Asymmetric development of the hippocampal region is common: a fetal MR imaging study.

BACKGROUND AND PURPOSE: Hippocampal development is poorly understood. This study evaluated the normal development of the hippocampal region during the fetal period by using MR imaging. MATERIALS AND METHODS: MR images of 63 fetuses without intracranial pathology were reviewed independently by 2 radiologists with no knowledge of the fetal GA. Three MR images were performed postmortem and 60 in vivo. The progress of hippocampal inversion was analyzed in coronal sections, and the left and right sides of the hippocampal region were compared in every case. RESULTS: The fetuses in the postmortem examinations were at GWs 17-18 and in the in vivo examinations, at GWs 19-36. The hippocampal sulcus was open, bi- or unilaterally, in 39 fetuses. The oldest was at GW 32. The sulcus was closed at GW 21 at the earliest, unilaterally. In 26/63 fetuses (41%), the deepening or closure of the hippocampal sulcus or hippocampal inversion was asymmetric; in 23 fetuses, the right side developed faster. A shallow collateral sulcus was found earliest at GW 17. A deep collateral sulcus was visible earliest at GW 26 unilaterally, but in all fetuses from GW 31 onward, it was seen bilaterally. The orientation of the collateral sulcus was not related to the GA. CONCLUSIONS: There are wide individual temporal variations in the development and the inversion process of the hippocampal sulcus as well as in the formation of the collateral sulcus. Asymmetric development is common, and in most of the asymmetric cases, the right hippocampus develops faster.

Spondylodiscitis in hemodialysis patients: a case series.

BACKGROUND: Although bacterial spondylodiscitis is one of the most serious complications in hemodialysis patients, it is often underdiagnosed, and few reports describe its course and clinical management. PATIENTS AND METHODS: We retrospectively reviewed 11 hemodialysis patients diagnosed with spondylodiscitis, during a 5-year period, and compared them with the general population followed at our center. Nine patients presented with fever on admission. Blood cultures were positive in all patients and Staphylococcus aureus was identified in 8. Ten patients had a central venous catheter as access for hemodialysis and the number of vascular accesses in the patients´ medical history was superior to the rest of our HD population. RESULTS: Four patients (36%) died during follow-up. None of the patients that underwent vancomycin and gentamicin antibiotic therapy died. CONCLUSION: Bacterial spondylodiscitis must be suspected whenever a patient on hemodialysis is admitted with fever and/or back pain. The presence of a central venous catheter and a history of multiple vascular accesses may be important risk factors. Prolonged antibiotic therapy with initial broad-spectrum coverage seems to be the best therapeutic approach.

Development of the hippocampal region demonstrated by fetal MRI. A preliminary report.

Coronal slices of three fetal MRIs performed post mortem and 37 performed in utero, all without intracranial pathology, was assessed. Progress of the hippocampal inversion was analyzed, the left and right sides were compared and occurrence of the collateral sulcus was revealed. The fetuses in the post mortem examinations were at gestation weeks (GW) 17-18 and in the in utero examinations at GW 19-35. The symmetric development of the hippocampal sulcus was revealed in 26 subjects and asymmetric in 14. The non-ovoid hippocampal formation could be evaluated at GW 24 at earliest and an ovoid hippocampus at GW 29. The collateral sulcus could be recognized at GW 17 in post mortem and at GW 22 in in utero examinations. From GW 29 onwards it was seen in all fetuses and it was symmetric in all but one case. Evaluation of the hippocampi is difficult on fetal MRI, especially in in utero examinations. The hippocampal development is not fulfilled at GW 21 as presumed. There is a wide temporal variation in the development of the hippocampal region, and the developmental process does not progress simultaneously in the right and left side of the same individual.

Spectrum of disorders associated with enlarged sylvian fissures in infancy.

Disproportionate enlargement of the sylvian fissures (ESF) on MRI of an infant's CNS suggests underdevelopment of the cortical operculum. We reviewed charts of infants with isolated ESF. Conditions associated with ESF included feeding difficulties and facial dysmorphism (syndromic or nonsyndromic). There may be an embryologic link between growth of the opercular cortex and development of the face.