The limbic degradation of aging brain: a quantitative analysis with diffusion tensor imaging.

INTRODUCTION: The limbic system primarily responsible for our emotional life and memories is known to undergo degradation with aging and diffusion tensor imaging (DTI) is capable of revealing the white matter integrity. The aim of this study is to investigate age-related changes of quantitative diffusivity parameters and fiber characteristics on limbic system in healthy volunteers. METHODS: 31 healthy subjects aged 25-70 years were examined at 1,5 TMR. Quantitative fiber tracking was performed of fornix, cingulum, and the parahippocampal gyrus. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) measurements of bilateral hippocampus, amygdala, fornix, cingulum, and parahippocampal gyrus were obtained as related components. RESULTS: The FA values of left hippocampus, bilateral parahippocampal gyrus, and fornix showed negative correlations with aging. The ADC values of right amygdala and left cingulum interestingly showed negative relation and the left hippocampus represented positive relation with age. The cingulum showed no correlation. The significant relative changes per decade of age were found in the cingulum and parahippocampal gyrus FA measurements. CONCLUSION: Our approach shows that aging affects hippocampus, parahippocampus, and fornix significantly but not cingulum. These findings reveal age-related changes of limbic system in normal population that may contribute to future DTI studies.

Hydatid cyst of paravertebral muscle mimicking disc herniation.

STUDY DESIGN: Case report. OBJECTIVE: To present a case of primary hydatid cyst in the lumbar subcutaneous tissue affecting posterior paravertebral muscle and mimicking disc herniation. SUMMARY OF BACKGROUND DATA: Cystic hydatid disease is a rare but significant parasitic disease in endemic areas. Musculoskeletal or soft tissue hydatidosis accounts for about 0.5% to 5% of all echinococcal infections in endemic areas and is almost secondary to the hepatic or pulmonary disease. Primary lumbar subcutaneous hydatid cyst affecting paravertebral muscle and extending to neural foramina is a very rare condition even in endemic areas. METHODS: A 25-year-old-female patient was admitted with swelling and pain in the right lumbar region for 3 months. The pain was reflecting in the right gluteal region and the right leg. Lumbar extension and right lateral flexion was painful and straight leg raising test was positive at right side. There was a mild hypoesthesia at L5 dermatome. According to the magnetic resonance image that the clinician obtained for initial diagnosis of lumbar disc herniation, we found multi-cystic masses located at the right paravertebral muscle at the level of L3-L5 which extended to L4-L5 neural foramina and at subcutaneous tissue at the right gluteal region. RESULTS: The patient was operated for the purpose of removal of cysts. Postoperatively, diagnosis of hydatid cyst was confirmed by histopathology. CONCLUSION: By this case, we emphasize that cystic hydatid disease should be taken into consideration in the differential diagnosis of low back pain and could mimic disc herniation. LEVEL OF EVIDENCE: N/A.

[Radiologic and morphologic evaluation of the lateral sacral mass]. / Lateral sakral kitlenin morfolojik ve radyolojik degerlendirilmesi.

OBJECTIVES: Morphologic measurements of the lateral sacral mass (LSM) and adjacent bone structures were made on dried sacrum specimens, together with radiologic evaluations on computed tomography (CT) scans in order to assess the appropriateness of this area in iliosacral screw applications. METHODS: On thirty dried human sacral bone specimens, morphologic measurements of the LSM were made by a compass sensitive to millimeters. Computed tomographic views of S1 and S2 pedicle-bodies and intervertebral foramina were obtained to make radiologic measurements by a millimeter-sensitive ruler to examine the relationship between LSM and the neural canal and intervertebral foramina. RESULTS: The average widths of the LSM on the posterior and anterior surfaces of the sacrum were as follows. Posterior aspect: 24.1 mm on S1, 18.4 mm on S2 levels on the right; 24.5 mm on S1 and 18.8 mm on S2 levels on the left. Anterior aspect: 28.9 mm on S1, 22.6 mm on S2 levels on the right; 29.1 mm on S1 and 23 mm on S2 levels on the left. The average (oblique) heights of LSM on the postero-lateral surface were 39 mm on S1, 28.6 mm on S2 levels on the right; 37.4 mm on S1, 27.6 mm on S2 levels on the left. The average depth of the sacral ala was 50.6 mm on the right, 50.7 mm on the left. The average posterior alar height was 26 mm on both sides. On CT scans, the average widths of pedicle+sacral ala were measured as 37.6 mm (right) and 36.3 mm (left) at the S1 pedicle-body level. The average widths of LSM were 22 mm (right) and 22.3 mm (left) at the S1 intervertebral foramina level. The average widths of pedicle+LSM were 27.8 mm (right) and 26.4 mm (left) at the S2 pedicle-body level. The average widths of LSM at the S2 intervertebral foramina level were 15.9 mm (right) and 16.3 mm (left). CONCLUSION: Our results suggest that iliosacral screw fixation may be more safely performed, especially at the S1 pedicle-body level and lateral to the sacral neural canal and intervertebral foramina. Injury to the neural tissues and surrounding structures is more unlikely if preoperative measurements of LSM are made on CT scans.