Kinematic and qualitative analysis of lower-extremity movements in preterm infants with brain lesions. (65/4477)

BACKGROUND AND PURPOSE: The purposes of this study were to evaluate the effects of preterm birth, severe brain lesions, and postterm age on kicking movements of young infants and to compare the prognostic value of kinematic analysis of kicking with a qualitative assessment of infants' spontaneous movements. SUBJECTS: The subjects were 12 full-term infants without brain injury, 12 low-risk preterm infants without brain injury, and 11 preterm infants with severe brain lesions (periventricular leukomalacia). METHODS: Videotape recordings of each infant's motor behavior in a supine position were made at 1 and 3 months postterm age. Kicking frequency, temporal organization of the kick cycle, coordination among different joints, and interlimb coordination were measured. A qualitative assessment for lower-extremity movements and a Gestalt judgment of general movement quality according to Prechtl's method were made from the same videotape recordings. RESULTS: Kinematic analysis showed only mild differences among the 3 groups of infants. Qualitative assessment of the lower-extremity movements, however, showed that preterm infants with brain lesions, and particularly those who later were found to have cerebral palsy, consistently had fewer segmental movements of the foot and abnormal general movements at both ages. CONCLUSION AND DISCUSSION: The data suggest that the mechanisms responsible for kicking movements in newborns and young infants do not appear to be influenced by the extrauterine environment or by brain lesions, at least at the ages studied. Qualitative assessment of lower-extremity and general movements seems to be more appropriate for clinical purposes.  (+info)

Knee-heel length measurement in healthy preterm infants. (66/4477)

AIM: To examine the reproducibility of crown-heel length measurement; the precision and reproducibility of knee-heel length measurement; and the association between the two in healthy preterm infants. METHODS: Paired crown-heel and knee-heel lengths were measured on 172 occasions by three observers in 43 preterm infants between 205 and 458 days of postconceptional age. RESULTS: Crown-heel length (CHL) measurement was highly reproducible, with a coefficient of variation (CV) of 0.41%. Knee-heel length (KHL) measurement was relatively precise (CV 0.78%), but less reproducible (intra-observer CV 1.77%, intra-observer CV 2.11%), especially in larger infants. The association between KHL and CHL was not consistent and varied with age. KHL was a poor predictor of CHL, with a 95% predictive interval of +/- 27.5 mm. CONCLUSIONS: KHL was less reproducible than CHL, especially in larger infants, and a poor predictor of CHL.  (+info)

Angiographic runoff score as a predictor of outcome following femorocrural bypass surgery. (67/4477)

OBJECTIVE: to evaluate the efficacy of the revised ad hoc scoring system in predicting the outcome of femorocrural bypass surgery. DESIGN: retrospective study. MATERIALS AND METHODS: seventy-seven infrainguinal bypass procedures to the crural arteries were performed in 69 patients with critical leg ischaemia. Preoperative angiographic findings were graded according to the revised ad hoc scoring system and other preoperative angiographic measures. RESULTS: the revised ad hoc scores were valuable in predicting the outcome of these grafts. The status of the outflow artery throughout its length had a great impact on the long-term outcome in terms of secondary patency, leg salvage, patients alive with legs, and survival rates. In situ autogenous saphenous grafts achieved the best immediate and long-term results. CONCLUSIONS: the revised ad hoc angiographic scoring method is useful in predicting the outcome of patients undergoing femorocrural arterial reconstruction. Patients with an outflow artery completely open throughout its length had excellent long-term results.  (+info)

Studies in calf venous pump function utilizing a two-valve experimental model. (68/4477)

OBJECTIVES: to explore the hydrodynamic mechanisms involved in the regulation of ambulatory venous pressure. DESIGN: an experimental model of calf venous pump was constructed with collapsible tubes and valves. MATERIAL: the model consisted of a conduit and a pump with an intervening competent valve. Another valve that could allow reflux into the pump was mounted above the pump. METHODS: conduit pressure and recovery times were monitored under conditions of different degrees of ejection fraction and reflux into the pump. Model variables included using poorly compliant tubes for the pump, the conduit and for both the pump and conduit. RESULTS: the latex tube exhibited a non-linear volume-pressure relationship and a bi-modal regimen of compliance. This bestowed pressure-buffering properties. Ambulatory venous hypertension resulted when reflux beyond buffering capacity occurred. Substituting less compliant PTFE for latex at the pump had a relatively minor effect on post-ejection pressure and recovery times. Using PTFE at the conduit had a profound but divergent effect on both of these parameters. Conduit capacitance reduction had a similar effect. CONCLUSION: conduit elastance plays a significant role in the regulation of ambulatory venous pressure in this experimental model. The hydrodynamic principles illustrated by the model may enhance our understanding of the human calf venous pump.  (+info)

Cutaneous reflexes of the human leg during passive movement. (69/4477)

1. Four experiments tested the hypothesis that movement-induced discharge of somatosensory receptors attenuates cutaneous reflexes in the human lower limb. In the first experiment, cutaneous reflexes were evoked in the isometrically contracting tibialis anterior muscle (TA) by a train of stimuli to the tibial nerve at the ankle. The constancy of stimulus amplitudes was indirectly verified by monitoring M waves elicited in the abductor hallucis muscle. There was a small increase in the reflex excitation (early latency, EL) during passive cycling movement of the leg compared with when the leg was stationary, a result opposite to that hypothesized. There was no significant effect on the magnitude of the subsequent inhibitory reflex component (middle latency, ML), even with increased rate of movement, or on the latency of any of the reflex components. 2. In the second experiment, the two reflex components (EL and ML) elicited in TA at four positions in the movement cycle were compared with corresponding reflexes elicited with the limb stationary at those positions. Despite the markedly different degree of stretch of the leg muscles, movement phase exerted no statistically significant effect on EL or ML reflex magnitudes. 3. In the third experiment, taps to the quadriceps tendon, to elicit muscle spindle discharge, had no effect on the magnitude of ML in TA muscle. The conditioning attenuated EL magnitude for the first 110 ms. Tendon tap to the skin over the tibia revealed similar attenuation of EL. 4. The sural nerve was stimulated at the ankle in the fourth experiment. TA EMG reflex excitatory and inhibitory responses still showed no significant attenuation with passive movement. Initial somatosensory evoked potentials (SEPs), measured from scalp electrodes, were attenuated by movement. 5. The results indicate that there is separate control of transmission in Ia and cutaneous pathways during leg movement. This suggests that modulation of the cutaneous reflex during locomotion is not the result of inhibition arising from motion-related sensory receptor discharge.  (+info)

Nocturnal leg cramps in children: incidence and clinical characteristics. (70/4477)

The records of 2527 healthy children seen in an ambulatory care clinic were evaluated for nocturnal leg cramps in the preceding 12 months, frequency and duration of the cramps, whether the cramps affected one leg or both legs at a time, whether there was associated muscle cramps in feet, whether the cramps occurred when the child was awake or asleep, and whether there was residual tenderness in the affected muscles. Nocturnal leg cramps were present in 185 children for an overall incidence of 7.3%. Leg cramps were noted only in children aged > or = 8 years. The incidence increased at 12 years and peaked at 16 to 18 years of age. A majority (81.6%) of the affected children had nocturnal leg cramps 1 to 4 times per year. The mean duration of episodes was 1.7 minutes. Leg cramps were unilateral in 98.9% of cases and the ipsilateral foot also was involved in 18.9% of cases. One hundred thirty-five (73%) children had leg cramps while asleep, and the remaining 23 (12.4%) children had leg cramps in either state. Fifty-seven (30.8%) children had residual tenderness in the affected muscles. The mean duration of residual tenderness was 33.2 minutes (range: 2 minutes-1 day). We conclude that nocturnal leg cramps are common in children aged > 12 years. A majority of the affected children have leg cramps 1 to 4 times per year. The cramps are usually unilateral and occur when the children are asleep. Normal duration of the leg cramp is < 2 minutes. Residual tenderness is present in approximately 30% of the affected children. Residual tenderness, if present, usually lasts for half an hour.  (+info)

Semi-closed femoropopliteal thromboendarterectomy: a prospective study. (71/4477)

OBJECTIVE: to study the primary patency rates of angioscopically controlled thromboendarterectomies of the superficial femoral artery. DESIGN: prospective open study. METHODS: between 1990 and 1995, femoropopliteal thromboendarterectomies were performed in 63 patients (41 male, 22 female). Postoperative follow up was performed at 3- to 6-month intervals using non-invasive pressure measurements plus IVDSA at 1 year. RESULTS: eight patients were not evaluable, leaving 55 patients eligible for follow-up analysis. Postoperative complications (arteriovenous fistulas, false aneurysms) were observed in 5.4% of patients. Immediate perioperative occlusions occurred in 7.3%, early occlusions in 21.8% and late occlusions in 16.4% of all cases. The mean follow-up was approximately 57 months. The mean primary patency rate at 5 years was 44.5% (28 patients with the superficial femoral artery still open). Six patients died during the follow-up period. CONCLUSIONS: in contrast to the very positive reports found in recent literature, this prospective study shows a lower five-year patency rate for semi-closed femoropopliteal thromboendarterectomy than for bypass grafting. Thromboendarterectomy cannot be considered as a standard procedure in revascularisation of the femoropopliteal region.  (+info)

The correlation of early flow disturbances with the development of infrainguinal graft stenosis: a 10-year study of 341 autogenous vein grafts. (72/4477)

PURPOSE: Although duplex surveillance of infrainguinal bypass grafts is widely accepted, the optimal frequency and intensity of graft surveillance remains controversial. Earlier reports have suggested that grafts can be stratified into high-risk and low-risk groups based on the presence or absence of early graft flow disturbances. The purpose of this study was to provide long-term data in determining whether early graft flow disturbances detected by means of duplex scanning can predict the development of intrinsic vein graft stenosis. METHODS: We reviewed a series of patients undergoing prospective duplex graft surveillance after autogenous infrainguinal bypass grafting procedures from 1987 to 1997. Patients included in the study underwent at least one duplex scan within 3 months of graft implantation and were observed for a minimum of 6 months. Grafts were categorized as abnormal when a focal flow disturbance with a peak systolic velocity greater than 150 cm/s was identified within 3 months of graft implantation. RESULTS: Of 341 vein grafts in 296 patients who met inclusion criteria, 89 grafts (26%) required revision for intrinsic stenosis; the mean follow-up period was 35 months (range, 6 months to 10 years). Early flow disturbances were detected in 84 (25%) grafts. Grafts with early flow disturbances were more likely to ultimately require revision (43% vs 21%; P =. 0001) and required initial revision earlier (8 months vs 16 months; P =.019). Eighty-two percent of initial graft revisions occurred in the first 2 postoperative years; 69% occurred in the first year. However, an annual 2% to 4% incidence of late-appearing graft stenosis persisted during long-term follow-up. An additional 24 patients (7% of grafts) required an inflow or outflow reconstruction. CONCLUSION: Grafts with early postoperative flow disturbances detected by means of duplex scanning have nearly three times the incidence of graft-threatening stenosis and an earlier requirement for revision, when compared with normal grafts. This suggests that the biology and etiology of these lesions may differ. These data support not only aggressive efforts to detect early graft lesions to stratify grafts at highest risk, but also continued lifelong graft surveillance to detect late-appearing lesions, inflow and outflow disease progression, and maximize graft patency.  (+info)