor nucleus. The patient had a slightly narrowed right palpebral fissure. It is indicated that crossing fibers toward the contralateral levator muscle of the eyelid may be also involved. The patient's diplopia completely resolved two months later after the onset.