Adult gangliocytoma arising within the lateral ventricle: A case report and review of the literature

Background: Gangliocytomas are rare neuronal tumors with an incidence of <1% of all central nervous system (CNS) neoplasms. They occur mostly in the pediatric age group, localizing within the cerebral cortex, most often the temporal lobe. Case Description: We report a case of an intracranial gangliocytoma arising within the lateral ventricle in a 66-year-old female. Magnetic resonance imaging of the brain showed a diffusely enhancing lobulated mass situated within the frontal horn of the right lateral ventricle with extension into the foramen of Monro and obstructive hydrocephalus. The patient underwent an interhemispheric transcallosal approach with gross total resection and relief of her hydrocephalus. Pathological examination showed clusters of highly pleomorphic neuron-like cells without evidence of neoplastic glial cells. Histopathological and immunohistochemistry findings were consistent with the diagnosis of gangliocytoma (World Health Organization Grade 1). Conclusion: Gangliocytomas are rare low-grade CNS neoplasms that can present in an older population within unusual locations and should be included within the differential whenever a suspicious lesion is encountered.

Validation of Sonographic Fronto-Occipital Ratio Based on Anatomical Landmarks compared to MR/CT-Derived Indexes in Children with Chiari II and Ventriculomegaly

Introduction: Ultrasound (US) based indexes such as fronto-occipital ratio (FOR) can be used to obtain an acceptable estimation of ventricular volume. Patients with colpocephaly present a unique challenge due to the shape of their ventricles. In the present study, we aim to evaluate the validity and reproducibility of modified US-FOR index in children with Chiari II-related ventriculomegaly. Methods: In this retrospective study, we evaluated Chiari II patients younger than one year who underwent head US and MR or CT scans for ventriculomegaly evaluation. MR/CT based FOR was measured in the axial plane by identifying the widest diameter of frontal horns, occipital horns, and the interparietal diameter (IPD). US based FOR (US-FOR) was measured using the largest diameter based on the following landmarks: frontal horn and IPD in the coronal plane at the level of the foramen of Monro, IPD just superior to the Sylvian fissures, and occipital horn posterior to the thalami and inferior to the superior margins of the thalami. Interclass correlation coefficients (ICC) were used to evaluate inter-rater reliability and Pearson correlation coefficients and Bland-Altman plots were applied to assess agreement between US and other two modalities. Results: Ninety paired US and MR/CT exams were assessed for agreement between US-FOR and MR/CT-FOR measurements. ICC showed an excellent inter-rater reliability for US-FOR (ICC=0.99, p<0.001) and MR/CT-FOR measurements (ICC=0.99, p<0.001). The mean (range) values based on US-FOR showed a slight overestimation in comparison to MR/CT-FOR [0.51 (0.36-0.68) vs 0.46 (0.34-0.64)]. Pearson correlation coefficient showed high cross-modality agreement for the FOR index (r=0.83, p<0.001). Bland-Altman plot showed excellent concordance between US-FOR and MR/CT-FOR with a bias of 0.05 (95% CI, -0.03-0.13) Conclusion: US-FOR in the coronal plane is a comparable tool for evaluating ventriculomegaly in Chiari II patients when compared with MR/CT-FOR, even in the context of colpocephaly.

A bi-foraminal craniometric-guided approach to endoscopic third ventriculostomy and biopsy of a pineal tumour

Background: Pineal tumors are very rarely encountered, with an incidence of <1% of intracranial lesions in adults. Life-threatening hydrocephalus due to obstruction of the third ventricle can result from the location of these tumours. Endoscopic third ventriculostomy (ETV) and tumor biopsy is a safe and feasible strategy, particularly if the tumor appears benign. This mitigates the high risks of uncontrollable venous bleeding from open and stereotactic biopsies. While typically performed using either ipsilateral single or dual bur holes, the location of the tumor may require modifications to the standard endoscopic techniques. Case Description: A 55-year-old male presented with signs of intracranial hypertension and was found to have obstructive hydrocephalus due to a pineal tumour. The tumour displayed a right-sided dominance when the pre-operative imaging was assessed, which would risk forniceal injury if biopsied via a right-sided burr hole. Craniometric measurements revealed a superior trajectory to the tumour via the left foramen of Monro. A biforaminal approach was performed, with a traditional ETV using a right coronal bur hole and biopsy via a left frontal bur hole. This minimized forniceal stretching and allowed a safe biopsy. Conclusion: The bi-foraminal approach has not been widely described in the literature but can potentially avoid morbidity with biopsy in patients with right-sided pineal tumours. We believe this technique should be considered, particularly in low-resource settings where neuroendoscopy is not commonly done, and where the use of ipsilateral single or dual-bur holes may lead to forniceal injury.

Obstruction at the level of foramen of monro causing obstructive hydrocephalus

Background: The foramen of monro is also known by the name of interventricular foramen. The study was conducted to determine the etiology, clinical picture, radiological features, and different modalities of management and related complications.Methods: A prospective study of 30 cases with diagnosis of hydrocephalus due to obstruction at the interventricular foramen. Lesions at the foramen of monro were addressed either by open craniotomy approach or neuroendoscopy approach. For open craniotomy transcortical or interhemispheric approach was preferred and Karl Storz’s LOTTA system was used for all the neuroendoscopic procedures.Results: Craniopharyngioma and colloid cysts were the most common pathology in children and adults respectively. Endoscopic approach was particularly helpful in decreasing the convalescence period and postoperative complications. Wound site CSF leak is the most commonly faced complications. In our study, out of 30 patients, males accounted for 23 (77%) cases and females for 7 (23%) cases. Majority were in the age group of 20-40 years. The most common presenting complaints of patients having foramen of monro obstruction with hydrocephalus were headache and vomiting. Gadolinium enhanced contrast MRI of brain was the investigation of choice for diagnosing these lesions.Conclusions: Endoscopic approach can be offered as a first line of treatment as a part of standard treatment in all patients having foramen of monro obstruction. It obviates the need for multiple shunt procedures. Although small solid lesions less than 3 cm in size can be addressed by endoscopic approach, the learning curve required for endoscopic approach to deal with solid lesions is very steep.

Lesions at the Foramen of Monro Causing Obstructive Hydrocephalus

The foramen of Monro has also been referred to by the name of interventricular foramen. The structures comprising this foramen are the anterior part of the thalamus, the fornix and the choroid plexus. Vital structures surround the foramen, the damage to which can be catastrophic leading to disability either temporary or permanent. In the literature it has been shown that tumors occurring in the area of interventricular foramen are rare and usually cause hydrocephalus. The operative approach depends upon the location of the tumor which can be either in the lateral or the third ventricle. Various pathologies which can lead to foramen of Monro obstruction and obstructive hydrocephalus include colloid cyst, craniopharyngioma, subependymal giant cell astrocytoma [SEGA], Neurocysticercosis, tuberculous meningitis, pituitary macroadenoma, neurocytoma, ventriculitis, multiseptate hydrocephalus, intraventricular hemorrhage, functionally isolated ventricles, choroid plexus tumors, subependymomas and idiopathic foramen of monro stenosis. In this chapter, we will discuss the various lesions at the level of foramen of Monro causing obstructive hydrocephalus and the management and associated complications of these lesions based on their type, clinical picture and their appearance on imaging.

Overcoming the Elusiveness of Neurosarcoidosis: Learning from Five Complex Cases

The involvement of the central nervous system in sarcoidosis can manifest with a variety of neurological symptoms, and most of them can be nonspecific. The diagnosis of neurosarcoidosis (NS) can therefore be very challenging without a tissue biopsy. Both computed tomography (CT) and magnetic resonance imaging (MRI) are important imaging modalities in the diagnosis of NS, and MRI is the modality of choice due to its superior soft-tissue contrast resolution. We present a case series of NS with interesting neuroimaging features, complex neurological presentations, and clinical courses. We identify five cases presenting with clinically isolated neurosarcoidosis (CINS) without any other signs or symptoms of systemic disease which were diagnosed as NS on biopsy. In the first case, we describe a patient with an intramedullary cervical spinal cord lesion. In the second case we describe a patient presenting with inflammatory changes and enhancement in the orbit. The third case demonstrates a lesion with calcification around the region of the foramen of Monro. The fourth case shows multiple ring-enhancing lesions. Lastly, the fifth case exhibits unusual findings with both optic neuritis and a cerebellar nodule. We aim to describe the complicated clinical course with neurological workup, neuro-imaging, and eventual diagnosis and treatment of these challenging cases to highlight the variable presentations of NS. This case series will remind clinicians that NS should always be in the differential diagnosis when a patient presents with nonspecific neurological symptoms with unusual neuroimaging findings.

Acute Necrotizing Encephalopathy in a Four-Year-Old Boy

Acute necrotizing encephalopathy is a devastating clinico-radiological syndrome characterized by fulminant neurological deterioration after an antecedent febrile illness, as well as the imaging hallmark of bilateral thalamic involvement. Herein, we describe a 4-year-old boy with typical clinical and neuroimaging features of acute necrotizing encephalopathy. The bithalamic swelling led to a block of cerebrospinal fluid circulation at the foramen of Monro, thereby causing the mild dilatation of lateral ventricles. The periventricular areas could, therefore, have been potentially affected by the acute necrotizing encephalopathy per se and/or transependymal edema secondary to obstructive hydrocephalus. The information from diffusion imaging allows for differentiation between these two pathophysiological processes.

Purely Intraventricular Desmoplastic Infantile Astrocytoma

Desmoplastic infantile astrocytomas (DIAs) are rare pediatric tumors characterized by superficial brain cortex involvement, along with the meninges of the supratentorial compartment, and are classified as grade I neoplasms according to the 2016 World Health Organization. A 5-year-old female patient was admitted to our unit with abnormal decorticate posturing, bilateral mydriasis with weak pupillary light reflex, and brisk lower limbs reflexes. Her medical history was unremarkable. Magnetic resonance imaging of the brain revealed a massive lesion with bilateral intraventricular growth mainly prevailing on the left and involving the ipsilateral foramen of Monro. After external ventricular drainage positioning, Dandy's transfrontal transcortical approach to the left lateral ventricle, a meticulous ependymal microsurgical dissection of the lesion was performed, resulting in an excision of the cystic component of the left lateral ventricle. A gross total removal of the lesion was performed with an en bloc resection of the deeper cystic part. Thirty days after surgery, the patient presented with fluent speech, conserved axial, and extremity sensorimotor functions, except a mild central facial paresis which progressively improved. To the best of our knowledge, this is the first case of DIA characterized by purely intraventricular growth. Tumor recurrence, although considered rare, represents an unpredictable event. Therefore, an adequate follow-up must be reserved for each patient.