Headaches: A Differential Diagnosis

Determining the cause of headaches can present one of the most complex and confusing diagnostic problems experienced in the dental and medical professions. Many headache victims may drift from doctor to doctor seeking relief from their symptoms. Misdiagnosis is not uncommon.

This paper presents an overview of the subject of nondentally related chronic orofacial pain, a discussion of possible predisposing factors, and an outline of diagnostic signs and symptoms. Reviewed are such disorders as migraine, sinusitis, trigeminal neuralgia, cluster headache, hypertension headache, and cervical neuralgia. Current approaches to the diagnosis and management of chronic facial pain are multifactorial and multidisciplinary. The importance of a comprehensive assessment of all possible factors before arriving at a diagnosis and treatment regimen is emphasized.     

Duodenal hematoma: the ring sign in MR imaging

Proper management of duodenal hematoma requires that an accurate diagnosis be made using noninvasive radiological methods. Conventional imaging may be nonspecific if there is no history of trauma or coagulopathy. Two cases of duodenal hematoma that were imaged by magnetic resonance (MR) and computed tomography (CT) are described. In both cases the hematoma had a well-defined concentric ring configuration on MR images, a finding which helped establish the diagnosis. MR imaging may provide tissue-specific characterization of duodenal hematomas.     

Cloning of glycoprotein IIIa cDNA from human erythroleukemia cells and localization of the gene to chromosome 17

Platelet aggregation requires the binding of adhesive proteins such as fibrinogen to the heterodimer of membrane glycoproteins IIb (GPIIb) and IIIa (GPIIIa). Human erythroleukemia (HEL) cells synthesize both GPIIb and GPIIIa. Using poly(A+) RNA purified from HEL cells, we constructed a cDNA library in the lambda gt10 phage vector. This library was screened with a 38mer oligonucleotide derived from a platelet GPIIIa peptide, and three overlapping cDNAs were isolated. The three inserts encompassed 3.5 kilobases (kb), including the entire coding region of mature GPIIIa (2,286 basepairs, bp) and 1.3 kb of 3' untranslated sequence. All 222 residues determined directly from platelet GPIIIa tryptic peptides exactly matched the HEL cell-deduced amino acid sequence. The HEL cell sequence matched a previously reported endothelial cell cDNA sequence except for eight nucleotides. Five of these nucleotide differences were silent changes consistent with genetic polymorphisms. The other three differences resulted in changes in the deduced amino acid sequence of GPIIIa; reexamination of the endothelial cell cDNA sequence in these three areas revealed that it is actually identical to the HEL cell sequence. The virtual identity of the endothelial and HEL cell cDNA sequences provides direct evidence that GPIIIa is a subunit common to cell-adhesion receptors present in more than one cell type. We localized the gene for GPIIIa to chromosome 17, the same chromosome to which we had previously mapped the gene for GPIIb.     

Do Textiles Impact DXA Bone Density or Body Composition Results?

External artifacts can confound dual-energy X-ray absorptiometry (DXA) measurements. It is often accepted that garments free of metal do not affect DXA results; however, little data exist in this regard. It is plausible that some textiles absorb radiation and thereby alter DXA results. We hypothesized that some dense or synthetic textiles, for example, reflective materials, might alter DXA-measured bone and soft tissue mass. Hologic and GE Lunar spine phantoms and a Bioclinica prototype total body phantom were imaged on a GE Lunar iDXA and Prodigy densitometer. Each phantom was scanned 10 times to establish mean values. Subsequently, 2 layers of various fabrics were placed over the entire top surface of the phantom, and 10 scans were performed without repositioning. Samples of natural, synthetic, or embellished fabric (including those with reflective material) and of varying thickness were used. Wilcoxon signed rank tests were used to compare the means between bare phantom and textile-covered phantom. Significant differences were demonstrated often, depending on the scanner, phantom, and textile used. A polyester fabric with reflective strip consistently altered measurements. For example, this fabric increased measured mean lumbar spine bone mineral density and total body bone mineral content by 0.008?g/cm² and 3.6?g, respectively (p?<?0.01). Similarly, mean total body fat decreased (?173 g) and lean mass increased (+213 g; p?<?0.01). Fat and lean mass were also affected by metallic thread, wool, blend denim, and shiny polyester (p?<?0.05), and lean mass was affected by cotton denim and sweatshirt material (p?<?0.0003). In conclusion, textiles can affect DXA-measured bone mineral density and body composition results. Even small amounts of reflective material could alter mass measurements by ~25% of the least significant change. Clothing made of dense textiles (e.g., wool and denim) or those with reflective material and metallic thread should be avoided during DXA scanning.     

Comparison of bone parameters by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography in Hutterite vs. non-Hutterite women aged 35-60 years

A previous report of elevated dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) Z scores suggests that Hutterite females might be significantly less likely to develop osteoporosis compared with other U.S. females. In the present study, we sought to determine if high Hutterite DXA BMD Z scores were elevated because of larger bone size. Hutterites reside in isolated, self-sufficient colonies with an emphasis on agricultural production, and girls enter a strenuous task rotation at age 15 years. We obtained cross-sectional bone measurements of the 66% distal tibia using peripheral quantitative computed tomography (pQCT) to compare bone size and geometry on 97 Hutterite and 30 non-Hutterite women, aged 35-60 years. Total body (TB) and lumbar bone mineral content (BMC), BMD, and bone area measurements by DXA were available on a subset of the study population. We identified no differences between groups in pQCT total bone area, cortical bone area, or cortical bone density. Larger bone area by DXA was apparent in Hutterites compared with non-Hutterites at the TB (least square means: 2038 +/- 8 cm2 vs. 1953 +/- 19 cm2, p < 0.05) and lumbar (least square means: 58 +/- 0.5 cm2 vs. 57 +/- 2 cm2, p < 0.01) sites. TB BMC adjusted for TB bone area was marginally higher in Hutterites compared with non-Hutterites (least square means: 2341 +/- 15 g vs. 2281 +/- 30 g, p = 0.08). Hutterites had marginally higher TB BMD Z scores when controlling for weight and age (least square means: 1.3 +/- 0.1 vs. 0.8 +/- 0.2, p = 0.07). Hutterites had higher lumbar BMC adjusted for lumbar bone area and weight (least square means: 65 +/- 1 g vs. 58 +/- 2 g, p < 0.01) and higher weight-and age-adjusted lumbar BMD Z scores (least square means: 1.1 +/- 0.1 vs. 0.1 +/- 0.4, p = 0.01). Our data indicate that a true advantage in trabecular bone density probably exists among Hutterite women aged 35-60 years. Hutterite women might be protected against age-related fractures because of their larger bone size and higher bone density at normally susceptible trabecular sites.     

Opportunistic Quantitative CT Bone Mineral Density Measurement at the Proximal Femur Using Routine Contrast‐Enhanced Scans: Direct Comparison With DXA in 355 Adults

For patients undergoing routine contrast‐enhanced CT examinations, an opportunity exists for concurrent osteoporosis screening without additional radiation exposure or patient time using proximal femur CT X‐ray absorptiometry (CTXA). We investigated the effect of i.v. contrast enhancement on femoral neck CTXA T‐score measurement compared with DXA. This cohort included 355 adults (277 female; mean age, 59.7 ± 13.3 years; range, 21 to 90 years) who underwent standard contrast‐enhanced CT assessment at 120 kV_p over an 8‐year interval, as well as DXA BMD assessment within 100 days of the CT study (mean 46 ± 30 days). Linear regression and a Bland‐Altman plot were performed to compare DXA and CTXA results. CTXA diagnostic sensitivity and specificity was evaluated with DXA as the reference standard. There was good correlation between DXA and CTXA (r² = 0.824 for both areal BMD and T‐scores) and the SD of the distribution of residuals was 0.063 g/cm² or 0.45 T‐score units. There was no trend in differences between the two measurements and a small bias was noted with DXA T‐score +0.18 units higher than CTXA. CTXA had a sensitivity for discriminating normal from low bone mineral density of 94.9% (95% CI, 90.6% to 97.4%). For opportunistic osteoporosis screening at routine post‐contrast abdominopelvic CT scans, CTXA produces T‐scores similar to DXA. Because femoral neck CTXA BMD measurement is now included in the WHO Fracture Risk Assessment Tool (FRAX) tool, this opportunistic method could help to increase osteoporosis screening because it can be applied regardless of the clinical indication for CT scanning. © 2016 American Society for Bone and Mineral Research.     

Randomized trial of physical activity and calcium supplementation on bone mineral content in 3- to 5-year-old children.

A meta-analysis of adult exercise studies and an infant activity trial show a possible interaction between physical activity and calcium intake on bone. This randomized trial of activity and calcium supplementation was conducted in 239 children aged 3-5 years (178 completed). Children were randomized to participate in either gross motor or fine motor activities for 30 minutes/day, 5 days per week for 12 months. Within each group, children received either calcium (1000 mg/day) or placebo. Total body and regional bone mineral content by DXA and 20% distal tibia measurements by peripheral quantitative computed tomography (pQCT) were obtained at 0 and 12 months. Three-day diet records and 48-h accelerometer readings were obtained at 0, 6, and 12 months. Higher activity levels were observed in gross motor versus fine motor activity groups, and calcium intake was greater in calcium versus placebo (1354 +/- 301 vs. 940 +/- 258 mg/day, p < 0.001). Main effects of activity and calcium group were not significant for total body bone mineral content or leg bone mineral content by DXA. However, the difference in leg bone mineral content gain between gross motor and fine motor was more pronounced in children receiving calcium versus placebo (interaction, p = 0.05). Children in the gross motor group had greater tibia periosteal and endosteal circumferences by pQCT compared with children in the fine motor group at study completion (p < 0.05). There was a significant interaction (both p < or = 0.02) between supplement and activity groups in both cortical thickness and cortical area: among children receiving placebo, thickness and area were smaller with gross motor activity compared with fine motor activity, but among children receiving calcium, thickness and area were larger with gross motor activity. These findings indicate that calcium intake modifies the bone response to activity in young children.