Back disorders among Israeli youth: a prevalence study in young military recruits.

BACKGROUND CONTEXT: Back problems are reported with increasing frequency in adults and adolescents. Most information is from self-reported questionnaires or studies with small sample sizes. Reports were usually focused on specific diseases and biased toward overdiagnosis. PURPOSE: To assess the prevalence of common back disorders among a large cohort of 17-year-old males and females recruited by the Israel Defense Forces (IDF). STUDY DESIGN: A retrospective cross-sectional prevalence study. PATIENT SAMPLE: Seventeen-year-old Israeli male and female military recruits reporting as directed by the IDF for preinduction medical examination between January 01, 1998 and December 31, 2006. OUTCOME MEASURES: Military functional limitation Grades 1 to 7 per diagnosis category. METHODS: Military recruits were examined and classified based on medical and orthopedic diagnoses. They were referred for orthopedic consultation as necessary. Four orthopedic classifications were used: spinal deformity (including kyphosis and scoliosis), back pain (including neck and radicular syndromes), spondylolysis/olisthesis, and limitations resulting from trauma or spinal surgery. Data were coded into a central database, and descriptive statistics are presented. RESULTS: The overall prevalence of back disorders among 828,171 17-year-old military recruits (61.5% male) was 16.8%. Back disorders resulting in significant functional limitation were diagnosed in 0.8% of recruits. The most prevalent diagnoses were spinal deformities (kyphosis and scoliosis, females 11.9%, males 11.5%) and back pain (females 3.0%, males 5.6%). Most of these diagnoses were rated as mild. CONCLUSIONS: When using objective criteria, overall back disorders in a large population of 17-year-old recruits were 17%, considerably lower than most reports. Back morbidity severe enough to prevent combat duty occurred at a rate of less than 1%, suggesting that serious back morbidity is not a frequent finding in this age group. LEVEL OF EVIDENCE: Symptom prevalence study, Level III.

The efficiency of 10-second resting heart rate for the evaluation of short-term heart rate variability indices.

BACKGROUND: High values of resting heart rate were found to be correlated with adverse outcomes in various patient groups. Heart rate variability (HRV) is a reliable technique in determining autonomic nervous system function. Our aim was to evaluate whether a 10-second resting heart rate obtained from a resting electrocardiogram (ECG), could be used as a reliable evaluation of short-term HRV. METHODS: Seventy-nine healthy volunteers were included in the study. All participants underwent a 10-second ECG, and 5-minute HRV measurement under strict criteria. RESULTS: A significantly negative correlation was found between resting heart rate and 5-minute max-RR, min-RR, standard deviation of normal RR intervals (SDNN), root mean square of successive differences of RR intervals (RMSSD), HRV triangular index, number of intervals differing by 50 milliseconds from the preceding interval (NN50), pNN50, standard deviation of the points perpendicular to the line of identity (SD1), standard deviation along the line of identity (SD2), and high frequency spectral component (HF). A significant positive correlation was found between resting heart rate and a 5-minute low frequency spectral component (LF) and LF/HF ratio. Specifically, max-RR and min-RR were found to have the best correlation with resting heart rate. CONCLUSIONS: Resting heart rate obtained from a 10-second ECG can be used for crude estimation of all HRV results in healthy individuals who do not take medications, with variable efficacy depending on the measured parameter. Resting heart rate was especially efficient in predicting max-RR and min-RR. Further research should focus on assessing the reliability of a resting heart rate for HRV evaluation, in patients with autonomic dysfunction and high-risk cardiac patients.

Reliability of Ultra-Short ECG Indices for Heart Rate Variability.

BACKGROUND: Heart rate variability (HRV) is an accepted and reliable means for assessing autonomic nervous system dysfunction. A 5-minute measurement of HRV is considered methodologically adequate. Several studies have attempted to use shorter recordings of 1-2 minutes or 10 seconds. The aim of this study was to determine the reliability of HRV parameters calculated from ultra-short electrocardiogram recordings. METHODS: Seventy healthy volunteers were recruited for the study. HRV was evaluated for 5 minutes according to accepted procedures. Thereafter, HRV parameters were recalculated from randomly selected 1-minute and 10-second intervals. The standard and ultra-short measurements were correlated using intraclass correlation coefficients. RESULTS: Good correlations between the 5-minute electrocardiograms (ECGs) and both the 1-minute and 10-second ECGs were noted for average RR interval, and root mean square of successive differences in RR intervals (RMSSD). No correlation was noted for standard deviation of the RR interval (SDNN) and several other HRV parameters. CONCLUSIONS: RMSSD, but not SDNN, seem a reliable parameter for assessing HRV from ultra-short (1 minute or 10 seconds) resting electrocardiographic recordings. Power spectral analysis and evaluation of other HRV parameters require longer recording periods. Further research is required to evaluate the importance of ultra-short RMSSD for cardiovascular risk stratification.

Lactic dehydrogenase isoenzymes in adolescents with multiple sclerosis.

Multiple sclerosis is an immune-mediated demyelinating disease with high morbidity and major mortality. To determine the potential use of lactic dehydrogenase activity and lactic dehydrogenase isoenzyme concentrations in cerebrospinal fluid as biomarkers of multiple sclerosis, we reviewed the files of all patients with multiple sclerosis who attended our tertiary pediatric medical facility from 1999-2005. The study group included three adolescent patients with multiple sclerosis (cerebrospinal fluid analysis at diagnosis) and one patient with recurrent optic neuritis (cerebrospinal fluid analysis during a disease episode). The isoenzyme pattern was abnormal in all patients with multiple sclerosis, with higher-than-normal levels of lactic dehydrogenase-2, lactic dehydrogenase-3, and lactic dehydrogenase-5 in two patients, and lower-than-normal levels of lactic dehydrogenase-4 in one patient. It was not necessarily, however, the same two patients who had the abnormally high levels of lactic dehydrogenase-2, -3, and -5. The patient with optic neuritis also exhibited an abnormal lactic dehydrogenase isoenzyme pattern that shared common features with the others. Multiple sclerosis appears to be characterized by an abnormal lactic dehydrogenase isoenzyme pattern in cerebrospinal fluid. The importance of this finding and its diagnostic potential use warrant further investigation.

Cerebrospinal fluid lactate dehydrogenase isoenzymes in children with bacterial and aseptic meningitis.

Differentiation of bacterial from aseptic meningitis may be difficult. Our aim was to determine the pattern of distribution of lactate dehydrogenase (LDH) isoenzymes in the cerebrospinal fluid (CSF) of patients with bacterial and aseptic meningitis. One hundred and fifty-seven patients with suspected meningitis were enrolled in the study. They were divided into 3 groups according to the culture- or bacterial antigen assay-proven diagnosis and CSF findings: bacterial meningitis (n = 31), aseptic meningitis (n = 65), and non-meningitis (n = 61). Total LDH level and percentages of LDH isoenzymes in the CSF were measured in each patient. Each group showed a distinct LDH isoenzyme distribution pattern, with a statistically significant difference among the groups in the percentages of the various isoenzymes. Compared with the non-meningitis group, total LDH activity in the CSF was high in the aseptic meningitis group (49.82+/-35.59 U/L, P < 0.001) and exaggerated in the bacterial meningitis group (944.53+/-112.3 U/L, P < 0.001). Low LDH-2 levels were unique to bacterial meningitis (P < 0.01), whereas high LDH-3 levels were characteristic of aseptic meningitis (P < 0.05). Both groups had low levels of LDH-1 and high levels of LDH-4 and LDH-5. In conclusion, the LDH isoenzyme pattern may be of clinical diagnostic value in meningitis, particularly when culture results are pending.