Disease relevance of Foramen Magnum

• The foramen magnum metastasis showed the same loss of heterozygosity (LOH) pattern as one of the original C1 metastases and the pituitary tumour tissue obtained at autopsy [1].
• Magnetic resonance imaging of his spine showed a large syrinx from C2 to T7, with significant foramen magnum stenosis and a Chiari Type I malformation [2].
• Results of our radiological analyses were consistent with the theories proposed for the pathogenesis of syringomyelia in the light of the CSF flow around the foramen magnum [3].
• CONCLUSIONS: Placement of the intraspinal component of a baclofen pump via the foramen magnum is a viable alternative for patients with spastic quadriparesis with prior lumbar fusion [4].
• The CSF flows in the aqueduct and at the foramen magnum were examined in 5 patients with communicating hydrocephalus (HC) and in 10 with benign intracranial hypertension (BIH) as well as in 5 healthy volunteers [5].

High impact information on Foramen Magnum

• Measurements from 156 midsagittal and 63 coronal MRI scans performed on 123 normal adults, placed the iter of the aqueduct 0.2 +/- 0.8 mm (mean +/- SD) below the incisural line and the cerebellar tonsils 0.1 +/- 2.1 mm below the foramen magnum line [6].
• The findings suggest that the P14 component is generated above the foramen magnum, whereas the cervical N13 has a spinal generator [7].
• We studied the effects on CSF dynamics at the foramen magnum and the clinical significance of the abnormal tonsillar motion in 14 patients with Chiari type I malformation and 14 control subjects using cine phase-contrast MRI [8].
• Modeling results revealed that the presence of a contralateral craniotomy significantly reduced surrogate tissue herniation through the foramen magnum, allowed surrogate tissue movement across the sagittal midline, and resulted in an appreciable increase in the shear strain in the contralateral cortex during the impact [9].
• Standard midline or lateral suboccipital approaches with opening of the foramen magnum and laminectomy of the involved cervical segments were sufficient for the great majority of tumors [10].

Biological context of Foramen Magnum

• CONCLUSION: Obstruction of the foramen magnum in patients with Chiari I malformation causes an abrupt systolic downward displacement of the spinal cord and impairs the recoil of CSF during diastole [11].
• METHODS: We studied the effect of tactile stimuli given to the toe tip on the sizes of following responses; motor evoked potentials (MEPs) elicited by transcranial magnetic or electrical stimulation (TMS or TES) over the motor cortex and magnetic stimulation at the foramen magnum level [12].

Anatomical context of Foramen Magnum

• A flexion-extension metrizamide-enhanced CT technique has been developed to study the craniocervical junction that refines evaluation of the relation between the spinal cord and the foramen magnum, atlas, and axis [13].
• Dynamic display of the acquired images demonstrated downward displacement of the presaturation bolus on the cerebellar tonsils and medulla oblongata (or upper cervical cord) at the C1 level in all preoperative examinations and in two patients after syringosubarachnoid shunting but with residual foramen magnum obstruction [14].
• Ontogenetic studies of the fetal tentorium suggest that its midline profile rotates inferoposteriorly towards the foramen magnum in response to disproportionate growth of the cerebrum [15].
• In 15 fresh specimens we exposed the posterior cranial fossa with a coronal cut through the foramen magnum and explored the course of each posterior medullary rootlet (PMR) arising from within the retro-olivary groove [16].
• Mercuric chloride was injected intracranially into the rat brain in the region of the fourth ventricle via the foramen magnum [17].

Associations of Foramen Magnum with chemical compounds

• After neuroradiological diagnosis the patients were operated on direct microsurgical disconnection of the arteriovenous shunt via an enlargement of the foramen magnum and a hemilaminectomy of C1 [18].
• Multiplanar metrizamide-enhanced CT imaging of the foramen magnum [19].
• Foramen magnum syndrome secondary to calcium pyrophosphate crystal deposition in the transverse ligament of the atlas [20].
• Thin-slice, axial, contiguous, CT was performed from the base of C2 to above the foramen magnum [21].
• Placement of baclofen pumps through the foramen magnum and upper cervical spine [4].

Gene context of Foramen Magnum

• The lesion was located in the cervico-thoracic spine (foramen magnum to T1) in one case, thoracic spine (T9-T12) with the back swelling at L2-4 level in the second, and in the third, one mass extended from C6 to T11 and the other mass was located in the L1-2 level, separately [22].
• The transfacial approach provides excellent access for this type of extensive midline tumor requiring resection from the suprasellar region down to the foramen magnum [23].
• The dura was opened at the area of the foramen magnum and C1 [24].
• Intradural extraosseous chordoma in the foramen magnum region. Case report [25].
• The recovery curve of the amplitude between the far field potentials P27 (which most probably reflects activity of the afferent volley at the level of foramen magnum) and N30 (which, by latency criteria, would reflect lemniscal or thalamic activity) showed a similar shape but with a shorter duration of the periods of super- and subnormality [26].

Analytical, diagnostic and therapeutic context of Foramen Magnum

• INTERVENTION: Decompression of the foramen magnum, C1 laminectomy, and meningeal biopsy were performed [27].
• A simple method for improved visualisation of the structures at the foramen magnum and upper cervical spine during supine metrizamide myelography by using autotomography is described [28].
• After a C-1 laminectomy-based foramen magnum decompression, arachnoid dissection and duraplasty were undertaken [29].
• CONCLUSIONS: This endonasal endoscopy provided excellent surgical exposure from the sella to the foramen magnum at the midline clivus and posterior fossa [30].

References