Tuber Cinereum Research Articles

Endoscope-assisted supraorbital approach to the retroinfundibular area: a cadaveric study

The purpose of this study is to investigate and evaluate the exposure and maneuverability of this areas provided by an endoscope-assisted supraorbital approach and to compare that to a microscopic supraorbital approach. We exposed microscopically the optico-carotid and the infrachiasmatic windows after a supraorbital craniotomy executed using an eyebrow incision. We then proceeded to explore the retroinfundibular area using these two windows either using the microscope alone or using the endoscope-microscope combination where the microscope was used to (1) guide instrument and endoscope insertion into the surgical field, and (2) explore (with microscopic 3-d vision) subsegments of the endoscopic field of view. We compared the exposure and surgical maneuverability of the approach utilizing the microscopic mode alone with the endoscope-assisted mode. We evaluated the exposure and the surgical maneuverability of key anatomical structures of the retroinfundibular area. The structures evaluated included the diaphragma sellae, the dorsum sellae, the posterior clinoid process, the pituitary stalk, the mammillary bodies, the tuber cinereum, the oculomotor nerves, the basal pons, the upper trunk of the basilar artery, the superior cerebellar arteries, the posterior cerebral arteries, the posterior communicating arteries and the basilar bifurcation. The exposure and the surgical maneuverability were significantly higher in the endoscope-assisted mode (P < 0.0001). Based on our study, the endoscope-assisted supraorbital retroinfundibular approach is associated with larger exposure and maneuverability than the pure microscopic approach. Further clinical information is required to verify the results of this study.

Optimal entry point and trajectory for endoscopic third ventriculostomy: evaluation of 53 patients with volumetric imaging guidance

An optimal entry point for endoscopic third ventriculostomy (ETV) helps protect critical structures from undue manipulation. A commonly accepted ideal entry point is 3 cm from the midline and 1 cm anterior to the coronal suture. The authors of this study reexamine this ideal entry point. Trajectory views from MR images or CT scans used for cranial image guidance in 53 patients (age range 3-85 years) who had undergone ETV were retrospectively evaluated. The trajectory from the tuber cinereum back through the center of the foramen of Monro was projected to the surface of the head. The relation of the entry point to the midline and the coronal suture was established. The mean perpendicular distance from the ideal entry point to the midline was 30.1 ± 7 mm (median 31.9 mm, range 12.5-42.2 mm). The mean perpendicular distance to the coronal suture was 8.9 ± 14.1 mm posterior (median 10.4 mm), ranging from 30.6 mm anterior to 35.8 mm posterior. The entry point tended to be located more posteriorly in women and adults: 5.8 ± 15.4 mm posterior in males versus 13.1 ± 13.2 mm posterior in females (p = 0.08) and 9.1 ± 14.8 mm posterior in adults versus 8.2 ± 11.7 mm posterior in children (p = 0.84). While the entry point may need to be modified from the ideal trajectory for other anatomical reasons, such as a trajectory through the motor cortex, in general, the authors found that the optimal entry point for ETV was more posterior than previously published and highly variable. Using image guidance or a customized trajectory based on analysis of a patient's own imaging is highly preferable to using an empirical ideal trajectory.

Challenges in the surgical treatment of epilepsy: hypothalamic hamartoma in infancy - case report

INTRODUCTION: Hypothalamic hamartoma is a rare congenital malformation, characterized by epilepsy, especially gelastic seizures, psychomotor developmental delay, mental retardation, behavioral disorders and precocious puberty. Epilepsy has early onset and is usually medically refractory. Etiology and pathophysiological mechanisms are unclear. The EEG can present disorganization and slowing of background activity and multifocal and/or generalized epileptogenic discharges. OBJECTIVE: To report the difficulties and challenges of neurosurgical treatment of a hypothalamic hamartoma in an infant. CASE REPORT: Infant with seizures since eight months old of age. The neurological investigation revealed a lesion in tuber cinereum suggestive of hamartoma. The epilepsy evolved with resistance to antiepileptic drugs, requiring neurosurgical procedure. The endoscopic resection could not be performed because the hamartoma was firmly attached to the hypothalamus. Currently, the child remains with tonic, clonic and atonic seizures. DISCUSSION: Lesionectomy performed by microsurgery or radiosurgery seems to be the most effective treatment for seizure control in patients with hypothalamic hamartomas who do not respond to clinical treatment. Callosotomy may be effective in selected cases, and lobectomy/cortical resections are not related to seizure control. In some patients, particularly in infants, lesionectomy and radiosurgery may be technically unfeasible.

Rathke′s cyst with ectopic neurohypophysis presenting as severe short stature with delayed puberty

Ectopic neurohypophysis (EN) is found in nearly half of children with growth hormone deficiency (GHD). Rathke's cyst (RC) is uncommon in children and when present, hypopituitarism is found in nearly half of them. We present a fourteen and half-year-old girl with severe short stature and delayed puberty who on evaluation was found to have GHD, secondary hypocortisolism, and hypogonadism. Imaging revealed hypoplastic anterior pituitary, stalk agenesis, EN at tuber cinereum and intrapituitary RC. This is perhaps the first report of simultaneous occurrence of EN and RC, which was seen in a girl with multiple pituitary hormone deficiency. A primary defect in pituitary development may explain this simultaneous occurrence of EN and RC and hence this severe anterior pituitary function deficit.

Endoscopic Third Ventriculostomy for Obstructive Hydrocephalus Caused by a Large Upper Basilar Artery Aneurysm After Coil Embolization

A 76-year-old female presented with a large upper basilar artery (BA) aneurysm causing obstructive hydrocephalus after coil embolization manifesting as diplopia. Magnetic resonance (MR) imaging and MR angiography showed a large BA top aneurysm. Coil embolization was performed. More than 6 months after the first coil embolization, the aneurysm had re-grown and we performed a second coil embolization. Soon after that, obstructive hydrocephalus at the aqueduct of the midbrain occurred. MR imaging was performed to evaluate whether there was enough space at the prepontine cistern for a third ventriculostomy and also to verify the posterior direction of the aneurysm growth because of the risk of rupturing the aneurysm during the operative procedure. Then, we performed an endoscopic third ventriculostomy (ETV) via a left-sided approach. We could easily identify the infundibular recess, mamillary bodies, and tuber cinereum in the third ventricular floor. We detected a pulsating upper BA aneurysm that appeared to have caused a reddish color change in the right mammillary body and the right side of the thalamus and midbrain. If there is sufficient space in the prepontine cistern for the surgical procedure, ETV is a good choice for the treatment of obstructive hydrocephalus associated with cerebral aneurysms.

Precocious puberty in children: A review of imaging findings.

Objectives:This review was aimed at determining the imaging findings in patients with precocious puberty.Results:Within a period of 8 years (from 2002 to 2010) there were 53 patients diagnosed with precocious puberty. Out of the 53 patients, 37 had undergone diagnostic imaging to detect the possible organic causes of precocious puberty. Imaging findings were positive in 31 patients and out of that, 3 patients had 2 findings each (34 abnormalities). Of the patients with positive imaging findings, central precocious puberty (gonadotrophin-dependent) was more common (81%; 25/31) and the causes included: tuber cinereum hamartoma (n = 10), glioma (n = 6), pineal gland tumour (n = 4), hydrocephalous (n = 3), arachnoid cyst (n = 2) and others (n = 3). Peripheral precocious puberty (gonadotrophin-independent) causes included: testicular adrenal rest tumour (n = 3), adrenal carcinoma (n = 1), ovarian granulosa thecal cell tumour (n = 1), and tuberous sclerosis (n = 1).Conclusion:Positive imaging findings were observed in 84% (31/37) of the subjects. Hypothalamic hamartoma was the most common imaging finding in central precocious puberty while testicular adrenal rest tumour was the most common imaging finding in peripheral precocious puberty.

When Baby’s giggles are not funny: seven years overlooked diagnosis in a case of gelastic seizures

Laughter actually has positive emotional effect. However, it could be pathologic when laughter is not related to emotion and occurs independent of a stimulus in the environment. We reported a 7-year-6-month old Thai boy who presented with ‘early giggles’ since the age of 2 months. Despite parental concerns, the symptoms were overlooked until seven years of age, when he developed complex partial seizures. An MRI study of the brain revealed a small ill defined lesion within the tuber cinereum that was compatible with hypothalamic hamartoma.&nbsp

Amenorrhea complicating endoscopic third ventriculostomy in the pediatric age group

Endoscopic third ventriculostomy (ETV) is an accepted option in the treatment of obstructive hydrocephalus in children and is considered by many pediatric neurosurgeons to be the treatment of choice in this population. The procedure involves perforation of the floor of the third ventricle, specifically, the tuber cinereum, which is part of the hypothalamic-pituitary axis of cerebral endocrine regulation. Endocrine dysfunction, such as amenorrhea, weight gain, and precocious puberty, which are recognized only months to years after the procedure, may be underreported because patients and physicians may not relate the endocrine sequelae to the ETV. Few detailed reports of endocrine-related complications following ETV exist to better understand these issues. In this study, the authors add to the literature with case descriptions of and correlative laboratory findings in 2 adolescent girls who underwent ETV for obstructive hydrocephalus and in whom amenorrhea subsequently developed.

Actual state of EndActive ventricular endoscopy

We assessed usability and applicability of a rigid, multidirectional steerable videoendoscope (EndActive, Karl Storz GmbH, Tuttlingen, Germany) for endoscopic third ventriculostomy and compared our experience with reports about other multidirectional endoscopes. The prototype is a 4-mm-diameter rigid videoendoscope with an integrated image sensor comprising an embedded light source, offering a free viewing direction in a range of 160° while the tip itself does not move. In five specimens (ten sides), we introduced the endoscope via precoronal burr holes through the lateral ventricle and foramen of Monro into the third ventricle. The endoscope's tip was positioned at the level of the mamillary bodies and the previously defined anatomical target structures; anteriorly, the optic chiasm, anterior commissure, infundibulum, tuber cinereum and posteriorly, the entrance to the mesencephalic aqueduct and posterior commissure were inspected. A single insertion of the videoendoscope was sufficient to explore with the multiplanar viewing mechanism the entire third ventricle. The prototype videoendoscope may be held like a microsurgical instrument in one hand. It is feasible to control movements precisely due to the reduced weight and ergonomic shape of the device. The prototype EndActive has the potential to fit in the current concept of ETV and enrich the setting adding working economy and viewing variability.

Quantitative Ventricular Neuroendoscopy Performed on the Third Ventriculostomy: Anatomic Study

One of the key elements for a successful endoscopic intervention in the ventricular system is the ability to recognize the anatomic structures and use them as a reference. To measure the choroid plexus with endoscopy in the interventricular foramen, together with the structures on the third ventricle floor, and to compare these variables. An observational prospective study was carried out on 37 brains of cadavers for which the cause of death was assessed at the Death Check Unit of the University of São Paulo in April 2008. This study was done on adults of both sexes with a rigid neuroendoscope. Endoscopic images were recorded, submitted for correction of distortion, and then measured. The measurements of the choroid plexus in the interventricular foramen, laterolateral distance of mammillary bodies, distance from the infundibular recess to the mammillary bodies, and area of the triangle in the tuber cinereum were 1.71 ± 0.77 mm, 2.23 ± 0.74 mm, 3.22 ± 0.82 mm, and 3.69 ± 2.09 mm, respectively. The ventricle floor was opaque in 84% of cases. The internal distance of mammillary bodies was absent in 89%. Associations between the translucent floor of the third ventricle and laterolateral distance of mammillary bodies, internal distance of mammillary bodies, and age were identified. Before this research, there was no record of the measurements of the choroid plexus in the interventricular foramen. The remaining variables of the present study show a greater number in normal brains compared with others.

EEG and video-EEG seizure monitoring has limited utility in patients with hypothalamic hamartoma and epilepsy

Hypothalamic hamartomas (HHs) are a malformation of the ventral hypothalamus and tuber cinereum, associated with gelastic seizures and epilepsy. We sought to determine the spectrum of electroencephalography (EEG) abnormalities in a large cohort of HH patients. Data was collected for HH patients undergoing evaluation between 2003 and 2007. Data included seizure history, prior treatment, and results of diagnostic studies. After informed consent, data were entered into a database. We reviewed 133 HH patients. Mean age at time of data analysis was 15.7 years (59.4% male). Most patients had gelastic (77%) and/or complex partial seizures (58%). Records for 102 EEG studies on 73 patients were reviewed. Interictal epileptiform abnormalities were seen in 77%, localizing predominately to the temporal and frontal regions. Records for 104 video-EEG (VEEG) studies on 65 patients were reviewed. Of 584 gelastic seizures (GS) captured, no ictal EEG change was noted in 438 (75%). Of GS with localizing features, 89% suggested onset from the temporal and/or frontal regions. There were 160 complex partial seizures (CPS). For those with localizing features, 100% localized to the temporal and/or frontal head regions. EEG and VEEG findings correlated with the side of HH attachment. VEEG did not influence outcome. EEG features in HH patients are diverse. The majority of gelastic seizures fail to demonstrate change in the EEG. The lack of EEG changes with many clinical seizures, and the false localization seen in those events with an ictal change suggest the utility of EEG is limited in the evaluation of these patients.

Exophytic hypothalamic cavernous malformation mimicking an extra-axial suprasellar mass

We report the case of a 31-year-old male who presented to the ER with a 1-week history of progressively worsening, throbbing, left retro-orbital headache, ptosis, and subjective worsening of short-term memory function. Initial review of systems and laboratory data were noncontributory. Non-contrasted CT demonstrated a large hyperdense mass centered in the suprasellar cistern without evidence of dissecting extra-axial hemorrhage. Though the initial appearance mimicked a basilar tip aneurysm or another primary extra-axial suprasellar pathology such as a hemorrhagic or proteinaceous craniopharyngioma, germinoma, or optic glioma, a second smaller, clearly intra-axial, hyperdense lesion was observed in the left periventricular forceps major white matter. Consideration for multiple cavernomas versus hypervascular metastatic disease such as renal malignancy, thyroid malignancy, or melanoma was raised. CTA confirmed normal intracranial vasculature. Subsequent MRI images showed an acutely hemorrhagic mass centered at the left paramedian hypothalamus and tuber cinereum with numerous secondary foci, demonstrating mature hemorrhagic elements and confirming the diagnosis of multiple cavernomas.

Anaesthetic considerations and perioperative features of endoscopic third ventriculostomy in infants: analysis of 57 cases

Endoscopic third ventriculostomy (ETV) is currently considered the best alternative to shunt systems in the treatment of triventricular hydrocephalus. However, there has been very few published data about the anaesthetic management and the complications of ETV procedure in infants. In this report, we detail our experience with 57 infants, who underwent ETV as an initial treatment for obstructive triventricular hydrocephalus between 2003 and 2010. Anesthesia chart-records were retrospectively investigated and perioperative data were classified according to the stages of the procedure. In this series, mean heart rate values showed a statistically significant difference in the period concerning the balloon dilatation of ventriculostomy orifice. An episode of bradycardia occurred in 2 patients during balloon dilatation. After the deflation of the balloon, bradycardia resolved immediately without administration of any medication. Video recordings of those two patients revealed that one of them had a narrow and opaque tuber cinereum, and the other had a shallow interpeduncular cistern. During ETV procedure in infants, bradycardia may be a serious complication especially when performing balloon dilatation of the ventriculostomy orifice. We believe that close communication between the surgeon and the anaesthetist is extremely essential in this stage of the procedure.

Unique concurrent appearance of two rare conditions in a young girl: central precocious puberty due to hypothalamic hamartoma and uncommon type of diabetes

Hypothalamic hamartomas (HH) are rare congenital nonneoplastic lesions of the tuber cinereum, which usually present as precocious puberty of central origin in young girls and respond well to treatment with long acting gonadotropin releasing hormone (GnRH) analogs. No association of this condition with diabetes mellitus of any form has been reported so far. On the other hand, diabetes mellitus in children and adolescents, when it is not autoimmune type 1 diabetes, is difficult to classify. We present a girl with early onset of central precocious puberty at the age of 8 months, due to hypothalamic hamartoma. Treatment with depot of a GnRH analog for a period of 9 years and 8 months was successful, and her puberty continued 6 months after the discontinuation of triptorelin. At the age of 9 years 6 months, the girl presented with diabetes. She was negative for islet, GAD and IA2 antibodies and her insulinemia and C-peptide remained within normal limits during the 2 years of follow-up. Her metabolic control is excellent with a combination of metformin and a low-dose of mixed insulin. To our knowledge, this is the first description of the simultaneous appearance of these two endocrinological conditions.

Endoscopic third ventriculostomy in adults: a technique for dealing with the neural (opaque) floor

An opaque (neural) floor of the third ventricle is considered an obstacle to safe penetration of the floor of the third ventricle in endoscopic third ventriculostomy (ETV). The direct technique of endoscopic coring ("cookie cut") of the opaque (neural) floor of the third ventricle is described in 41 cases among a total of 101 consecutive adult ETVs. A 0° endoscope in a 4.6-mm irrigating sheath was used to press and core ("cookie cut") a section of the tuber cinereum, thereby exposing the underlying membranes and vasculature. Thereafter, the endoscopic apparatus was used to penetrate the membrane into the prepontine space. Among 101 consecutive ETVs performed in adults, there were 41 instances of an opaque floor in which the coring technique was used. The basilar artery (BA) complex was in the intended path of penetration in 13 cases. There were no perioperative deaths or vascular injuries. No cases were aborted because of the opaque floor or the configuration of the BA complex. The clinical success rate in the opaque floor group was 80% (33 of 41 patients). An opaque (neural) floor is frequently seen in adults during ETV. Removing the floor by the core ("cookie cut") method is a safe means of revealing the underlying BA complex and membranous structures prior to penetration into the prepontine cistern. On occasion, the BA complex may be in the path of penetration, and one can maneuver the endoscope to displace the vasculature to successfully accomplish the ETV.

Cystic hamartoma of the tuber cinereum

Dear Editor, Hamartomas of the tuber cinereum have been reported in the past [1]; however, a cyst of the tuber cinereum per se has never been reported. We report a case of cystic hamartoma of the tuber cinereum along with its management. A 17-year-old male presented with complaints of generalised tonic–clonic seizures 5 years ago and subnormal intelligence. There was progressive cognitive decline with somnolence for 6 months. The visual acuity was difficult to assess; however, he would communicate with relatives and hold objects when asked to without groping. The right pupil reacted well to light and the left one was non-reactive suggesting left visual loss. It was not possible to examine the fundus. A magnetic resonance imaging (MRI) brain scan showed a non-enhancing cystic lesion (5×5 cm) occupying the interpeduncular and prepontine cistern with splaying of cerebral peduncles, pushing the posterior hypothalamus anterosuperiorly and the mamillary bodies posterosuperiorly (Fig. 1a, b). There was no significant change in the size of the lesion when compared to the CT scan of the head done 3 years ago. There were no endocrine abnormalities. In view of progressive cognitive decline and possible visual compromise, he underwent surgery through the right transylvian route. The carotico-optic, inter-optic and carotico-oculomotor space were occupied by a cystic lesion with a smooth wall resembling a normal brain. A small part of this normal-looking wall was biopsied letting out clear fluid. The fluid was similar to cerebrospinal fluid. The cyst collapsed, though partly, and the wall could be traced to the tuber cinereum. The stalk was not seen separately. The Omaya reservoir was placed into the cyst through the right frontal burr hole. Histopathology revealed normal glial tissue with a few normal-looking neurons. There was no epithelial lining seen. There was no significant improvement in the patient's clinical status, and he continued to remain in the same status even after 3 months. The seizure frequency, however, reduced. Post-operative scan revealed a minimal decrease in the size of the lesion. Re-aspirating the cyst did not help. A hamartoma is a non-neoplastic heterotopic nodule resembling the normal hypothalamic grey matter. It results from a faulty development in an organ and is composed of an abnormal mixture of its constituent elements. It develops and grows at virtually the same rate as do the normal components of the organ of its origin. It does not compress adjacent tissues. During the fifth and sixth week of gestation, the ventral aspect of the neuroaxis approaches the anterior tip of the end of the notochord. Hypothalamic hamartomas of this region may be due to tissue displacement during that period [1]. The clinical features of the lesions in this region are: (1) isosexual precocious puberty (commonest presentation); (2) seizure disorders, gelastic epilepsy and partial complex P. S. Salunke (*) : S. Sura Department of Neurosurgery, PGIMER, Chandigarh 160012, India e-mail: drpravin_salunke@yahoo.co.uk

Central Precocious Puberty due to Hypothalamic Hamartomas Correlates with Anatomic Features but Not with Expression of GnRH, TGFα, or KISS1

Background/Aims: Hypothalamic hamartomas are the most common identifiable cause of central precocious puberty (CPP). Hamartoma characteristics proposed to be associated with CPP include specific anatomic features and expression of molecules such as gonadotropin-releasing hormone (GnRH), transforming growth factor α (TGFα), and GRM1A, which encodes the type 1 metabotropic glutamate receptor α isoform. We sought to determine whether hamartomas that cause CPP could be distinguished by anatomic features, expression of these molecules, or expression of KISS1, whose products signal through the receptor GPR54 to stimulate GnRH release. Methods: Clinical records and radiologic images were reviewed for 18 patients who underwent hamartoma resection for intractable seizures; 7 had precocious puberty. Resected tissue was examined for expression of GnRH, GnRH receptor (GnRHR), TGFα, KISS1, GPR54, and GRM1A. Results: Hypothalamic hamartomas associated with CPP were more likely to contact the infundibulum or tuber cinereum and were larger than hamartomas not associated with CPP. GnRH, TGFα, and GnRHR were expressed by all hamartomas studied. Expression of KISS1, GPR54, and GRM1A did not differ significantly between hamartomas associated and not associated with CPP. Conclusion: Anatomic features rather than expression patterns of candidate molecules distinguish hypothalamic hamartomas that are associated with CPP from those that are not.

Endoscopic third ventriculostomy in patients with a diminished prepontine interval

Fenestration of the floor of the third ventricle is vital to the success of endoscopic third ventriculostomy (ETV) in treating patients with noncommunicating hydrocephalus. A generous prepontine interval (PPI) is generally accepted as one anatomical feature that may affect the safety and functionality of ETV. Whether a diminished PPI influences the safety or success of ETV, however, has not been adequately assessed. A review was conducted on the last 100 ETV procedures performed by the first author (M.M.S.). From archived preoperative MR imaging studies, the PPI was measured between the dorsum sellae and the basilar artery. For any patient with an interval of <or=1 mm, the technical and functional success of the procedure was recorded. Technical success was defined when a surgically created fenestration was accomplished without patient morbidity. Functional success was defined as the patient not needing any additional CSF diversionary procedure within 3 months after ETV. In the entire cohort, the PPI ranged from 0 to 9.5 mm (mean 3.2 mm). There were 15 procedures performed in patients with a PPI of <or=1 mm. In all 15 procedures, a fenestration of the tuber cinereum was accomplished without vascular injury or patient morbidity. The ETV was successful in 11 patients (73.3%). All 4 failures occurred in children who had surgery during infancy (mean age 11 months). Patients with an obliterated or reduced PPI can safely undergo ETV. The functional success rate appears equivalent to historical controls. Most failures in this series may be attributed to other patient characteristics, namely young age at the time of ETV.

Staged Use of the Transsphenoidal Approach to Resect Superior Third Ventricular Craniopharyngiomas

Craniopharyngiomas are benign tumors, usually originating from the infundibulum or tuber cinereum. Their surgical treatment is challenging because of their relationship to neural and vascular structures. Large craniopharyngiomas that invade the upper third of the third ventricle are a common reason for patients to need a second operation to accomplish a gross total resection. Transsphenoidal approaches are being increasingly used in the treatment of craniopharyngiomas. Large craniopharyngiomas involving the superior third ventricle are most commonly resected through a staged approach, often involving a transcortical or interhemispheric route. The authors describe the use of an extended transsphenoidal approach as a second-stage operation to resect the intraventricular component of a large craniopharyngioma in an illustrative case. The authors find this to be an excellent indication for an endoscopic extended transsphenoidal approach in selected cases.

Sectional Anatomy of the Optic Pathways on the Coronal Plane

The purpose of this study was to provide practical data for the imaging diagnosis of the optic pathways. Sectional anatomy of the optic pathways on the coronal plane was investigated on 15 sets of serial coronal sections of the head of Chinese adult cadavers and 6 sets of serial coronal magnetic resonance imaging of normal adults. On the coronal plane, we recognized the special structures of optic pathways by 5 key sections. (1) The midorbital optic nerve lay superomedially in the center of the adipose body of the orbit, surrounded by the subarachnoid space and the sheath of the optic nerve. (2) The optic chiasma was transverse between the optic and infundibular recesses of the portion of the floor of the third ventricle and it lay below the A1 segment of the anterior cerebral artery and above the tuber cinereum and the pituitary stalk, C2 or C3 segment of the internal carotid artery laterally. (3) The optic tract lay between the crus cerebri and the amygdaloid, the tail of the caudate nucleus laterally. The anterior choroidal artery inferiorly and downward M2 segment of the middle cerebral artery lay between the uncus and the crus cerebri. (4) The lateral geniculate body lay between the crus cerebri medially and the tail of the caudate nucleus laterally, the uncus and P2 segment of the posterior cerebral artery inferiorly. (5) The optic radiation formed the lateral wall of the lateral ventricle both in the temporal horn and in the occipital horn. The optic radiation was separated from the wall of the occipital horn by the tapetum, a thin layer of fibers derived from the splenium of the corpus callosum. Coronal sectional anatomy and magnetic resonance imaging of the optic pathways revealed similar results. This study provides a good understanding of the structures of the optic pathways by correlation of coronal sections of the head of adult cadavers with the coronal magnetic resonance images of normal adults.