Can osteopathic manipulative treatment modify the posture in elderly people? - a single-case study.

In this research, we have studied the consequences of three consecutive osteopathic manipulative sessions (OMS) on postural control by using a single-case research (SCR) design. The patient was a 77 years old woman complaining of altered balance and low-back pain. OMS were delivered by a single practitioner. The pain level was self-rated by using a visual Borg scale. The posture was monitored on a force platform. Postural parameters were deduced from the analysis of the centre of foot pressure (CoP) displacement. The statistical significance of the observed differences was established by using an SCR-related effect size indicator (i.e. Taunovlap). Our results indicate that OMS decrease the patient's pain, modify CoP mean position and decreased the length and velocity of the CoP displacement. Furthermore, modifications of the body oscillations were observed after OMS. This work indicates that OMS can improve body balance and that SCR allows the objective evaluation of the consequences of OMS.

Partial return of motor function in paralyzed legs after surgical bypass of the lesion site by nerve autografts three years after spinal cord injury.

Spinal cord injuries often result in irreversible loss of motor and somatosensory functions below the lesion level. Treatment is limited to physiotherapy aimed at compensating disability. We previously showed that re-establishment of tissue continuity can be achieved in animal models through nerve autografts implanted between the rostral spinal ventral horn and the caudal ventral roots. Rostral motor neuron axons could thus reach peripheral targets, leading to some return of motor function. We used a similar approach in a paraplegic patient with stabilized clinical states three years after spinal cord traumatic damage at the T9 level. Three segments from autologous sural nerves were implanted into the right and left antero-lateral quadrant of the cord at T7-8 levels, then connected to homolateral L2-4 lumbar ventral roots, respectively. Eight months after surgery, voluntary contractions of bilateral adductors and of the left quadriceps were observed. Muscular activity was confirmed by motor unit potentials in response to attempted muscle contraction. Motor-evoked potentials from these muscles were recorded by transcranial magnetic stimulation. These data support the hypothesis that muscles have been re-connected to supra-spinal centers through motor neurons located in the rostral stump of the damaged cord. They suggest that delayed surgical reconstruction of motor pathways may contribute to partial functional recovery.

Load compensation tasks evoke tremor in cerebellar patients: the possible role of long latency stretch reflexes.

'Tremor' is one of the clinical signs of cerebellar dysfunction. Its nature remains subject to debate, one hypothesis being that of a predominant role of peripheral afferences in its genesis. This study was designed to study whether load compensating tasks, evoking sudden stretch, and thus stimulation of peripheral afferences induced tremor in cerebellar patients. We study the kinematics and EMG pattern of a load compensating task which consists of maintaining a constant elbow position despite the onset and cessation of a 2 Nm torque loading the elbow flexors in eight cerebellar patients and six controls. Angular position and velocity, and EMG of the biceps and triceps are recorded at a sampling rate of 1 kHz. In normal subjects, trajectories are simple with little overshoot of the aimed position. EMG analysis shows a long latency stretch response (LLSR) which initiates a phasic and then tonic voluntary activity. In cerebellar patients, the two prominent cinematic features are hypermetria and tremor. The stretch response is of the same latency, but the EMG pattern is modified with bursts of activity related to the tremor. These results show severe perturbations of load compensating tasks in cerebellar patients. We discuss the possible role of the exaggeration of LLSR in both hypermetria and tremor.

Two patterns of results in polyneuropathies investigated with the H reflex. Correlation between proximal and distal conduction velocities.

The Hoffman (H) reflex of the soleus muscle has been used to study peripheral neurological disorders in 79 cases of chronic renal insufficiency prior to the initiation of haemodialysis, and in 94 cases of chronic alcoholism. In both groups, care was taken to ensure that the subjects examined could not be suspected of any other type of neuropathy. The results have been compared with those obtained in 42 normal subjects. The nerve conduction velocity in the reflex pathway was evaluated by an H index formula in which the conduction time (interval between M and H responses) is related to the length of the nervous pathway (a function of the subject's height). This method demonstrated a marked reduction in the conduction velocity of the proximal parts of the peripheral nerves, in both uraemic and alcoholic subjects. The maximal amplitude of the reflex response was evaluated in relation to the maximal amplitude of the direct motor response (H max/M max). It was shown that this ratio diminishes very greatly and very rapidly in the course of alcoholic polyneuritis, while, at comparable conduction velocities, the amplitude of the reflex response is much less changed in chronic renal insufficiency. These results prove that there is a noteworthy difference between uraemic and alcoholic polyneuropathy. Its significance is discussed in the context of currently knwon histopathological and electrophysiological data on the polyneuritides. From a practical point of view, the H reflex appears to be an effective tool for the investigation of peripheral neuropathy in man.

Early phase of vincristine neuropathy in man. Electrophysiological evidence for a dying-back phenomenon, with transitory enhancement of spinal transmission of the monosynaptic reflex.

Ten patients with Hodgkin's disease were examined before and after each administration of vincristine sulfate (2 intravenous injections of 1.4 mg/m2 of body surface during the first week of each month for 3 months). The motor conduction velocity of the peroneal nerve, the conduction velocity in palmar sensory fibres of the median nerve, and the conduction velocity in the H reflex pathway remained unchanged. The amplitude of distal muscle (extensor digitorum brevis) and sensory nerve (median) potentials decreased, while the maximal response of more proximal muscles (soleus) was not significantly modified. The soleus T response quickly decreased, although at the same time the H response was increased in the days following administration of vincristine. Thus the T/H ratio seems to be the only convenient electrophysiological method of evaluating the functional impairment of primary afferent distal segments. These results show that vincristine induces a transitory excitability enhancement of the monosynaptic reflex. It is suggested that the drug may cause an increase in the firing rate in proximal segments of injured Ia fibres. Apart from this phenomenon the electrophysiological results lead to the conclusion that vincristine induces distal axonal degeneration, similar to that in other toxic neuropathies (e.g. acrylamide or n-hexane) where a dying-back process has been clearly demonstrated.

[Digital vibration syndrome and carpal tunnel syndrome: possible neurophysiological differences?]. / Syndrome digital des vibrations et syndrome du canal carpien: deux entités electrophysiologiques différentes?

Workers using vibrating tools are exposed to vascular and nervous symptoms called vibration syndrome (VS); moreover, the same subjects show increased prevalence of possible carpal tunnel syndrome (CTS). To determine the diagnostic criteria of both syndromes, we studied clinical and neurophysiological signs and differences in 18 patients with VS and in 18 with CTS; neither group had any other pathologic symptoms. Clinical symptoms clearly distinguished the 2 groups of patients: Raynaud's phenomena were mainly observed in patients with VS (83% of cases), whereas Tinel's sign was found exclusively in patients with CTS (56% of cases). Neurophysiological results were qualitatively similar in both patients groups compared to control group results, showing a significant decrease in median motor and sensory nerve conduction velocities (NCV), a significantly higher motor distal latency and a lower nerve action potential amplitude. These group results and the scattering of interindividual results did not allow us to classify any given patient in one group or the other. Nevertheless, statistical analysis showed differences between the 2 patient groups: median abnormalities were more severe, especially as revealed by the abductor pollicis brevis electromyogram, in patients with CTS, whereas ulnar motor distal latency and motor and sensory NCV were abnormal, exclusively in 50% of patients with VS. These results lend support to the assumption that the mechanical and vascular mechanisms responsible for lesions in both groups of patients may differ in nature or occur in a different sequence.

Prognostic significance of electrophysiological investigations in stroke patients: somatosensory and motor evoked potentials and sympathetic skin response.

A prospective 3-month follow-up examination was carried out in 12 patients with supratentorial stroke. Motor evoked potentials (MEP), somatosensory evoked potentials (SEP) and sympathetic skin responses (SSR) were performed 1-7 days, 30 days and 3 months after stroke. The functional outcome measured by a daily activity index (Barthel index) was assessed 3 months after the stroke. There was a significant correlation between SEP and MEP results obtained for the first week and recovery of sensation and motility 3 months later. When initially normal, motor potentials evoked by transcranial magnetic stimulation had a significant predictive value for long-term functional outcome, whereas SEP and SSR did not. SSR present at the initial stage was correlated with the state of consciousness.

[Signal processing in electromyography: a review]. / Le traitement du signal en électromyographie: mise au point.

Automatic analysis of electromyography (EMG), signals, first operated in 1950 with analogic machines, steeply expanded from 1980 when fast computers and worthwhile programs became available. On-line measurement of response area and latency, averaging of low amplitude waves, fast sorting of motor unit potential shape parameters, computation of the "jitter" between two muscle fibers, turns/amplitude and spectral analysis of interferential pattern records, are some examples of programs currently offered in modern EMG machines. Other techniques are still reserved for research purposes: scanning EMG, decomposition of nerve and muscle compound potentials, measurement of the threshold and firing rate of motor units, trace analysis using tracking models. Finally, the credit for artificial intelligence systems (knowledge based systems, fuzzy logic, neuronal networks) is still not clearly stated.

Electrophysiological study of a case of diffuse loss of sweating with segmental hyperhidrosis associated with areflexia.

Electrophysiological investigations were carried out on a 43 year-old man with segmental hyperhidrosis in three radicular territories, generalized anhidrosis elsewhere and areflexia. A recurrent labial herpetic rash and a history of sweating disorders in his grandfather were the only associated clinical data. Sympathetic skin response was found to be absent in anhidrotic territories, including the hands and feet, although it was present in hyperhidrotic territories. Peripheral adrenergic sympathetic fibers evaluated by photoplethysmography were normally responsive, as were visceral vegetative regulations involved in cardiovascular control during postural changes or exercise. The present case is compared to the previously described Ross Syndrome, associating segmental hypohidrosis, areflexia and tonic pupils. Our results and observations in the literature are consistent with the occurrence of lesions affecting postganglionic cholinergic fibres of the sympathetic system.

[Are intraluminal electrodes reliable for recording myoelectric activity of the small intestine?]. / Les électrodes annulaires endoluminales sont-elles fiables pour le recueil de l'activité myoélectrique de l'intestin grêle?

In humans except for the postoperative state, electromyographic activity of the small bowel can only be recorded with intraluminal electrodes. The aim of this study was to validate the use of intraluminal electrodes in pigs by comparing the signal recorded from such electrodes to those recorded with surgically implanted electrodes. A polyethylene probe equipped with bipolar ring-shaped electrodes was placed in the lumen of the proximal jejunum of 6 pigs, at the same level as intramuscular implanted electrodes. The signals were recorded in conscious pigs fed normally. By comparison to the myoelectric activity recorded from the intramuscular implanted electrodes, the intraluminal electrodes provided reliable spike burst detection (sensitivity 85 p. 100; positive predictive value 91 p. 100) in the fasted and fed state, and good identification of migrating myoelectric complexes. Spectral analysis showed the same frequency patterns for signals obtained with both types of electrodes. In conclusion, intraluminal ring-shaped electrodes allow reliable detection of small bowel myoelectric activity and may represent a useful tool for motility studies in man.

[Ptosis and mastication disorders revealing concurrent myasthenia gravis and chronic polyradiculoneuritis]. / Ptosis et troubles de la mastication révélateurs d'une association myasthénie et polyradiculonévrite chronique.

Although myasthenia gravis (MG) has frequently been associated with other autoimmune disorders, it has only rarely been reported in conjunction with diseases of the nervous system. A 74-year-old patient with hypertension suddenly presented left unilateral ptosis and mastication disorders. Clinical examination showed a concomitant loss of strength distally and reduced deep tendon reflex. Electrophysiologic data indicated a diagnosis of MG and chronic inflammatory demyelinating polyneuropathy; acetylcholine receptor antibody was elevated at 4.1 nmol/L (normal < 2 nmol/L). Improvement was rapid after initiation of pyridostigmine in association with corticosteroid (1 mg/kg/day). One month later, the cranial nerve deficit disappeared and strength was normal. It is likely that a basic abnormality of immune regulation was responsible for the emergence of diseases with different clinical presentations, but similar immunopathogenesis. Corticosteroid seemed to be the most effective treatment.

[Neuromuscular synapse: molecular mechanisms of acetylcholine vesicular exocytosis]. / Synapse neuromusculaire: mécanismes moléculaires de la libération vésiculaire de l'acétylcholine.

The transmission of excitation from motor neurones to muscle fibers at the neuromuscular junction is made through liberation of acetylcholine. This is concentrated into vesicles according to an exchange with H(+) ions. Increase of intracellular calcium concentration leads some vesicles to mobilise and target with the neuron plasma membrane, where they are docked and preconditioned via the formation of a SNARE complex between vesicular proteins and plasma membrane proteins. Energy and control of these transports and reactions are provided by several kinds of enzymes and chaperone molecules. Arrival of an action potential causes depolarisation of the motoneurone axon terminal and opening of large conductance calcium channels. The last step, directly linked to calcium input, leads the membranes to fuse and acetylcholine to immediately leave the neuron towards the synaptic space.

[Phrenic stimulation in C1-C2 tetraplegia. Apropos of a case]. / Stimulation phrénique dans les tétraplégies C1-C2. A propos d'un cas.

The authors report a case of post traumatic tetraplegia at the C1-C2 level in a young man of 16 with total respiratory paralysis treated with mechanical ventilation and a tracheotomy. Thirty months after the accident, an Avery S 232(1) diaphragmatic pacemaker was surgically implanted by the mediastinal approach. The technique was rapidly successful and enabled satisfactory ventilation and phonation two months after the implantation. The patient is currently treated at home with no signs of diaphragmatic fatigue 20 months after the implantation of the stimulator.

[Mechanisms which control the peripheral nerve excitability]. / Mécanismes qui contrôlent l'excitabilité des nerfs périphériques.

Peripheral nerve excitability is currently tested via the strength/duration curves, and by measuring the minimal intensity level (rheobase) of an efficient stimulation, and the minimal duration (chronaxy) for a stimulus equal to two times the minimal threshold. New "threshold tracking techniques" were recently described (Bostock et al., 1991), which afford an automatic evaluation of nerve excitabilty. These methods investigate the mechanisms responsible for the membrane potential: passive ionic currents, activity of ionic pumps like the Na-K-ATPase; and the dynamic behaviour of large conductance sodium, potassium, and calcium channels, responsible for the generation and conduction of action potentials. Results obtained must however be evaluated taking into account the following items: stimulation is delivered through the skin and subcutaneous tissue; a nerve trunk is explored, and not a single fiber; most often the response is recorded over a muscle, hence through neuromuscular synapses.

[Electrophysiological investigation of polyneuropathies]. / Exploration électrophysiologique des polyneuropathies.

Needle electromyography, nerve conduction velocity measurement and recording of T, H or F waves, are the most commonly used methods to investigate patients with polyneuropathies. The grade, distribution, and functional type of the lesions are to be determined. A classification is proposed according to acute or chronic character of the neuropathy course and to prevailing signs of demyelination or axonal degeneration.

[Peripheral neuropathies of chronic renal insufficiency. Review]. / Neuropathies périphériques des insuffisants rénaux chroniques. Revue.

Described at the end of the 19th century, investigated from the development of dialysis since 1960, peripheral neuropathy occurs almost constantly in patients with a pre-dialytic renal failure. Clinical signs are mainly sensory ones Severe nerve deficiencies are rarely found. Electrophysiological techniques are performed to quantify the demyelinating and axonal lesions, to verify the long term adequacy of dialysis, and to observe improvement after kidney transplantation. Diabetes and vascular lesions can induce important axonal damage. Nerve entrapments (Median nerve in the carpal tunnel) are frequent and may worsen in a few months. Factors involved in the development of peripheral neuropathy in uremic patients remain partly unknown.

Late facilitations of motor evoked potentials by contralateral mixed nerve stimulation.

The effect on motor evoked potentials (MEPs) of a peripheral afferent volley (a single square pulse delivered to the contralateral median nerve at the wrist) was studied in abductor digiti minimi muscle of 9 normal patients following magnetic stimulation of the motor cortex. Long intervals were used (200-700 msec) between the electrical conditioning stimulus and magnetic test stimulation. An MEP amplitude increase, with no change in latency, was observed when the C-T interval was about 500 msec, and the motor threshold was decreased by the conditioning stimulation. The observed long latency and duration of the facilitation effect would seem consistent with activation of suprasegmental areas.