Search results for "Optic Chiasm"
showing 10 items of 10 documents
A case of intrasellar aneurysm simulating a pituitary adenoma
1959
A case of intrasellar aneurysm simulating a pituitary adenoma has been reported. The literature on the subject has been reviewed. The diagnostic difficulties related to intrasellar aneurysms and the role that arteriography should play in the study of chiasmatic lesions have been discussed.
Contralateral and ipsilateral microsurgical approaches to carotid-ophthalmic aneurysms.
1997
Objective The vicinity of carotid-ophthalmic aneurysms to the roof of the cavernous sinus, to the anterior clinoid process, and to the optic nerve or the optic chiasm requires well-defined surgical techniques. Although microsurgical techniques with ipsilateral direct approaches to these aneurysms have been described in detail, studies about contralateral strategies for the microsurgical treatment of carotid-ophthalmic aneurysms are rare and are mainly confined to case reports. The aim of this study is to describe how to decide on the ipsilateral and contralateral microsurgical approaches to such aneurysms and to demonstrate the surgical techniques for the ipsilateral and contralateral expos…
Biportal neuroendoscopic microsurgical approaches to the subarachnoid cisterns. A cadaver study.
1996
A preclinical cadaver study was performed to develop the technique of biportal neuroendoscopic dissection in the subarachnoid space of the basal cisterns and to test the feasibility, utility, and safety of this new technique. In 23 fresh post-mortem adult human cadavers and 2 formalin-fixed adult human head specimen a total of 33 biportal endomicrosurgical dissections into and within the basal cisterns were carried out. Following suction of cerebrospinal fluid from the subarachnoid space 0 degree-, 30 degrees-, and 70 degrees-lens-scopes (Aesculap AG, Tuttlingen, Germany) with outer diameters of 4.2 mm and trochars with outer diameters of 5 to 6.5 mm were introduced into the surgical field.…
Inferior altitudinal hemianopia associated with a tumor in the posterior fossa: report of a case
1984
Altitudinal hemianopias may be related to chiasmatic involvement. A case in which horizontal inferior hemianopia is associated with a tumor in the posterior fossa producing a triventricular hydrocephalus is described. The visual field defect is interpreted as a consequence of the pressure by a dilated third ventricle upon the chiasmatic area.
Intracranial pathology of the visual pathway.
2004
Intracranial pathologies involving the visual pathway are manifold. Aligning to anatomy, the most frequent and/or most important extrinsic and intrinsic intracranial lesions are presented. Clinical symptoms and imaging characteristics of lesions of the sellar region are demonstrated in different imaging modalities. The extrinsic lesions mainly consist of pituitary adenomas, meningeomas, craniopharyngeomas and chordomas. In (asymptomatic and symptomatic) aneurysms, different neurological symptoms depend on the location of aneurysms of the circle of Willis. Intrinsic tumors as astrocytoma of any grade, ependymoma and primary CNS-lymphoma require the main pathology in the course of the visual …
Vergleich der Wertigkeit von Magnetresonanztomographie und Computertomographie bei Patienten mit Nelson-Syndrom
1992
The hypophyses of 13 patients with Nelson syndrome following bilateral adrenalectomy were examined by MRI and CT. Diffuse enlargement of the hypophysis was demonstrated in 8 patients by CT and in 9 by MRI. Compared with CT, MRI provides better demonstration of tumour development, such as abnormal convexity of the cranial margin of the hypophysis (MRI 4/13, CT 1/13), displacement of the infundibulum (MRI 4/13, CT 0/13) or optic chiasm (MRI 2/13, CT 0/13). MRI also provides diagnostically important differentiation between scar tissue and recurrence of tumour following hypophysectomy (MRI 1/3, CT 0/3) and more accurate demonstration of infiltration of the cavernous sinus (MRI 4/13, CT 2/13). C…
Morphological and electrophysiological evidence for habenular influence on the guinea-pig pineal gland
1981
The central innervation of the guinea-pig pineal gland was investigated by histological and electrophysiological methods: Staining the pineal gland and the epithalamus, a double route of central innervation could be shown in the anterior part of the organ: (a) Fibres from the habenular nuclei, mainly from the lateral part, penetrate the organ via the pineal stalk. (b) Other fibres join the striae medullares and running in the habenulae reach the organ more dorsally. The fibres end in the intercellular space where they form a dense network. In 15 male guinea-pigs under urethane anesthesia, two series of unit recording experiments were performed: (a) Recordings were made from 128 units in the…
Electrophysiological characterization of the pineal gland of golden hamsters.
1987
In one of the most-widely used species in pineal gland research, the strongly photoperiodic golden hamster, Mesocricetus auratus, no electrophysiological data on pinealocytes are currently available. To fill this gap, in the present study 185 spontaneously active pinealocytes from male golden hamsters were recorded extracellularly, both during day- and night-time (light: dark cycle 12 ∶ 12, lights on at 07.00 h). As in other species, pinealocytes exhibited action potentials of 1–2 ms duration. An irregular firing pattern was observed in 95% of the pinealocytes, the remainder fired more regularly or showed a phasic discharge pattern. The firing frequencies ranged from 0.2 to 25 Hz and showed…
Endoscopic transventricular third ventriculostomy through the lamina terminalis
2010
Object Endoscopic third ventriculostomy (ETV) has become a well-accepted option for obstructive hydrocephalus. However, standard ventriculostomy at the floor of the third ventricle might not be feasible under certain conditions. Here, the authors report in detail on their initial experience with an alternative option of endoscopic ventriculostomy through the lamina terminalis via a transventricular route. Methods Endoscopic third ventriculostomy through the lamina terminalis from a transventricular transforaminal route was evaluated in 4 cadaveric human heads and in 4 clinical cases. Results In all 4 human cadavers, an opening of the lamina terminalis via a transventricular approach could …
Cavernous malformation of the optic chiasm: An uncommon location
2015
Background: Cavernous malformations (CMs) of the optic chiasm are rare lesions often presenting with acute chiasmal syndrome or a progressive visual loss. The case of a 48-year-old female with an intrachiasmatic CM is presented. Case Description: The patient presented with an insidious history of progressive visual loss. Magnetic resonance imaging (MRI) showed a CM in the suprasellar region. The patient was operated via a right pterional approach with a complete lesion removal. The postoperative course was uneventful. Early postoperative ophthalmological examination revealed minimal improvement of the vision in the left eye. Conclusion: The clinical, neuroradiological, and intraoperative fi…