Chiasma Opticum

Pressure, among other things, causes hypopituitarism, meningism, compression of the Chiasma Opticum and visual disturbances.  

Both phenomena could be explained by a reversed crossing of foveal projections in the Chiasma Opticum constituting a genetic vulnerability which, in case of additional defects of binocular balance, could result in a foveal convergence stimulus being executed as a divergence movement by one of the eyes.  

At the end of the experimental period, animals were sacrificed and the optic nerves were dissected at the front level of Chiasma Opticum.  

Treatment may consist of surgical (removing of the tumour and Chiasma Opticum decompression), pharmaco and radiotherapy.  

2000) proposing that schizophrenic vulnerability might consist of the temporal instead of the nasal foveal projections crossing over in the Chiasma Opticum has been provided by an experiment in which pinholes are used to isolate foveally stimulated from peripherally stimulated vergence.  

PATIENTS: Empyema of the Chiasma Opticum region with neuritis nervi optici and bilateral acute amaurosis was observed in a 13 year old boy with sinusitis sphenoidalis and ethmoidalis. In addition to physical examination, cranial computer tomography or magnetic resonance imaging of the brain including sinuses and Chiasma Opticum should be applied early.  

Histologic examination of the brain revealed degeneration of the right optic nerve and right half of the Chiasma Opticum as well as left tractus opticus (opposite side); furthermore, degenerative changes with slight inflammation of the right vestibular nuclei were observed.  

The topographic part deals with the incorporation of the pituitary gland in the sella turcica, its relationship to the meninges, the subarachnoid cavity and other neighbouring structures, especially the sphenoidal sinus, the posterior ethmoidal cells as well as the Chiasma Opticum.  

Furthermore demyelination of the visual pathways, including Chiasma Opticum, was seen.  

Retrobulbar part of the optic nerve and Chiasma Opticum were investigated.  

The basal ganglia, thalamus, hypothalamus and Chiasma Opticum could not be found, although atrophic hypophysis, eyeballs and optic nerves were present.  

The neurons were classified as fast or slow ones, according to their response latency to electrical stimulation of the Chiasma Opticum.  

We report a case of spinal seeding of a pilocytic astrocytoma of the Chiasma Opticum.  

A native and contrast CT scan visualized a tumour close to the suprasellar cisterna reaching the Chiasma Opticum.  

Optic nerve axons decussate in the Chiasma Opticum, except for a small ipsilateral projection to the area preoptica.  

The first was performed at the level of caudal border of the Chiasma Opticum (CB deafferentation) and separated the medio-basal hypothalamus (MBH) from the anterior hypothalamic area (AHA).  

Simultaneously we found primary and secondary traumatic changes of Chiasma Opticum in 10 cases.  

The tumour localized in the hypothalamus and extended into the intracranial parts of the optic nerves and Chiasma Opticum.  

Contraindications are lesions of the bulbus oculi and the fundus, lesions of the Chiasma Opticum and a posttraumatic amaurosis caused by a sinus-cavernosus-fistula.  

The influence of somatosensor stimulation and electric stimulation in the mesencephalic reticular formation upon evoked potentials (EP) of the motor cortex (MC) produced by electric stimulation of the Chiasma Opticum and the Corpus geniculatum laterale, respectively, was investigated in unnarcotized, immobilized cats.  

About 90% of the retinal axons are crossing in the Chiasma Opticum.  

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