Septo-optic dysplasia, first described by de Morsier in 1956, is an uncommon congenital midline structural abnormality of the brain, including agenesis of septum pellucidum, primitive optic ventricle and dysplasia of the optic chiasm, optic nerves, and infundibulum. Agenesis of septum pellucidum, initially thought to be an integral part of this syndrome, is inconstant and not an essential part of the disorder. Also, it reveals a variable spectrum of associated abnormalities in disturbed hypothalamic-pituitary function. We recently experienced 3 patients of septo-optic dysplasia who showed bilateral optic disc hypoplasia clinically and midline structural abnormalities in computerized tomography(CT) or magnetic resonance imaging(MRI).
Brain ; Humans ; Optic Chiasm ; Optic Nerve ; Septo-Optic Dysplasia* ; Septum Pellucidum

PURPOSE: This is study of whether 3-D conformal radiotherapy for carcinomas of the ethmoid sinus were better than those treated with conventional 2-D plan. MATERIALS AND METHODS: The 3-D conformal treatment plans were compared with conventional 2-D plans in 4 patients with malignancy of the ethmoid sinus. Isodose distribution, dose statistics, and dose volume histogram of the planning target volume were used to evaluate differences between 2-D and 3-D plans. In addition, the risk of radiation exposure of surrounding normal critical organs are evaluated by means of point dose calculation and dose volume histogram. RESULTS : 3-D conformal treatment plans for each patient that the better tumor coverages by the planning target volume with improved dose homogeneity, compared to 2-D conventional treatment plans in the same patient. On the other hand, the radiation dose distributions to the surrounding normal tissue organs, such as the orbit and optic nerves are not significantly reduced with our technique, but a substantial sparing in the brain stem and optic chiasm for each patient. CONCLUSION : Our findings represented the potential advantage of 3-D treatment planning for dose homogeniety as well as sparing of the normal tissue surrounding the tumor. However, further investigational studies are required to define the clinical benefit.
Brain Stem ; Ethmoid Sinus* ; Hand ; Humans ; Optic Chiasm ; Optic Nerve ; Orbit ; Radiotherapy, Conformal*

Cavernous malformations (CMs) arising from the optic nerve and chiasm are extremely rare. The authors present a case of 39-year-old woman with CMs of the optic chiasm. She was referred due to sudden onset of bitemporal hemianopsia and headache, the so-called 'chiasmal apoplexy'. MRI findings suggested a diagnosis of hemorrhage and vascular malformation of the optic chiasm. Pterional craniotomy revealed an intrachiasmatic cavernous malformation with hemorrhage. The malformation was totally excised, but field deficits remained unchanged after surgery.
Adult ; Caves ; Craniotomy ; Female ; Headache ; Hemianopsia ; Hemorrhage ; Humans ; Optic Chiasm ; Optic Nerve ; Stroke ; Vascular Malformations

A twenty nine-year-old woman has suffered for ten years from progressive proptosis and loss of vision in the right eye. Her right eye had deviated out-and-upwards, and its visual acuity was tested by hand motions. With the help of a brain and orbit CT, the tumor was found around the optic nerve and in the parasellar area. This tumor was surgically removed twice by Kroenlein operation and craniotomy, and was treated with irradiation(total dose: 5400 RAD). It was histopathologically diagnosed as astracytoma grade I. In the consecutive study, no evidence of recurrence of the tumor in either the orbit or brain was found.
Brain ; Craniotomy ; Exophthalmos ; Female ; Hand ; Humans ; Optic Chiasm* ; Optic Nerve Glioma* ; Optic Nerve* ; Orbit ; Recurrence ; Visual Acuity

The association of abnormalities of the optic nerves, optic chiasm, and optic tracts with anomalies of the midline structures in the brain-an absent septum pellucidum etc was reported and called "septo-optic dysplasia". Also, it was noted that septo-optic dysplasia could be associated with hypopituitary dwarfism. It occurs more commonly in first born children and children born to young or diabetic mothers. We report a case of septo-optic dysplasia with literature, who had complained of severe visual impairment associated with nystagmus, bilateral optic nerve hypoplasia, absent septum pellucidum, and normal range of hormone studies.
Child ; Dwarfism ; Humans ; Mothers ; Optic Chiasm ; Optic Nerve ; Reference Values ; Septo-Optic Dysplasia* ; Septum Pellucidum ; Vision Disorders ; Visual Pathways

To demonstrate the effect of diaschisis and to evaluate its possible mechanism in acute unilateral infarction, the changes of regional cerebral flows(rCBF's) on the both MCA territories and both cerebellum were measured by the hydrogen clearance method using the unilateral cerebral and cerebellar infarction model. Cerebral infarction model was made by left middle cerebral artery(MCA) occlusion through the transorbital approach and cerebellar infarction was made by coagulation of cerebellar vessels through retromastoid craniectomy. Experimental groups consisted of left MCA occlusion group-12cats, left MCA occlusion with callosal section group-15cats and cerebellar infarction group-13cats. After measurement of rCBF for 8 hours at fixed intervals the animals were sacrificed and immediately thereafter 50ml of 2% triphenyl tetrazolium chloride(TTC) solution was immediately injected in order to examine the size of infarction. The results were as follows ; 1) After occlusion of left MCA, the rCBF of ipsilateral MCA territory decreased abruptly and significantly(p<0.001), reaching unmeasurable value 1 hour after occlusion. The rCBF of contralateral cerebellum decreased 25.5~32.6% of control value. On the ipsilateral MCA territory the rCBF decreased 18.5~41.0% and the rCBF of ipsilateral cerebellum decreased 19.0~30.0% of control value(p<0.01). 2) In the group of left MCA occlusion with callosal section, the rCBF of contralateral MCA territory decreased 4.8~16.4% of control value but it is less marked and not significant statistically(p>0.05). 3) In the group of cerebellar infarction, the rCBF of contralateral cerebellum and both MCA territories did not decrease significantly in either group of cerebellar blood flow less than 10ml/ 100g/min or 10~20ml/ 100g/min. 4) In the experimental group of left MCA occlusion, infarction revealed 40.2+/-2.8% of coronal plane through the optic chiasm showing high percentage of infarction yield with small standard deviation. In the cerebellar infarction model the extent of infarction was 36.0+/-10.0% of horizontal planes of cerebellum in the group of rCBF below 10ml/100g/min. In the group of rCBF of 10~20ml/100g/min the extent of infarction was 22.0 +/-12.0%. These findings show the crossed cerebellar as well as interhemispheric diaschisis and support the importance of neural pathway in the mechanism of diaschisis. However further studies for long-term results and mechanism of diaschisis are needed.
Animals ; Cerebellum ; Cerebral Infarction* ; Corpus Callosum ; Hydrogen ; Infarction ; Middle Cerebral Artery ; Neural Pathways ; Optic Chiasm

To demonstrate the effect of diaschisis in acute unilateral cerebral infarction, the changes of regional cerebral and cerebellar blood flow(rCBF) following experimental occlusion of one middle cerebral artery(MCA) were studied in 15 mongrel cats, following occlusion of left MCA by coagulation using transorbital approach, rCBF's of both MCA trerritories and both cerebellum were measured simultaneously by the hydrogen clearance technique. Sham operation group consisted of 5 cats, in which transorbital exposure of left MCA was performed and the rCBF's were measured in the same manner as the experimental group without cauagulation of left MCA. After measurement of rCBF for 8 hours at fixed intervals, the animals were sacrificed and immediately thereafter 25 ml of 2% triphenyl tetrazolium chloride(TTC) solution was injected through each common carotid artery. The brain was removed and immersed in 10% buffered fomalin solution for two weeks, then the coronal plane through optic chiasm was examined for the cerebral infarction. As results, contralateral MCA territory and both cerebellum showed diaschisis after occlusion of left MCA, and contralteral cerebellar rCBF decreased more, showing characteristics of crossed cerebellar as well as interhemispheric diaschisis. Sham operation group showed no infarction, and in experimental group 40.2+/-1.3% of the coronal plane through the optic chiasm was infracted, showing high percentage of infarction with small standard deviation.
Animals ; Brain ; Carotid Artery, Common ; Cats ; Cerebellum ; Cerebral Infarction* ; Hydrogen ; Infarction ; Middle Cerebral Artery ; Optic Chiasm

Ischemia is a rare cause of the optic chiasmal syndrome and is sometimes hard to define. The present report describes a 73 year ~ old male with abruptly developed visual field defect involving bitemporal hemianopsia and inferior binasal quadrantanopsia. The MRI study revealed focal anterior hypothalarnic atrophy which might be due to focal infarction. These findings are suggesting common blood supply of superior chiasmal circulation and anterior inferior hypothalamus.
Atrophy ; Hemianopsia ; Humans ; Hypothalamus ; Infarction* ; Ischemia ; Magnetic Resonance Imaging ; Male ; Optic Chiasm* ; Visual Fields

PURPOSE: Pilocytic astrocytoma is a benign tumor predominantly arising from cerebellum in pediatric age. But it occasionally arises in supratentorium. We describe radiologic findings of supratentorial pilocytic astrocytoma. MATERIALS AND METHODS: Eleven CT and 7 MR examinations in 11 patients were retrospectively reviewed with attention to location, CT density, MR signal intensity, and degree and pattern of contrast enhancement on CT and MR. RESULTS: The tumors were located around the third ventricle (hypothalamus in three cases, optic chiasm in three cases) and in cerebral hemisphere (temporal lobe in three cases, frontal lobe in one case, thalamus in one case). On CT, the tumors were all sharply demarcated and rarely associated with edema. The tumors showed moderate to strong contrast enhancement. Necrosis appeared frequently in tumors around the third ventricle in contrast to frequent cyst formation in hemispheric masses. On MR, the tumors appeared hypo- or isointense on T1- weighted images and hyperintense on T2- weighted images. After administration of contrast agent, the tumors showed intense enhancement more than that of CT. CONCLUSION: The typical location and radiologic findings described above are helpful in the diagnosis of the supratentorial pilocytic astrocytoma.
Astrocytoma* ; Cerebellum ; Cerebrum ; Diagnosis ; Edema ; Frontal Lobe ; Humans ; Necrosis ; Optic Chiasm ; Retrospective Studies ; Thalamus ; Third Ventricle

The juvenile pilocytic astrocytoma has histologically the same features as the adult type one. Contrary to the adult type, the parallel arrangement of fibrils in long thin tapering cells of the tumor is peculiarly independent of the environment in which the tumor is growing and it gives rise to the main tumor mass that is usually well circumscribed. The overall incidence is relatively rare of all the brain tumor, it occurs in children mainly from three to five of age. Its predilection sites are the hypothalamus and the optic chiasm. We are reporting an experience of a juvenile pilocytic astrocytoma in a three years old female patient, involving the hypothalamus, basal ganglia and deep white matter of the temporoparietal lobe of the left side.
Adult ; Astrocytoma* ; Basal Ganglia ; Brain Neoplasms ; Child ; Female ; Humans ; Hypothalamus ; Incidence ; Optic Chiasm