Pathology of propylene glycol administered by perineural and intramuscular injection in rats.
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Biomedical subjects
Publications and source records attributed to N Chino.
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To analyse the mechanism by which sensory inputs are integrated, interactions of somatosensory evoked potentials (SEPs) in response to simultaneous stimulation of two nerves were examined in 12 healthy subjects. Right, left and bilateral median nerves were stimulated in random order so that a precise comparison could be made among the SEPs. The arithmetical sum of the independent right and left median nerve SEPs was almost equal within 40 msec of stimulus onset to that evoked by the simultaneous stimulation of bilateral median nerves. However, a difference emerged after 40 msec. The greatest difference was recorded after 100 msec. Sensory information from right and left median nerves may interact in the late phase of sensory processing. Left median, left ulnar, and both nerves together were stimulated. The sum of the SEPs of left median and ulnar nerves was not equal to that evoked by the simultaneous stimulation of the two nerves even at early latencies. Differences between them were first recorded at 14-18 msec and became greater after 30-40 msec. It is suggested that the neural interactions between impulses in the median and ulnar nerves begin below the thalamic level.
Somatosensory vertex potentials (SVPs) were examined in 12 healthy subjects in response to painful electrical stimulation of the finger. SVPs consisted of N1, P1, and N2. The average latencies of the 3 peaks were 150, 225, and 350 msec, respectively. The latency and amplitude of each potential were reproducible for each subject. Recovery functions of the SVPs were analyzed in 10 subjects. A pair of stimuli were delivered to the right or left finger with interstimulus intervals (ISIs) of 50, 100, 150, 200, 350, 500 and 650 msec. SVPs partially recovered with the shortest ISI (50 msec). Full recovery could not be obtained even with the longest ISI (650 msec). Differences in recoveries within 650 msec of ISI were not observed between right and left stimulations. To examine the interaction between SVPs evoked by right and left finger stimulation, recovery functions from prior contralateral finger stimulation were analyzed with the same ISIs. SVP recoveries for right after left or left after right patterns of stimulus delivery were nearly the same as those for ipsilateral ones. It is suggested that SVPs are generated at nearly the same site in the sensory pathway regardless of the side stimulated.
Two experiments using transcranial magnetic stimulation (TMS) were undertaken to investigate facilitatory effects of thinking about a specific movement without voluntary discharges on motor-evoked potentials (MEP). First, surface electromyographic (EMG) responses from the abductor pollicis brevis were recorded with maximal stimulator output in the three conditions: the muscle being at rest, contracting with 10% of maximal muscle activity, and with the subject "only thinking" about thumb abduction (nine subjects). Median value of MEP amplitudes during "only thinking" was twice that at rest (P = 0.008) and one-half that during voluntary contraction (P = 0.008). Second, needle EMG responses from the first dorsal interosseus were compared at rest, during thinking about index finger abduction, and during TMS at threshold intensity. Four normal subjects were tested with stimulation of each cerebral hemisphere for a total of eight tests. The number of detectable MEP responses of 20 stimuli to one hemisphere was counted for each condition of rest or thinking. The mean MEP response rate during thinking (58%) was higher than that at rest (12%) (P < 0.005). These results demonstrate that thinking about a specific movement has facilitatory effects on MEP and that the degree of facilitation in thinking is smaller than in voluntary contraction.
The difficulty patterns of FIM (Functional Independence Measure) in Japan were determined and compared with patterns found in the United States to assess whether FIM can be used for worldwide comparisons of ADL (the activities of daily living). The FIM was measured for 190 stroke patients in several hospitals throughout Japan. The scores at admission and discharge were converted to an interval scale by Rasch analysis. Right and left brain lesion patients were analyzed separately. The FIM items were divided into two groups: motor items and cognitive items to minimize misfit. A degree of misfit was acceptable, except for bowel and bladder management, stairs, bathing, and expression. Motor items, eating, and bowel and bladder management were the easiest; stairs, bathing, and tub/shower transfers were the most difficult. The difficulty patterns of patients with left and right hemisphere lesions were almost identical. Bathing and tub/shower transfer were more difficult for Japanese patients than for those studied in the United States. Concerning the cognitive items, expression was easiest for patients with right hemisphere lesions but most difficult for those with left hemisphere lesions. Social interaction was easier for Japanese patients with left hemisphere lesions than the other patients. The item difficulty patterns in Japan differs slightly from those in the United States because of cultural differences. As countries show different patterns of difficulty, we must be careful when making international comparisons of FIM data converted by Rasch analysis.
Despite advances in the study of exercise for acute myocardial infarction (AMI) patients, few studies on exercise for post-AMI heart rupture patients have been reported. We assessed three cases of heart rupture (of the left ventricular free wall in two cases and of the ventricular septum in one case) in post-AMI patients who underwent three-graded exercise. Two of the three patients were operated on, whereas one patient was managed conservatively for heart rupture. Two of the three cases had also suffered cerebral infarction post-AMI. The exercise program was composed of three grades, slow level walking (grade 1), mild reconditioning and activities of daily living (ADL) exercises (grade 2), and optional endurance training using machines below 75% of predicted maximal heart rate (grade 3). Electrocardiograms and blood pressure were monitored during all exercises. All patients had muscle weakness, poor endurance capacity, as well as low cardiac function (28-47% of left ventricular ejection fraction). Two patients underwent grades 1 and 2 exercise programs, and the other performed grades 1, 2, and 3 exercise programs over a 3- to 10-wk period. We observed improvement in the double product, work capacity, and ADL without congestive heart failure, ischemic attack, or serious arrhythmias. However, the youngest patient, who underwent the grade 3 exercise program, died from a cardiac event 10 mo after onset of AMI. We conclude that post-AMI heart rupture patients should undergo delayed, gradual, low-level graded exercise (4-6 metabolic equivalents), with monitoring of blood pressure and electrocardiograms to improve work capacity, ADL, and the quality of life. However, daily activity and exercise intensity should be promptly supervised for those with severely deteriorated cardiac functions to prevent sudden cardiac event.
The Walkabout is a new hip-knee-ankle-foot orthotic (HKAFO) system with a medial single hip joint (MSH-KAFO) invented by S. McKay in 1992. Compared with other HKAFO systems, the hip joint part is compact and removable, so it has distinguishable, real merits: ease in donning and doffing the device, compatibility with a wheelchair, and cosmesis. We clinically tested five patients, paraplegic because of spinal cord injury, using the MSH-KAFO system. All were males, aged 26-36 yr old. Their functional levels were L-1 (2 cases), T-10 (2 cases), and T-5 (1 case). All patients could stand stably without crutches and walk in parallel bars immediately the first time they wore the braces. After a few hours of crutch-walking exercises, all could walk independently with Lofstrand crutches. Their walking velocities ranged from 10 to 37.5 (mean, 19.9) m/min at the follow-up points (mean, 7.1 mo). With four cases, we measured oxygen uptake for predictions of energy consumption. At comfortable walking, predicted energy consumptions were from 1.31 to 3.89 (mean, 2.75) METs. Compared with the data in literature, these seemed to be at the same level with normal walking and lower than the KAFOs walking level. Our results suggest that MSH-KAFO is a very convenient standing and walking device for paraplegics and is compatible with wheelchair use.
Functional recovery in a rather late stage after stroke was examined in 70 stroke patients using the Stroke Impairment Assessment Set (SIAS) and the Functional Independence Measure (FIM). The SIAS and the FIM were administered at three and six months after the onset of stroke. Motor items and the abdominal manual muscle testing item improved in more than 30 percent of patients. The motor subscore of the FIM changed from 60.8 to 73.4, and the cognitive subscore changed from 28.4 to 30.4. The relationship between impairment and disability was evaluated using the neural network method with the software, Skiltran. The change of the FIM motor subscore from three months to six months was used as an output variable, and the change in the SIAS items and the FIM motor subscore were included as input variables. As a result of the connection weight obtained from this network, the change in the fifth motor item (one of the tone items, abdominal manual muscle testing) and the unaffected side grip as well as the FIM at three months had a strong connection to the change of the FIM. It is compatible with ordinary experience that function of both the affected and unaffected side influences the level of disability. Contribution of the impairment to the disability indicates the importance of taking into consideration the impairment for predicting prognosis and selecting adequate treatment when we carry out stroke rehabilitation. In conclusion, we described the relationship between the SIAS and the FIM using the neural network in stroke patients and proved the importance of the impairment to predict the outcome of disability.
The Functional Independence Measure for Children (WeeFIM) was developed based on the FIMSM instrument to assess disability in children aged six months to seven years. Its reliability and validity have been studied, and normative data are available for American children. The WeeFIM instrument is potentially an internationally useful instrument, but data from other countries are lacking. The objectives of this study are to examine whether the WeeFIM instrument is applicable to Japanese children and to describe preliminary normative data. To study interrater reliability, we had two examiners assess 20 nondisabled children and calculated weighted kappas for individual item scores and intraclass correlation coefficients for total scores and motor and cognitive subscores. We then assessed 110 nondisabled children ages six months to seven years to obtain normative data and compared them with the American data. In 51 of these healthy children, we compared total WeeFIM scores with developmental ages as obtained with the Tsumori test, a standardized developmental test widely used in Japan to assess its concurrent validity. The weighted kappas were greater than 0.8, and the intraclass correlation coefficients were greater than 0.98. Total scores and motor and cognitive subscores increased with age, reaching a plateau at 60 to 72 months, which is similar to the American data. There were three patterns of chronologic changes in individual item scores: items showing high correlations with age (Spearman's rho > 0.8; grooming, dressing, memory, etc.), moderate correlations (0.8 > rho > 0.7; eating, bladder, comprehension, etc.), and lower correlations (0.7 > rho > 0.6; locomotion and chair transfer). Total scores correlated significantly with developmental ages (Spearman's rho = 0.938), but there was a discrepancy between each item score and the pass-or-fail patterns of the Tsumori test. This study demonstrated the applicability of the WeeFIM instrument to Japanese children with satisfactory reliability and validity and provided preliminary normative data for future studies.
This study was designed to examine the scale quality of our newly developed short behavior scale and to identify its role in predicting the functional outcome of stroke patients. The short behavior scale consists of six items that assess cognitive function related to the daily behavioral status of a patient in activities of daily living and exercise. It can be scored quickly through observation of a patient's behavior. We assessed 190 stroke inpatients, who had a mean age of 61 years. The mean days and length of stay from onset were 47.3 and 138.2, respectively. We examined internal consistency with the Cronbach's alpha coefficient. Interrater reliability was tested by having two examiners evaluate 30 patients independently. We studied how the short behavior scale correlated with the admission Functional Independence Measure, Mini-Mental State Examination scores, and speech and visuospatial functions. We also studied how the short behavior scale contributed to the prediction of discharge Functional Independence Measure raw scores with stepwise multiple regression analysis. In another group of 116 patients, we cross-validated our predictive equation. The Cronbach's alpha coefficient was 0.88. The intraclass correlation coefficient was 0.84 for total score. The short behavior scale correlated significantly with cognitive Functional Independence Measure scores and Mini-Mental State Examination scores. We could explain 70.8% of the variance of discharge Functional Independence Measure scores from the Short Behavior Scale, days from onset to admission, age, speech scores, and admission Functional Independence Measure scores. Stability of the predictive equation was shown in cross-validation to a second sample of 116 patients. In conclusion, our newly developed short behavior scale proved reasonable and would be useful to enhance the precision of outcome prediction in stroke rehabilitation.
The Functional Independence Measure for Children (WeeFIM) instrument was developed, based on the FIM instrument, to assess disability in children aged 6 mo to 7 yr. Normative data are reported for American and Japanese children, and it is increasingly used for the disabled. Our purpose was to confirm scale quality and to determine the difficulty pattern of the WeeFIM in Japan. The WeeFIM was measured in 225 children (113 girls and 112 boys) aged 6 mo to 7 yr without developmental delays. The scores were converted to an interval scale by Rasch analysis, which assumes unidimensionality of the measurement items, determines the degree of the fit to the assumption, and decides item difficulty. When the WeeFIM items were divided into two groups of motor and cognitive items to minimize misfit, the degree of misfit was acceptable, except for eating, bladder management, tub/shower transfer, and comprehension. For the motor items, grooming, bathing, and bladder control were more difficult, and stairs, bed/chair transfer, and walk or wheelchair were easier. Concerning the cognitive items, expression and comprehension were easier, and problem-solving was most difficult. When we compared item difficulty patterns in the four age groups (6-21 mo, 22-45 mo, 46-62 mo, and 63-100 mo), we found no differences, except in toilet transfer. It was more difficult for younger children, possibly because of its different pattern of chronological change, which shows rapid changes from dependent to independent levels over a short period of time. Our study confirmed the scale quality of the WeeFIM instrument with Rasch analysis and demonstrated the difficulty pattern of the WeeFIM in nondisabled Japanese children.
We previously reported reliability and validity of our newly developed comorbidity scale (CS) for stroke outcome research based on a retrospective sample. The objectives of this study were to cross-validate the comorbidity scale in a new prospective sample and to investigate longitudinal changes of the comorbidity scale during hospitalization. In a prospective sample of 175 stroke patients admitted to five nonacute rehabilitation hospitals in Japan, we analyzed the frequency and grading of comorbidities and compared the comorbidity scale with demographic data, impairment as assessed with the Stroke Impairment Assessment Set (SIAS), and disability as measured with the Functional Independence Measure (FIM(SM)). The results were compared with our previous retrospective study. We also studied longitudinal changes by measuring the comorbidity scale on admission, 2 wk later, and at discharge of 67 patients. As a result, the comorbidity scaling was significantly lower in the prospective sample, and it increased at the second measurement and then plateaued. Among the comorbidities, hypertension ranked first, followed by shoulder pain, and diabetes mellitus. Similar to our previous retrospective study, the comorbidity scale correlated positively with age and length of stay and correlated negatively with the SIAS motor item scores and the FIM scores. In conclusion, the present study suggested concurrent and predictive validity of the comorbidity scale in a prospective sample as well and clarified the comorbidity characteristics of stroke inpatients.
Respiratory complications, such as pneumonia and atelectasis, are major causes of mortality and inhibit rehabilitation programs in spinal cord injury. Tetraplegic patients cannot cough enough to clear their sputum because of expiratory muscle weakness, mainly of the abdominal muscles. However, tetraplegics are still able to activate some muscles during coughing. Some tetraplegics, even though they cannot contract the abdominal muscles, can cough effectively. It was supposed that some accessory expiratory muscles were activated during coughing in tetraplegics. We, therefore, studied the peak expiratory flow rate, expiratory muscle strength, and the activities of the pectoralis major and latissimus dorsi muscles in 11 complete tetraplegics. Peak expiratory flow rate was measured by spirometry. Expiratory muscles strength was assessed by maximal expiratory mouth pressure; muscle activity was assessed by means of the root mean square voltage obtained by surface electromyography. The results showed that peak expiratory flow rate, maximal expiratory mouth pressure, and root mean square of these two muscles were correlated with neurological level. Peak expiratory flow rate was correlated with peak expiratory flow rate. Peak expiratory flow rate was correlated with the root mean square voltage of the pectoralis major and latissimus dorsi muscles. It was supposed that these two muscles were activated as accessory expiratory muscles and play an important role in expiratory function in tetraplegic patients.
Two-dimensional (fore-aft and vertical) acceleration of locomotion was measured in 10 normal subjects and 13 patients with idiopathic olivopontocerebellar atrophy who were ataxic but able to walk without any assistance. Accelerometers were tightly placed on the third lumbar vertebra. Asymmetry and unsmoothness indices of locomotion defined from the line spectra of the accelerometric data were computed. Reproducibility of the indices was checked in the normal subjects and patients. The index values were significantly correlated with visual rating of gait unsteadiness in the patients. The indices for vertical components were significantly increased when subjects walked slowly. Effects of weights and bandages on gait were analysed by the fore-aft components of the indices. They were attached to both lower extremities. Weighting or bandaging did not change, or even increased the index values in most of the normal subjects. The indices were also unchanged in the patients. However, some of the patients showed significant improvement with weights or bandages. Mechanisms of therapeutic effects of weighting and elastic bandages on ataxia are discussed.
T1 relaxation time (T1 time), T2 relaxation time (T2 time), and proton (rho) density in the thigh muscles of 20 normal healthy volunteers and three patients with muscle atrophy in the lower extremity were measured in order to select the useful MRI parameters for neuromuscular diagnosis. Since the standard deviation (SD) of both T1 and T2 times in each muscle was found to be within a relatively small range, these values were expected to be useful MRI parameters for neuromuscular diagnosis. On the contrary, rho density was not a valid parameter for diagnosis, as it was demonstrated to have large SDs in the muscles. The differences of these parameters in the three patients also supported the fact that MRI was useful for discriminating between the various types of muscular abnormalities based on relaxation times. The longer T1 and T2 times in women suggested that the content of water in skeletal muscle was higher in women than in men. Moreover, the T1 time in the dominant limbs was found to be shorter than in the non-dominant limbs for rectus femoris only in both men and women, while there were no differences in T2 time in these muscles.
The relationship between Wallerian degeneration in the brain stem and degree of motor impairment is discussed. Using MRI we studied 172 supratentorial stroke patients, whose motor impairment was graded according to Brunnstrom stage. Wallerian degeneration was represented by a T2 high-intensity area in the brain stem, and its cross-sectional extent was measured at the cerebral peduncle level. Wallerian degeneration was detected in 99 patients (57.6%). The area of T2 high intensity was significantly correlated with Brunnstrom stage. Multiple regression analysis showed that the upper extremity stage contributed most to the visualization of Wallerian degeneration. This is partly because the pyramidal tract participates in fine and precise movement. The extent of the area of Wallerian degeneration is found to be helpful in making a prognosis with respect to motor impairment in the upper extremity.
The pixel values in fat/water suppression magnetic resonance (MR) images were measured for the thigh muscles of 18 healthy volunteers to investigate age-related changes in muscle water and fat content. Prior to the human studies the reproducibility of the data was confirmed using phantoms. The standard deviations (SDs) of the pixel values for one of the phantoms examined five times were found to be within a relatively narrow range. Both the pixel values in the fat suppression images (PV1) and the pixel values in the water suppression images (PV2) of all muscles tended to be higher in the oldest group. The results indicate that the water and fat content of skeletal muscles is higher in aged persons. Moreover, the PV1 in the non-dominant limbs was found to be increased in the extensor muscles of the knee joints, while the PV2 in the non-dominant limbs did not show a significant difference, except for the rectus femoris.
The effect of magnetic stimulation on reciprocal Ia inhibition of the human leg was investigated. Stimulation of the common peroneal nerve at the fibula head at the threshold of the alpha motoneuron axons resulted in inhibition of the soleus (SOL) H reflex at a conditioning-test interval of 2 ms. Magnetic stimulation over the contralateral motor cortex resulted in complex modulations of the SOL H reflex, including a short latency facilitation followed by inhibition. This inhibition may have been conveyed by Ia inhibitory interneurons projecting to SOL motoneurons. To test for convergence, whether or not the magnetic stimulation was capable of facilitating disynaptic reciprocal Ia inhibition of the SOL H reflex induced by stimulation of the peroneal nerve, the two stimuli were given together or separately. We observed the inhibition significantly increased when the two stimuli were given together than separately. These results suggest that the Ia inhibitory interneurons projecting to SOL motoneurons in humans might receive convergent input from the motor area of the brain and from Ia afferents of the tibialis anterior (TA) muscle in humans as well as in other animals.