Transient locked-in syndrome and basilar artery vasospasm.

BACKGROUND: Cerebral vasospasm is the main cause of neurological mortality and morbidity following subarachnoid hemorrhage. Basilar artery vasospasm (BAVS) is associated with a high morbidity and may have multiple clinical presentations. METHODS: We report the case of a 43 years-old man with BAVS presenting as a reversible locked-in syndrome (LIS) after stopping sedation. RESULTS: The symptoms were successfully managed by intra-arterial infusion of vasodilators and balloon angioplasty. Magnetic resonance imaging did not reveal any brainstem lesion 48 h after the complication, demonstrating a hemodynamic mechanism. CONCLUSION: LIS can reveal BAVS. Its diagnosis relies on clinical examination. In this case, rapid neuro-interventional treatment permitted reversal of symptoms. This could not have been possible under sedation.

Three-dimensional rotational angiography in the assessment of the angioarchitecture of brain arteriovenous malformations.

BACKGROUND AND PURPOSE: The angioarchitecture of brain arteriovenous malformations (BAVM) still remains a complex subject of study despite advances in medical imaging techniques. For this reason, the present study aimed to assess whether or not 3D rotational angiography (3DXA) might improve the assessment of BAVM. PATIENTS AND METHODS: Included prospectively were 72 patients who had undergone conventional digital subtraction angiography (DSA) and 3DXA for pretherapeutic assessment of BAVM prior to radiosurgery. Dimensional criteria, arterial-feed patterns, venous drainage, points of weakness and vascular densities (VD) of the nidus and shunt zone were studied. RESULTS: 3DXA detected all arteriovenous shunts by revealing abnormal venous enhancement. Post-processing tools similar to CT and MRI may also be used to make complex 3D reconstructions. In addition, the technique provided significant help for volumetric estimations, extraction of arterial feeders and origins of draining veins, and analysis of the 3D conformation of the nidus. Furthermore, 3DXA detected significantly more points of weakness, such as intranidus aneurysms and venous anomalies (P<0.005). In 65% of cases, a gradient of vascular enhancement intensity was found between the arteries and draining veins surrounding or comprising the nidus. VD, or the percentages of space occupied by the enhanced vascular elements, was evaluated in both the nidus and shunt zone. VD in the shunt zone was highest in untreated patients with no history of bleeding (P<0.005). CONCLUSION: 3DXA offers a useful approach to BAVM exploration and can improve our knowledge of lesional angioarchitecture, necessary for the planning of therapeutic strategies.

[Imaging of brain tumors in children]. / Imagerie des tumeurs cérébrales de l'enfant.

Few studies exist in the literature on pediatric brain tumors examined with advances MRI techniques. The aim of this review is to try to find out some specific tissular characteristics of the main cerebral tumors encountered in children, especially through diffusion imaging, perfusion imaging and proton magnetic resonance spectroscopy (MRS). However, hemispheric cerebral tumors are not as common as in the adult population.

MR imaging of brain maturation.

Magnetic resonance imaging (MRI) is the imaging tool of choice to evaluate brain maturation and especially brain myelination. Magnetic resonance imaging also provides functional insight through diffusion images and proton spectroscopy. In this review the MRI techniques are analyzed for both pre- and postnatal periods. The origin of MR signal changes is also detailed in order to understand normal myelination evolution and the consequences on brain maturation of the different pathologies encountered prior and after birth. Because MRI is "blind" in terms of signal on conventional sequences after 2 years of age, a particular attention is given to diffusion images and proton spectroscopy of the developing brain.

Neuroimaging of neonatal encephalopathies.

Neonatal brain disorders consist of a wide chapter including brain malformations, hypoxic-ischemic encephalopathy (HIE), intracranial infections, perinatal trauma and metabolic encephalopathy. We will focus here on HIE, intracranial infections (especially materno-fetal infection with or without prolonged and/or premature rupture of membranes) and metabolic encephalopathy, those three conditions being the most frequent so far in our experience. Neonatal stroke is also analyzed. Moreover minor perinatal events might be superimposed on an already damaged (infective, edematous, metabolically abnormal or maldeveloped) brain, highlighting the main role and potential benefits of neuroimaging during the neonatal period. The different methods of brain imaging are thus reported with their advantages and disadvantages.