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The Canada Health Act appears to me to be clear in both its intent and purpose.[1][1] It leaves little room for the establishment of alternative providers, essentially only for noninsured purposes (routine magnetic resonance imaging not being one of them). If the government is serious, then it needs

To assess the clinical effectiveness of the Odstock dropped foot stimulator by analysis of its effect on physiological cost index (PCI) and speed of walking. This functional electrical stimulation (FES) device stimulates the common peroneal nerve during the swing phase of gait.A retrospective study of patients who had used the device for 4 1/2 months.One hundred fifty-one patients with a dropped foot resulting from an upper motor neuron lesion.A medical physics and biomedical engineering department of a district general hospital specializing in the clinical application of FES and a neurophysiotherapy department at a separate hospital.Changes in walking speed and effort of walking, as measured by PCI over a 10-meter course.There was a 92.7% compliance with treatment. Stroke patients showed a mean increase in walking speed of 27% (p.01) and reduction in PCI of 31% (p.01) with stimulation, and changes of 14% (p.01) and 19% (p.01), respectively, while not using the stimulator. Multiple sclerosis patients gained similar orthotic benefit but no "carry-over."The measured differences in walking with and without stimulation were statistically significant in the stroke and multiple sclerosis groups. In this study use of the stimulator improved walking. Those with stroke demonstrated a short-term "carry-over" effect.

Objective: To determine the perceived benefit, pattern and problems of use of the Odstock Dropped Foot Stimulator (ODFS) and the users' opinion of the service provided. Design: Questionnaire sent in a single mailshot to current and past users of the ODFS. Returns were sent anonymously. Setting: Outpatient-based clinical service. Subjects: One hundred and sixty-eight current and 123 past users with diagnoses of stroke (CVA), multiple sclerosis (MS), incomplete spinal cord injury (SCI), traumatic brain injury (TBI) and cerebral palsy (CP). Intervention: Functional electrical stimulation (FES) to correct dropped foot in subjects with an upper motor neuron lesion, using the ODFS. Main outcome measures: Purpose-designed questionnaire. Results:• Return rate 64% current users (mean duration of use 19.5 months) and 43% past users (mean duration of use 10.7 months). • Principal reason cited for using equipment was a reduction in the effort of walking. • Principal reasons identified for discontinuing were an improvement in mobility, electrode positioning difficulties and deteriorating mobility. • There were some problems with reliability of equipment. • Level of service provided was thought to be good. Conclusion: The ODFS was perceived by the users to be of considerable benefit. A comprehensive clinical follow-up service is essential to achieve the maximum continuing benefit from FES-based orthoses.

Erythromelalgia is not a commonly recognized or diagnosed condition that affects the lower extremities. The first reported case was in 1878, when Mitchell suggested the term "erythromelalgia." This condition is characterized by a burning sensation with erythema of the involved extremity. When the extremity is lowered, or heat is applied, the pain is intensified. The application of cold or elevation of the extremity will have the opposite effect of decreasing the pain. Erythromelalgia is classified as primary or idiopathic if there is no accompanying disease process. Secondary erythromelalgia is associated commonly with myeloproliferative syndrome-related thrombocythemia, and is mostly evident in adult onset of the condition. Treatment for adults with erythromelalgia includes a single daily dose of aspirin, but children who have no associated underlying disorder find little to no relief with acetylsalicylic acid.

The auditory brainstem evoked potential (ABEP) is probably the potential with the most names and acronyms in the field. The potential is also commonly known as the auditory brainstem response (ABR), the auditory evoked potential (AEP), the brainstem auditory evoked potential (BAEP), and the short-latency AEP [1]. However, despite its large number of names, it is one of the simpler potentials recorded in the operating room. Auditory stimulation results in a train of evoked potentials that extend for a prolonged period of time (up to 250 ms). However in the operating room, we are predominantly concerned with the short-latency, subcortical responses, often termed the short-latency auditory evoked potentials. Colleagues in audiology use the longer latency potentials in their assessment of hearing [2].

The authors conducted a study to determine the neurophysiological capacity of the neural placode in spina bifida neonates and to determine if the spinal nerve roots in these neonates had normal stimulation.The authors present a case series of 2 neonates born with open neural tube defects who underwent neural tube closure within 24 hours of birth. Neurophysiological monitoring and electrical stimulation of the placode and nerve roots was performed before and after closure of the neural tube.Stimulation of nerve roots resulted in evoked electromyographic responses in distinct muscle groups, indicative of the myotome innervation pattern. Stimulation threshold did not change significantly after closure of the placode. Stimulation within the placode generated an alternating pattern of activity in the left and right legs.Closure of the neural tube did not affect the stimulation threshold of the nerve roots, which remained easily excitable. The viability of the nerve roots suggests that they may be candidates for neural prostheses in the future. The neural placode contains basic neural elements for generating a locomotor-like pattern in response to tonic neural inputs.

Afferent inputs are known to modulate the activity of locomotor central pattern generators, but their role in the generation of locomotor patterns remains uncertain. This study sought to investigate the importance of afferent input for producing bilateral, coordinated hindlimb stepping in adult cats. Following complete spinal transection, animals were trained to step on the moving belt of a treadmill until proficient, weight-bearing stepping of the hindlimbs was established. Selective dorsal rhizotomies of roots reaching various segments of the lumbosacral enlargement were then conducted, and hindlimb stepping capacity was reassessed. Depending on the deafferented lumbosacral segments, stepping was either abolished or unaffected. Deafferentation of mid-lumbar (L3/L4) or lower-lumbar (L5-S1) segments abolished locomotion. Locomotor capacity in these animals could not be restored with the administration of serotonergic or adrenergic agonists. Deafferentation of L3, L6, or S1 had mild effects on locomotion. This suggested that critical afferent inputs pertaining to hip position (mid-lumbar) and limb loading (lower-lumbar) play an important role in the generation of locomotor patterns after spinal cord injury.

There is an idea abroad in Qumran scholarship that exegesis in Dead Sea sectarian literature is generically scribal. It is commonly supposed that scribes are responsible for the literary content of Dead Sea sectarian literature. The scribes of Qumran are deemed naturally to have been able to compare multiple copies of a work in their library or their scriptorium. The task of producing a working definition of a Second Temple Jewish scribe is complicated, firstly, by the existence of two distinct approaches to constructing ancient Jewish scribes, and secondly, by a general lack of distinction between scribes and copyists, that is, exegetes and mere technicians. A reasonable case can be made for the existence of a generically scribal exegesis in biblical manuscripts. The influential studies of Ann Matthews Martin and Emanuel Tov focus on surviving ancient scribal realia , that is, material manuscript copies preserving the vestiges of ancient writers work. Keywords: ancient Jewish scribes; ancient scribal realia ; Dead Sea sectarian literature; Qumran scholarship; scribal exegesis

The Odstock dropped foot stimulator (ODFS) is a foot switch controlled single channel neuromuscular stimulator for correction of dropped foot. Following a randomized controlled trial, the ODFS was recommended for use in the United Kingdom's National Health Service and a clinical service established. The patient performance was assessed by measurement of walking speed over 10 m, physiological cost index (PCI), and by questionnaire. After 4.5 months stroke patients (n = 111) showed a mean increase in walking speed of 27% and reduction in PCI of 31% with stimulation and changes of 14% and 19%, respectively, unassisted. Multiple sclerosis patients (n = 21) gained similar orthotic benefit but no carry over. The principal reason cited for using the equipment was that it reduced the effort of walking. The principal reasons identified for discontinuing were an improvement in mobility, electrode positioning difficulties, and deteriorating mobility. A comprehensive clinical follow-up service is essential to achieve the maximum continuing benefit from FES based orthosis.

Intensive treadmill training after incomplete spinal cord injury can improve functional walking abilities. To determine the changes in muscle activation patterns that are associated with improvements in walking, we measured the electromyography (EMG) of leg muscles in 17 individuals with incomplete spinal cord injury during similar walking conditions both before and after training. Specific differences were observed between subjects that eventually gained functional improvements in overground walking (responders), compared with subjects where treadmill training was ineffective (nonresponders). Although both groups developed a more regular and less clonic EMG pattern on the treadmill, it was only the tibialis anterior and hamstring muscles in the responders that displayed increases in EMG activation. Likewise, only the responders demonstrated decreases in burst duration and cocontraction of proximal (hamstrings and quadriceps) muscle activity. Surprisingly, the proximal muscle activity in the responders, unlike nonresponders, was three- to fourfold greater than that in uninjured control subjects walking at similar speeds and level of body weight support, suggesting that the ability to modify muscle activation patterns after injury may predict the ability of subjects to further compensate in response to motor training. In summary, increases in the amount and decreases in the duration of EMG activity of specific muscles are associated with functional recovery of walking skills after treadmill training in subjects that are able to modify muscle activity patterns following incomplete spinal cord injury.

Following spinal cord injury (SCI), prolonged muscle spasms are readily triggered by brief sensory stimuli. Animal and indirect human studies have shown that a substantial portion of the depolarization of motoneurons during a muscle spasm comes from the activation of persistent inward currents (PICs). The brief (single pulse) sensory stimuli that trigger the PICs and muscle spasms in chronically spinalized animals evoke excitatory post-synaptic potentials (EPSPs) that are broadened to more than 500 ms, the duration of depolarization required to activate a PIC in the motoneuron. Thus, in humans, we investigated if post-synaptic potentials (PSPs) evoked from brief (1 year), incomplete SCI. In non-injured controls, a single shock or brief (

Transcranial direct current stimulation (tDCS) of the human motor cortex at an intensity of 1 mA has been shown to be efficacious in increasing (via anodal tDCS) or decreasing (via cathodal tDCS) the excitability of corticospinal projections to muscles of the hand. In this study, we examined whether tDCS at currents of 2 mA could effect similar changes in the excitability of deeper cortical structures that innervate muscles of the lower leg. Similar to the hand area, 10 min of stimulation with the anode over the leg area of the motor cortex increased the excitability of corticospinal tract projections to the tibialis anterior (TA) muscle, as reflected by an increase in the amplitude of the motor evoked potentials (MEPs) evoked by transcranial magnetic stimulation. MEP amplitudes recorded at rest and during a background contraction were increased following anodal tDCS and remained elevated at 60 min compared to baseline values by 59 and 35%, respectively. However, in contrast to the hand, hyperpolarizing cathodal stimulation at equivalent currents had minimal effect on the amplitude of the MEPs recorded at rest or during background contraction of the TA muscle. These results suggest that it is more difficult to suppress the excitability of the leg motor cortex with cathodal tDCS than the hand area of the motor cortex.

Objective: To determine the mechanisms underlying the mirroring of distal movements in both upper and lower limbs present in one individual from birth. Methods: Transcranial magnetic stimulation (TMS), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), voluntary and reflexly evoked electromyograms (EMG) and force measurements were used to obtain information about the motor pathways responsible for the mirror movements. Results: MRI showed a significant loss of brain tissue from one hemisphere and fMRI indicated a significant functional reorganization had taken place. An obligatory mirroring of voluntary movement on the sound side occurs on the affected side, but some independent movement can be produced on the affected side, if enabled by weak contractions on the sound side. TMS mapping revealed bilateral projections from one hemisphere and virtually absent projections from the primary motor cortex of the other hemisphere. Spinal reflexes were restricted to the stimulated side. Transcortical reflexes were evoked bilaterally from the sound side, but not from the affected side. Conclusions: The physiological and imaging data are consistent with a mirroring from the intact motor cortex via the supplementary motor area. Significance: Mirror movements in this individual represent a major cortical reorganization and a partial solution to the neonatal loss of substantial amounts of brain tissue. 2007 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

The physiological control of stepping is governed both by signals descending from supraspinal systems and by circuitry residing within the lumbosacral spinal cord. The goal of this study was to evaluate the capacity of physiologically based controllers to restore functional overground locomotion after neurological damage, such as spinal cord injury when used in conjunction with functional electrical stimulation. For this purpose we implemented and tested two controllers: 1) an intrinsically timed system that generated a predetermined rhythmic output and 2) a sensory-based system that used feedback signals to make appropriate transitions between the unloaded (flexion) and loaded (extension) phases of the gait cycle. A third controller, a combination of the intrinsically timed and sensory-driven controllers, was implemented and two sessions were conducted to demonstrate the functional advantages of this approach. The controllers were tested in anesthetized cats, implanted with intramuscular electrodes in six major extensor and flexor muscles of the hindlimbs. The cats were partially supported on a sliding trolley that was propelled by the hindlimbs along a 2.5-m instrumented walkway. Ground reaction forces and limb positions were measured by force plates in the walkway and by accelerometers secured to the legs of the cat, respectively. The controllers were used to generate patterns of stimulation that would elicit alternating flexor (swing) and extensor (stance) movements in the hindlimbs. Using either the intrinsically timed or sensory-driven controllers, the cats were able to travel a distance of 2.5 m, taking five to 12 steps. Functional stepping sequences were more easily achieved using the intrinsically timed controller as the result of a lower sensitivity to the selection of initial stimulation parameters. However, unlike the sensory-driven controller, the intrinsically timed controller was unable to adjust to overcome walkway resistance and muscle fatigue. Neither system was consistently able to ensure load-bearing stepping. Therefore we propose the use of a “combined controller” that relies heavily on intrinsic timing but that can be reset based on sensory signals. A combined controller such as this one may provide the best solution for restoring robust overground locomotion after spinal cord injury.

We thank Drs. Wilkinson and Kaufmann for their interest in our study1 and their considered response to it. We thank them for highlighting the Canadian Association of Neurophysiological Monitoring course through the Michener Institute in Toronto, and point out that a training scheme has been approved by the Alberta College of Medical Diagnostic and Therapeutic Technologists (www.acmdtt.ca) at the University of Alberta Hospital, and is also being used in Saskatoon. We agree that patient safety can be improved through the use of highly skilled, well-trained individuals in the operating room. We differ from Wilkson and Kaufmann with regard to the issue of interpretation, however. In our view, the IOM situation should not be different from that in the outpatient laboratory. A skilled individual performs the technical aspect of the task and provides an impression of the test. The test itself is interpreted by a clinical practitioner. The patient’s physician (most responsible physician; MRP) integrates this interpretation with other clinical signs and knowledge to form a diagnosis and treatment plan. Indeed, many reports from the electroencephalography laboratory (or the radiology department, which also follows this model) end with the statement that “clinical correlation is required.” In the intraoperative neuromonitoring (IOM) setting we see this as being a Certification of Neurointraoperative Monitoring (or a Canadian equivalent when/if available) technologist placing electrodes, running the tests and providing an impression and a doctor or clinically trained doctoral-level neurophysiologist providing real-time interpretation to the surgeon (MRP). It is the surgeon’s responsibility to decide what to do with the interpretation. In our survey most surgeons did not want to provide interpretation of the data, and we believe most are not suitably trained or experienced to do so. Although our practice patterns differ from those in the United States it is worth noting that the American Medical Association (Policy H-410.957) states that IOM is the practice of medicine and that its interpretation requires a suitably trained individual (Policy H-35.971). The Canadian Medical Association does not have equivalent policies, but also does not define what is the practice of medicine.

TPS3093 Background: Enhancing T-cell function in cancer patients (pts) through T-cell co-stimulatory pathways such as OX40 has the potential to overcome cancer-induced immune suppression. MEDI6469,...

TPS7103 Background: Myelodysplastic syndrome (MDS) is a group of clonal bone marrow disorders associated with an increased risk of transformation to acute myeloid leukemia (AML). Despite recent pro...

Intermuscular coherence analysis can be used to assess the common drive to muscles. Coherence in the beta-frequency band (15-35 Hz) is thought to arise from common cortical sources. Intermuscular coherence analysis is a potentially attractive tool for the investigation of motor cortical excitability changes because it is non-invasive and can be done relatively quickly. We carried out this study to test the hypothesis that intermuscular coherence analysis was able to detect cortical excitability changes in healthy subjects following transcranial direct current stimulation (tDCS). tDCS has been shown to increase (anodal stimulation) or decrease (cathodal stimulation) the size of the muscle potential evoked by TMS. We found that anodal tDCS caused an increase in motor evoked potential (MEP) size that was paralleled by an increase in beta-band intermuscular coherence. Similarly, the reduction in MEP size produced by cathodal tDCS was paralleled by a reduction in beta-band intermuscular coherence, while sham stimulation did not result in any change in either MEP amplitude or beta-band intermuscular coherence. The similar pattern of change observed for MEP and intermuscular coherence may indicate similar mechanisms of action, although this cannot be assumed without further investigation. These changes do suggest that at least some of the action of tDCS is on cortical networks, and that combined tDCS and intermuscular coherence analysis may be useful in the diagnosis of pathologies affecting motor cortical excitability.

In human spinal cord injury, the neuronal mechanisms mediating the improvement of locomotor function in response to intensive treadmill training are not well understood. In this study, we examined if such recovery is mediated, in part, by increases in residual corticospinal drive to muscles of the leg during walking. To do this, we measured the coherence of electromyogram (EMG) activity between two antagonist muscles (intermuscular coherence), specifically at frequencies between 24 and 40 Hz, which is thought to indicate common drive to two muscles from corticospinal inputs. In 12 subjects with incomplete spinal cord injury, intermuscular coherence was measured between hamstrings and vastus lateralis EMG that was activated during walking on a motorized treadmill. Before training, appreciable coherence in the 24–40 Hz frequency band was only present in subjects with moderate volitional motor strength in their leg muscles ( n = 8 subjects) compared with subjects with little or no leg muscle strength ( n = 4 subjects), reconfirming that 24–40 Hz frequency coherence is likely mediated by common supraspinal inputs. After training, increases in 24–40 Hz coherence only occurred in the eight subjects with moderate leg muscle strength who also exhibited improvements in locomotor recovery as assessed by the 21 point WISCI II scale (termed responders). In contrast, development of intermuscular coherence in the 24–40 Hz frequency band did not occur in the four subjects with absent or weak muscle strength. These subjects also did not improve in their locomotor ability as reflected in unchanging WISCI II scores (termed nonresponders). Lower-frequency coherence (5–18 Hz), which is thought to contain common drive from spinal inputs, did not change in either group. In a subset of subjects that were previously assessed with transcranial magnetic stimulation (TMS) before and after training ( n = 5 responders and 3 nonresponders), there was a significant and positive relationship between increases in 24–40 Hz coherence and increases in evoked muscle responses to TMS of the primary motor cortex. Taken together, increases in higher-frequency EMG coherence in subjects with residual voluntary muscle strength and its parallel relation to changes in TMS-evoked responses provides further evidence that improvements in locomotor function from treadmill training are mediated, in part, by increases in corticospinal drive to muscles of the leg during walking.

Primary orthostatic tremor is characterized by 16-Hz motor activity that is coherent between muscles. It has been suggested that this tremor originates in the brain. This view is questioned by findings from a patient with complete paraplegia who experiences intermittent leg spasms at rest. The EMG activity within the spasms showed a 16-Hz component that was coherent between muscles unilaterally and bilaterally. This raises the possibility that the spinal cord could be the source of orthostatic tremor.

Statistically valid detection of evoked responses from magnetoencephalographic (MEG) sensors is complicated by temporal autocorrelation. By decorrelating time series and transforming them toward normality, the discrete wavelet transform (DWT) allows the analyst to test for an association between stimulus and sensor time series with appropriate degrees of freedom. Eswaran et al. (Neurosci. Lett. 2002a;331:128–32) used a 151-channel fetal MEG system to obtain serial recordings from 10 pregnant subjects. There were 3–8 recordings per subject. In each recording session, the fetus was stimulated by 500 Hz and 1 KHz tones with a relative frequency of 80–20%, respectively. In this new analysis of the same data, the fetal MEG signals were compared to two different stimulus waveforms: the frequent tone and the Novel stimulus, defined as a change in pitch. WaveDetect was developed to determine whether there was a significant association between the stimuli and the MEG traces. This test is performed by taking the DWT of each series and then computing the Spearman correlation between the wavelet coefficients for an appropriate scale. A significant response (i.e., correlated stimulus–sensor pair) was detected from each patient. This result suggests that the combination of serial recordings and WaveDetect may ensure reliable detection of auditory evoked responses.

Three paraplegics have been implanted with stimulators of the lumbar anterior roots. Twelve roots were trapped in slots, each with three electrodes, a central cathode and two anodes, but the anodes in all the slots were connected together to reduce the number of wires. Cross-talk between roots was observed at lower levels than expected. Cross-talk was assessed from the ratio of the root's threshold to the threshold of the contralateral response (expected ratio: 72). Two hypothetical reasons for this low ratio were: that the cathode current was not equally shared by the anodes; or that the contralateral responses were reflex. Experiments showed that neither explanation was valid. The ratio of the contralateral to ipsilateral threshold for individual slots (K(1)) was sometimes low because the ipsilateral threshold was high. By taking the ratio of the lowest contralateral response to lowest ipsilateral response, for all roots in each subject (K(2)), the ratio should approach the theoretical value. However, for the two subjects with small slots, it was 7.9 and 15.3, much less than 72, suggesting that the original theory was incorrect. Approximate calculations of the activation function suggest that the reason may be that roots which run close to a slot, but not through it, may pass through a virtual anode region outside the ends of the slots, and that anodal break stimulation in those regions causes the cross-talk. Our estimate is that this cross-talk would be expected to occur at intensities above 5.3 times the cathodal threshold. If the roots are stimulated in pairs, below the levels of cross-talk, experimental results show that the moments obtained in response are additive to within 5%.

Cutaneomuscular reflexes have been recorded from the first dorsal interosseous muscle during a sustained abduction of the index finger of 20 subjects (25 recordings) following stimulation of the digital nerves at the following frequencies: 2 Hz, 3 Hz, 5 Hz, 7 Hz and 9 Hz, presented in random order. Five hundred stimuli were given at each frequency. EMG was rectified and consecutive batches of 100 sweeps of each set of 500 responses were averaged time locked to the stimulus. All reflex components, E1, I1 and E2, exhibit habituation with the E1 component habituating the most and the I1 component the least. There was considerable variation in the rate of habituation between subjects. The rate of habituation was independent of the frequency of stimulation. Reflex responses were recorded from the triceps brachii muscle in eight subjects; this reflex response habituated at a faster rate than the E2 component recorded from the first dorsal interosseous muscle. These results are discussed in relation to the choice of stimulus parameters for the clinical testing of cutaneous reflexes. We conclude that it is important to consistently average the same number of responses.

In Reply .— I am pleased that the letter by Norton et al gives us the opportunity to clarify the significance and limitations of the findings of our study on the association between maternal use of selective serotonin reuptake inhibitors (SSRIs) during pregnancy and neonatal neurobehavior. As we described in our article, maternal depression during pregnancy is an important public health concern, with implications not only for the health of the mother but also for the health and development of the infant. Treatment of this condition has focused on mothers using SSRIs, with the assumption that these medications are safe for the developing fetus. Our concern is that this assumption is based on research that indicates that prenatal SSRI exposure has little or no impact on development, because exposed infants are born mostly of full birth weight, at full term, and show few physical anomalies. However, over the past 30 years, significant research literature has demonstrated that, in addition to these measures, neurobehavioral assessments provide a measure of …

To describe a consecutive series of children with laryngeal mobility disorders assessed by laryngeal electromyography (LEMG), to propose a grading system for LEMG findings, and to determine whether the LEMG grades correlate with requirement for tracheostomy.Retrospective, observational, uncontrolled study.A single pediatric otolaryngology practice.Children who had LEMG performed and a minimum follow-up of 3 months.Demographic characteristics, diagnoses, surgical procedures, number of LEMG procedures, and complications were obtained. The LEMG results from the thyroarytenoid and posterior cricoarytenoid muscles were graded 0 to 4 according to amplitude and relation to the phase of respiration. A correlation analysis between the need for tracheostomy and the baseline LEMG score as well as a multivariable analysis to determine the predictors of requirement for tracheostomy were performed.Between April 28, 2008, and November 2, 2011, 43 LEMG procedures were performed on 23 patients (13 girls; mean [SD] age, 1.5 [2.85] years). Eight required tracheostomy. Among the 23 patients, 16 had laryngeal paralysis (11 bilateral, 5 unilateral), 4 had laryngeal dyskinesia, and 3 had miscellaneous conditions. Fourteen had secondary large airway lesions, and 14 had a nonairway diagnosis that affected respiration. The overall LEMG results correlated negatively with requirement for tracheostomy (r = -0.4; P.05) and were 86.36% accurate compared with endoscopy. No predictors for tracheostomy were identified.The LEMG grading was accurate and correlated with the requirement for tracheostomy. Combined with endoscopy, the grading may help better characterize laryngeal mobility disorders.

The act of walking seems so simple when we perform it; we just put one leg in front of the other, and most of us are able to do other things at the same time. Watching children who are learning to walk, however, provides us with some insights into how complicated the whole process is and the tremendous level of sensori-motor integration required for safe walking. For a number of years we have known that infants can step on a moving treadmill belt before they can walk independently (Yang & Gorassini, 2006). Adults with complete spinal cord injuries can also be trained to step on a moving treadmill belt (Yang & Gorassini, 2006) and this has provided some of the strongest evidence to date for the existence of human spinal central pattern generators (Dietz, 2003). However, for over-ground walking a spinal pattern generator does not appear to be sufficient. Supraspinal control is needed to provide both the drive for locomotion as well as the coordination to negotiate a complex environment. In this issue of The Journal of Physiology, Petersen et al. (2010) describe a series of recordings made on children while they walk on a treadmill at a self-selected pace and while they perform a static ankle dorsiflexion. Using the technique of intramuscular coherence they examined changes in common drive from the motor cortex to the tibialis anterior muscle. This method is an elegant approach to studying nervous system function. Surface EMG recordings that are entirely non-invasive can be used to obtain information concerning the neural drive that produces an action. Most commonly, recordings for coherence analysis have been made from pairs of muscles, such as in our study of incomplete spinal cord-injured subjects (Norton & Gorassini, 2006). Recordings from two sites of the same muscle, as used in this study of children, are more suited to this analysis than pairs of muscles. Neural drive to two portions of a muscle is likely to be higher than to two independent muscles, even if they act synergistically. Care must be taken to avoid cross-talk between the electrode pairs but this group have previously shown techniques that avoid this problem (Hansen et al. 2005). Although many techniques exist for assessing the neural control of movement, such as reflex studies and motor-evoked potentials, a big advantage of the coherence approach is that it does not perturb the system. This method assesses the control of the movement as it happens, rather than the prior state or readiness of the system (Nielsen, 2002). There are shortcomings, however; in particular we are left to wonder about the remaining non-coherent activity. How much is lost as an artifact of the analysis technique and how much represents non-coherent neural drive is uncertain. We do not know the true maximum coherence if all drive came from a single corticospinal origin. For instance, at 24 Hz the highest level of coherence is well under 0.5 and in many instances and frequencies the coherence is below 0.1, potentially leaving up to 90% of the drive at that frequency of unknown origin. What is remarkable in the study by Petersen et al. (2010) is the relationship between the age of the subject and the coherence in the β-band during static contractions and γ-band during walking. These clear age-related differences indicate that the neural drive to the movement changes with age and could be considered as a marker for skill level in these relatively young children. By kinematic measures, these children appeared to have increased their skill level, as evidenced by reduced movement variability. Previous studies have shown changes in coherence with visuo-motor skill learning for this muscle (Perez et al. 2006) and others (Semmler et al. 2004). Changes in motor unit synchrony during development have also been reported (James et al. 2008) but this is the first study to examine the changes during a functional, lower-limb task such as walking without overt motor training. It is yet to be determined whether the developmental increase in coherence relates to a maturation of functional coordination within the corticospinal tract or this neural drive displacing non-cortical drive to the muscle.

Background Prior research has shown that resources have an impact on birth outcomes. In this paper we ask how combinations of telemedical and hospital-level resources impact transports of mothers expecting very low birth weight (VLBW) babies in Arkansas. Methods Using de-identified birth certificate data from the Arkansas Department of Health, data were gathered on transports of women carrying VLBW babies for two six-month periods: a period just before the start of ANGELS (12/02-05/03), a telemedical outreach program for high-risk pregnancies, and a period after the program had been running for six months (12/03-05/04). For each maternal transport, the following information was recorded: maternal race-ethnicity, maternal age, and the birth weight of the infant. Logistic regression was used to assess the relationship between the predictors (telemedicine, hospital level, maternal characteristics) and the probability of a transport. Results Having a telemedical site available increases the probability of a mother carrying a VLBW baby being transported to a level III facility either before or during birth. Having at least a level II nursery also increases the chance of a maternal transport. Where both level II nurseries and telemedical access are available, the odds of VLBW maternal transports are only modestly increased in comparison to the case where neither is present. At the individual level, Hispanic mothers were less likely to be transported than other mothers, and teenaged mothers were more likely to be transported than those 18 and over. A mother's being Black or being over 35 did not have an impact on the odds of being transported to a level III facility. Conclusion Combinations of resources have an impact on physician decisions regarding VLBW transports and are interpretable in terms of the capacity to diagnose and absorb risk. We suggest a collegial review of transport patterns and birth outcomes from areas with different levels of resources as a vehicle for moving the entire system of care forward over time. With such an evidence-based review in place, the collegial relations among level III specialists and obstetricians from around the state can, over time, develop workable protocols for when and how level III facilities should be involved.