Frontal aslant tract: Anatomy and tractography description in the Mexican population.

Background: The aim of the study was to describe the origin, course, and termination of frontal aslant tract (FAT) in the Mexican population of neurosurgical referral centers. Methods: From January 2018 to May 2019, we analyzed 50 magnetic resonance imaging (MRI) studies in diffusion tensor imaging sequences of patients of the National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez." Five brains were fixed by the Klingler method and dissected in the neurosurgery laboratory of the Hospital Civil de Guadalajara to identify the origin, trajectory, and ending of the FAT. Results: FAT was identified in 100% of the MRI and brain dissections. The origin of the FAT was observed in 63% from the supplementary premotor area, 24% from the supplementary motor area, and 13% in both areas. Its ending was observed in the pars opercularis in 81%, pars triangularis in 9%, and in both pars opercularis and ventral premotor area in 10% in the magnetic resonance images, with a left side predominance. In the hemispheres dissections, the origin of FAT was identified in 60% from the supplementary premotor area, 20% from the supplementary motor area, and 20% in both areas. Its ending was observed in the pars opercularis in 80% and the pars triangularis in 20%. It was not identified as an individual fascicle connected with the contralateral FAT. Conclusion: In the Mexican population, FAT has a left predominance; it is originated more frequently in the supplementary premotor area, passes dorsal to the superior longitudinal fascicle II and the superior periinsular sulcus, and ends more commonly in the pars opercularis.

Acute Disseminated Encephalomyelitis with Baló-like Lesion by Scorpion Sting: Case Report.

Acute disseminated encephalomyelitis (ADEM) has been linked to immunizations, viral infections, and occasionally to arthropods stings. Its association with scorpion stings has not been described. A 29-year-old man, who after being stung by a scorpion presented right hemiparesis and language impairment. Brain MRI showed subcortical bihemispheric lesion characteristics of ADEM and a bigger one compatible with Baló concentric sclerosis (BCS). Patient was managed with steroids, showing complete clinical improvement. Magnetic resonance imaging (MRI) after 6 months showed cavitation of the bigger lesion with no new findings. In 2 years of follow-up, there is no clinical relapse or new lesions in MRI. Although cases of ADEM have been reported due to venom of chilopoda and hymenoptera, the scorpion sting can be considered as another new cause; this case being even more relevant due to present a Baló-like lesion in MRI.