Trans-lamina Terminalis Approach for Resection of Third Ventricular Tumor.

Granular cell tumors are rare vascular neoplastic lesions of the sellar and suprasellar region that usually arise from the pituitary stalk but can originate as low as the posterior pituitary or as high as the tuber cinereum.1 Complete resection, although ideal, can yield high rates of endocrine or visual morbidity.1,2 On headache workup, a 66-year-old woman was found to have a 1.2 × 1.1 × 1.3-cm contrast-enhancing lesion in the anterior-inferior third ventricle, posterior to the infundibulum. Endocrine testing was unremarkable, and a lumbar puncture was nondiagnostic. An open biopsy and possible resection were selected by the patient over short-interval imaging. A translamina terminalis approach was selected over a transsphenoidal approach to preserve the third ventricular floor (Video 1). A right frontotemporal craniotomy was performed, including flattening of the lesser sphenoid wing. The optic chiasm was exposed via subfrontal microsurgical dissection, and the lamina terminalis was opened sharply. A firm, vascular tumor was identified extending into the anterior-inferior aspect of the third ventricle. Frozen pathologic analysis was nondiagnostic. Given the proximity of the optic chiasm, a complete piecemeal microsurgical resection was performed, preserving the floor and lateral walls of the third ventricle and optic apparatus. Final pathology was a granular cell tumor. Postoperatively, the patient had transient diabetes insipidus, with preserved vision and normal endocrine function on follow-up. The trans-lamina terminalis approach can be used for safe resection of anterior third ventricular tumors. Preservation of the floor and walls of the third ventricle is critical to avoid morbidity.

Ventricular volumetry and free-water corrected diffusion tensor imaging of the anterior thalamic radiation in idiopathic normal pressure hydrocephalus.

BACKGROUND AND PURPOSE: The pathophysiology of idiopathic normal pressure hydrocephalus (iNPH) has not been completely clarified. We investigated the brain structure in iNPH using automatic ventricular volumetry, single-tensor diffusion tensor imaging (DTI) and bi-tensor free-water (FW) imaging analyses while focusing on cognitive impairments before and after lumboperitoneal shunt surgery. MATERIALS AND METHODS: This retrospective study included 12 iNPH patients with structural magnetic resonance imaging (MRI) and diffusion MRI (dMRI) on a 3T-MRI scanner who underwent neuropsychological assessments before and after shunting and 8 healthy controls. Ventricular volumetry was conducted on structural MRI datasets using FreeSurfer. Ventricular volume was compared pre- and postoperatively. Correlation analyses were performed between ventricular volume or volume change and neuropsychological scores or score change. Tract-based spatial statistics were performed using dMRI datasets for group analyses between iNPH and controls and between pre- and post-surgery iNPH patients and for correlation analyses using neuropsychological scores. Tract-specific analyses were performed in the anterior thalamic radiation (ATR), followed by comparison and correlation analyses. RESULTS: The third ventricular volume was significantly decreased after shunting; its volume reduction negatively correlated with a neuropsychological improvement. Compared with controls, iNPH patients had lower fractional anisotropy and higher axial, radial, and mean diffusivities, and FW in the periventricular white matter including ATR, resulting in no difference in FW-corrected indices. Single-tensor DTI indices partially correlated with neuropsychological improvements, while FW-corrected indices had no correlations. CONCLUSION: Third ventricle enlargement is possibly linked to cognitive impairment and FW imaging possibly provides better white matter characterization in iNPH.

Secondary hypersomnia as an initial manifestation of neuromyelitis optica spectrum disorders.

The identification of AQP4-IgG, a specific and pathogenic antibody of NMO/SD has led to a broadening of the clinical spectrum of manifestations of NMO/SD including the presence of encephalic symptoms. Lesions are often distributed on peri­ependymal area and sometimes affected the diencephalon leading to sleep disorders. We report a case of hypersomnia with polysomnographic documentation during the first attack of NMO/SD. Brain MRI revealed bilateral hypothalamic lesions around the third ventricle, whereas optic nerves and spinal cord were intact. The record of the nocturnal video-polysomnography followed by multiple sleep latency tests (MSLT) revealed an abnormal shortened sleep period with a single sleep onset in REM allowing secondary central hypersomnia diagnosis. The recovery of hypersomnia was complete within few months without psychostimulant treatment and the diencephalic lesion disappeared. Thus, diencephalic form of NMO/SD seems to cause narcolepsy or non-narcoleptic central hypersomnia and have a good recovery.

Third Ventricle Obstruction by Thalamic Intracerebral Hemorrhage Predicts Poor Functional Outcome Among Patients Treated with Alteplase in the CLEAR III Trial.

INTRODUCTION: The Clot Lysis: Evaluating Accelerated Resolution of IVH trial examined whether irrigating the ventricular system with alteplase improved functional outcomes in patients with small intracerebral hemorrhage (ICH) and large intraventricular hemorrhage (IVH). Thalamic ICH location was common and was associated with poor outcome. One possible explanation is thalamic ICH-associated mass effect obstructing the third ventricle. We hypothesized that patients with thalamic ICH obstructing the third ventricle would have worse functional outcomes compared to patients without obstructing lesions. METHODS: ICH obstruction of third ventricle was defined as third ventricle compression on 1 or more axial computed tomography slices visually impeding cerebral spinal fluid flow. If the third ventricle was casted with IVH, it was scored as such. Multivariable logistic regression analyses were used to determine whether obstruction of the third ventricle predicts poor functional outcomes defined as modified Rankin score (mRS) 4-6, higher mRS, and mortality at 180 days. Models were adjusted for thalamic ICH location, ICH volume, IVH volume, age, hydrocephalus, baseline Glasgow coma scale, and percentage of low cerebral perfusion pressures during treatment. RESULTS: Among saline-treated patients, obstruction of the third ventricle by IVH was a significant predictor of higher mRS at 180 days (OR 1.87, CI 1.01-3.47) and mortality at 180 days (OR 2.73, CI 1.27-5.87) while obstruction by ICH was not. In contrast, among alteplase-treated patients, obstruction by ICH was a significant predictor of mRS 4-6 (OR 3.20, CI 1.30-7.88) and higher mRS at 180 days (OR 2.33, CI 1.24-4.35), while obstruction by IVH was not. CONCLUSIONS: Poor outcomes were associated with mass-related obstruction of the third ventricle from thalamic ICH in alteplase-treated patients and from IVH in saline-treated patients. Once the ventricular system is cleared with alteplase, obstruction of cerebral spinal fluid flow from thalamic ICH might become important in functional recovery.

Fluorescence guided resection with 5-aminolevulinic acid of a pilomyxoid astrocytoma of the third ventricle / Resección guiada por fluorescencia con ácido 5-aminolevulínico de un astrocitoma pilomixoide del tercer ventrículo

Fluorescence-guided resection with 5-aminolevulinic acid has been shown to be useful in the resection of certain brain tumors other than high grade gliomas, facilitating the intraoperative differentiation of neoplastic tissue. The technique enables the surgeon to ensure that no tumor fragments remain, thereby achieving higher rates of complete resection. Tihan first described pilomyxoid astrocytomas in 1999. They are currently classified as grade II astrocytoma according to the WHO classification system and, because of their tendency to recur and their dissemination through the cerebrospinal fluid pathways, they are considered to be more aggressive than pilocytic astrocytoma. As a result, management of these tumors must be more aggressive, always aiming for complete macroscopic resection whenever possible. In this article, we present a case of pilomyxoid astrocytoma of the third ventricle in which the use of fluorescence-guided resection with 5-ALA facilitated complete resection. Imaging tests performed after five years revealed no signs of recurrence and no adjuvant radiotherapy or chemotherapy was required. This article also comprises a review of the literature concerning the characteristics and management of this tumor, which was recently considered to be a different histopathological entity

La resección guiada por fluorescencia con 5-ALA se ha mostrado útil en tumores diferentes a los gliomas de alto grado, permitiendo la diferenciación intraoperatoria del tejido tumoral. La técnica permite revisar el lecho quirúrgico para comprobar que no quedan fragmentos tumorales, consiguiéndose así mejorar las tasas de resección completa. El astrocitoma pilomixoide, descrito en 1999 por Tihan, se clasifica actualmente como un astrocitoma grado II en la clasificación de la OMS y es considerado como una variante con mayor agresividad que el astrocitoma pilocítico por su tendencia a la recidiva y a la diseminación por el líquido cefalorraquídeo. Por ello el tratamiento debe ser más agresivo, fundamentado en una resección macroscópicamente completa siempre que se pueda. En este artículo presentamos el caso de un astrocitoma pilomixoide del tercer ventrículo en el que la fluorescencia con 5-ALA permitió una resección completa, sin signos de recidiva en pruebas de imagen a los 5 años, sin haber precisado tratamiento complementario con radioterapia ni quimioterapia. Se hace además una revisión de la literatura acerca de las características y el manejo de este tumor recientemente considerado como una entidad histopatológica diferente

Neurogenic fever in a patient with a chordoid glioma.

Chordoid gliomas are rare tumours. Despite being considered low-grade neoplasms, recent reviews have reported generally poor prognosis due to complications involving severe hypothalamic symptoms. We report a patient aged 30 years with chordoid glioma. What makes this case report interesting is the presence of neurogenic fever, which was already present before the final diagnosis of the brain tumour and also several months after the surgical removal. Since the patient underwent a subtotal resection of the tumour, it remains unclear whether the fever was due to hypothalamic dysfunction or remnants of the tumour. We also performed temperature logging with a continuous-monitoring recording device.

Voluntary exercise induces neurogenesis in the hypothalamus and ependymal lining of the third ventricle.

In the adult hypothalamus and ependymal lining of the third ventricle, tanycytes function as multipotential progenitor cells that enable continuous neurogenesis, suggesting that tanycytes may be able to mediate the restoration of homeostatic function after stroke. Voluntary wheel running has been shown to alter neurochemistry and neuronal function and to increase neurogenesis in rodents. In the present study, we found that voluntary exercise improved the survival rate and energy balance of stroke-prone spontaneously hypertensive rats (SHRSP/Kpo). We also investigated the effect of exercise on the proliferation and differentiation of hypothalamic cells using immunoreactivity for tanycytes and neural markers. The proliferation of elongated cells, which may be the tanycytes, was enhanced in exercising SHRSP compared to sedentary rats before and after stroke. In addition, the proliferation of cells was correlated with the induction of fibroblast growth factor-2 in the subependymal cells of the third ventricle and in the cerebrospinal fluid. Some of the newborn cells of exercising SHRSP showed differentiation into mature neurons after stroke. Our results suggest that voluntary exercise correlates with hypothalamic neurogenesis, leading to recovery of homeostatic functions in the adult brain after stroke.

Asymptomatic Interhypothalamic Adhesions in Children.

With the use of high-resolution MR imaging techniques, we have increasingly observed anomalies of the hypothalamus characterized by a band of tissue spanning the third ventricle between the hypothalami, often without associated clinical sequelae. Historically, hypothalamic anomalies are highly associated with symptoms referable to a hypothalamic hamartoma, midline congenital disorder, hypothalamic-pituitary dysfunction, or seizures, with very few asymptomatic patients reported. The interhypothalamic tissue described in our cohort was observed incidentally through the routine acquisition of high-resolution T1WI. No referable symptoms were identified in most of the study group. In the appropriate patient population in which associated symptoms are absent, the described hypothalamic anomalies may be incidental and should not be misdiagnosed as hypothalamic hamartomas.

Focal atrophy of the hypothalamus associated with third ventricle enlargement in autism spectrum disorder.

The hypothalamus is a brain structure containing multiple nuclei that mediate essential behavioral, autonomic, and endocrine functions including oxytocin synthesis. Oxytocin is a neuropeptide linked to complex social cognition and behaviors necessary for an effective social interaction. Oxytocinergic system dysfunction has been linked to social deficits in autism spectrum disorders (ASD). Limited studies have been carried out on the hypothalamus because of its small size and methodological constraints in current technologies. This neuroimaging study examines hypothalamic atrophy in ASD in comparison with a typically developing population (a) by directly measuring gray matter (GM) density with a region-of-interest analysis using voxel-based morphometry in a homogenous sample of participants controlled for age and intelligence quotient; (b) for generalization, by measuring third ventricular volume, on the basis of its position bilaterally surrounded by the hypothalamus, using Freesurfer in a heterogeneous sample of participants. A voxel-based morphometry analysis of cerebrospinal fluid density on the first sample provides a link between GM density and third ventricle volume. Our results show decreased hypothalamic GM density and increased third ventricle volume in ASD compared with typically developing patients. Our findings provide neuroanatomical insights into social deficits in ASD within the hypothalamus that might be relevant for other psychiatric conditions.

Episodic memory impairment in systemic lupus erythematosus: involvement of thalamic structures.

Episodic memory deficits in systemic lupus erythematosus (SLE) have been frequently reported in the literature; however, little is known about the neural correlates of these deficits. We investigated differences in the volumes of different brain structures of SLE patients with and without episodic memory impairments diagnosed by the Rey Auditory Verbal Learning Test (RAVLT). Groups were paired based on age, education, sex, Mini Mental State Examination score, accumulation of disease burden (SLICC), and focused attention dimension score. Patients underwent magnetic resonance imaging (MRI). Cortical volumetric reconstruction and segmentation of the MR images were performed with the FreeSurfer software program. SLE patients with episodic memory deficits presented shorter time of diagnosis than SLE patients without episodic memory deficits. ANOVA revealed that SLE patients with episodic memory deficits had a larger third ventricle volume than SLE patients without episodic memory deficits and controls. Additionally, covariance analysis indicated group effects on the bilateral thalamus and on the third ventricle. Our findings indicate that episodic memory may be impaired in SLE patients with normal hippocampal volume. In addition, the thalamus may undergo volumetric changes associated with episodic memory loss in SLE.

Sustained alterations of hypothalamic tanycytes during posttraumatic hypopituitarism in male mice.

Traumatic brain injury is a leading cause of hypopituitarism, which compromises patients' recovery, quality of life, and life span. To date, there are no means other than standardized animal studies to provide insights into the mechanisms of posttraumatic hypopituitarism. We have found that GH levels were impaired after inducing a controlled cortical impact (CCI) in mice. Furthermore, GHRH stimulation enhanced GH to lower level in injured than in control or sham mice. Because many characteristics were unchanged in the pituitary glands of CCI mice, we looked for changes at the hypothalamic level. Hypertrophied astrocytes were seen both within the arcuate nucleus and the median eminence, two pivotal structures of the GH axis, spatially remote to the injury site. In the arcuate nucleus, GHRH neurons were unaltered. In the median eminence, injured mice exhibited unexpected alterations. First, the distributions of claudin-1 and zonula occludens-1 between tanycytes were disorganized, suggesting tight junction disruptions. Second, endogenous IgG was increased in the vicinity of the third ventricle, suggesting abnormal barrier properties after CCI. Third, intracerebroventricular injection of a fluorescent-dextran derivative highly stained the hypothalamic parenchyma only after CCI, demonstrating an increased permeability of the third ventricle edges. This alteration of the third ventricle might jeopardize the communication between the hypothalamus and the pituitary gland. In conclusion, the phenotype of CCI mice had similarities to the posttraumatic hypopituitarism seen in humans with intact pituitary gland and pituitary stalk. It is the first report of a pathological status in which tanycyte dysfunctions appear as a major acquired syndrome.

Active cognitive reserve influences the regional atrophy to cognition link in multiple sclerosis.

Recent research indicates that cognitive reserve mitigates the clinical expression of neuropsychological impairment in multiple sclerosis (MS). This literature primarily uses premorbid intelligence and lifetime experiences as indicators. However, changes in current recreational activities may also contribute to the maintenance of neural function despite brain atrophy. We examined the moderation effects of current changes in recreational activity on the relationship between brain atrophy and information processing speed in 57 relapsing-remitting MS patients. Current enrichment was assessed using the Recreation and Pastimes subscale from the Sickness Impact Profile. In patients reporting current declines in recreational activities, brain atrophy was negatively associated with cognition, but there was no such association in participants reporting stable participation. The MRI metric-by-recreational activity interaction was significant in separate hierarchical regression analyses conducted using third ventricle width, neocortical volume, T2 lesion volume, and thalamic volume as brain measures. Results suggest that recreational activities protect against brain atrophy's detrimental influence on cognition.

Hypothalamic immunopathology in anti-Ma-associated diencephalitis with narcolepsy-cataplexy.

IMPORTANCE: Idiopathic narcolepsy with cataplexy is thought to be an autoimmune disorder targeting hypothalamic hypocretin neurons. Symptomatic narcolepsy with low hypocretin level has been described in Ma antibody­associated encephalitis; however, the mechanisms underlying such an association remain unknown. OBSERVATIONS: We described a 63-year-old man with clinical criteria for diencephalic encephalitis with sleepiness, cataplexy, hypocretin deficiency, and central hypothyroidism, together with brainstem encephalitis reflected by supranuclear ophtalmoparesis and rapid eye movement sleep behavior disorder with underlying abnormalities on brain magnetic resonance imaging. An autoimmune process was demonstrated by the detection of antibodies against Ma protein. Death occurred 4 months after disease onset without any tumor detected. Neuropathology, immunohistochemistry, and immunoreactivity results were compared with those obtained in idiopathic narcolepsy-cataplexy and with normal control brains. The principal findings revealed almost exclusive inflammation and tissue injury in the hypothalamus. The type of inflammatory reaction suggests cytotoxic CD8+ T lymphocytes being responsible for the induction of tissue injury. Inflammation was associated with complete loss of hypocretinergic neurons. Autoantibodies of the patient predominantly stained neurons in the hypothalamus and could be absorbed with Ma2. CONCLUSIONS AND RELEVANCE: The encephalitic process, responsible for narcolepsy-cataplexy and hypocretin deficiency, reflects a CD8+ inflammatory-mediated response against hypocretin neurons.

The transventricular preforniceal approach for exophytic chiasmatic/hypothalamic astrocytomas extending into the anterior third ventricle.

BACKGROUND: Surgical treatment of large exophytic chiasmatic/hypothalamic astrocytomas extending into the anterior third ventricle remains a challenging task for neurosurgeons. In particular, when the tumor extends from the chiasmatic region upward to the foramen of Monro, damage to the fornix and other neurovascular structures is a major concern. OBJECTIVE: To describe the technique used in the transventricular preforniceal surgical approach to remove the superior and superoposterior part of the tumor in the third ventricle for treatment of exophytic chiasmatic/hypothalamic astrocytoma. METHODS: The transventricular preforniceal approach was used in two cases of exophytic chiasmatic/hypothalamic astrocytoma. The approach is summarized in 4 procedures: 1) exposure of the anterior horn of the lateral ventricle by the transcallosal approach, 2) identification of the foramen of Monro and the fornix, 3) incision of the septum pellucidum or the wall of the lateral ventricle, in front of the columns of the fornix, and 4) removal of the tumor through the space between the anterior commissure and the columns of the fornix. RESULTS: Because the tumor compressed the foramen of Monro posteriorly and stretched the space between the anterior commissure and the columns of the fornix, the posterosuperior part of the tumor in the third ventricle was successfully removed through the surgical corridor in front of the columns of the fornix. In both cases, tumors were successfully removed using this approach without damaging the fornix and the anterior commissure. Residual tumor was removed using an anterior interhemispheric translamina terminalis approach in a two-stage surgery. CONCLUSIONS: The transventricular preforniceal approach can be applied for removing the superior part of exophytic chiasmatic/hypothalamic astrocytomas, because the space between the anterior commissure and the fornix is stretched by the tumor, providing an appropriate surgical corridor.

Anatomic study of the lamina terminalis: neurosurgical relevance in approaching lesions within and around the third ventricle.

BACKGROUND: The lamina terminalis (LT) represents an important neurosurgical corridor by which to fenestrate the third ventricle into the subarachnoid space or to approach lesions of the third ventricle. However, a comprehensive review of its anatomy and approaches to it for various pathologies is lacking in the literature. We studied the anatomy of the LT in 21 cadavers and described the LT as observed in cadaveric dissections. We also reviewed the literature regarding the detailed anatomy and pathology of the LT. In addition, a case illustration that demonstrates the use of this structure as a corridor to third ventricular tumors is presented. Our aim was to explore the anatomy of the LT through cadaveric dissection, a review of the literature, and a case study. METHODS: Twenty-one adult cadaver heads underwent microdissection of the LT with a focus on the working distance available to enter the third ventricle and related vascular structures. RESULTS: Inferior to the anterior communicating artery was the safer region to open due to the lack of perforating arteries. A working distance of approximately 1 cm can be expected through the LT. CONCLUSIONS: This information may aid neurosurgeons during approaches through and around the LT.

Anteroventral third ventricle (AV3V) lesion affects hypothalamic neuronal nitric oxide synthase (nNOS) expression following water deprivation.

Neuronal nitric oxide synthase (nNOS) has been reported to be up-regulated in the hypothalamic supraoptic nucleus (SON) during dehydration which in turn could increase nitric oxide (NO) production and consequently affect arginine vasopressin (AVP) secretion. The anteroventral third ventricle (AV3V) region has strong afferent connections with the SON. Herein we describe our analysis of the effects of an AV3V lesion on AVP secretion, and c-fos and nNOS expression in the SON following dehydration. Male Wistar rats had their AV3V region electrolytically lesioned or were sham operated. After 21 days they were submitted to dehydration or left as controls (euhydrated). Two days later, one group was anaesthetized, perfused and the brains were processed for Fos protein and nNOS immunohistochemistry (IHC). Another group was decapitated, the blood collected for hematocrit, osmolality, serum sodium and AVP plasma level analysis. The brains were removed for measurement of neurohypophyseal AVP content, and the SON was punched out and processed for nNOS detection by western blotting. The AV3V lesion reduced AVP plasma levels and c-fos expression in the SON following dehydration (P<0.05). Western blotting revealed an up-regulation of nNOS in the SON of control animals following dehydration, whereas such up-regulation was not observed in AV3V-lesioned rats (P<0.05). We conclude that the AV3V region plays a role in regulating the expression of nNOS in the SON of rats submitted to dehydration, and thus may affect the local nitric oxide production and the secretion of vasopressin.

Vacuolar pathology in the median eminence of the hypothalamus after hyponatremia.

The median eminence of the hypothalamus is an important conduit by which neurosecretory hormones from hypothalamic nuclei are delivered to the pars nervosa (neural lobe) of the pituitary en route to the bloodstream. Dilutional hyponatremia was produced in adult rats to determine the effect on the morphology of the median eminence of the hypothalamus. Hyponatremia was caused by reducing electrolyte and organic osmolyte reserves to block the excretion of water through delivery of the nephrotoxin mercuric chloride (HgCl2). Histological examination of the brain 1 day after a hyponatremic insult revealed vacuolation within the median eminence of the hypothalamus. No other lesions were found in other parts of the brain after hyponatremia. The hyponatremic lesion consisted of a band of closely packed vacuoles that crossed the floor of the third ventricle. Vacuoles associated with hyponatremia were predominantly in the subependymal, fiber, reticular, and palisade layers of the median eminence. Vacuolation was not observed in the tanycyte layer of the median eminence. This study indicates that the median eminence is a potentially vulnerable site in human hyponatremic conditions that should be evaluated further in relevant animal models.

Hypothalamic lesions in multiple sclerosis.

OBJECTIVES: To determine the frequency of hypothalamic lesions in patients with multiple sclerosis (MS) using conventional MRI (cMRI) protocols. METHODS: Brain cMRI (1.5 Tesla) scans of 105 Caucasian patients with classical MS (50 with stable and 55 with more active disease) and 12 patients with longitudinal extensive myelopathy (LEM) were reviewed retrospectively. NMO-IgG antibody was assayed in patients with hypothalamic lesions. RESULTS: Hypothalamic lesions were found in 13.3% of MS patients and in none of the LEM patients. A higher frequency of hypothalamic lesions was found in patients with active MS (18.2%) than in the stable group (8.0%), but this did not reach statistical significance (p=0.13). Patients with hypothalamic lesions also had more lesions in other cerebral structures. None of the LEM patients had hypothalamic lesions. No patients with hypothalamic lesions were positive for NMO-IgG. CONCLUSIONS: Hypothalamic lesions in MS are more frequent than previously reported and are not associated with NMO-IgG antibody.

Anterior interhemispheric approach for 100 tumors in and around the anterior third ventricle.

OBJECTIVE: We report our experience with anterior interhemispheric approach for tumors in and around the anterior third ventricle, including surgical technique, instrumentation, pre- and postoperative hormonal disturbances, and resection rate. METHODS: One hundred patients with 46 craniopharyngiomas, 12 hypothalamic gliomas, 12 meningiomas, 6 hypothalamic hamartomas, and 24 other lesions were operated on using an anterior interhemispheric approach with or without opening of the lamina terminalis. This surgical approach involves no frontal sinus opening; a narrow (approximately 15-20 mm in width) access between the bridging veins, which is sufficient to remove the tumor totally; and sparing of the anterior communicating artery. Specially designed long bipolar forceps and scissors are necessary for this approach, and concomitant use of angled instruments (endoscope, aspirator, and microforceps) is required frequently. The postsurgical follow-up period varied from 4 months to 18 years. RESULTS: Total removal of the neoplasm was accomplished in 37 of 46 patients with craniopharyngiomas (80.4%), whereas subtotal resection was performed in hypothalamic gliomas. No significant differences in pre- and postoperative hormonal disturbances were observed in 37 craniopharyngiomas and 10 hypothalamic gliomas. There was no operative mortality. Visual acuity was preserved or improved in 68 of 75 patients assessed. The Karnofsky Performance Scale score did not deteriorate in 72 of 75 patients tested. CONCLUSION: The minimally invasive anterior interhemispheric approach, with or without opening of the lamina terminalis, is useful for removal of tumors in and around the anterior third ventricle, such as craniopharyngiomas and hypothalamic gliomas.