[CT scan and MRI applications in the field of neuroimaging]. / Intérêt du scanner et de l'IRM dans les pathologies neurologiques.

Le scanner et l'IRM sont les deux principales techniques d'imagerie diagnostique et de suivi des pathologies neurologiques. Elles sont complémentaires mais se distinguent par leur disponibilité et leur accessibilité, et le caractère irradiant de la première, sans parler de la différence des coûts d'examens. Etablir un état des lieux revient à relever l'intérêt de l'utilisation de l'une ou l'autre des techniques en situation d'urgence ou dans le cadre d'un bilan différé. Les applications du scanner et de l'IRM sont discutées dans ces deux contextes et l'état de développement actuel des deux techniques intégrant les avancées technologiques et les perspectives futures sont évoquées.

CT and MRI are the main imaging techniques used for diagnosis and follow-up of neurological disorders. These techniques are complementary but differ from each other by availability and accessibility, and the radiation effect of the first one, let alone the cost. Writing a state of the art regarding this topic means to highlight the interest of each technique in emergency imaging as well as in the late assessment. The applications of both techniques are discussed according to the context and in addition, the current development and future perspectives are mentioned.

[Eye's traumatic enucleation : need for a multidisciplinary management]. / Enucléation traumatique bilatérale des yeux : une prise en charge multidisciplinaire s'impose.

We report a rare case of a 33 year-old man victim of a public assault resulting in bilateral enucleation of the orbits. The optic nerves were ripped or even pulled out with subsequent subarachnoïdal hemorrhage as well as chiasm lesions. Meaning castration, such an act may express a psychiatric or a neurologic disorder. The management must be multidisciplinary by a team that includes emergency doctors, radiologist, ophthalmologist, neurosurgeon as well as psychiatrist and neurologist.

Nous rapportons le cas rare d'un patient de 33 ans victime d'une énucléation des deux yeux par agression sur la voie publique. Les nerfs optiques ont été sectionnés voire avulsés, causant une hémorragie méningée et des lésions du chiasma optique. Symbole de castration, un tel acte peut exprimer une pathologie psychiatrique ou neurologique. La prise en charge doit être pluridisciplinaire par une équipe comportant urgentiste, radiologue, neurochirurgien, ophtalmologue, mais aussi psychiatre et neurologue.

MRI of the cervical spinal cord predicts respiratory dysfunction in ALS.

For patients with amyotrophic lateral sclerosis (ALS), the primary therapeutic goal is to minimize morbidity. Non-invasive ventilation improves survival. We aim to assess whether Magnetic Resonance Imaging (MRI) of the cervical spinal cord predicts the progression of respiratory disorders in ALS. Brain and spinal MRI was repeatedly performed in the SOD1G86R mouse model, in 40 patients and in healthy controls. Atrophy, iron overload, white matter diffusivity and neuronal loss were assessed. In Superoxide Dismutase-1 (SOD1) mice, iron accumulation appeared in the cervical spinal cord at symptom onset but disappeared with disease progression (after the onset of atrophy). In ALS patients, the volumes of the motor cortex and the medulla oblongata were already abnormally low at the time of diagnosis. Baseline diffusivity in the internal capsule was predictive of functional handicap. The decrease in cervical spinal cord volume from diagnosis to 3 months was predictive of the change in slow vital capacity at 12 months. MRI revealed marked abnormalities at the time of ALS diagnosis. Early atrophy of the cervical spinal cord may predict the progression of respiratory disorders, and so may be of value in patient care and as a primary endpoint in pilot neuroprotection studies.

MALDI-TOF MS contribution to the diagnosis of Campylobacter rectus multiple skull base and brain abscesses.

Campylobacter rectus is rarely associated with invasive infection. Both the isolation and the identification requirements of C. rectus are fastidious, probably contributing to an underestimation of its burden. We report the case of a 66-year-old man who developed several skull base and intracerebral abscesses after dental intervention. Campylobacter rectus was isolated from the brain biopsy. Within 45 minutes of reading the bacterial plate, the strain was accurately identified by MALDI-TOF MS. This rapid identification avoided the extra costs and delays present with 16S rRNA gene sequencing and allowed for a rapid confirmation of the adequacy of the empirical antibiotic treatment.

Late diagnosis of intestinal malrotation treated with gastrojejunal bypass : a case report.

We report the case of a male African patient who presented at day 8 of life with recurrent episodes of proximal small intestine occlusion, which was treated conservatively, because of misdiagnosis. Physical and cognitive development was normal throughout with, however, some episodes of stagnation. At the age of 15 years the recurrence of symptoms, not responding to the current conservative treatment, resulted in severe weight loss with BMI at 11 kg/m(2). The œsogastroduodenal barium study disclosed an extrinsic duodenal compression compatible with a congenital duodenal band. Because of the major concerns related to the patient and to the medical environment, jejunostomy for feeding was first performed to improve his weight. A year later the intestinal malrotation was cured by gastrojejunal bypass. The postoperative clinical course was favorable. The patient resumed a normal life and schooling. His BMI is currently 21.5 kg/m(2).

Developmental differences of the major forebrain commissures in lissencephalies.

BACKGROUND AND PURPOSE: Changes of the major forebrain commissures in lissencephaly have not been systematically studied. We investigated the developmental differences of the commissures in patients with varying types of lissencephaly to determine whether specific commissural features may help in distinguishing lissencephaly phenotypes. MATERIALS AND METHODS: MR imaging of 124 patients was retrospectively reviewed. Patients were classified as having cLIS, vLIS, and CBSC, according to cortical phenotype; few patients had genetic diagnoses. Abnormalities of the CC, AC, and HC were recorded, and the overall shape was regarded as hypogenetic, hypoplastic, dysmorphic, a thin flat callosal body with a vertical splenium, and a convex upward callosal body, compared with age-matched controls. Correlations between commissural characteristics and cortical patterns were analyzed by using the Monte Carlo simulation of χ(2), extension to m × n table, and Fisher exact tests as appropriate (P < .05). RESULTS: Patients were classified as having cLIS (57.4%), vLIS (38.4%), or CBSC (4.2%). The most common callosal developmental anomaly was hypogenesis with an absent rostrum, a small inferior genu, and a small splenium. An angled (90°) splenium was found to be significantly associated with cLIS, as was an excessively convex upward callosal body with VLDLR. ACC with an enlarged AC was found in all cases of ARX. CONCLUSIONS: Specific patterns of the commissure anomalies were associated with certain types of lissencephaly. Callosal anomalies were more common than those of the AC or HC. Developmental variations of commissures may be useful as an imaging criterion in differentiating the groups of lissencephalies and may give insight into the processes causing these malformations.

Pontine tegmental cap dysplasia: MR imaging and diffusion tensor imaging features of impaired axonal navigation.

BACKGROUND AND PURPOSE: Malformations of the brain stem are uncommon. We present MR imaging and diffusion tensor imaging (DTI) features of 6 patients with pontine tegmental cap dysplasia, characterized by ventral pontine hypoplasia and a dorsal "bump," and speculate on potential mechanisms by which it forms. MATERIALS AND METHODS: Birth and developmental records of 6 patients were reviewed. We reviewed MR imaging studies of all patients and DTIs of patient 3. Potential developmental causes were evaluated. RESULTS: All patients were born uneventfully after normal pregnancies except patient 6 (in utero growth retardation). They presented with multiple cranial neuropathies and evidence of cerebellar dysfunction. Variable hypotonia and motor dysfunction were present. Imaging revealed ventral pontine hypoplasia and mild cerebellar vermian hypoplasia, in addition to an unusual rounded to beaklike "bump" on the dorsal surface of the pons, extending into the fourth ventricle. Color fractional anisotropy maps showed the bump to consist of a bundle of axons directed horizontally (left-right). The bump appeared, on morphologic images, to be continuous with the middle cerebellar peduncles (MCPs), which were slightly diminished in size compared with those in healthy infants. Analysis of the DTI was, however, inconclusive regarding the connections of these axons. The decussation of the MCPs, transverse pontine fibers, and longitudinal brain stem axonal pathways was also abnormal. CONCLUSIONS: Our data suggest that the dorsal transverse axonal band in these disorders results from abnormal axonal pathfinding, abnormal neuronal migration, or a combination of the 2 processes.

Brain (1)H-MR spectroscopy in clinical neuroimaging at 3T.

After more than 10 years of use, clinical neuroimaging spectroscopy has proven to be invaluable in the MRI assessment of several brain diseases. The metabolic characterization of diverse brain lesions and pathological conditions is well established by spectroscopy studies at 1.5 T, but recently, an increase in the number of 3T magnets has noticeably improved routine neuroimaging in general. For brain proton spectroscopy, the use of higher magnetic fields has been promising in terms of increasing the signal/noise ratio across the spectrum and widening the frequency bandwidth to allow clearer separation of peaks that are otherwise too close to each other at 1.5 T, especially glutamate, glutamine and gamma-aminobutyric acid (GABA). The individual detection and quantification of these metabolites will add more details to the characterization of brain diseases, and allow the inclusion of more brain pathologies. Moreover, the ongoing advances in dedicated hardware and integrated software have led to more accurate and automated postprocessing, offering neuroradiologists a more user-friendly interface. This is an up to date review of the main clinical applications of brain proton MR spectroscopy that are potentially improved at 3T, taking into account the peculiarities of higher magnetic fields. It is based on both the literature and our own clinical experience, starting from July 2005 and including more than 250 scans at 3T (unpublished material), and emphasizes, for every indication, a practical approach to brain MRS to achieve the optimal clinical impact.

Apparent diffusion coefficient (ADC) and magnetization transfer ratio (MTR) in pediatric hypoxic-ischemic brain injury.

BACKGROUND AND PURPOSE: a review of the literature reveals the increasing interest in using Diffusion magnetic resonance imaging, with diffusion weighted images (DWI) and ADC (Apparent Diffusion Coefficient) quantitation, in pediatric hypoxic-ischemic brain injury. However, ADC and MTR (Magnetization Transfer Ratio) as quantitative tools have not been investigated together in these pathological conditions in young pediatric patients. The aim of this study was to apply a quantitative method by using ADC and MTR calculation in order to propose a reproducible quantitation of brain parenchymal lesions. METHODS: we conducted a prospective study including all children presenting with suspected cerebral hypoxic-ischemic injury. 15 children were included, among them 10 males and 5 females aged from 36 weeks of gestation to 17 months with a median age of 10,5 months. All MR examinations were performed at 1.5 Tesla unit including conventional MR (T1, T2 and Inversion-recovery sequences) and DWI with ADC map. ADC and MTR ROI (region of interest) measurements were made, in the frontal subcortical and periventricular white matter (WM) as well as in the gray matter (GM=basal ganglia), and in focal lesions. RESULTS: ADC and MTR values were abnormal in focal lesions and in diffuse injury with no evidence of lesion on conventional MRI and DWI. We observed a strong inverse correlation between these ADC and MTR (R=0,66 in WM; R=0,61 in GM). CONCLUSION: ADC and MTR calculation may be helpful as a reproductive method to quantify the lesions and detect diffuse lesions in hypoxic-ischemic pediatric brain injury.

[Management of patients after a first seizure]. / Conduite á tenir devant une première crise convulsive.

Neuroimaging evaluation in patients after a first seizure could be easily determined on the basis of seizure history, neurological examination, blood sample analysis and electroencephalography. The main objectives of the initial work-up are to differentiate a true seizure event from seizure-like symptoms, to exclude a single seizure as a manifestation of non organic cause and finally to consider the seizure as a result of cerebral lesion or inaugurate epilepsy. When a new onset seizure is diagnosed, urgent neuroimaging is recommended only in patients with focal neurological deficit, persistent or worsening alteration in the level of consciousness and when clinical and biological data lead to a suspected vascular or infectious etiology. Brain CT scan is usually more available in emergency to identify the cause of seizure. It may have an important role for the therapeutic strategy and may defer MRI investigation. Nevertheless, brain MRI must be performed in emergency when CT scan is not conclusive despite a severe clinical condition or in case of cerebral venous thrombosis. Imaging modalities depend on clinical data, patient age and suspected epilepsy type.

Supratentorial functional disturbances in two children with cerebellar cortical dysplasia.

When evaluating children with mental retardation, subtle cerebral and cerebellar morphologic anomalies are often noted at Magnetic Resonance Imaging (MRI). Some, such as cerebellar cortical dysplasia (CCD), have been considered as subtle markers of cerebral dysgenesis. Their functional significance and their effect on brain function, remain unknown. To study supratentorial functional disturbances related to CCD we performed Positron-Emission-Tomography (PET) studies in two children with isolated CCD, in order to investigate the degree of involvement of supratentorial structures. One had developmental delay, motor disturbances and ataxia, and the other one only had mental retardation. PET studies revealed hypoperfusion and hypometabolism within the vermis, thalamus and the right striatum in one case, and hypometabolism in the basal ganglia and cerebellar deep grey nuclei in the other case. Our results could lead to a hypothesis explaining motor disturbances as well as cognitive impairment, and could suggest a pathological functional significance of CCD. Nevertheless, the relationship between these findings and mental retardation needs further investigation.

[Natural evolution of an aneurysm of the V4 segment of the vertebral artery into a giant aneurysm. A case report]. / Evolution naturelle d'un anévrisme du segment V4 de l'artère vertébrale vers un anévrisme géant. A propos d'un cas.

We report the case of a 78-year-old female with an aneurysm of the V4 segment of the vertebral artery and a six-year follow-up without any surgical or endovascular treatment. The natural evolution of a small aneurysm into a giant aneurysm is rarely observed. We discuss the pathophysiology of the development and growth of such aneurysms through a review of the literature.

[Aseptic osteonecrosis of alcoholic origin: a case report]. / Ostéonécrose aseptique d'origine alcoolique: à propos d'un cas.

Alcohol-induced aseptic osteonecrosis is not infrequent but multifocal osseous destruction is very rare. Alcoholic patients often present lipidic metabolism perturbation with fat embolism and are susceptible to develop diffuse intravascular coagulation in terminal microcirculation of femoral and humeral heads. The authors report one case of multifocal alcohol-induced osteonecrosis in a 74 year-woman. She presented with bilateral osteonecrosis of the humeral heads and total osteolysis of the neck and the head of the hips. Hepatic cirrhosis and chronic pancreatitis were additional risk factors inducing intra-osseous thrombosis.