Non-adrenal tumors of the adrenal area; what are the pitfalls?

Discovery of an adrenal mass is nowadays a frequent situation. While adrenal tumors can cause a variety of symptoms, more often than not they are diagnosed incidentally on imaging exams such as CT-scan or MRI performed for another purpose. However, any retroperitoneal supra-renal mass can have an extra-adrenal origin. Indeed, operated non-adrenal masses initially but wrongly diagnosed as an adrenal disease represent about 3.5% of adrenalectomies. These differential diagnoses principally include retroperitoneal tumors that are malignant in two thirds of cases (lymphomas, sarcomas, neurogenic or germinal tumors), and more rarely vascular anomalies or congenital malformations, which are most frequently left-sided due to the wide variety of anatomical structures surrounding the left adrenal gland. Several lesions can originate from the adrenal gland or be located near the gland (paraganglioma, ganglioneuroma). Even though unilateral adrenalectomy is associated with low morbidity, ignorance of these differential diagnoses can cause ill-adapted management; overly conservative surgery in case of sarcoma is one example. Some of these lesions have characteristic clinical or imaging features (cystic lymphangioma, angiomyolipoma…). In other cases, assessment of hormonal secretion is required and additional exams (MRI, percutaneous biopsy, PET-scan with 18-Fluorodeoxyglucose) can correct an erroneous diagnosis. The above diagnostic approach allows appropriate management (with or without surgery). The purpose of this review was to highlight the main differential diagnoses of adrenal masses, to describe their characteristics, and to discuss their therapeutic management.

[Cerebrovascular malformation revealed during the prethrombolysis workup in acute ischemic stroke. Impact on therapeutic decision making]. / Malformation vasculaire cérébrale découverte dans le bilan pré-thrombolyse d'un infarctus cérébral. Impact sur la décision thérapeutique.

Intravenous recombinant tissue plasminogen activator for acute ischemic stroke is contraindicated in patients harboring an asymptomatic intracranial vascular malformation, whether it is incidentally discovered at the time of the initial cerebral imaging or previously known. Because thrombolysis is associated with a risk of serious intracerebral hemorrhage, it is theoretically possible that this treatment increases the risk of bleeding or rupture of these malformations. However, this risk seems very low in clinical practice. We report two cases, one with a probable brainstem cavernous malformation treated with alteplase for a supratentorial ischemic stroke who developed just after treatment a fatal brainstem hemorrhage, and another one with asymptomatic dural arteriovenous fistula, treated by endovascular thrombectomy solely. This approach was safe and effective, and the patient had an endovascular embolization of the fistula one month later as it became symptomatic. Based on the literature, we discuss the bleeding risk of asymptomatic intracranial vascular malformations in acute ischemic stroke patients treated with alteplase, depending on the type of malformation (intracranial aneurysm, arteriovenous and cavernous malformation or fistula), and the alternative therapeutic options.

The vestibulocochlear nerve (VIII).

The vestibulocochlear nerve (8th cranial nerve) is a sensory nerve. It is made up of two nerves, the cochlear, which transmits sound and the vestibular which controls balance. It is an intracranial nerve which runs from the sensory receptors in the internal ear to the brain stem nuclei and finally to the auditory areas: the post-central gyrus and superior temporal auditory cortex. The most common lesions responsible for damage to VIII are vestibular Schwannomas. This report reviews the anatomy and various investigations of the nerve.

The lower cranial nerves: IX, X, XI, XII.

The lower cranial nerves innervate the pharynx and larynx by the glossopharyngeal (CN IX) and vagus (CN X) (mixed) nerves, and provide motor innervation of the muscles of the neck by the accessory nerve (CN XI) and the tongue by the hypoglossal nerve (CN XII). The symptomatology provoked by an anomaly is often discrete and rarely in the forefront. As with all cranial nerves, the context and clinical examinations, in case of suspicion of impairment of the lower cranial nerves, are determinant in guiding the imaging. In fact, the impairment may be located in the brain stem, in the peribulbar cisterns, in the foramens or even in the deep spaces of the face. The clinical localization of the probable seat of the lesion helps in choosing the adapted protocol in MRI and eventually completes it with a CT-scan. In the bulb, the intra-axial pathology is dominated by brain ischemia (in particular, with Wallenberg syndrome) and multiple sclerosis. Cisternal pathology is tumoral with two tumors, schwannoma and meningioma. The occurrence is much lower than in the cochleovestibular nerves as well as the leptomeningeal nerves (infectious, inflammatory or tumoral). Finally, foramen pathology is tumoral with, outside of the usual schwannomas and meningiomas, paragangliomas. For radiologists, fairly hesitant to explore these lower cranial pairs, it is necessary to be familiar with (or relearn) the anatomy, master the exploratory technique and be aware of the diagnostic possibilities.

Facial nerve: from anatomy to pathology.

The facial nerve (CN VII) emerges from the facial nerve nucleus in the pons. It is accompanied by CN VIII along its cisternal pathway, as well as at the internal auditory meatus. Its petrous pathway includes a labyrinthine segment, a horizontal tympanic segment and a vertical mastoid segment until the stylomastoid foramen. It then continues to the parotid gland. Pontine impairment is usually associated with other neurological symptoms. Lesions of the cerebellopontine angle (most often meningioma and schwannoma) initially result in impairment of CN VIII. The impairment of CN VII takes second place. Peripheral impairment (outside of a traumatic context) is most often due to Bell's palsy.

Infectious and metabolic brain imaging.

Central nervous system infectious and metabolic disease is a vast domain. We have chosen to focus particularly on five pathological conditions: brain abscess, herpes encephalitis, Creutzfeldt-Jacob disease, posterior reversible encephalopathy and central pontine myelinolysis. We will pay particular attention to MRI signs and the specific sequences to use in each condition, in addition to the conventional sequences, in order to avoid diagnostic traps. Once the MRI exploration is complete, the diagnosis still cannot be established without knowing the clinical and metabolic context.

[Ischemic stroke related to pauci-symptomatic acute aortic dissection. Risks of intravenous thrombolysis]. / Infarctus cérébral par dissection aortique pauci-symptomatique. Les risques de la thrombolyse, à propos de deux observations.

INTRODUCTION: Acute aortic dissection involving the cervical arteries often induces cerebral infarction. In this context, there is a high risk of hemorrhage and thrombolytics are contra-indicated. OBSERVATION: We report two patients with a cerebral infarction which occurred after a pauci-symptomatic and undiagnosed aortic dissection treated with thrombolysis. The outcome was poor for both patients. DISCUSSION: Ischemic strokes related to acute aortic dissection often involve the right carotid artery territory and may manifest without pain. A systematic assessment of supra-aortic arteries might help to identify the underlying diagnosis. CONCLUSION: Acute aortic dissection should be systematically mentioned in the management of the acute ischemic stroke.

Paediatric moyamoya in mainland France: a comprehensive survey of academic neuropaediatric centres.

BACKGROUND: Epidemiological data of paediatric moyamoya disease/syndrome (MMD/MMS) in non-Asian populations are scarce. METHODS: A questionnaire was sent to every French neuropaediatric academic centre to estimate the prevalence, incidence, familial form rate and location of paediatric MMD/MMS cases. Specific paediatric data were also retrieved from the most recent nationwide Japanese study. RESULTS: A 100% response rate was obtained. The prevalence of paediatric MMD/MMS was estimated at 0.39/100,000 children (95% CI: 0.28-0.49), and the incidence was estimated at 0.065/100,000 children/year (95% CI: 0.025-0.12), with 7.5% familial cases. The prevalence was homogenous within the different administrative areas. CONCLUSIONS: This comprehensive survey of MMD/MMS in academic neuropaediatric centres suggests that the prevalence of the disease in children in France is approximately 1/20th of that estimated in Asia.

[Skull base osteomyelitis]. / Ostéite de la base du crâne.

Skull base osteomyelitis is a rare but serious infection. It typically afflicts immunosuppressed patients and should be suspected in patients with persistent otitis complicated by cranial nerve palsy (VII, IX and XII). The most frequent germ is pseudomonas aeruginosa. Contiguous spread of infection occurs along neurovascular structures and weaker regions of the skull base, then into the soft tissue compartments of the face and nasopharynx. Diagnosis and treatment should be made early for this disease with poor prognosis and high mortality.

[Vascular emergencies of the head and neck]. / Urgences vasculaires cervicofaciales.

The clinical manifestations of vascular lesions of the head and neck may be variable (hemorrhagic, ischemic, compressive). Diagnosis often is made at the time of acute presentation, but delayed manifestations, sometimes long after the initial presentation, should not be overlooked. Hemorrhagic manifestations are characterized by epistaxis, corresponding mainly to lesions of the nasal cavities but involvement of the internal carotid artery should be excluded (life threatening). In addition, some vascular malformations may lead to severe hemorrhage. Ischemic manifestations typically result from arterial dissection. A venous origin is also possible. Carotid-cavernous fistulas rarely lead to hemorrhagic or ischemic manifestations and tend to result in ocular manifestations, typically delayed and sometimes misleading.

[Arterial ischemic stroke in the healthy child. Practical approach (neonate and foetus excluded)]. / Accident artériel ischémique cérébral d'apparence primitive chez l'enfant. Démarche pratique (nouveau-né et foetus exclus).

Primary stroke can be due to embolism or an obstructive process of the vascular wall. Embolism may come from a parietal lesion of a large artery in the neck (traumatic dissections), from a cryptic cardiopathy, from a venous thrombosis associated with a right-left shunt. Among pathologies of endocranial arteries, the most frequent is the acute, postviral arteriopathy of the sus-clinoïd carotid, which evolves toward stabilisation or regression. Insidious obstructive arteriopathies of the Willis circle, including development of a transparenchymal suppletive circulation (Moya-Moya disease), cumulate chronic circulatory insufficiency and repetitive strokes. Inflammatory multifocal cerebral arteriopathies mainly involve mean and small arteries. Most of them are secondary to a multisystemic disease, but some are primary. The basic investigation is anatomical and begins with MRI. Emergency conventional cerebral angiography is discussed when heparinotherapy is difficult to decide (evolutive thrombosis), or when an endovascular intervention appears possible (anoeuvrism). Secondarily, conventional angiography is indicated in any chronic situation where a precise anatomical follow-up is necessary. Investigations of the cardiovascular system, of the thrombophilic risk, of a dysimmune process are discussed according to the clinico-anatomical diagnosis.

Patterns of the Cranial Venous System from the Comparative Anatomy inVertebrates. Part III. The Ventricular System and Comparative Anatomy of the Venous Outlet of Spinal Cord and Its Homology with the Five Brain Vesicles.

SUMMARY: Ontogenetically, the ventricular venous systemmay develop in order to drain the gray matter(cells of the mantle layer of the neural tube) which migrates dorsally. On primitive brain vesicles of submammals especially fish, amphibianand reptile, the ventricular venous system is the major venous collector located on the middorsal surface, in between the meningeal layers comparable to the subarachnoid space in mammals. The ventricular venous system functions as a major drainage system for the brain vesicles in these submammals but its role decreases when the other two venous systems develop. Concerning the route of venous exit from the brain vesicles, we found that it resembles the spinal cord but could not be found all the way along the brain vesicles.

Patterns of the Cranial Venous System from the Comparative Anatomy in Vertebrates. Part II.The Lateral-Ventral Venous System.

SUMMARY: Comparing the adult submammalian brain with the human embryonic brain, some patterns of venous drainage are quite similar. The veins lying on the lateral surface of the brain in submammals resemble those of the human embryo. In addition, the new longitudinal venous anastomosis ventral to the brain vesicles occurring late in human embryonic development seems to be similar to the late appearance of the basal vein and the ventral brain stem venous plexus found in adult mammals including man. The evolution of the new structures of the brain vesicles throughout the vertebrate series may have an induction role on the appearance of the cranial venous system. This part of the article series focuses on the evolution of the lateral-ventral venous system of the five brain vesicles. Nevertheless, the limitation of this article is due in part to the paucity of circumstantial papers and different names used for the veins.

White matter abnormalities in mild traumatic brain injury: a diffusion tensor imaging study.

BACKGROUND AND PURPOSE: Traumatic axonal injury is a primary brain abnormality in head trauma and is characterized by reduction of fractional anisotropy (FA) on diffusion tensor imaging (DTI). Our hypothesis was that patients with mild traumatic brain injury (TBI) have widespread brain white matter regions of reduced FA involving a variety of fiber bundles and show fiber disruption on fiber tracking in a minority of these regions. MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. Twenty-one patients with mild TBI were investigated (men:women, 12:9; mean age +/- SD, 32 +/- 9 years). In a voxel-based comparison with 11 control subjects (men:women, 8:3; mean age, 37 +/- 9 years) using z score analysis, patient regions with abnormally reduced FA were defined in brain white matter. MR imaging, DTI, and fiber tracking characteristics of these regions were described and analyzed using Pearson correlation, linear regression analysis, or the chi(2) test when appropriate. RESULTS: Patients had on average 9.1 regions with reduced FA, with a mean region volume of 525 mm(3), predominantly found in cerebral lobar white matter, cingulum, and corpus callosum. These regions mainly involved supratentorial projection fiber bundles, callosal fibers, and fronto-temporo-occipital association fiber bundles. Internal capsules and infratentorial white matter were relatively infrequently affected. Of all of the involved fiber bundles, 19.3% showed discontinuity on fiber tracking. CONCLUSION: Patients with mild TBI have multiple regions with reduced FA in various white matter locations and involving various fiber bundles. A minority of these fiber bundles show discontinuity on fiber tracking.

Extracranial vertebral artery involvement in neurofibromatosis type I. Report of four cases and literature review.

SUMMARY: Neurofibromatosis type 1 (NF-1) is one of the most common inherited diseases and as an autosomal dominant genetic disorder results from NF-1 gene mutation with 100% penetration and wide phenotypic variability. The disease can involve a wide variety of tissues derived from all three embryonic layers. NF-1 vasculopathy has been described primarily in peripheral arteries, but arteries supplying the CNS may also be involved. Of those, extracranial vertebral involvement is the commonest and most important. A series of four patients with NF-1 and vascular disease of the vertebral artery is described with a review of the pathophysiology, vascular phenotypes, their management and the pertinent literature.

[Transarterial embolisation of intracranial dural arteriovenous malformations with ethylene vinyl alcohol copolymer (Onyx18)]. / Embolisation par voie artérielle de malformations artérioveineuses durales intracrâniennes à l'aide d'ethylvinyl alcool copolymère (Onyx18).

OBJECTIVE: To report our recent experience in transarterial embolisation of dural arteriovenous malformations (DAVM) using a new liquid embolic agent, Onyx18. PATIENTS AND METHODS: 6 patients were enrolled in this series. Clinical presentation was separated into 2 groups: aggressive (n=2), non aggressive (n=4). The DAVM was located at the superior sagittal sinus (n=1), at the transverse sinus (n=2), at the condylian canal (n=1), in the lesser sphenoid wing region (n=1), and in the tentorium region (n=1). The DAVM drained directly into a condylian or a cortical vein for three patients and into a venous sinus with cortical venous reflux for the three others. In this latter situation, the sinus was anatomically excluded from the normal brain venous drainage. RESULTS: A full brain angiogram including both internal carotid arteries, both external carotid arteries and ipsilateral vertebral artery, was performed before and after each treatment. The feeder chosen after a selective catheterisation for Onyx18 injection was always meningeal. Each treatment consisted of a single Onyx injection after one unique feeder catheterisation. Complete anatomical exclusion of the DAVM was achieved and demonstrated by the post treatment angiogram in all cases. There was no clinical complication after the treatment. CONCLUSION: Onyx18 used is a safe treatment for DAVMs. When its injection is performed in optimal conditions, it fills the total DAVM and its drainage vein or sinus after a single arterial feeder catheterisation.

[MR-angiography of the head and neck vessels: technical considerations and clinical indications]. / ARM des vaisseaux cervico-encéphaliques: technique, principales applications cliniques.

Magnetic resonance angiography (MRA) is a very valuable tool in the routine evaluation of patients with stroke syndrome. It provides powerful noninvasive imaging of the cervical and intracranial vessels allowing the detection and the diagnosis of vascular anomalies. MRA usefully supplements, during the same examination, the analysis by MRI of the cerebral parenchyma. We will describe the indications of the various techniques (MRA with and without injection of contrast media) and show the value, artifacts and limitations of MRA in atherosclerotic stenosis or occlusive disease and in arterial dissections. This noninvasive vascular assessment will depend on the initial therapeutic orientation. Within the framework of the hemorrhagic stroke, we will discuss the role and the interest of dynamic MR angiography in the tracking and control of intracranial aneurysms and also the contribution of this newer sequences with gadolinium injection in the detection of cerebral vascular malformations.

Ehlers-Danlos syndrome type IV and recurrent carotid-cavernous fistula: review of the literature, endovascular approach, technique and difficulties.

We report the follow-up of a previously published case (Forlodou et al. Neuroradiology 38:595-597, 1996) of carotido-cavernous fistulas (CCFs) in a patient presenting with type IV Ehlers-Danlos syndrome (EDS 4) that were successfully treated twice by an endovascular approach. Initial treatment with a detachable balloon was in 1994 for a right CCF, and, 8 years later, a left CCF was treated by selective transarterial occlusion of the cavernous sinus with coils. Unfortunately, the patient suffered from a spontaneous post-operative intracranial haemorrhage in the left hemisphere and died. Review of the literature, technical considerations for bilateral CCF and complication are discussed.