[Diffusion tensor imaging and tractography of central pontine myelinolysis]

International audienceOBJECTIVES: To illustrate the value of diffusion tensor imaging and tractography in the diagnosis and follow-up of central pontine myelinolysis. CASE REPORT: We report a case of central pontine myelinolysis in a 29 year old woman, also anorexic, studied using MR Diffusion Tensor Imaging (DTI) and Fibre Tracking (FT) focused on the pons, and compared with the studies of 5 normal volunteers. Tractography showed a swollen aspect of the right corticospinal fiber tract correlating with mild left lower extremity deficit at clinical evaluation. The pontine fibers were posteriorly displaced but intact. The sensory tracts were also intact. Apparent Diffusion Coefficient values were increased and Fractional Anisotropy was decreased in the lesions. Follow up imaging showed persistent abnormal ADC and FA values in the pons although the left cortico-spinal tract returned to normal, consistent with the clinical outcome. CONCLUSION: Diffusion Tensor Imaging MR and Fiber tractography are a new method to analyse white matter tracts. It can be used to prospectively evaluate the location of white matter tract lesions at the acute phase of central pontine myelinolysis and follow up

Computed temography of the anterior skull base in Kallmann syndrome reveals specific ethmoid bone abnormalities associated with olfactory bulb defects.

Context: Kallmannsyndrome (KS) is characterized by congenital hypogonadotropic hypogonadism (CHH) and an impaired sense of smell related to defective development of the olfactory system. Objective: The aim of the study was to use high-resolution computed tomography (CT) to detect specific abnormalities in the ethmoid bone region surrounding the olfactory bulbs in patients with KS. Patients: Thirty-seven KS patients were compared to normosmic CHH (nCHH) patients (n=15) and controls (n=30) of similar age. Design and Methods: We conducted a prospective study in a single referral center. Subjects underwent CT in bone windows with axial, coronal, and sagittal reconstructions centered on the olfactory fossa (OF) and cribriform plate (CP). We characterized the OF structure by measuring OF height, width, and surface area and a series of angles. The CP foramina were counted bilaterally. Olfactory bulb magnetic resonance imaging, performed in parallel, was compared with CT findings. Results: OF height, width, and surface area were all significantly lower in KS patients than in nCHH patients and controls (P < .0001). KS patients also had wider angles than nCHH patients and controls (P < .0001). KS subjects with olfactory bulb agenesis on magnetic resonance imaging or who harbored KAL1 mutations had the most marked changes in OF measurements and angles. Coronal OF height distinguished KS patients from controls with the best sensitivity and specificity. The mean number of CP foramina was similar in KS, nCHH, and control subjects. Conclusions: KS is associated with specific ethmoid bone abnormalities. The preserved number of CP foramina in KS patients suggests that the integrity of olfactory structures is not mandatory for their formation during fetal development or their maintenance in adult life

Cystic form of cervical lymphadenopathy in adults. Guidelines of the French Society of Otorhinolaryngology (short version). Part 2–etiological diagnosis procedure: Clinical and imaging assessment

International audienceThe authors present the guidelines of the French Society of Otorhinolaryngology (SFORL) for clinical and radiological assessment of cystic neck lymphadenopathy of unknown primary in adults. Most cases concern head and neck carcinoma metastasis, often in the oropharyngeal area, or less frequently differentiated thyroid carcinoma or non-keratinizing nasopharyngeal carcinoma.Methods: A multidisciplinary task force was commissioned to carry out a review of the literature on the etiological work-up in cystic neck lymphadenopathy in adults: clinical examination, conventional imaging (ultrasound, CT, MRI) and metabolic imaging. Guidelines were drafted based on the articles retrieved, and graded A, B, C or expert opinion according to decreasing level of evidence.Results: Oriented clinical examination, cervical and thyroid ultrasound scan and contrast-enhanced neck and chest CT scan are recommended in the assessment of cystic neck lymphadenopathy of unknown primary in adult patients. PET-CT is recommended prior to panendoscopy, to identify the primary tumor.Conclusion: Clinical and radiological assessment is fundamental for etiologic diagnosis of cystic neck lymphadenopathy in adult patients, and should be completed by cytological examination before in initiating treatment