Neuroimaging in the diagnosis and treatment of intracranial pressure disorders.

OBJECTIVE: To review the clinical features, proposed pathophysiology, and the role of medical imaging in the diagnosis and treatment of idiopathic intracranial hypertension and spontaneous intracranial hypotension. METHODS: The authors conducted a narrative review of the current literature on intracranial hypertension and hypotension syndromes, with a focus on imaging findings and role of neurointerventional radiology as a therapeutic option for these pathologies. RESULTS: Idiopathic intracranial hypertension commonly presents in obese women of childbearing age, being headache and papilledema the main clinical manifestations. Characteristic radiological findings consist of increased cerebrospinal fluid around the optic nerve, partially empty sella turcica and stenosis of the transverse sinuses. Transverse sinus stenting is a treatment alternative that has proven valuable utility in the recent years. Spontaneous intracranial hypotension in most of cases presents with orthostatic headache and has predilection for female population. The typical radiological features in the brain consist of subdural fluid collections, enhancement of the dura, engorgement of the venous structures, pituitary enlargement, and sagging of the brain. In this pathology, a cerebrospinal fluid leak in the spine associated with a defect in the dura, meningeal diverticulum, or a cerebrospinal fluid-venous leak must be actively ruled out. CONCLUSIONS: Neurologic complaints secondary to changes in intracranial pressure exhibit certain clinical features that in combination with fairly specific radiological patterns allow a highly accurate diagnosis. The diverse specialists in neurosciences should be aware of the multiple image modalities in the study of these syndromes as well as the treatment alternatives by neurointerventional radiology.

Diagnostic Neuroradiology Subspecialty Training: 1 Versus 2 Years; the Canadian Perspective.

BACKGROUND: Canada began a national reform of its post-graduate medical education training programs to a Competence By Design (CBD) model. Trends from accredited neuroradiology programs from the past 10 years were investigated to inform educators and stakeholders for this process. METHODS: A 13-question electronic survey was sent to program directors of all 8 accredited neuroradiology training programs in Canada. Data was requested for each year on the 2008-2019 graduating classes. Questions pertained to program enrolment; program completion; post-training employment; and the sufficiency of 1-year training programs. RESULTS: Response rate was 100%. Over the timeframe studied, the 2-year programs increased in size (P = 0.007), while the 1-year programs remained steady (P = 0.27). 12.2% of trainees enrolled in the 2-year program dropped out after 1 year, and were considered 1-year trainees thereafter. A higher proportion of 2-year trainees obtain positions within academic institutions (89.5 vs 67.2%, P = 0.0007), whereas a higher proportion of 1-year trainees obtain positions within non-academic institutions (29.3 vs 8.1%, P = 0.0007). A higher proportion of those with Canadian board certification in diagnostic radiology who completed a 2-year program obtained a position within a Canadian academic institution compared to non-certified 2-year trainees (P < 0.001). 71.4% of program directors agreed that a 1-year program was sufficient for non-academic staff positions. CONCLUSION: The length of the training program has significant impact on employment in academic vs non-academic institutions. This information can be used to guide the upcoming CBD initiative for neuroradiology programs.

Magnetic resonance imaging of the temporal lobe: normal anatomy and diseases.

OBJECTIVE: This pictorial essay will review the magnetic resonance imaging anatomy of the temporal lobes and describe the major pathologic processes of this complex area. CONCLUSIONS: Magnetic resonance imaging is an essential tool in the investigation of a patient with suspected temporal lobe pathology. Various conditions may affect this anatomic region, and, therefore, classification of imaging findings into specific groups may help provide a more focused differential diagnosis.

The forgotten lacrimal gland and lacrimal drainage apparatus: pictorial review of CT and MRI findings and differential diagnosis.

The lacrimal gland is a bilobed serous gland located in the superolateral aspect of the orbit. Lacrimal system pathologies can be broadly divided into pathologies of the lacrimal gland and those of the nasolacrimal drainage apparatus. These include distinct congenital, infectious, inflammatory, and benign, indeterminate, and malignant neoplastic lesions. Trauma and resultant fractures affecting lacrimal drainage apparatus is not part of this review; only non-traumatic diseases will be discussed. CT is the initial modality of choice because of its ability to delineate lacrimal system anatomy and demonstrate most lacrimal drainage system abnormalities and their extent. It also assesses bony architecture and characterizes any osseous changes. MRI is helpful in further characterizing these lesions and better assessing involvement of the surrounding soft tissue structures. In this pictorial review, we will review the anatomy of the lacrimal system, describe CT/MRI findings of the common and uncommon lacrimal system abnormalities and discuss relevance of imaging with regards to patient management.

Atypical resting state functional connectivity in mild traumatic brain injury.

OBJECTIVES: This study aimed to investigate changes in three intrinsic functional connectivity networks (IFCNs; default mode network [DMN], salience network [SN], and task-positive network [TPN]) in individuals who had sustained a mild traumatic brain injury (mTBI). METHODS: Resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired from 27 mTBI patients with persistent postconcussive symptoms, along with 26 age- and sex-matched controls. These individuals were recruited from a Level-1 trauma center, at least 3 months after a traumatic episode. IFCNs were established based on seed-to-voxel, region-of-interest (ROI) to ROI, and independent component analyses (ICA). Subsequently, we analyzed the relationship between functional connectivity and postconcussive symptoms. RESULTS: Seed-to-voxel analysis of rs-fMRI demonstrated decreased functional connectivity in the right lateral parietal lobe, part of the DMN, and increased functional connectivity in the supramarginal gyrus, part of the SN. Our TPN showed both hypo- and hyperconnectivity dependent on seed location. Within network hypoconnectivity was observed in the visual network also using group comparison. Using an ICA, we identified altered network functional connectivity in regions within four IFCNs (sensorimotor, visual, DMN, and dorsal attentional). A significant negative correlation between dorsal attentional network connectivity and behavioral symptoms score was also found. CONCLUSIONS: Our findings indicate that rs-fMRI may be of use clinically in order to assess disrupted functional connectivity among IFCNs in mTBI patients. Improved mTBI diagnostic and prognostic information could be especially relevant for athletes looking to safely return to play, as well for individuals from the general population with persistent postconcussive symptoms months after injury, who hope to resume activity.

A nonsynonymous polymorphism in cannabinoid CB2 receptor gene is associated with eating disorders in humans and food intake is modified in mice by its ligands.

Marijuana use activates cannabinoid receptors (CB-Rs) producing several behavioral effects related to addiction, mood, and appetite. We investigated the association between CNR2 gene, which encodes cannabinoid CB2 receptor (CB2-R) and eating disorders in 204 subjects with eating disorders and 1876 healthy volunteers in Japanese population. The effect of treatment with CB2-R ligands on mouse food consumption was also determined. The CB2-R ligands used suppressed food intake in a time- and strain-dependent manner when food was available ad libitum and during the 12-h fast except, AM 630-the CB2-R antagonist that stimulated food consumption in food-deprived mice. There is an association between the R63Q polymorphism of the CNR2 gene and eating disorders (P = 0.04; Odds ratio 1.24, 95% CI, (1.01-1.53). These results suggest that cannabinoid CB2-R is involved in the endocannabinoid signaling mechanisms associated with the regulation of food intake and in eating disorders.

The treatment of advanced prostatic carcinoma with total androgenic blockade using bilateral orchidectomy and flutamide: experience at the National Cancer Institute in Mexico.

This prospective trial was undertaken to determine the benefits of the combination of bilateral orchidectomy with flutamide, both in terms of survival and quality of life for patients with advanced prostatic carcinoma. All patients were previously untreated and received 750 mg/d of flutamide immediately after bilateral orchidectomy. The mean age was 68.9 +/- 9.4 years. Pain disappeared or decreased in 83% of patients at 3 months, 62% of patients at 6 months, and 25% of patients at 12 months. The survival was 62% at 12 months and 58% at 24 months. No patients discontinued treatment with flutamide as a result of side effects. In conclusion, total androgenic blockade with flutamide and bilateral orchidectomy was seen to be a safe and effective approach that increases survival and improves the quality of life of patients with advanced prostatic carcinoma. A greater number of patients and a larger follow-up is necessary to substantiate the improvement in survival.

Stereotactic radiosurgery in the management of angiographically occult vascular malformations.

PURPOSE: To evaluate the role of stereotactic radiosurgery in the treatment of angiographically occult vascular malformations (AOVMs). METHODS AND MATERIALS: From 1987 to 1996, 21 patients, 10 males and 11 females, median age of 41 years (range: 7-75 years), with an intracerebral AOVM underwent stereotactic radiosurgery at our institution. All were considered at high risk for surgical intervention. The vascular lesions were located in the brainstem (17 patients), basal ganglia (2), occipital lobe (1), and cerebellum (1). Diagnosis was based on high-resolution magnetic resonance imaging (MRI). Clinical presentation at onset included previous intracerebral hemorrhage (20 patients) and epilepsy (1). All patients were treated with a linac-based radiosurgical technique. The median dose delivered was 25 Gy (range 13-50 Gy), typically prescribed to the 80-90% isodose surface (range 50-90%), which corresponded to the periphery of the vascular malformation. Patients were followed by clinical neurologic assessment and by MRI on a regular interval basis. RESULTS: Follow-up was obtained in 20 patients; clinical or MRI information was not available for 1 patient, and this patient was excluded from our analysis. At a median follow-up of 77 months (range: 4-141 months), follow-up MRIs postradiosurgery do not demonstrate any changes in the appearance of the AOVM. Four patients developed an intracranial bleed at 4, 8, 35, and 57 months postradiosurgery. Annual hemorrhage rates were considerably higher in the observation period preradiosurgery than postradiosurgery (30% vs. 3.2%, p < 0.001). Complications postradiosurgery were observed in 4 patients. Three patients developed mild to moderate edema surrounding the radiosurgical target, expressed at 5, 8, and 24 months, respectively. In all cases, the edema was transient and resolved completely on subsequent MRIs. One of the 4 patients developed radiation necrosis 8 months after radiosurgery. CONCLUSION: The use of stereotactic radiosurgery in the treatment of AOVM continues to be controversial. Our results appear to show a reduction in the risk of symptomatic hemorrhage post treatment. Patients with previous history of hemorrhage or progressive neurologic deficit and small, well circumscribed lesions may benefit from a trial of stereotactic radiosurgery.

Brainstem involvement with mycosis fungoides: an unusual central nervous system complication.

Changes in the brainstem were demonstrated with MR imaging in a patient with mycosis fungoides. Previous reports of CNS involvement in this rare disease have not had similar findings.

MR imaging findings in African trypansomiasis.

We report the initial and follow-up brain findings in a 42-year-old male patient with CNS involvement with African trypansomiasis. Initial MR imaging demonstrated diffuse hyperintensity in the basal ganglia bilaterally as well as involvement of the internal capsule, external capsule, and extreme capsule. Follow-up examination at 1 year revealed decreased signal intensity in the previously affected areas; however, ventricular enlargement indicative of atrophy was readily apparent.

Exophytic primitive neuroectodermal tumor of the spinal cord.

We present a case of an exophytic spinal primitive neuroectodermal tumor that, radiologically, simulated an extramedullary nerve sheath tumor, meningioma, or metastatic tumor deposit. MR imaging provided discrete anatomic localization of the tumor, enabling exclusion of multicentricity in the brain and spinal cord.

Bilateral thalamic glioma: review of eight cases with personality change and mental deterioration.

PURPOSE: To describe the clinical, radiographic, and neuropathologic features of bilateral thalamic glioma. METHODS: We searched our hospital records (1963 to present) to identify patients diagnosed as having the disease. RESULTS: Our search revealed eight patients, ranging in age from 8-63 years, with bithalamic tumor diagnosed by angiography, CT, and/or MR. All patients displayed personality changes and/or mental deterioration, including memory loss, inattention, confusion, hallucination, hyperphagia, or slow mentation. Unilateral motor weakness was also noted in six cases. The tumor always involved the medial aspect of the left and right thalami, but was often more extensive. The pathology was determined to be grades I-IV astrocytoma, confirmed by stereotactic biopsy or autopsy in six. Mild to moderate hydrocephaly occurred in some cases and was considered to be a contributing factor to mental deterioration. No correlation was found between age and type of tumor. CONCLUSIONS: Bilateral glioma of the dorsomedial and intralaminar nuclei of the thalamus can be a primary cause of dementia that has not been well-recognized in the past. CT and particularly MR should be considered for patients presenting with personality change or dementia, because of the possible presence of this unusual but devastating disease.

Subarachnoid-pleural fistula complicating thoracotomy: case report and review of the literature.

We describe a patient who developed a persistent pleural effusion due to a subarachnoid-pleural fistula after operation for lung carcinoma and then review the literature on iatrogenic subarachnoid-pleural fistulas.

Interhemispheric subdural hematoma.

Although relatively uncommon, interhemispheric subdural hematoma (ISDH) occurs more frequently than was suspected before the advent of computerized tomographic (CT) scanning. When its mass is sufficiently large to compress the medial cerebral hemisphere, specific focal neurological abnormalities may occur. These include weakness of the contralateral leg, or contralateral hemiparesis with the leg being weaker than the arm. On the unenhanced CT scan ISDH is seen as a crescent shaped, midline hyperdensity. Treatment is dictated by the clinical course. Evacuation of the hematoma by parasagittal craniotomy is recommended if the symptoms are pronounced.

MRI diagnosis of brainstem cavernous angiomas presenting as tumours.

We report experience with 11 patients misdiagnosed for years, on the basis of computed tomography (CT) and angiography, as harbouring brainstem tumours in whom magnetic resonance imaging (MRI) demonstrated cavernous angiomas. Seven had undergone external irradiation, 2 had a ventriculo-peritoneal shunt, 2 developed aseptic femur necrosis following corticosteroid treatment, 1 had undergone a biopsy with a pathological diagnosis of glioma. CT had depicted ill-defined, hyperdense, faintly enhancing lesions. Angiography was normal, or showed an avascular mass or subtle venous pooling. MRI delineated discrete lesions, typical of cavernous angiomas, with a mixed hyperintense, reticulated, central core surrounded by a hypointense rim. Six patients subsequently underwent stereotactic radiosurgery without changes in clinical status or lesion. Although hemorrhagic neoplasms may mimic the clinical course and MRI appearance of cavernous angiomas, MRI is useful in the diagnosis of brainstem cavernous angiomas and should be performed in patients with suspected brainstem tumours.

MRI of the brachial plexus: modified imaging technique leading to a better characterization of its anatomy and pathology.

Magnetic resonance imaging (MRI) is the imaging modality of choice for the evaluation of the brachial plexus due to its superior soft tissue resolution and multiplanar capabilities. The evaluation of the brachial plexus however represents a diagnostic challenge for the clinician and the radiologist. The imaging assessment of the brachial plexus, in particular, has been traditionally challenging due to the complexity of its anatomy, its distribution in space and due to technical factors. Herein, we describe a modified technique used in our institution for the evaluation of the brachial plexus which led to a substantial decrease in scanning time and to better visualization of all the segments of the brachial plexus from the roots to the branches, in only one or two images, facilitating therefore the understanding of the anatomy and the interpretation of the study. To our knowledge, we are the first group to describe this technique of imaging the brachial plexus. We illustrate the benefit of this modified technique with an example of a patient with a lesion in the proximal branches of the left brachial plexus that was clinically suspected but missed on conventional brachial plexus imaging for six consecutive years. In addition, we review the common and infrequent benign and malignant pathology that can affect the brachial plexus.

Progressive multifocal leukoencephalopathy restricted to the posterior fossa in a patient with systemic lupus erythematosus.

Progressive multifocal leukoencephalopathy is a neurological infectious disease caused by the John Cunningham polyomavirus (JCV), an opportunistic agent with worldwide distribution. This disease is frequently seen in immunosuppressed patients and rarely associated with systemic lupus erythematosus. In the central nervous system PML demyelinating lesions occur in the supratentorial compartment. The authors describe a rare case of PML secondary to SLE treatment with atypical presentation restricted to the posterior fossa.

An Atlas of Infectious and Parasitic Diseases of the Central Nervous System. A Cooperative Study of SILAN (Sociedad Iberolatinoamericana de Neurorradiologia).

Infectious diseases of the central nervous system vary in frequency in different locations in America and Europe. What is common in Brazil can be a sporadic presentation in Europe. Cooperative work gathering experiences from neuroradiologists working in various places can be achieved and will help to identify uncommon cases that can present in our daily practice.

Behavioral effects of CB2 cannabinoid receptor activation and its influence on food and alcohol consumption.

Consumers of marijuana typically feel a strong, compulsive desire to consume food. Although past research revealed that the CB1 cannabinoid receptor is a potent regulator of food intake, the functional presence of neuronal CB2 cannabinoid receptors in the brain has been controversial. The role of CB2 receptors in food and alcohol consumption and the behavioral effects of CB2 receptor ligands are not well characterized. This is because CB2 cannabinoid receptors were thought to be absent from the brain and expressed primarily in immune cells and in the periphery. We tested the effects of peripheral injections of CB2 antagonist AM 630, CB2 agonist PEA, and CB1 antagonist AM 251 on male C57BL/6, Balb/c, and DBA/2 mice at the beginning of the night cycle and after overnight 12-hour fasts. We also investigated the effects of the putative CB2 agonist, JWH015, and CB2 antagonist, SR144528, in mouse motor function tests and in the two-compartment black and white box. Under standard conditions, the CB2 antagonist AM 630 inhibited food consumption in C57BL/6 mice and DBA/2 mice, but failed to block food intake of Balb/c mice. The CB2 agonist PEA had no significant effect on food consumption in Balb/c mice, and reduced food intake in C57BL/6 and DBA mice. The CB1 antagonist AM 251 inhibited food ingestion in the three mouse strains at variable times. After 12-hour food deprivation, the CB2 antagonist AM 630 increased food consumption in C57Bl/6 mice, but failed to produce significant changes in food intake for Balb/c and DBA/2 mice. The CB2 agonist PEA also reduced food consumption in all three mice strains at variable times. In comparison to the CB2 ligands, CB1 antagonist AM 251 inhibited food ingestion in the mouse strains. A general pattern of depression in locomotor activity was induced by JWH 015 in both males and females in the three mouse strains tested as the dose was increased. The development and enhancement of alcohol preference was observed after chronic treatment with CB2 agonist JWH 015 in stressed mice, but not in controls. In the DBA/2 strain, the spontaneous locomotor activity and stereotype behavior was enhanced by acute administration of low doses of SR144528. There was a reduction in CNR2 gene expression in the ventral mid-brain region of mice that developed alcohol preference, but not in those that did not develop alcohol preference. These effects of CB2 cannabinoid receptor ligands in in vivo behavioral tests are provided as functional evidence that CB2-Rs in the brain play a role in food and alcohol consumption and in the modification of mouse behavior.