The locked-in syndrome (LiS) was broken down on the basis of neurological symptoms in 12 patients. The criteria of classical LiS are total immobility except for vertical eye movements and blinking. If any other movements are present one should consider the condition as incomplete LiS. Total immobility, including all eye movements, combined with signs of undisturbed cortical function in the EEG led to the concept of total LiS. The anatomical basis for this condition consists of lesions in both cerebral peduncles which interrupt the pyramidal and corticobulbar tracts, the supranuclear fibers for horizontal gaze and the postnuclear oculomotor fibers. As to the course, chronic and transient LiS have been described.

Study design: It has been previously demonstrated that sustained nonpatterned electric stimulation of the posterior lumbar spinal cord from the epidural space can induce stepping-like movements in subjects with chronic, complete spinal cord injury. In the present paper, we explore physiologically related components of electromyographic (EMG) recordings during the induced stepping-like activity. Objectives: To examine mechanisms underlying the stepping-like movements activated by electrical epidural stimulation of posterior lumbar cord structures. Materials and methods: The study is based on the assessment of epidural stimulation to control spasticity by simultaneous recordings of the electromyographic activity of quadriceps, hamstrings, tibialis anterior, and triceps surae. We examined induced muscle responses to stimulation frequencies of 2.2-50 Hz in 10 subjects classified as having a motor complete spinal cord injury (ASIA A and B). We evaluated stimulus-triggered time windows 50 ms in length from the original EMG traces. Stimulus-evoked compound muscle action potentials (CMAPs) were analyzed with reference to latency, amplitude, and shape. Results: Epidural stimulation of the posterior lumbosacral cord recruited lower limb muscles in a segmental-selective way, which was characteristic for posterior root stimulation. A 2.2 Hz stimulation elicited stimulus-coupled CMAPs of short latency which were approximately half that of phasic stretch reflex latencies for the respective muscle groups. EMG amplitudes were stimulus-strength dependent. Stimulation at 5-15 and 25-50 Hz elicited sustained tonic and rhythmic activity, respectively, and initiated lower limb extension or stepping-like movements representing different levels of muscle synergies. All EMG responses, even during burst-style phases were composed of separate stimulus-triggered CMAPs with characteristic amplitude modulations. During burst-style phases, a significant increase of CMAP latencies by about 10 ms was observed. Conclusion: The muscle activity evoked by epidural lumbar cord stimulation as described in the present study was initiated within the posterior roots. These posterior roots muscle reflex responses (PRMRRs) to 2.2 Hz stimulation were routed through monosynaptic pathways. Sustained stimulation at 5-50 Hz engaged central spinal PRMRR components. We propose that repeated volleys delivered to the lumbar cord via the posterior roots can effectively modify the central state of spinal circuits by temporarily combining them into functional units generating integrated motor behavior of sustained extension and rhythmic flexion/extension movements. This study opens the possibility for developing neuroprostheses for activation of inherent spinal networks involved in generating functional synergistic movements using a single electrode implanted in a localized and stable region.

In 1999, a Task Force on Mild Traumatic Brain Injury (MTBI) was set up under the auspices of the European Federation of Neurological Societies. Its aim was to propose an acceptable uniform nomenclature for MTBI and definition of MTBI, and to develop a set of rules to guide initial management with respect to ancillary investigations, hospital admission, observation and follow‐up.

We hypothesized that the formation of foam cells and fatty streaks requires a postsecretory oxidative modification of lipoproteins that targets them for rapid uptake by macrophages. Lipid peroxidation may in part depend on the concentration of tissue iron, one of the major oxidants in vivo. We analyzed the relation between sonographically assessed carotid atherosclerosis and body iron stores in a population sample of 847 men and women aged 40 to 79 years. In a logistic regression analysis adjusting for age, sex, and all major vascular risk markers, ferritin emerged as one of the strongest indicators of carotid artery disease in both sexes (40 to 59 R ecent advances in understanding vascular lipid metabolism have yielded new insights into the mechanisms that determine endothelial injury and plaque development. In particular, the postseCTetory modification of lipoproteins has attracted increasing attention.1 Oxidative changes in the surface structure of low-density lipoproteins enhance the affinity to macrophage scavenger receptors, giving rise to the formation of foam cells and fatty streaks. -3 Prominent iron stores may promote lipid peroxidation and accelerate atherogenesis and cardiovascular disease. This hypothesis recently received empirical support from a large population study (Kuopio Ischaemic Heart Disease Risk Factor Study) that demonstrated an enhanced risk of myocardial infarction in middle-aged men with elevated concentrations of serum ferritin.4 These findings, however, do not necessarily imply a causal role of iron in atherogenesis. Enhanced reperfusion injury, direct cardiotoxicity of high myocardial iron deposits, vasospastic events, and increased blood viscosity may also be significant. 57 We designed the current study to investigate the relation between sonographically assessed carotid atherosclerosis and body iron stores as estimated by serum ferritin. 89 We also investigated physiologically normal iron status and addressed sex differences in the amount of body iron and the manifestation of atherosclerotic vascular disease.Received November 30, 1993; revision accepted June 29, 1994. From the Department of Neurology (S.K., F.A., F.G., F.S., J.W.) and Department of Laboratory Medicine (EJ.), University Ginic Innsbruck (Austria), and the Department of Internal Medicine, Hospital of Bruneck (G.E., A.M., G.R., F.O.) (Italy).Correspondence to Dr J. Willeit, Department of Neurology, University of Innsbruck, AnichstraBe 35, A-6020 Innsbruck, Austria.years; odds ratio, 1.54 per 100 /xg/L; P<.001). The predictive significance of ferritin was found to be synergistic with that of hypercholesterolemia. Variations in body iron stores between sexes may partly explain evident sex differences in the expression of carotid atherosclerosis. In the elderly (£60 years) the predictive significance of ferritin was found to decrease parallel to that of apolipoprotein B. The current study suggests a possible role of body iron in early atherogenesis. (ArUriosder Thromb. 1994;14:1625-1630 Key Words • carotid ...

Objectives: The purpose of this study was to evaluate the eect of spinal cord stimulation (SCS) on severe spasticity of the lower limbs in patients with traumatic spinal cord injury (SCI) under close scrutiny of the site and parameters of stimulation. Materials and methods: Eight SCI patients (four women, four men) were included in the study. Levels of spasticity before and during stimulation were compared according to a clinical rating scale and by surface electrode polyelectromyography (pEMG) during passive¯exion and extension of the knee, supplemented by a pendulum test with the stimulating device switched either on or o over an appropriate period. Results: Both the clinical and the experimental parameters clearly demonstrated that SCS, when correctly handled, is a highly eective approach to controlling spasticity in spinal cord injury subjects. The success of this type of treatment hinges on four factors: (1) the epidural electrode must be located over the upper lumbar cord segment (L1, L2, L3); (2) the train frequency of stimulation must be in the range of 50 ± 100 Hz, the amplitude within 2 ± 7 V and the stimulus width of 210 ms; (3) the stimulus parameters must be optimized by clinically assessing the eect of arbitrary combinations of the four contacts of the quadripolar electrode; and (4) amplitudes of stimulation must be adjusted to dierent body positions. Conclusions: Severe muscle hypertonia aecting the lower extremities of patients with chronic spinal cord injuries can be eectively suppressed via stimulation of the upper lumbar cord segment. Spinal Cord (2000) 38, 524 ± 531