Bone status after long-term anticonvulsant therapy in epileptic patients: evaluation using quantitative ultrasound of calcaneus and phalanges

Effects of antiepileptic therapy on bone mineral status evaluated by phalangeal quantitative ultrasound in pediatric patients with epilepsy and motor impairment

BACKGROUND

In epileptic patients with motor disability, it's difficult to disentangle the effects of antiepileptic drugs (AEDs) on bone health from those provoked by impaired mobility. The aim of this study was to evaluate the effects of AEDs on bone mineral status by phalangeal quantitative ultrasound (QUS), a no-radiation and non-invasive method, in pediatric patients with motor impairment and epilepsy.

METHODS

We enrolled 56 patients (31 females, 25 males) with epilepsy and motor impairment and 24 children with only motor disability (13 females, 11 males). Patients were stratified by Gross Motor Function Classification System Scale (GMFCS) in 4 groups: group A1 with epilepsy and mild motor impairment (GMFCS levels I-II), group A2 with only mild motor impairment, group B1 with epilepsy and severe motor impairment (GMFCS levels III-V), group B2 with only severe motor impairment. The bone mineral status was evaluated by phalangeal QUS and amplitude-dependent speed of sound (AD-SoS) Z-score was calculated for each patient.

RESULTS

The four groups showed no significant differences in age, gender and 25-hydroxyvitamin D levels. The group B1 had a statistically lower amplitude-dependent speed of sound Z-score as compared to group A2 (P<0.05). The multivariate analysis of independent factors revealed a significant correlation between amplitude-dependent speed of sound Z-score and Gross Motor Function Classification System levels (P=0.004). The mean Z-score value decreased by 0.53, increasing the motor impairment.

CONCLUSIONS

The bone mineral status measured as AD-SoS strongly correlates with severity of motor disability evaluated by GMFCS as compared to antiepileptic therapy and 25-hydroxyvitamin D levels.

Greater Calcium Intake is Associated with Better Bone Health Measured by Quantitative Ultrasound of the Phalanges in Pediatric Patients Treated with Anticonvulsant Drugs

We aimed to investigate and compare the effects of chronic antiepileptic therapy on bone health in pediatric patients using quantitative ultrasound of the phalanges (QUS) and controlling for potential confounding factors, particularly nutrient intake. The amplitude-dependent speed of sound (Ad-SoS) was measured in 33 epileptic children and 32 healthy children aged 6.5 ± 3.1 and 6.3 ± 1.1 (mean ± SD) years, respectively. There were no significant differences in the demographics such as age, weight and height between epileptic children and the control group children. None of the children in the epileptic or the treatment group were found to have a vitamin D deficiency. There were no significant differences in laboratory tests between groups. Lower QUS figures were found in the epileptic children (p = 0.001). After further adjustment for potential confounders such age, height, weight, calcium intake, vitamin D intake, physical activity and sex, the differences remained significant (p < 0.001). After further classification of the participants based on the tertile of calcium intake, no significant differences were found between patients and healthy controls in the greatest tertile of calcium intake (p = 0.217). We conclude that anticonvulsant therapy using valproate may lead to low bone mass in children and that an adequate intake of calcium might counteract such deleterious effects.

Dual-energy X-ray absorptiometry versus quantitative ultrasonography in diagnosing osteoporosis in patients with refractory epilepsy and chronic antiepileptic drug use

BACKGROUND

The aim of this study was to assess the feasibility of calcaneal quantitative ultrasonography (QUS) as a screening method for increased risk of osteoporosis in a unique population of people with chronic epilepsy, intellectual disability (ID), and chronic use of antiepileptic drugs.

METHODS

A total of 205 patients from a long-stay care facility for people with epilepsy underwent dual-energy X-ray absorptiometry (DXA) and QUS of the calcaneus. T-scores for both DXA and QUS were calculated and correlated.

RESULTS

A total of 195 patients (95.1%) were successfully measured with DXA and 204 (99.5%) with QUS. High correlations were found between DXA and QUS T-scores: r = 0.666 (QUS versus T-score total femur), r = 0.631 (QUS versus T-score femur neck) and r = 0.485 (QUS versus T-score lumbar spine). All correlations were statistically significant (p = 0.01).

CONCLUSION

QUS showed a strong correlation with DXA and proved to be a feasible measuring method in a population with ID and epilepsy. Including osteopenia in the screening process increases the sensitivity of QUS to identify those patients at risk for the development of bone diseases.

Quantitative ultrasound in osteoporosis and bone metabolism pathologies

Quantitative ultrasound (QUS) has been introduced in the medical field for the study of bone tissue to identify changes in the tissue that could suggest the presence of osteoporosis and bone fragility. The ultrasound technique is simple, versatile, and its low cost and lack of ionizing radiation have led to the diffusion of this method worldwide. The present article is an overview of the most relevant developments in the field of quantitative ultrasound, in clinical and experimental settings. The advantages and limitations of the present technique and suggestions for its use in the clinical practice are reported.

Quantitative ultrasound in the assessment of skeletal status

Quantitative ultrasound (QUS) is a non-invasive technique for the investigation of bone tissue in several pathologies and clinical conditions, especially in the field of osteoporosis. The versatility of the technique, its low cost and lack of ionising radiation have led to the diffusion of this method worldwide. Several studies have been conducted in the last years to investigate the potential of QUS in multiple areas with promising results; the technique has been applied in the prediction of osteoporotic fractures, in monitoring therapies, in the investigation of secondary osteoporosis, in paediatrics, neonatology and genetics. Our review article gives an overview of the most relevant developments in the field of quantitative ultrasound, both in clinical and in experimental settings.

Bone health in patients with brain tumors

BACKGROUND

Several factors, including the use of antiepileptic drugs, glucocorticoids, anticoagulants, chemotherapy, radiation therapy, and hemiplegia-associated osteopenia, render patients with brain tumor susceptible to bone disease.

METHODS

The authors review the pathophysiology of these factors and their impact upon bone integrity.

RESULTS

Steps that can be taken to minimize or eliminate bone morbidity including measurement of bone mineral density at treatment onset, adequate calcium intake, vitamins D and K supplementation, adequate sunlight exposure, weight-bearing exercises, fall prevention, avoidance of antiepileptic drugs linked to osteopenia, and judicious use and choice of glucocorticoids and anticoagulants are suggested.

CONCLUSIONS

Medical management of osteoporosis related to brain tumor treatment with bisphosphonates, teriparitide, and calcitonin is beneficial, as is kyphoplasty for symptomatic vertebral compression fractures.

The adverse effects of antiepileptic drugs in children

Efficacy of antiepileptic drugs (AEDs) are often equivalent, hence selection of an AED is often determined by the adverse effects (AEs). The development of neurocognitive AEs is almost inevitable with use of AEDs, especially in high-risk groups. Teratogenesis with major or minor malformations is of great concern during the first trimester of pregnancy, but an increasing body of information suggests that potential neurocognitive developmental delay may also occur with use of AEDs in the latter part of pregnancy. Decreased bone mineral density has been found in adults and children receiving both enzyme-inducing AEDs and valproate, an enzyme-inhibiting drug. AEDs may influence the lipid profile, body weight, reproductive, hormonal and other endocrine functions, and sleep architecture. There are age-specific AEs related to pharmacokinetic differences that have been highlighted in this review with emphasis on the pediatric population. A classification of AEs using different parameters is also included.

Quantitative ultrasound measurements in diabetic and nondiabetic patients with end-stage renal disease

The aim of the study was to assess skeletal status in diabetic and nondiabetic subjects with end-stage renal disease (ESRD). One hundred twenty-three patients with ESRD (57 patients with diabetes: 9 type 1 and 48 type 2) and 66 nondiabetic patients were evaluated. Control group comprised 1541 subjects (614 males and 927 females). Diabetes and/or renal insufficiency was the only reason of bone disease and, in control group, no factors known to influence bone metabolism (chronic diseases or prolonged medications) were noted. Skeletal status was evaluated by quantitative ultrasound measurements at the hand phalanges using DBM 1200 (IGEA, Carpi, Italy), which measures amplitude-dependent speed of sound (Ad-SoS [m/s]). Because of some differences in mean age in subgroups of patients and controls, comparisons were performed using values of Z-score. In all diabetic patients, Z-score was significantly higher compared with nondiabetics (p < 0.05). In all type 1 diabetes patients, Z-score was significantly lower than in all nondiabetic patients (p < 0.05) and in patients with type 2 diabetes (p < 0.001). Z-score was also significantly lower in type 2 diabetics than in nondiabetic females (p < 0.00001) but did not differ in males. Comparisons between Z-scores in controls and patients showed that Z-score in nondiabetic females was significantly lower than in female controls (p < 0.000001), and in nondiabetic males--diabetic type 2 males as well as females--Z-score did not differ vs. results in adequate control group. Z-score was significantly lower in patients with diabetes type 1 vs. all controls (p < 0.001). Correlation analysis showed in all nondiabetic patients that Z-score was negatively affected by duration time of dialysis (r = -0.37, p < 0.01) and parathyroid hormone (PTH) serum level (r = -0.35, p < 0.01). In patients with type 1 diabetes, only PTH influenced significantly Z-score (r = -0.76, p < 0.05) and, in patients with type 2 diabetes, no significant correlations were obtained. Subjects with type 1 diabetes seemed to be sensitive for skeletal disturbances in a course of renal insufficiency, whereas subjects with type 2 diabetes did not show such skeletal pathology as shown by ultrasound measurements at hand phalanges.

A 6-month longitudinal study of bone mineral density with antiepileptic drug monotherapy

Antiepileptic drugs (AEDs) can affect bone metabolism, but the exact mechanisms or differences in individual drugs are still unknown. The purpose of this study was to prospectively investigate the alterations in bone mineral density (BMD) and markers of bone metabolism induced by different AEDs in Koreans with epilepsy. Subjects included 33 drug-naïve, newly diagnosed patients with epilepsy aged between 18 and 50. BMD at right calcaneus and various markers for bone metabolism were measured before and after 6months of AED monotherapy including carbamazepine, valproic acid, and lamotrigine. Carbamazepine caused a significant decrease in BMD, which was accompanied by a decrease in the level of vitamin D (25-OHD(3)). BMD and vitamin D were not affected by 6months of valproic acid or lamotrigine therapy. Interestingly, valproic acid and lamotrigine, but not carbamazepine, significantly increased osteocalcin, a marker of bone formation. All AEDs almost doubled the parathyroid hormone level, whereas urinary Pyrilinks, a marker of bone resorption, was not affected by those AEDs. These findings suggest that carbamazepine, a hepatic enzyme-inducing drug, decreases BMD.

Anti-epileptic medication and bone health

BACKGROUND

Epilepsy is a common chronic neurological disorder, usually requiring long-term treatment with anti-epileptic drugs (AED). Many studies have reported that AED therapy is associated with metabolic bone disease and is a major iatrogenic risk factor for fractures. There remains uncertainty about the type(s) of bone disease due to AED treatment, and the pathogenesis of AED-associated fractures.

RATIONALE

Deficits in bone mineral density (BMD) are widely reported in AED-treated patient populations. However, much of the research conducted to date has been limited by factors such as small sample size, potentially biased subject selection, a lack of selection of appropriate control data, and failure to take account of important confounding influences. The pathogenesis of AED-associated fractures is likely to be multifactorial, due to factors including reduced BMD, impaired bone quality (due to osteoporosis and/or osteomalacia), increased propensity to fall, and fractures associated with seizures or loss of consciousness.

RECOMMENDATIONS

Patients receiving long-term AED should be monitored for indices of bone health, including BMD and vitamin D status. Lifestyle factors should be optimized, vitamin D status maintained, and fall prevention strategies introduced as appropriate. Good seizure control is important. The use of additional, specific osteoporosis therapy is not evidence-based in this setting, but would appear reasonable in patients with clinically significant decreases in BMD, applying current treatment guidelines for osteoporosis.

CONCLUSION

There is a pressing need for improved understanding of the pathogenesis of AED-associated bone disease, for better definition of the risk associated with specific AED regimens, and for the development of evidence-based preventive and treatment approaches in this common but neglected disorder.

Cross-sectional reference data for phalangeal quantitative ultrasound from early childhood to young-adulthood according to gender, age, skeletal growth, and pubertal development

Bone mineral status by phalangeal quantitative ultrasound (QUS, DBM Sonic, IGEA, Carpi, Modena, Italy) was examined in 3044 (1513 males and 1531 females) healthy subjects, aged 2-21 years. The aim of the study was to provide a reference database for phalangeal QUS parameters, amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT), both expressed as centiles and Z score, according to gender, age, height, weight, body mass index (BMI), and pubertal stage to be used for estimating bone mineral status in patients with disorders of growth or of bone and mineral metabolism. In both sexes, AD-SoS and BTT increased significantly (P<0.0001) according to all the anthropometric variables. Females showed higher values than males in the age groups 9-14 for AD-SoS (P<0.04-P<0.0001) and in the age groups 11-13 for BTT (P<0.02). Males had higher BTT values than females in the age groups 6-8 and 15-21 (P<0.04-P<0.0001). AD-SoS was higher (P<0.02-P<0.0001) in females than in males at pubertal stages 2, 3, and 4, but it was higher (P=0.001) in males compared with females at pubertal stage 5. BTT was higher in males than females at pubertal stages 1 (P<0.0001), 2 (P<0.01), and 5 (P<0.0001). In both sexes, AD-SoS and BTT were significantly correlated between them (r=0.92, P<0.0001) and with all the anthropometric variables (r=0.53-r=0.85, P<0.0001). Age, weight, BMI, and pubertal stage were independent predictors of AD-SoS in males; age and pubertal stage were independent predictors of AD-SoS in females. In both sexes, height and pubertal stage, and also age only in females, were independent predictors of BTT. In conclusion, our data show that gender, age, height, and timing of sexual maturation are main determinants of bone structure and geometry, and that both these two processes may be captured by phalangeal QUS. It may be a useful tool to assess bone mineral status from early childhood to young-adulthood with a very small confounding effect related to bone sizes and without exposing the subjects to a source of radiation.

Quantitative ultrasound measurements at the calcaneus in natural and surgically induced menopause

OBJECTIVE

The aim of the study was to assess skeletal status in natural and surgically induced menopausal women regarding the presence of previous osteoporotic fracture.

METHODS

Ninety-three females after bilateral oophorectomy in mean age of 56.8+/-8.3y. (48 without and 45 with fracture, groups 1 and 2, respectively) and 285 females with natural menopause in mean age of 56.4+/-7.0y (176 without and 109 with fracture, groups 3 and 4, respectively) were studied. Mean age, age of menopause, years since menopause (YSM), duration of fertile period (durFER) and body size did not differ between women after surgical and natural menopause and between non-fractured and fractured groups. No additional factors known to influence bone metabolism (either diseases or medications) or osteoporosis treatment were noted in the subjects studied. Skeletal status was evaluated by quantitative ultrasound (QUS) of the calcaneum using the Achilles system (Lunar, USA).

RESULTS

Calcaneal QUS results were significantly higher: in women after natural than surgical menopause (p<0.05), in non-fractured females after natural menopause than in non-fractured females after surgical menopause (p<0.001) and in women after natural menopause without fracture compared with those with fracture (p<0.000001). The same comparisons between fractured groups and between women after surgical menopause with and without fracture revealed no significant differences. QUS parameters were regressed in a stepwise, multiple regression analysis on age, YSM, durFER, weight and height for all groups. In group 1, YSM had a negative influence and durFER was a protective factor; in group 2, age and durFER were a negative factors and YSM had no influence; in group 3, age and YSM were a negative factors (no role of durFER) and in group 4, only YSM had a negative influence, and durFER was a protective factor.

CONCLUSION

Surgical menopause seems to be a risk factor for osteoporotic fracture because of low ultrasound values.

Bone and Mineral Metabolism

Although bones are normally thought of as supporting structures that fracture when one falls, bone is actually a very active metabolic organ. It is vital in the regulation of calcium and phosphate metabolism, magnesium storage, and in buffering metabolic acido-sis. Bone and mineral metabolism and some of their disorders are presented in this article.

Effect of temperature on the longitudinal variability of quantitative ultrasound variables

It is unclear whether longitudinal change in phantom measurements bears any relation to the long-term in vivo instrument performance of quantitative ultrasound devices. Longitudinal quantitative ultrasound phantom data were obtained by measuring the manufacturer-provided phantom at ambient temperature and two different sets of Leeds phantoms at either ambient temperature or following a phantom temperature-control protocol. Measurements were performed using the Achilles Plus bone densitometer. Changes in longitudinal phantom data were compared to in vivo quantitative ultrasound data obtained from seven healthy, young volunteers. A cosinor model with linear trend and Hotelling's T2-test were used to quantify seasonal rhythms and long-term drift in quantitative ultrasound variables. Temperature effects and marked seasonal rhythms on quantitative ultrasound phantom measurements were evident but were far less apparent in vivo. Longitudinal precision of quantitative ultrasound variables was poorer for the manufacturer-provided phantom than for phantoms that were subjected to a temperature-control protocol or for healthy volunteers. This study has shown that longitudinal precision and longitudinal change differs between in vivo and phantom data. Longitudinal quantitative ultrasound measurements for monitoring change in skeletal status cannot, as yet, be properly controlled.

Quantitative ultrasound at the hand phalanges in 2850 females aged 7 to 77 yr: a cross-sectional study

In the study, skeletal status was evaluated in 2850 females aged 7 to 77 yr using quantitative ultrasound (QUS amplitude-dependent speed of sound [Ad-SoS]). Ad-SoS ranged from 1923 +/- 30 to 1876 +/- 81 m/s, and the peak value (2121 m/s) was achieved in 19-yr-old females. Ad-SoS increased significantly between subgroups aged 11 and 12 yr, 12 and 13 yr, 13 and 14 yr, 14 and 15 yr, and 15 and 16 yr. After the age of 19 yr the only significant drop was noted between age groups 47 and 48 yr. Ad-SoS was regressed on age, weight, and height for age ranges 7 to 11 yr.(before an increase in Ad-SoS), 12 to 19 yr (from the onset of the increase to the peak value), and older than 19 yr to menopause. In females after menopause, years since menopause (YSM) were taken into consideration. In the two youngest groups Ad-SoS was affected positively by age, and in the two next groups, age had a negative influence on Ad-SoS, whereas weight had a negative and height a positive influence in all groups. YSM did not influence the Ad-SoS value. It was concluded that QUS measurements at the hand phalanges are a useful tool in assessment of skeletal status in the female population.

Antiepileptic drugs and reduced bone mineral density

There is a growing interest in recognizing the association between antiepileptic drugs and reduced bone mineral density. Although the literature regarding this association has been available for more than three decades, the management of this complication remains unclear. We review the relevant literature regarding antiepileptic drugs and reduction in bone mineral density with the aim of developing some guidelines for practical management of this problem. This review focuses on the mechanism of antiepileptic drug-induced bone loss, its recognition, and its management.

Epilepsy and bone health in adults

Adults taking antiepileptic drugs (AEDs) have an augmented risk for osteopenia and osteoporosis because of abnormalities of bone metabolism associated with AEDs. The increased fracture rates that have been described among patients with epilepsy may be related both to seizures and to AEDs. The hepatic enzyme-inducing AEDs phenytoin, phenobarbital, and primidone have the clearest association with decreased bone mineral density (BMD). Carbamazepine, also an enzyme-inducing drug, and valproate, an enzyme inhibitor, may also adversely affect bone, but further study is needed. Little information is available about specific effects of newer AEDs on bone. Physicians are insufficiently aware of the association between AEDs and bone disease; a survey found that fewer than one-third of neurologists routinely evaluated AED-treated patients for bone disease, and fewer than 10% prescribed prophylactic calcium and vitamin D. Physicians should counsel patients taking AEDs about good bone health practices, and evaluation of bone health by measuring BMD is warranted after 5 years of AED treatment or before treatment in postmenopausal women.

Quantitative ultrasound at the hand phalanges in women on hormone replacement therapy

The aim of the observational study was to evaluate the influence of hormone replacement therapy (HRT) on the results of quantitative ultrasound (US) at the hand phalanges in 732 women (mean age about 53 years). Among them were 228 postmenopausal women treated within 6 months after the last menstrual bleeding (group 1), 90 postmenopausal women taking HRT after a break between menopause and the onset of the therapy of about 2 years (group 2) and 414 controls. Mean age and body size did not differ significantly between groups studied. Years since menopause (YSM) did not differ significantly between group 2 and controls. Skeletal status was assessed using DBM Sonic 1200 (IGEA, Carpi, Italy), which measures amplitude-dependent speed of sound (Ad-SoS) in m/s. Ad-SoS was significantly higher in both groups on HRT than in controls (p < 0.000001), and in group 1 compared with group 2 (p < 0.05). The duration of HRT did not affect Ad-SoS values. The influence of age on Ad-SoS values was significantly weaker in women on HRT than in controls and YSM did not influence Ad-SoS value in postmenopausal women taking HRT. In controls, YSM negatively and significantly affected Ad-SoS value. In conclusion, HRT administered in perimenopause or early postmenopause had a significant influence on quantitative US measurements at the hand phalanges, and the difference between both treated groups suggests that HRT ought to be indicated directly after the last menstrual bleeding.

The usefulness of quantitative ultrasound at the hand phalanges in the detection of the different types of nontraumatic fractures

The aim of this retrospective study was to determine whether quantitative ultrasound (QUS) at the hand phalanges has the ability to discriminate between individuals without and with different types of nontraumatic fractures. All women (n = 2466) (age range 38-88 years) not affected by metabolic diseases or under treatment with drugs known to interfere with bone metabolism were divided into controls without fractures (n = 1883) and women with nontraumatic previous fractures (n = 583). Fractures were the result of minimal trauma involving a fall from a standing height or less during normal daily activity. Fractured group was divided into subgroups on the basis of the types of fractures: hip, spine, wrist or other fractures. Skeletal status was assessed using the DBM Sonic 1200 (IGEA, Carpi, Italy) which measures the amplitude-dependent speed of sound, Ad-SoS (m/s) in the distal metaphyses of the proximal phalanges of the second through fifth finger of the dominant hand. Women with hip, spine, wrist or other fractures had significantly lower Ad-SoS values than controls (1814 +/- 60 m/s, 1829 +/- 57 m/s, 1870 +/- 64 m/s, 1893 +/- 66 m/s, respectively, vs. 1943 +/- 73 m/s, p < 0.001). Ad-SoS revealed the following areas under the ROC curve: 0.91 +/- 0.027 for hip fracture, 0.89 +/- 0.019 for spine fracture, 0.77 +/- 0.012 for wrist fracture and 0.70 +/- 0.023 for other fractures. By multiple logistic regression analysis, the probability of having fracture, estimated as odds ratio for each 1 SD reduction in Ad-SoS, was: 3.49 (95% CI, 1.57-7.75) for hip, 3.25 (95% CI, 1.94-5.45) for spine, 2.24 (95% CI, 1.86-2.70) for wrist and 1.81 (95% CI, 1.36-2.40) for other fractures. The present study demonstrates the ability of phalangeal QUS to discriminate between subjects with and without different types of nontraumatic fractures. Phalangeal QUS revealed the best sensitivity and specificity in discriminating hip- and spine-fractured patients from controls.

Assessment of bone quality by quantitative ultrasound of proximal phalanges of the hand and fracture rate in children and adolescents with bone and mineral disorders

Bone quality by quantitative ultrasound and fracture rate were assessed in 135 (64 males) children and adolescents aged 3-21 y with bone and mineral disorders such as chronic anticonvulsants or glucocorticoids treatment, juvenile rheumatoid arthritis, celiac disease, paucity of intrahepatic bile ducts, autoimmune hepatitis, genetic diseases, idiopathic juvenile osteoporosis, disuse osteoporosis, beta-thalassemia major, survivors of acute lymphoblastic leukemia, liver transplantation, calcium deficiency, and nutritional or X-linked hypophosphatemic rickets. Amplitude-dependent speed of sound through the distal end of the first phalangeal diaphysis of the last four fingers of the hand was measured by an ultrasound device. In the majority of patients cortical area to total area ratio by metacarpal radiogrammetry (n = 120) and lumbar bone mineral density (BMD) by dual-energy x-ray absorptiometry (n = 99) were also assessed. In patients with X-linked hypophosphatemic rickets radial BMD by single-photon absorptiometry instead of lumbar BMD was measured. Mean values of amplitude-dependent speed of sound, cortical area to total area ratio, lumbar BMDarea, or lumbar BMD corrected for bone sizes estimated by a mathematical model (BMDvolume), as well as mean values of radial BMD in patients with X-linked hypophosphatemic rickets, expressed as z score, were significantly reduced (p < 0.0001) in comparison with their reference values (-1.7 +/- 1.0, -2.0 +/- 0.9, -3.0 +/- 1.3, -1.9 +/- 1.0, -2.7 +/- 0.7, respectively). A positive relationship was found between amplitude-dependent speed of sound and cortical area to total area ratio (r = 0.90, p < 0.0001), lumbar BMDarea (r = 0.62, p < 0.0001), or lumbar BMDvolume (r = 0.66, p < 0.0001). Fifty-two patients (38.5%) had suffered fractures in the 6 mo preceding the bone measurements, the radial distal metaphysis being the most frequent fracture site (28.8%). Mean values of amplitude-dependent speed of sound, cortical area to total area ratio, lumbar BMDarea, or lumbar BMDvolume, expressed as z score, of fractured patients were significantly lower (p < 0.0001) than those of fracture-free patients (-2.2 +/- 1.0 and -1.4 +/- 0.8, -2.6 +/- 0.9 and -1.7 +/- 0.7, -3.5 +/- 1.2 and -2.5 +/- 1.0, -2.5 +/- 1.0 and -1.3 +/- 0.7, respectively). Phalangeal quantitative ultrasound may be a useful method to assess bone quality and fracture risk in children and adolescents with bone and mineral disorders.

Adverse effects of antiepileptic drugs on bone structure: epidemiology, mechanisms and therapeutic implications

Antiepileptic drugs (AEDs) were first associated with disorders of bone in both adults and children in the late 1960s. The most severe manifestations of these disorders are osteopenia/osteoporosis, osteomalacia and fractures. Bone disease has been described in several groups of patients receiving AEDs. Groups identified as being more vulnerable to AED-associated bone disease include institutionalised patients, postmenopausal women, older men and children. Radiological and histological evidence of bone disease is found in patients taking AEDs. Numerous biochemical abnormalities of bone metabolism have also been described. The severity of bone and biochemical abnormalities is thought to correlate with the duration of AED exposure and the number of AEDs used. In monotherapy, the AEDs most commonly associated with altered bone metabolism are phenytoin, primidone and phenobarbital (phenobarbitone). To date there have been no reports of altered bone metabolism in individuals receiving the newer anticonvulsants (specifically lamotrigine, topiramate, vigabatrin and gabapentin). The mechanisms of AED-associated bone disease are not clearly elucidated; however, several theories have been proposed to explain the link. No definitive guidelines for evaluation or treatment have yet been determined.

Seizures, hormones and sexuality

Sexual disorders (both hyposexuality and sexual dysfunction) are common in people with epilepsy, occurring in up to two-thirds of patients. However, characteristically, patients do not spontaneously report these problems. Nocturnal penile tumescence testing suggests that the erectile dysfunction has a neurophysiological component. The aetiology remains uncertain but is likely to be multifactorial, involving neurological, endocrine, iatrogenic, cognitive, psychiatric and psychosocial factors. Epilepsy-related factors include the age of onset/duration of epilepsy along with the seizure type and focus. In addition, seizure frequency might be relevant as successful epilepsy surgery can result in an improvement in sexual functioning despite remaining on anticonvulsant medication. Endocrine changes (raised sex hormone binding globulin and reduced free testosterone) have been reported in men with epilepsy, especially when treated with hepatic-enzyme inducing antiepileptic drugs. Studies have not been performed evaluating anticonvulsants that do not induce hepatic enzymes such as lamotrigine. The association between these endocrine changes and hyposexuality is not known. The relationship between seizures, hormones and anticonvulsant medication in women is explored, focusing on issues such as catamenial epilepsy, the menopause, hormone replacement therapy and the polycystic ovarian syndrome. Suggestions for future research and treatment issues are discussed.

Quantitative ultrasound (QUS) at the calcaneus and hand phalanges in Polish healthy postmenopausal women

In a cross-sectional study, 109 postmenopausal, healthy women, mean age 58.8 years, were studied. The aim of the study was to compare quantitative ultrasound (QUS) performed at two measurement sites of the same persons (correlations between parameters studied, age, and years since menopause (YSM)-related changes, influence of body size). Bone status was established using measurements at the calcaneus by Achilles (Lunar, USA), which measures speed of sound (SOS [m/s], CV% = 0.22%), broadband ultrasound attenuation (BUA [dB/MHz], CV% = 1.8%), stiffness index (SI [%], CV% = 1.3%), and by DBM Sonic 1200 (Igea, Italy), which measures amplitude-dependent speed of sound (Ad-SoS [m/s], CV% = 0.64%) at the hand phalanges. Mean and SD values were: SOS = 1498 +/- 24.8 m/s, BUA = 104.6 +/- 9.4 dB/MHz, SI = 69.2 +/- 12.3%, Ad-SoS = 1879 +/- 90.1 m/s. Age- and YSM-related changes were as follows: age-SOS r = -0.37, p < 0.0001, age-BUA r = -0.33, p < 0.001, age-SI r = -0.36, p < 0.001, age-Ad-SoS r = -0.62, p < 0.00001, YSM-SOS r = -0.27, p < 0.01, YSM-BUA r = -0.32, p < 0.001, YSM-Ad-SoS r = -0.44, p < 0.00001, YSM-SI r = -0.29, p < 0.01. In stepwise, multiple regression analyses of ultrasound parameters on age, YSM, height, and weight, the following equations were obtained: SOS [m/s] = 1564.9 - 1.1 x age [y], r = -0.37, p < 0.0001; BUA [dB/MHz] = 88.7 + 0.28 x weight [kg] - 0.36 x YSM [y], r = -0.51, p < 0.00001; SI [%]) = 79.2 - 0.5 x age [y] + 0.28 x weight [kg], r = -0.47, p < 0.00001; Ad-SoS [m/s] = 2287 to 6.9 x age [y], r = -0.62, p < 0.00001. In conclusion, QUS at the calcaneus and hand phalanges express similar trends in skeletal changes due to aging and the postmenopausal period, although measurements at the phalanges seem to be more sensitive for detecting bone changes, due to faster decrease rate of the Ad-SoS value than calcaneal measurements.

Therapeutic safety monitoring: what to look for and when to look for it

This review focuses on the safety problems associated with antiepileptic drugs (AEDs) as revealed by laboratory testing and clinical examination. There are two classes of side effects: (a) common and mild and (b) rare and severe. Allergic reactions to AEDs are common and usually mild. However, on rare occasions, they can progress to more severe cutaneous disorders, including Stevens-Johnson syndrome and toxic epidermal necrolysis. Severe allergic reactions to AEDs range from immune responses with fever to multiorgan dysfunction. Allergic rashes may be genetically or immunologically determined. Laboratory abnormalities produced by AEDs are common and mild, and include hepatic enzyme elevation associated with phenytoin and mild elevation in ammonia associated with valproate. Serious, although rare, idiosyncratic side effects, such as aplastic anemia, hepatotoxicity, and thrombocytopenia, have also occurred with AEDs. These reactions are largely confined to the "classic" AEDs. With the exception of felbamate, AEDs approved in the past decade have not been plagued by severe idiosyncratic reactions. Subtle endocrine abnormalities, including variations in thyroid function tests and bone metabolism, and the often subclinical effects on peripheral nerve conduction produced by phenytoin and carbamazepine, are also examined.

Influence of vitamin D administration on bone ultrasound measurements in patients on anticonvulsant therapy

BACKGROUND

The objective of the study was to evaluate bone mass status (as measured by bone ultrasound) in patients on anticonvulsant therapy, and the influence that Vitamin D administration exerts over it.

MATERIALS AND METHODS

We measured and compared the basal serum levels of 25(OH)D3, parathyroid hormone (PTH), and phalangeal bone ultrasound (Ad-SOS), in 30 adult patients who were taking anticonvulsant drugs, with a control group of similar age and sex. We then gave the patients a large oral dose of 3 mg (120.000 UI) of 25(OH)D3, and repeated the measurements after one month.

RESULTS

Basal 25(OH)D3 and Ad-SOS values were significantly lower, and PTH values significantly higher (P< 0.0001 in all), in the patient group. The low Ad-SOS values for the patients were independent of the treatment, but directly related to basal 25(OH)D3 levels (r = 0.45, P<0.01). There was a negative association between PTH and 25(OH)D3 (r = -0.64, P<0.0001), and no correlation between PTH y Ad-SOS (r = -0.20, p NS). After ingestion of the large dose of the vitamin D, the patient group registered a significant (P<0.0001) increase in 25(OH)D3 levels, their Ad-SOS values increased (P<0.0001) nearly to the mean basal value of the control group, and PTH decreased significantly (P<0.0001).

CONCLUSIONS

These findings justify the need to assure adequate vitamin D intake in patients being treated with anticonvulsants, independently of the treatment, age, sex, and activity status, in order to prevent osteomalacia.