Circadian blood pressure rhythm in patients with higher and lower spinal cord injury: simultaneous evaluation of autonomic nervous activity and physical activity

OBJECTIVE

To examine the relationships among the circadian rhythms of blood pressure, autonomic nervous function, and physical activity of patients with varying levels of spinal cord injury.

DESIGN AND METHODS

We studied 19 patients with spinal cord injury [10 tetraplegic patients with cervical cord injury (C4-C7), and nine paraplegic patients with thoracic cord injury (Th6-Th12)] compared with 16 control subjects. A new multibiomedical recorder was used to measure blood pressure (every 30 min), cardiac vagal activity (hourly frequency of R-R50), and physical activity (integrated acceleration/min) for 24 h under hospital conditions. Systemic sympathetic nervous activity and sympathoadrenal functioning were assessed by examination of hormone levels in the blood.

RESULTS

Daytime and night-time values were compared; the variations in systolic and diastolic blood pressures and heart rate were slight in members of the tetraplegia group, but almost normal differences were observed in members of the paraplegia group. The circadian profile of cardiac vagal activity was normal for both patient groups, suggesting that an alteration in the sympathetic nervous rhythm had occurred in the tetraplegic patients. The plasma norepinephrine level was lower in members of the tetraplegia group than it was in members of the control group (P< 0.001), but was normal in members of the paraplegia group. The plasma level of epinephrine was lower in members of the tetraplegia (P< 0.05) and the paraplegia (P < 0.1) groups than it was in members of the control group. Daytime physical activity of members of both groups of patients was lower than that of subjects in the control group (P< 0.001 for both).

CONCLUSION

The central sympathoexcitatory pathway to the upper thoracic cord plays a critical role in the maintenance of normal circadian blood pressure rhythm in humans. Motor nerve functioning and sympathoadrenal secretion are not essential to this regulation.

Transient cortical blindness following bypass graft angiography. A case report

Transient cortical blindness, an uncommonly recognized complication of cerebral angiography, is an exceedingly rare event after cardiac catheterization and angiography. This report describes a sixty-two-year-old patient who had transient cortical blindness following bypass graft angiography. In this case, the authors showed that cortical blindness was associated with the breakage of the blood-brain barrier (BBB) and an increase in vascular permeability rather than with primary cerebral circulatory insufficiency. When the possibility exists that an excess volume of contrast medium may enter the cerebral circulation as in this case, that is, following a coronary artery bypass graft (CABG) using the internal mammary artery (IMA), precautionary measures may be necessary such as changing the type of contrast medium to be used or decreasing the volume injected. When cortical blindness occurs, it is a serious clinical problem whether transient or permanent. Therefore, the circumstances leading to this complication should be understood to determine suitable treatment and management.

Prognosis of cervical spinal cord injury in correlation with magnetic resonance imaging

Magnetic resonance (MR) images of 18 patients with a cervical spinal cord injury were analysed for prognostic signs of paralysis. Serial MR images were obtained within 48 hours (acute stage), then 2 weeks (subacute stage) and an average of 12 months (range 6-24 months) after injury. The patterns of signal intensity in the acute stage were divided into two types, slightly-low/low (SL/L) type and slightly-low/high (SL/H) type on T1-weighted images (T1WI) and T2-weighted images (T2WI). The patterns in the subacute stage were divided into two types, high/high (H/H) type and normal/high (N/H) type on T1WI and T2WI. Six patients showed SL/L type in the acute stage and H/H type in the subacute stage. Five of the patients had a paralysis of grade A and one of grade B at admission which remained unchanged after treatment. One patient showed SL/H type in the acute stage and H/H type in the subacute stage. The patient had a paralysis of grade A that improved to no more than grade B. The remaining 11 patients showed SL/H type in the acute stage and N/H type in the subacute stage. Their paralysis was from grade B to D at admission and grade D or E at the follow up. The signal intensity of SL/L type in the acute stage and H/H type in the subacute stage are bad prognostic signs.

[Detection of myocardial ischemia by 99mTc-Teboroxime myocardial SPECT: a comparison with 201Tl myocardial SPECT]

Exercise myocardial SPECT using 99mTc-Teboroxime was performed and the regions of ischemic area were compared with 201Tl myocardial SPECT in 8 patients with coronary artery disease. All patients had no evidence of previous myocardial infarction, and underwent bicycle ergometer exercise according to a standardized multistage exercise protocol. At peak exercise, 555 MBq 99mTc-Teboroxime or 75 MBq 201Tl was injected intravenously. After termination of exercise, images were obtained with a gamma camera rotating through a 180 degrees arc from 45 degrees right anterior oblique to 45 degrees left posterior oblique. The concordance of 99mTc-Teboroxime SPECT and 201Tl SPECT was 63% in ischemic region and 83% in normal region. Furthermore, one patient underwent dipyridamole infusion and 99mTc-Teboroxime SPECT was carried out. The images obtained by dipyridamole 99mTc-Teboroxime SPECT were equivalent to the images of exercise 201Tl SPECT. 99mTc-Teboroxime SPECT seems useful for the detection of the coronary artery disease. It was suggested that evaluation of the myocardial viability in acute phase of myocardial infarction can be possible by using 99mTc-Teboroxime SPECT.

The causes and clinical significance of exercise-induced silent myocardial ischemia evaluated by ischemic range and intensity with exercise Tl-201 myocardial SPECT

We investigated the causes and long-term prognosis of exercise-induced silent myocardial ischemia (SMI) by means of exercise Tl-201 myocardial SPECT (Ex-SPECT) in 97 patients with effort angina or old myocardial infarction (OMI). These patients were proven to have significant stenosis by coronary angiography. The subjects were divided into three groups based on the presence or absence of Tl-201 redistribution or angina during exercise testing. Group one consisted of 34 patients who had redistribution on Ex-SPECT and angina during exercise testing: the painful myocardial ischemia (PMI) group. The second group consisted of 38 patients who had redistribution on Ex-SPECT, but no angina during exercise testing: the SMI group. The third group consisted of 25 patients who had no redistribution: the RD (-) group. The ischemic range and intensity were quantified by the defect volume ratio (DVR) and defect severity index (DSI), respectively. Comparison of the DVR and DSI values for the PMI and SMI groups revealed that the DVR and DSI values for the SMI group were lower than those of the PMI group. Also the prognosis of the SMI group tended to be worse than that of the RD (-) group. Thus, we concluded that the SMI and PMI group should receive identical treatment.

[Problems of Mason-Likar lead system in treadmill exercise electrocardiography]

A Mason-Likar (M-L) leads system has been widely used in the exercise electrocardiography (ECG) using treadmill for the detection of myocardial ischemia. In routine treadmill exercise ECG using M-L lead, we often observe different patterns of ST-T forms those of II, III and aVF on bipolar leads. In this study, on 213 patients, conventional 12 lead ECG and the M-L lead placement ECG were recorded both at supine and standing positions. A careful analysis was made on all the records of patterns, durations, and amplitudes of QRS and T waves. We also evaluated the ST trendgram of patients with no ischemic changes proven exercise TI-201 myocardial single photon emission tomography (SPECT). Quantitative examination showed no significant differences between those in precordial leads of the standard and the M-L lead system in any subjects. The augmented amplitude of QRS and T waves, the disappearance of abnormal Q-waves in II, III, aVF lead, the negative inversion in QRS phase in lead aVL an left axis deviation were often recognized with M-L lead placement. In treadmill exercise ECG, ST depression more than 1 mm in II, III, aVF lead was noted 14 out of 17 patients with no ischemic changes. The all ST-T changes showed "not-decrescendo" type in ST trendgram. We concluded that rigorous evaluation for electrical axis, the configuration of ST-T waves and the existence of myocardial ischemia in leads II, III, aVF was necessary on treadmill exercise ECG using M-L lead replacement.

Spatial distribution of late potentials assessed by signal-averaged body surface mapping

In order to evaluate the spatial location of late potentials (LPs), we designed a new system for the body surface mapping of signal-averaged, filtered ECG using 45 thoracic unipolar leads (5 X 9 array). Signals from patients with old myocardial infarction (MI, N = 8), arrhythmogenic right ventricular dysplasia (N = 1) and dilated cardiomyopathy (N = 2) were amplified and passed through a digital bandpass filter (60-300Hz). Departure maps, LP isopotential maps, and LP30 area maps were generated and superimposed. The LP30 duration was determined as the section between the filtered QRS endpoints and points 30 msec before. Isopotential maps of the LPs showed distinct positive and negative regions. In 8 cases with MI, the extreme was related to the zones indicated by departure maps, and LP30 area maps also corresponded to the departure areas. Most importantly, the spatial distribution for the LP30 area map was different for each type of disease. In conclusion, body surface LP isopotential maps and LP30 area maps may provide useful information concerning the spatial distribution of LPs.

[Relationship between the occurrence of late potential and the location and size of myocardial infarction evaluated by thallium-201 SPECT]

High-frequency, low amplitude signals, late potentials (LPs), in the terminal portion of the body surface QRS of the signal-averaged ECG were frequently observed in ventricular tachycardia (VT) following myocardial infarction (MI). In this study, we evaluated the correlation between the occurrence of LPs and the size and location of MI estimated by Thallium-201 myocardial SPECT in 30 MI patients. The positive LPs were identified by the value of %RMS 40, the percent ratio of the root mean square voltage in the last 40 msec of the QRS complex to that of the total filtered QRS from the signal averaged ECG using bipolar X, Y, Z leads. The spatial distributions of LPs were evaluated by the LP30 area maps obtained by the body surface mapping using forty-five unipolar electrodes. Sixty projections were obtained over 180 degree by rotating gamma camera after 5 minutes intravenous injection of 74 MBq of Thallium-201. After low-pass filtering, images were reconstructed into short-axis, horizontal long-axis and vertical long-axis tomograms. The maximum count circumferential profiles for each short-axis cuts were generated from the apical to basal cut and they were expressed into two-dimensional polar functional maps (apex to the center), Bull's-eye map, to represent myocardial Tl distribution. Normal limits of myocardial Tl distribution were established as the mean minus 2 standard deviation from those of normal subjects. The MI size was estimated as defect volume ratio (DVR), the percent ratio of abnormal region to that of total volume of left ventricle. Significant differences in DVR were observed among MI with LPs and without LPs.(ABSTRACT TRUNCATED AT 250 WORDS)

The disease pattern and causes of death of spinal cord injured patients in Japan

In recent years, the lifespan of patients with spinal cord injury (SCI) in Japan has been markedly prolonged, resulting in changes in the pattern of diseases developing after SCI and causes of death. We carried out a questionnaire survey on these problems and obtained the following results: 1. Disease pattern in SCI patients. The morbidity during 3 days in October 1987 and the past history after SCI were investigated in 426 SCI patients, and the results were compared with those in the national health survey carried out by the Japanese government in 1984. The incidence of urological complications and pressure ulcer was high, as was to be expected. In addition, the incidence of diabetes, hypertension, skin diseases, peptic ulcer, and hepatic disease were also significantly higher in the SCI patients. 2. Causes of death in SCI patients. Causes of death were analysed in 522 SCI patients who died, and the results were compared with those of the survey undertaken in 1967. The major causes of death were urinary tract infections and respiratory dysfunction in the early stage of cervical cord injury. Comparison with the results of the survey in 1967 showed a significant decrease in deaths from urinary tract infection; and a significant increase in those from CVA.

Reaction times of normal subjects and amputees with below-knee and above-knee prostheses during stepping

Reaction times (RTs) of nine normal subjects and 11 amputees with prosthetic limbs were examined in standing posture and during stepping movement. There were significant differences of RTs between standing and stepping, and between the phases of the stepping cycle in both the normal subjects and the BK or AK amputees with prosthetic limbs. The attentional demand during stepping movement and the applicability of probe RT procedure to assess prosthetic limb were briefly discussed.

Serum group I pepsinogen (PG I) levels and their changes in the healing process of the ulcer in patients with and without unoperated recurrent ulcer

We measured serum group I pepsinogen (PG I) levels in subjects with endoscopically normal gastric and duodenal mucosa and patients with peptic ulcer. The release mechanism of PG I into blood stream was also investigated. The mean (+/- S.E.) serum PG I level in 136 subjects with endoscopically normal mucosa was 61 +/- 2 ng/ml and the normal range was calculated to be 30-109 ng/ml from the frequency distribution. In the patients with unoperated recurrent duodenal ulcer, the serum PG I levels remained high with the healing process of the ulcer. On the other hand, in the patients with non-recurrent duodenal ulcer and those with recurrent or non-recurrent gastric ulcer, the serum PG I levels decreased with the healing process of the ulcer gradually and significantly from the value in the active stage. These findings suggest that duodenal ulcer patients with high levels of serum PG I throughout the healing process of the ulcer tend to have the recurrence. Therefore, the serial measurements of serum PG I with the healing process will be helpful for the prediction of ulcer recurrence. Administration of atropine caused a significant decrease in serum PG I in the patients with duodenal ulcer, which suggests the vagal control of PG I release in duodenal ulcer patients.

A 10 year follow-up of diabetes in a rural area of Japan using the 50 g oral glucose tolerance test

We performed a 10 year follow-up study on diabetics using the 50 g oral glucose tolerance test in a rural area of Japan. In untreated borderline diabetics, high or normal insulin responders became normal for glucose tolerance 10 years later. However, low insulin responders became overt diabetics or remained borderline diabetics. Therefore, insulinogenic index was considered to be one of the most valuable indexes in the prospective investigation of untreated borderline diabetics.

Effect of passive movements on reaction time of the rectus femoris in normal subjects and patients with paraparesis

Electromyographic reaction times (EMG-RTs) of the right knee extension were examined in eight normal subjects and eight patients with paraparesis under three conditions; during passive knee flexion (PFLX), passive extension (PEXT) and no passive movements (STAT). EMG-RTs of the three conditions were not significantly different between the normal and the patient group. A two-way analysis of variance (condition x group) showed that the main effect of condition was significant, but that of group and the interaction were not. Both in the normal and the patient group the shortest EMG-RTs of all was obtained in PEXT, followed by that of STAT and PFLX. Effect of passive movements on EMG-RTs in the patients whose position sense of the knee and muscle strength of the knee extension were within normal range did not vary with the abnormality of tactile sense and/or myotatic reflexes. The results indicated that activities of the pyramidal tract neurons in carrying out a movement were directly influenced by kinesthetic information of the moving limb.