Breathing pattern adjustments during the first year following cervical spinal cord injury.

The alterations in lung function and breathing pattern were examined in 6 quadriplegics at 3, 6 and greater than 12 months post injury, and were compared to 6 able bodied controls. Subjects were studied in both the seated and supine positions. Functional residual capacity (FRC), forced vital capacity (FVC), inspiratory capacity (IC), and maximum mouth pressure (Pimax) at FRC were measured. Total lung capacity (TLC) and residual volume (RV) were calculated. Resting breathing pattern was assessed for 20 minutes from a spirogram derived from summed rib cage and abdominal strain gauge signals. At 3 months in quadriplegics, TLC was reduced (p less than 0.05), RV increased (p less than 0.01) and FRC was normal in sitting; in supine, only TLC was reduced (p less than 0.05); Pimax was decreased (p less than 0.01) in both positions in quadriplegics at 3 months, but increased over the first year in the seated position (p less than 0.01). There were no alterations in breathing pattern at any time interval in quadriplegics in supine. In contrast, at 3 months post injury in sitting, expiratory time (Te) was shortened (p less than 0.05), tidal volume (Vt) was decreased, and heart rate elevated as compared to controls (p less than 0.05). Inspiratory time (Ti) was not significantly shortened at 3 months in quadriplegics, but a lengthening of Ti occurred between 3 and 6 months (p less than 0.025) resulting in increased Vt, and heart rate decreased to normal. Vt/Ti was reduced, and did not alter with time. The lengthening of Ti/Ttot observed in supine in control subjects (p less than 0.025), was not observed in quadriplegics. Quadriplegics sighed as frequently in supine as did controls at all stages post injury, whereas they decreased sighing frequency in sitting at 3 and 6 months post injury (p less than 0.05). The improvement in resting breathing pattern observed in quadriplegics in sitting with time, may be due to increased accessory muscle function, improved chest wall stability and thoracoabdominal coupling, or a combination of these factors. It is also possible that the alterations in breathing pattern were a response to cardiovascular adjustments occurring in the same time frame. Quadriplegics retain the sigh reflex, but do not take as many big breaths in sitting as they do in supine, probably due to the increased work of breathing in the seated posture.

Breathing pattern in chronic quadriplegia.

The resting breathing pattern in 14 chronic C6 and C7 traumatic quadriplegics was compared with six age-matched healthy controls. All quadriplegics had complete motor loss below the lesion level and were at least two years postinjury. Tests were performed with subjects seated. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1.0), inspiratory capacity (IC), and maximum inspiratory mouth pressure (Pimax) were measured. Resting breathing pattern was assessed for 20 minutes using mercury in rubber strain gauges and a computer-assisted data acquisition and analysis program. Inspiratory time (Ti), expiratory time (Te), and tidal volume (Vt) were measured, and the remaining timing components were calculated from these values. The variability of breathing was assessed by comparing the coefficients of variation of each variable. The FVC, IC, and Pimax were significantly reduced; Vt was significantly lower (p less than 0.01) and frequency significantly elevated (p less than 0.05) in quadriplegics. The decreased Vt in quadriplegics was due entirely to a significantly decreased mean inspiratory flow (p less than 0.01); Ti was the same in quadriplegics as in controls. The ratio of mean Ti to total cycle time (Ti/Ttot) was significantly longer in quadriplegics (p less than 0.005). There was no difference in variability of breathing between the two groups for any timing component of ventilation. There was no significant difference in sighing frequency between groups for either breaths greater than 2x mean Vt or breaths greater than 3x mean Vt. Chronic quadriplegics demonstrated a rapid, shallow breathing pattern, probably due to the mechanical restrictions resulting from paralysis of the thorax musculature. They retained the ability to sigh, suggesting that chest wall afferents may not be required in this process.

Spinal fractures complicating ankylosing spondylitis. A long-term followup study.

Twenty-two spinal fractures in 20 patients with chronic ankylosing spondylitis are reported. Nineteen fractures occurred in the cervical region. Fourteen of the fractures were caused by minor falls, 3 by falls down steps, 4 by motor vehicle accidents, and 1 by cardiopulmonary resuscitation. Long-term followup (mean 3.2 years) of 9 fractures diagnosed early and managed conservatively showed bony union of all fractures. No patient deteriorated neurologically and 3 patients made major recovery. Long-term followup is also reported on 6 patients in whom the diagnosis was delayed. The difficulties in diagnosis and management are discussed.

Histocompatibility antigens in paraplegic or quadriplegic patients with sacroiliac joint changes.

HLA typing for the A and B loci and radiographic examination of the sacroiliac joints were performed in 54 randomly selected patients with paraplegia or quadriplegia of more than 3 years' duration. The sacroiliac joints were abnormal in 24 patients. No association was found between any of the HLA antigens of the A and B loci and the sacroiliac joint changes. There was, however, an increased incidnece of sacroiliac joint changes in quadriplegic as compared to paraplegic patients.

Electromyographic temporal analysis of gait: normal human locomotion.

The telemetered electromyographic (EMG) activity of pretibial muscles (tibialis anterior), triceps surae (lateral gastrocnemius), medial hamstring group and quadriceps (vastus lateralis) of 20 normal subjects was examined during locomotion. The ages of the subjects ranged from 8 to 72 years (mean, 37 years). A microswitch shoe was used to correlate the EMG activity with eight specific components of the gait cycle. Tibialis anterior showed two peaks of activity, the first at the swing-stance transition, the second at the stance-swing transition. Gastrocnemius showed a single peak of activity recorded during push-off. The medial hamstring showed its greatest activity during deceleration in the swing phase. Vastus lateralis demonstrated peak activity at the transition from swing to stance. The mean cadence was 106 steps per minute. Swing phase occupied 39.6% and stance phase 60.4% of the gait cycle.

Electromyographic temporal analysis of gait: hemiplegic locomotion.

The telemetered electromyographic (EMG) activity of quadriceps, hamstrings, triceps surae and pretibial muscles on the affected side of 20 adult hemiplegic subjects was examined during locomotion. The subjects ranged in age from 29 to 68 years (mean, 52.1). Duration of the lesions ranged from 1 month to 8 years: in 11 subjects the duration of the lesions ranged from 1 to 9 months (mean, 4.9 months), and in the remaining 9 subjects from 1 to 8 years (mean, 4 years 2 months). Shoes with five microswitches, two in the heel and three in the sole, were used to correlate the EMG activity with eight specific components of the gait cycle. The results of the study showed a loss of the phasic pattern associated with normal locomotion. The hemiplegic subjects showed the greatest activity in the period of midstance. Expressed as a percentage of the total cycle, the mean stance time of the paretic lower limb was 67% and the mean swing time was 33%. The unaffected lower limb showed a stance phase of 80% and a swing phase of 20%.