The fetal head of Infants born with iniencephaly are hyperextended while the foramen magnum is enlarged and opens through the widened cortex is thinned.
22.
The "'opisthion "'is the midpoint on the posterior margin of the foramen magnum and is a cephalometric landmark.
23.
The currently accepted radiographic definition for a Chiari malformation is that cerebellar tonsils lie at least 5mm below the level of the foramen magnum.
24.
The resulting hollow sphere can then be drained of air like a balloon and pulled out through the " foramen magnum ".
25.
It begins at the foramen magnum where branches of the two vertebral arteries exit, merge, and descend along the anterior spinal cord.
26.
Cranial features show a flatter face, u-shaped dental arcade, small canines, an anterior foramen magnum, and heavy brow ridges.
27.
Arnold-Chiari malformation is a malformation of the medulla through the foramen magnum, sometimes causing hydrocephalus as a result of obstruction of cerebrospinal fluid outflow.
28.
The alar ligaments, together with the apical ligaments, are attached from the sloping upper edge of the odontoid peg to the margins of the foramen magnum.
29.
Cervical vertebrae possess transverse foramina to allow for the vertebral arteries to pass through on their way to the foramen magnum to end in the circle of Willis.
30.
The presence of myoclonus above the foramen magnum effectively excludes spinal myoclonus; further localisation relies on further investigation with electromyography ( EMG ) and electroencephalography ( EEG ).
