Comparison of Trends in the Incidence of Traumatic Spinal Cord Injury in Daily Life, Automobile Accidents, and Industrial Accidents: A National Multi-Insurance Study in Korea

Background@#To examine the incidence of traumatic spinal cord injury (TSCI) from all etiologies, we measured and compared the incidence of TSCI from three national or quasinational databases in South Korea, namely, the National Health Insurance Service (NHIS), automobile insurance (AUI), and Industrial Accident Compensation Insurance (IACI). @*Methods@#We reviewed patients with TSCI reported in the NHIS database between 2009 and 2018, and in the AUI and IACI databases between 2014 and 2018. TSCI patients were defined as those first admitted to the hospital with a diagnosis of TSCI according to the International Classification of Diseases (10th revision) criteria. Age-adjusted incidence was calculated using direct standardization using the 2005 South Korean population or the 2000 US population as the standard population. The annual percentage changes (APC) of TSCI incidence were calculated. The Cochrane–Armitage trend test was performed according to the injured body region. @*Results@#In the NHIS database, age-adjusted TSCI incidence using the Korean standard population increased significantly from 2009 to 2018 (from 33.73 per million in 2009 to 38.14 per million in 2018, APC = 1.2%, P = 0.014). Contrarily, age-adjusted incidence in the AUI database significantly decreased from 13.88 per million in 2014 to 11.57 per million in 2018 (APC = – 5.1%, P = 0.009). In the IACI database, the age-adjusted incidence showed no significant difference, while crude incidence showed a significant increase (from 22.02 per million in 2014 to 28.92 per million in 2018, APC = 6.1%, P = 0.038). According to the age group, all the three databases showed high incidences of TSCI in those in their 60s and 70s or older. Among those in their 70s or older, the incidence of TSCI increased dramatically in the NHIS and IACI databases, while no significant trend was found in AUI database. In 2018, the number of TSCI patients was the highest among those over 70 years of age in the NHIS, whereas among those in their 50s were the highest in both AUI and IACI. The proportion of patients with cervical spinal cord injury was the most common in all these databases. @*Conclusions@#The differences in trends in the incidence of TSCI may be due to the different etiologies and different characteristics of subjects depending on insurance type. These results imply the need for tailored medical strategies for the different injury mechanisms represented by three national insurance services in South Korea.

Assessment of Dysarthria Using One-Word Speech Recognition with Hidden Markov Models

BACKGROUND: The gold standard in dysarthria assessment involves subjective analysis by a speech–language pathologist (SLP). We aimed to investigate the feasibility of dysarthria assessment using automatic speech recognition. METHODS: We developed an automatic speech recognition based software to assess dysarthria severity using hidden Markov models (HMMs). Word-specific HMMs were trained using the utterances from one hundred healthy individuals. Twenty-eight patients with dysarthria caused by neurological disorders, including stroke, traumatic brain injury, and Parkinson's disease were participated and their utterances were recorded. The utterances of 37 words from the Assessment of Phonology and Articulation for Children test were recorded in a quiet control booth in both groups. Patients were asked to repeat the recordings for evaluating the test–retest reliability. Patients' utterances were evaluated by two experienced SLPs, and the consonant production accuracy was calculated as a measure of dysarthria severity. The trained HMMs were also employed to evaluate the patients' utterances by calculating the averaged log likelihood (aLL) as the fitness of the spoken word to the word-specific HMM. RESULTS: The consonant production accuracy reported by the SLPs strongly correlated (r = 0.808) with the aLL, and the aLL showed excellent test–retest reliability (intraclass correlation coefficient, 0.964). CONCLUSION: This leads to the conclusion that dysarthria assessment using a one-word speech recognition system based on word-specific HMMs is feasible in neurological disorders.

The Impact of Acute Phase Domain-Specific Cognitive Function on Post-stroke Functional Recovery

OBJECTIVE: To assess whether the cognitive function in the acute stage evaluated by domain-specific neuropsychological assessments would be an independent predictor of functional outcome after stroke. METHODS: Forty patients underwent 4 domain-specific neuropsychological examinations about 3 weeks after the onset of stroke. The tests included the Boston Naming Test (BNT), the construction recall test (CRT), the construction praxis test (CPT), and the verbal fluency test (VFT). The Korean version of Modified Barthel Index (K-MBI) at 3 months and the modified Rankin Scale (mRS) at 6 months were investigated as functional outcome after stroke. Functional improvement was assessed using the change in K-MBI during the first 3 months and subjects were dichotomized into 'good status' and 'poor status' according to mRS at 6 months. The domain-specific cognitive function along with other possible predictors for functional outcome was examined using regression analysis. RESULTS: The z-score of CPT (p=0.044) and CRT (p<0.001) were independent predictors for functional improvement measured by the change in K-MBI during the first 3 months after stroke. The z-score of CPT (p=0.049) and CRT (p=0.048) were also independent predictors of functional status at post-stroke 6 months assessed by mRS. CONCLUSION: Impairment in visuospatial construction and memory within one month after stroke can be an independent prognostic factor of functional outcome. Domain-specific neuropsychological assessments could be considered in patients with stroke in the acute phase to predict long-term functional outcome.

Correlates of Bone Mineral Density and Sagittal Spinal Balance in the Aged

OBJECTIVE: To investigate the relationship between bone mineral density (BMD) and sagittal spinal balance in the Korean elderly population. METHODS: The retrospective study included subjects aged 60 years and above, who had whole-spine lateral radiography and dual-energy X-ray absorptiometry (DEXA) within a year's gap between each other. Sagittal vertical axis (SVA) for evaluation of sagittal spinal balance and five spinopelvic parameters were measured through radiography. The presence of compression fracture was identified. Correlations of BMD T-scores with SVA and with the spinopelvic parameters were assessed using Pearson correlation coefficient (PCC). Linear regression analyses were performed between SVA and the clinical and radiologic variables. RESULTS: One hundred twenty-two subjects (42 males and 80 females; mean age, 69.93+/-5.5 years) were included in the study. BMD, femur or spine, was not correlated with SVA or any spinopelvic parameters in both genders (PCC<+/-0.2), except that spine BMD in men was associated with sacral slope. Univariate regression analysis revealed association between SVA and lumbar lordosis, pelvic tilt, and compression fractures in both genders; it was also associated with age and pelvic incidence in females and with sacral slope in males. Multivariate linear regression model showed lumbar lordosis and compression fracture as variables affecting SVA in both sexes; pelvic incidence was another factor affecting SVA in women only. CONCLUSION: BMD was not associated with sagittal spinal balance in the aged. Sagittal spinal balance was explained partly by lumbar lordosis and compression fracture. Further study is warranted to understand progression of sagittal imbalance with age.

Evaluating the Differential Electrophysiological Effects of the Focal Vibrator on the Tendon and Muscle Belly in Healthy People

OBJECTIVE: To investigate the electrophysiological effects of focal vibration on the tendon and muscle belly in healthy people. METHODS: The miniaturized focal vibrator consisted of an unbalanced mass rotating offset and wireless controller. The parameters of vibratory stimulation were adjusted on a flat rigid surface as 65 microm at 70 Hz. Two consecutive tests on the different vibration sites were conducted in 10 healthy volunteers (test 1, the Achilles tendon; test 2, the muscle belly on the medial head of the gastrocnemius). The Hoffman (H)-reflex was measured 7 times during each test. The minimal H-reflex latency, maximal amplitude of H-reflex (Hmax), and maximal amplitude of the M-response (Mmax) were acquired. The ratio of Hmax and Mmax (HMR) and the vibratory inhibition index (VII: the ratio of the Hmax after vibration and Hmax before vibration) were calculated. The changes in parameters according to the time and site of stimulation were analyzed using the generalized estimating equation methods. RESULTS: All subjects completed the two tests without serious adverse effects. The minimal H-reflex latency did not show significant changes over time (Wald test: chi2=11.62, p=0.07), and between the two sites (chi2=0.42, p=0.52). The changes in Hmax (chi2=53.74, p<0.01), HMR (chi2=20.49, p<0.01), and VII (chi2=13.16, p=0.02) were significant over time with the adjustment of sites. These parameters were reduced at all time points compared to the baseline, but the decrements reverted instantly after the cessation of stimulation. When adjusted over time, a 1.99-mV decrease in the Hmax (chi2=4.02, p=0.04) and a 9.02% decrease in the VII (chi2=4.54, p=0.03) were observed when the muscle belly was vibrated compared to the tendon. CONCLUSION: The differential electrophysiological effects of focal vibration were verified. The muscle belly may be the more effective site for reducing the H-reflex compared to the tendon. This study provides the neurophysiological basis for a selective and safe rehabilitation program for spasticity management with focal vibration.