[Basal ganglia calcification]. / Calcifications des noyaux gris centraux.

Calcifications of the basal ganglia are frequently seen on the cerebral CT scans and particularly in the globus pallidus. Their frequency increases physiologically with age after 50 years old. However, pathological processes can also be associated with calcium deposits in the gray nuclei, posterior fossa or white matter. Unilateral calcification is often related to an acquired origin whereas bilateral ones are mostly linked to an acquired or genetic origin that will be sought after eliminating a perturbation of phosphocalcic metabolism. In pathological contexts, these calcifications may be accompanied by neurological symptoms related to the underlying disease: Parkinson's syndrome, psychiatric and cognitive disorders, epilepsy or headache. The purpose of this article is to provide a diagnostic aid, in addition to clinical and biology, through the analysis of calcification topography and the study of different MRI sequences.

Susceptibility Vessel Sign on MRI Predicts Favorable Clinical Outcome in Patients with Anterior Circulation Acute Stroke Treated with Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: The susceptibility vessel sign on MR imaging has been reported to indicate acute occlusion from erythrocyte-rich thrombus. The purpose of this study was to evaluate the influence of the susceptibility vessel sign seen on MR imaging before treatment on the clinical outcome after mechanical thrombectomy for anterior circulation acute stroke. MATERIALS AND METHODS: We retrospectively included 73 consecutive patients who were treated for anterior circulation acute stroke by mechanical thrombectomy from December 2009 to September 2013. Each patient underwent MR imaging before mechanical thrombectomy. The presence (susceptibility vessel sign+) or absence of the susceptibility vessel sign (susceptibility vessel sign-) was recorded. Mechanical thrombectomy was performed either alone or in association with IV tPA according to the site and time after occlusion. Good functional outcome was defined by an mRS ≤ 2 at 3 months in susceptibility vessel sign+ and susceptibility vessel sign- groups. Patient clinical characteristics, initial NIHSS score and ASPECTS, site of occlusion, time between onset to groin puncture, TICI after mechanical thrombectomy, NIHSS score at day 1, and spontaneous hyperattenuation on CT at day 1 were also analyzed. RESULTS: Fifty-three patients with susceptibility vessel sign+ and 20 with susceptibility vessel sign- were included in our study. mRS ≤ 2 at 3 months occurred in 65% patients in the susceptibility vessel sign+ group and 26% in the susceptibility vessel sign- group (P = .004). On multivariate analysis, the susceptibility vessel sign was the only parameter before treatment that could predict mRS ≤ 2 at 3 months (OR, 8.7; 95% CI, 1.1-69.4; P = .04). CONCLUSIONS: Our study strongly suggests that the susceptibility vessel sign on MR imaging before treatment is predictive of favorable clinical outcome for patients presenting with anterior circulation acute stroke and treated with mechanical thrombectomy.

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.

Management of ischemic stroke in the hyperacute phase.

Over the last 15 years, advances in acute ischemic stroke (AIS) management have led to a significant reduction in the morbidity and mortality related to this serious disease. This has resulted from progress in imaging technology, increased access to imaging procedures, enhanced coordination in stroke care from emergency departments to rehabilitation centers, development of organized inpatient stroke units, and to the widespread use of acute thrombolysis. Once the diagnosis of AIS is confirmed by neuroimaging, the etiological work up is conducted in parallel with therapeutic measures by stroke units. The intravenous administration of recombinant tissue plasminogen activator (rt-PA) remains the most beneficial intervention in emergency stroke management, but it must be administered within 4.5 hours following the onset of symptoms and only in eligible patients. Recently, several procedures for increasing the efficacy of arterial recanalization have emerged, including intra-arterial administration of thrombolytic agents, mechanical reopening techniques, development of new thrombolytic agents, protocol modifications that allow treatment beyond 4.5 hours or in individuals >80 years old, and remote patient evaluation via telemedicine. So far, no potentially neuroprotective drug has shown to improve outcome following stroke. In addition, pulmonary status, blood pressure, glucose, temperature, and cardiac function must be closely monitored in patients undergoing treatment for AIS. Complications such as cerebral edema, hemorrhagic transformation, seizure, infection, and venous thromboembolic disease worsen the prognosis, and must be prevented or treated. Like myocardial infarction, ischemic stroke should be considered as a treatable emergency. Widespread public education regarding stroke symptoms, novel treatments, and time constraints for effective therapy should increase the number of patients that present within the first hours after stroke. Since "time is brain," early presentation is key to transforming trial results into effective stroke therapies.

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.