Drug-resistant temporal lobe epilepsy is associated with postural control abnormalities.

Epilepsy is responsible for falls that are not systematically associated with seizures and that therefore suggest postural impairment. There are very few studies of postural control in patients with epilepsy and none of them focus on temporal lobe epilepsy (TLE), although part of the vestibular cortex is located in the temporal cortex. The aim of this study was to evaluate the characteristics of postural control in a homogeneous population of patients with complex partial TLE. Twenty-six patients with epilepsy and 26 age-matched healthy controls underwent a sensory organization test combining six conditions, with and without sensory conflicting situations. Patients with epilepsy displayed poorer postural control, especially in situations where vestibular information is necessary to control balance. In addition to potential antiepileptic drug side effects, vestibular dysfunction could be related to the temporal pathology. Our study allows for a better understanding of the mechanism underlying falls in this population of patients.

Visual sensorial preference delays balance control compensation after vestibular schwannoma surgery.

BACKGROUND: Balance control performance after vestibular schwannoma surgical removal follows a course that is characterised by a deterioration in postural performance immediately after unilateral vestibular deafferentation (uVD) and a recovery process (vestibular compensation). However, sensory strategies for balance vary during tumoral growth, which could lead to differences in the preferential use of sensory afferences. This longitudinal study aimed to assess the post-operative sensorimotor strategies of postural regulation according to sensory preference of balance control before surgery. METHODS: Twenty-two patients with vestibular schwannoma (11 relying less on vision (G1), 11 relying more on vision (G2), to control balance before surgery), underwent vestibular, subjective visual vertical (SVV), static posturography and sensory organisation (SOT) tests, before and 8 days, 1 and 3 months after surgery. RESULTS: In G1 patients, little static posturographic and SOT performance deterioration after uVD was observed, despite vestibular test and SVV modifications. In G2 patients, uVD-related modifications followed a time-course characterised by a degradation in posturographic and SOT, vestibular and SVV performances immediately after uVD and a progressive restoration and even improvement 1 month and particularly 3 months after surgery. CONCLUSIONS: High preference for vision before surgery intervenes in postural degradation immediately after surgery, thus delaying the short-term effects of vestibular compensation on postural control. Long-term performance being similar whatever the visual status before surgery, the time-dependent implementation of the central adaptive mechanisms due to neuroplasticity leads to a modification of neurosensory information hierarchy, allowing reliance on appropriate information, the gain varying according to the postural task to be performed.

The practice of physical and sporting activity in teenagers with idiopathic scoliosis is related to the curve type.

Idiopathic scoliosis (IS) is correlated with a muscular disequilibrium of the spine and an alteration of balance control, efficient performance of the latter being necessary for physical and sporting activities (PSA). However, the type of the IS curve has different effects on muscle and on balance control according to the primary curve location. This study aimed to determine the relationships between IS type and PSA practice. One hundred and sixty-nine girl adolescents with IS [double major curve (DMC) scoliosis: n=74; single major curve (SMC) scoliosis: n=95] and 100 age-matched control girl adolescents completed an epidemiological questionnaire informing on curricular and extracurricular PSA. Adolescents with DMC scoliosis practised more PSA than those with SMC scoliosis. Moreover, among all PSA referenced, gymnastic activities are the most practiced PSA both in IS teenagers, whatever the curve type, and in controls. Besides, teenagers practising gymnastics were more numerous in those with DMC scoliosis than those with SMC scoliosis and controls. The highest proportion of adolescents with DMC scoliosis practising PSA, especially gymnastics, could be linked to the fact that they are less subject to scoliosis-related biomechanical repercussions leading to a better balance control, which is essential in these PSA.

Why do idiopathic scoliosis patients participate more in gymnastics?

The influence of physical and sporting activities (PSA) on idiopathic scoliosis (IS) is still obscure. The aim of this study was to investigate whether such an influence exists and if so, to determine its characteristics. Two hundred and one teenagers with IS and a control group of 192 adolescents completed an epidemiological questionnaire. Those practising gymnastics were more numerous in the IS group than in the control group. Moreover, the practice of gymnastics was chosen before IS was diagnosed. As gymnastic activities are considered neither as a therapy nor as a precursor of IS, the distribution observed could be linked to a common factor that both increases the likelihood of IS and favors the practice of gymnastics. Joint laxity (JL) may be such a common factor, and was therefore tested (wrist and middle finger) on 42 girls with IS and 21 girls of a control group. IS patients, practising gymnastics or not, showed a higher JL than the control group practising gymnastics or not. Furthermore, the groups practising gymnastic activities did not show higher JL levels than the other groups. Children with a high JL could be drawn toward gymnastics because of their ability to adapt to the constraints of this sport. Girls with a high JL may therefore be prone to developing IS. The fact that most teenagers with IS practise gymnastics could be related to a higher JL.

Bilateral subthalamic nucleus stimulation improves balance control in Parkinson's disease.

BACKGROUND: Parkinson's disease (PD), the most common basal ganglia degenerative disease, affects balance control, especially when patients change balance strategy during postural tasks. Bilateral chronic stimulation of the subthalamic nucleus (STN) is therapeutically useful in advanced PD, and reduces the motor signs of patients. Nevertheless, the effects of STN stimulation on postural control are still debatable. AIMS: To assess the impact of bilateral STN stimulation on balance control in PD and to determine how basal ganglia related sensorimotor modifications act on neurosensorial organisation of balance and motor postural programming. METHODS: Twelve subjects aged 45-70 years underwent unified Parkinson's disease rating scale motor (part III) clinical tests, static and dynamic posturography, including sensory organisation and adaptation tests, shortly before and six months after bilateral implantation of electrodes into the STN. RESULTS: The postoperative static test showed an improvement in postural control precision both in eyes open and eyes closed conditions. The dynamic test highlighted the decreased number of falls and the ability of the patients to develop more appropriate sensorimotor strategies when stimulated. The sensory organisation test showed an improvement of equilibrium score and, thus, a better resolution of sensorial conflicts. CONCLUSIONS: STN stimulation allowed a reduction in rigidity and therefore an improvement in the ability to use muscular proprioception as reliable information, resulting in vestibulo-proprioceptive conflict suppression. STN stimulation has a synergistic effect with levodopa for postural control. Accordingly, non-dopaminergic pathways could be involved in postural regulation and STN stimulation may influence the functioning of these pathways.

Improved muscle strength and power in elderly exercising regularly.

Since the number of elderly people with a sedentary lifestyle is considerable and still growing, regular exercise could be an extra stimulant to compensate for the decrease in functional capacities. The potential positive effects of physical and sporting activities (PSA) on muscular function in relation to the period of practice were studied. Muscular strength and power were evaluated by dynamometric knee and ankle tests on 40 healthy subjects aged over 60 years old, split into four groups according to the period of practice. Higher muscular performance was obtained in subjects who had always practised PSA, whereas subjects who had always been inactive displayed the worst muscular performances. Subjects who had begun PSA practice lately had good muscular strength and power, close to those of the AA group, whereas the subjects who had stopped the practice at an early age did not perform as well. Life-long PSA attenuates the age-related loss of muscle function, and initiation at old age improves it. This, and the absence of any beneficial effects of PSA stopped when young, indicates that the actual activity level is an important determinant of skeletal muscle function at old age. Practicing PSA increases muscular strength and power and thus improves daily living activities in elderly people.