Wall Of Third Ventricle Research Articles

Third ventricular cavernoma: Report of two cases.

Sir/Madam, Cerebral parenchyma is the most common site for a cavernoma in the nervous system. Intraventricular cavernomas are rare and constitute 2.5-10.8% of cerebral cavernomas.[1] Third ventricular cavernomas are even rare, only 25 cases have been reported in the literature.[2] We report two more cases of third ventricular cavernomas. The first patient was a 54-year-old man, who presented with acute headache and vomiting. He was unconscious on arrival in casualty. CT scan showed third ventricular hemorrhage [Figure 1a]. He underwent external ventricular drainage, followed by ventriculo-peritoneal (VP) shunt later. An MRI done at 10 days after ictus showed a mixed density lesion with hemorrhagic component occupying the third ventricle with broad base on the floor [Figure 1b]. He underwent tranacallosal-interhemispheric approach and total excision of the lesion. The tumor was arising from the floor of the third ventricle. Histopathology was cavernoma. After surgery the patient developed diabetes insipidus, which was managed with desmopressin. Figure 1 (a) CT scan showing hemorrhage in third ventricle. (b) MRI showing a heterogeneous lesion in the third ventricle with bleed The second patient was a 6-year-old girl who presented with headache and vomiting for 2 months. CT scan showed a calcified in third ventricle with hydrocephalus [Figure 2a]. MRI showed a heterogeneous lesion occupying the entire third ventricle [Figure 2b]. There was no evidence of recent hemorrhage. She underwent VP shunt followed by subfrontal approach, and only partial excision of the lesion as the lesion was densely adherent to the floor of the third ventricle. Histopathology was cavernoma. After surgery she developed transient hyponatremia, which was managed medically. Figure 2 (a) CT scan showing calcified tumor in third ventricle. (b) MRI showing a heterogeneous lesion in the third ventricle Third ventricular cavernomas can present with signs and symptoms of any third ventricular tumors, however they usually present with symptoms of hydrocephalus.[2] Presentation as intraventriuclar hemorrhage is uncommon, and only three cases have been reported.[2] Our first patient presented with hemorrhage, and second with hydrocephalus. They can arise from the suprachiasmatic region, foramen of Monroe, lateral wall or floor of third ventricle.[3] Both of our patients had cavernomas arising from floor of third ventricle. The imaging appearance is that of typical cavernomas. The close differential diagnosis in the absence of hemorrhage is third ventricular craniopharyngioma. The natural history of intraventricular cavernoma is not known. There is a risk of hemorrhage and acute hydrocephalus if the lesion is not excised completely. However, there is risk of hypothalamic damage in case of complete resection of lesion arising from floor of third ventricle, as it happened in our first case. It may be worthwhile doing only a VP shunt for hydrocephalus if the lesion is arising from the floor of the third ventricle.[4]

The pathological features of Wernicke encephalopathy

Case reportA 47-year-old man with a history of alcoholic liver diseasewas found dead at his home address on the floor, lying facedown. He had been unwell for 2 months prior to death andhad complained of abdominal pain. He also had a diagnosisof prolonged QT interval.At autopsy there was no evidence of liver failurealthough the liver was fatty and fibrotic. There was acongenital anomaly of the coronary arteries with the cir-cumflex coronary artery arising from the right sinus ofValsalva with significant narrowing of the ostium. Therewas no evidence of trauma and toxicological screening ofblood was unremarkable. Biochemical analysis of vitreoushumor revealed elevated sodium (144 mmol/L) and creat-inine (217 lmol/L) levels in keeping with terminal dehy-dration and renal failure, with a normal b-hydroxy butyrate(thus excluding alcoholic ketoacidosis).Althoughthebrainappearedexternallyunremarkablewithnovermal atrophy of the cerebellum, sectioning of the mammillarybodiesdemonstratedsymmetricalhemorrhagehighlysuggestiveof Wernicke encephalopathy (Figs. 1, 2). Focal hemorrhagicareas were also noted within the walls of the third ventricle.Microscopically the mammillary bodies displayedrecent microhemorrhages and prominent microvascularproliferation with endothelial swelling typical of Wernickeencephalopathy (Fig. 3). The mammillothalamic tracts andthe walls of third ventricle also contained microhemor-rhages. There was patchy microvacuolation of the neuropilwith unremarkable neurons, fibrous astrocytes, and occa-sional perivascular macrophages containing hemosiderin,indicative of more chronic disease. Mild extravasation oferythrocytes and prominent congested vessels were notedwithin medullary dorsal motor vagal nuclei.Death was attributed to natural causes, most likelyinvolving a combination of cardiac and alcohol-relateddisease. The striking finding was of clinically unsuspectedWernicke encephalopathy.DiscussionWernicke encephalopathy is a neurological disorderresulting from thiamine (vitamin B-1) deficiency [1].Although in Western countries it occurs predominantly inalcoholics, related to poor dietary intake and impairedutilization, it can also be caused by a variety of otherconditions that interfere with normal thiamine metabolism.These include starvation, bariatric surgery, hyperemesisgravidarum, human immunodeficiency virus/acquiredimmunodeficiency syndrome (HIV/AIDS), and in infantsgiven thiamine-deficient formulas [1, 2].The clinical prevalence of Wernicke encephalopathy isuncertain as autopsy studies indicate that the condition islikely under-diagnosed during life [3]. Delay in diagnosismay result from nonspecific symptoms that resembleintoxication. The symptoms, severity, and the regions ofthe brain that are affected are also variable due to a

Inside the musician's brain

Artistically rendered 3D magnetic resonance imaging (MRI) showing virtual ventriculoscopy with visualization of the roof and posterior wall of the human third ventricle. Between the thalami rendered in rainbow colors, the paired internal cerebral veins at the roof of the third ventricle resemble a pair of tuning fork. The base of the tuning fork is made up of the Habenular commissure, the pineal recess and the posterior commissure forming the posterior wall of the third ventricle. The cerebral aqueduct can be seen immediately below the colorful band-shaped posterior commissure.

Spatiotemporal dynamics of the expression of estrogen receptors in the postnatal mouse brain

This study reports on the spatiotemporal dynamics of the expression of estrogen receptors (ERs) in the mouse central nervous system (CNS) during the early postnatal and the peripubertal period. At postnatal day 7 (P7), neurons with strong nuclear immunostaining for both ERalpha and ERbeta1 were widely distributed throughout the brain. Sucrose density gradient sedimentation followed by western blotting supported the histochemical evidence for high levels of both ERs at P7. Over the following 2 days, there was a rapid downregulation of ERs. At P9, ERalpha expression was visible only in the hypothalamic area. Decline in ERbeta1 expression was slower than that of ERalpha, and ERalpha-negative, ERbeta1-positive cells were observed in the dentate gyrus and walls of third ventricle. Between P14 and P35, ERs were undetectable except for the hypothalamic area. As before P7, the ovary does not produce estrogen but does produce 5alpha-androstane-3beta, 17beta-diol (3betaAdiol), an estrogenic metabolite of dihydrotestosterone, we examined the effects of high levels of 3betaAdiol in the postnatal period. We used CYP7B1 knockout mice which cannot hydroxylate and inactivate 3betaAdiol. The brains of these mice are abnormally large with reduced apoptosis. In the early postnatal period, there was 1-week delay in the timing of the reduction in ER expression in the brain. These data reveal that the time when ERs might be activated in the brain is limited to the first 8 postnatal days. In addition, the importance of aromatase has to be reconsidered as the alternative estrogen, 3betaAdiol, is important in neuronal function in the postnatal brain.

Tryptophan metabolism via serotonin in human CSF of different brain sites using a new neuroendoscopic technique

Abstract A new neuroendoscopic technique has permitted a precise and accurate exploration of all the cerebral ventricles, making possible the study of the CSF of the lateral ventricles and, above all, the CSF adjacent to the walls of the third ventricle in humans. The concentrations of tryptophan and its metabolites via serotonin were measured in the CSF of different sites of the cerebral cavity, in particular in the third ventricle. Patients affected with non-communicating hydrocephalus undergoing neuroendoscopic third ventriculostomy were enrolled in the study. As controls, subjects not suffering from any neurological disease, who underwent lumbar subarachnoid anaesthesia for minor surgical procedures, provided lumbar CSF, and patients affected by Chiari malformation provided cisternal and right ventricular CSF. Tryptophan concentration was higher in right ventricular CSF than in lumbar CSF. Serotonin (5-HT) was detectable in the CSF of the right ventricle of hydrocephalic individuals. 5-Hydroxyindoleacetic acid (5-HIAA) was higher in the right ventricular CSF than in the cisternal and lumbar CSF both in controls and hydrocephalic subjects. However, the 5-HIAA level was higher in the right ventricular and cisternal CSF in hydrocephalic individuals in comparison to controls. 5-HT presented the highest concentration in the pineal recess, whereas the highest amounts of 5-HIAA were found in the choroids plexus, third and right ventricles and the lowest in the pineal recess, subarachnoid space and intepeduncular cistern. Melatonin is more concentrated within the ventricles, in particular the third ventricle, and in the CSF pineal recess. The use of this neuroendoscopic technique in hydrocephalic patients provides new insight into the metabolic pathway of tryptophan via serotonin in the CSF.

The distribution of neural nitric oxide synthase-positive cerebrospinal fluid-contacting neurons in the third ventricular wall of male rats and coexistence with vasopressin or oxytocin

The detailed distribution of neural nitric oxide synthase (nNOS)-positive cerebrospinal fluid-contacting neurons (CSF-CN) was studied in the wall of the third ventricle of rats by anti-nNOS immunohistochemistry. The coexistence of nNOS and 8-arginine vasopressin (AVP) or oxytocin (OT) was also investigated in the CSF-CN using double labeling immunohistochemistry. The results demonstrated a widespread occurrence of nNOS-CSF-CN throughout the wall of the hypothalamic third ventricle. The vast majority of nNOS-CSF-CN cell bodies were of magnocellular type, commonly classified as oval, fusiform, multipolar, and inverted pear shape. These cell bodies were located in the ependyma, the subependyma, or the parenchyma, and their processes inserted in the ependymal layer or directly contacted with the CSF space. Electron microscopy demonstrated many nNOS-immunoreactive somas, dendrites, and/or axons that were situated at the subependyma, the ependyma, or the supraependyma. Generally, the distribution of OT-CSF-CN in the third ventricular wall was similar to the nNOS-CSF-CN and the ratio of NOS/OT co-expression was approximately 88%. In comparison, the distribution of AVP-CSF-CN was mainly restricted to the rostral part of the third ventricle and the ratio of nNOS/AVP co-expression was only about 6%. The widespread presence of nNOS-CSF-CN-expressing OT in the third ventricular region suggests that NO is an important messenger in the CSF-hypothalamo-hypophyseal neuroendocrine regulation that may in part act in concert with OT.

Cerebral osmoregulation of renal sodium excretion--a response analogous to thirst and vasopressin release.

Studies in sheep have shown that renal excretion of sodium may be under osmoregulatory control. When sheep become dehydrated, or are infused intravenously with hypertonic saline, they increase renal Na excretion in addition to secreting vasopressin and developing a thirst. These natriuretic, antidiuretic, and dipsogenic responses to dehydration and hypertonicity can be greatly reduced by lowering the cerebrospinal fluid NaCl concentration or by prior ablation of tissue in the anterior wall of the third ventricle. Lowering of cerebrospinal fluid NaCl concentration also prevents postprandial natriuresis which normally occurs in association with a postprandial increase in plasma Na concentration and tonicity. We propose that there is a cerebral osmoregulatory control of Na excretion which may interact with volume influences from the cardiovascular system to regulate renal Na output. The effector mechanism from brain to kidney mediating such cerebral control of Na excretion is probably hormonal.

Ultrastructure of the subfornical organ of the Japanese quail, Coturnix coturnix.

The structure of the subfornical organ (SFO) of the Japanese quail has been studied by light and electron microscopy. The SFO is a small semiglobular bulge in the midline on the rostrodorsal wall of the third ventricle between the anterior commissure and tela choroidea. The organ consists of three main parts, anterior stalk, the corpus and the posterior stalk. The anterior stalk is covered by ependymal cells with a few cilia, but the corpus and posterior stalk are characterized by a distinctive lack of cilia and by flat or bulging cell surfaces, which have the appearance of cobble stones. The large bulbous protrusions in the ependymal surface of the posterior stalk suggest a secretory function into the ventricle. In the subependymal layer, there are a few parvocellular neurons that contain small mitochondria, moderately developed Golgi apparatus, lysosomes, dilated cisternae of rER and a few dense-cored granules of 100–120 nm in diameter. They appear to be secretory in nature. Two types of glial cells occur in the subependymal and internal layers. One is small and spindle-shaped with a dense nucleus and elongated cytoplasmic processes; it may be microglial. The other is a small polygonal cell with rounded nucleus and clear cytoplasm containing bundles of filaments; it may be a protoplasmic astrocyte. The neuropil contains three types of axons. The first contains dense-cored granules, 80 nm in diameter, and clear vesicles, 40–60 nm in diameter and is involved in axosomatic synapses. The second type contains dense granules, 120 nm in diameter, and clear vesicles, 40–80 nm in diameter, and shows axodendritic synapses. The third contains peptidergic granules about 100–120 nm in diameter and seems to belong to the organ-specific nerve cells. These axons terminate at the perivascular space of the blood capillaries, suggesting secretion into the blood.

Scanning electron microscopy of the wall of the third ventricle of the brain of Rana temporia. II. Electron microscopy of the ventricular surface of the pars ventralis of the tuber cinereum.

Scanning electrom microscopy of the ventricular surface of the pars ventralis of the tuber cinereum of the frog Rana temporaria shows that it can be divided in (1) a dorsolateral area, characterized by the presence of very numerous large, solid, bulbous protrusions (2) a medial area, where the large bulbous structures are completely absent and which is diffusely covered with very numerous cilia, (3) a transiotional area located between the two other regions. The large bulbs, shown by scanning electron microscopy, correspond with the end-bulbs of thick ventricular dendrites of nerve cells revealed by transmission electron microscopy. At least many of these intra-ventricular bulbs are dendritic endings of peptidergic neurosecretory neurons, which have been tentatively identified as adenohypophysiotropic neuro-hormone producing neurons (Derickx et al., 1972, 1973a, 1973b). The structural features of the dendritic endings plead in favour of a possible receptive role.

Scanning electron microscopy of the wall of the third ventricle of the brain of Rana temporaria

Scanning electron microscopy of the wall of the third ventricle of the brain of Rana temporaria