Beiderseitiger Fasciculus arcuatus bulbi mit einseitiger Degeneration auf der Seite der sekundÄren Pyramidendegeneration

A morphometric analysis of the circumolivary fiber bundle of the human brainstem

“…According to the number of ipsilateral circumolivary fiber bundles, we expand the current state of knowledge as well. Most studies up to this date described one single fiber bundle (Smith, 1904 ; Hajós, 1914 ; Juba, 1935 ; De Caro et al, 1998 ; Stonebridge et al, 2020 ), Marburg ( 1945 ) and Swank ( 1934 ) were able to differentiate a doubled left-sided circumolivary bundle. We were able to detect a two-stranded fiber bundle in one-sixth of our cases ( n = 5) and even observed a left brainstem side, which showed three fiber bundles.…”

“…Hajós ( 1914 ) as well as Smith ( 1904 ) established unilateral cases of circumolivary fiber bundles in more than 85% of their cases, Swank ( 1934 ) found almost 70% of the circumolivary fibers on the left brainstem side. Furthermore, two bilateral cases (Juba, 1935 ; Marburg, 1945 ) and three unilateral right-sided circumolivary fiber bundles (Swank, 1934 ; De Caro et al, 1998 ) have to be pointed out. According to our investigations, the circumolivary fibers were also found in approximatly 60% of the cases on the left side.…”

“…Circumolivary fibers or anterior external arcuate fibers are to be understood as fibers on the ventrolateral surface of a human medulla oblongata. The fibers run downwards from either the anterior median fissure, the pyramid, or both, run around the inferior pole of the olive and turn upwards to reach the restiform body of the inferior cerebellar peduncle (Smith, 1904 ; Hajós, 1914 ; Swank, 1934 ; Juba, 1935 ; Marburg, 1945 ; De Caro et al, 1998 ). These fibers can form a macroscopically visible bundle on the brainstem.…”