Balance improvements in healthy subjects are independent to postural strategies involved in the training.

BACKGROUND: Adequate postural strategies have a pivotal role in ensuring balance during the performance of daily or sport activities. These strategies are responsible for the management of center of mass kinematics and depend on the magnitude of perturbations and posture assumed by a subject. RESEARCH QUESTION: Are there differences in postural performance after a standardized balance training performed in sitting versus standing posture in healthy subjects? Does a standardized unilateral balance training with the dominant or non-dominant limb improve balance on trained and untrained limbs in healthy subjects? METHODS: Seventy-five healthy subjects reporting a right-leg dominance were randomized into a Sitting, Standing, Dominant, Non-dominant or Control groups. In the Experiment 1, Sitting group performed a 3-week balance training in seated posture, whereas Standing group performed the same training in bipedal stance. In the Experiment 2, Dominant and Non-dominant groups underwent a 3-week standardized unilateral balance training on the dominant and non-dominant limbs, respectively. Control group underwent no intervention and was included in both experiments. Dynamic (Lower Quarter Y-Balance Test with the dominant and non-dominant limbs and trunk and lower limb 3D kinematics) and static (center of pressure kinematics in bipedal and bilateral single-limb stance) balance were assessed before and after the training, and at 4 weeks follow-up. RESULTS: A standardized balance training in sitting or standing posture improved balance without between-group differences, while a unilateral balance training with the dominant or non-dominant limb improved postural stability on the trained and untrained limbs. Trunk and lower limb joints range of motion increased independently to their involvement in the training. SIGNIFICANCE: These results may allow clinicians to plan effective balance interventions even when a training in standing posture is not possible or in subjects with restricted limb weight-bearing.

Creatine transporter defect diagnosed by proton NMR spectroscopy in males with intellectual disability.

Creatine deficiency syndrome due to mutations in X-linked SLC6A8 gene results in nonspecific intellectual disability (ID). Diagnosis cannot be established on clinical grounds and is often based on the assessment of brain creatine levels by magnetic resonance spectroscopy (MRS). Considering high costs of MRS and necessity of sedation, this technique cannot be used as a first level-screening test. Likewise, gene test analysis is time consuming and not easily accessible to all laboratories. In this article feasibility of urine analysis (creatine/creatinine (Cr/Crn) ratio) performed by nuclear magnetic resonance (NMR) as a first level-screening test is explored. Before running a systematic selection of cases a preliminary study for further molecular analysis is shown. NMR urine spectra (n = 1,347) of male patients with an ID without a clinically recognizable syndrome were measured. On the basis of abnormal Cr/Crn ratio, three patients with the highest values were selected for molecular analysis. A confirmatory second urine test was positive in two patients and diagnosis was further confirmed by a decreased brain creatine level and by SLC6A8 gene analysis. A de novo mutation was identified in one. Another patient inherited a novel mutation from the mother who also has a mild ID. A repeat urine test was negative in the third patient and accordingly creatine level in the brain and SLC6A8 gene analysis both gave a normal result. We conclude that Cr/Crn ratio measured by NMR for male patients represents a rapid and useful first level screening test preceding molecular analysis.

A missense mutation in the coiled-coil domain of the KIF5A gene and late-onset hereditary spastic paraplegia.

BACKGROUND: To our knowledge, up to now, only 2 mutations in the KIF5A gene, a member of the kinesin superfamily, have been identified as the molecular cause of early-onset autosomal dominant hereditary spastic paraparesis (ADHSP). OBJECTIVE: To assess the genetic defect in a family with late-onset ADHSP. PATIENTS AND METHODS: Only the proband agreed to undergo complete neurological testing and mutational analysis. The proband was screened for mutations in the spastin, atlastin, NIPA1, and KIF5A genes, either by denaturing high-performance liquid chromatography or sequence analysis. RESULTS: The history of the family was consistent with ADHSP characterized by late onset of the disease. Mutational analysis results were negative for the spastin, atlastin, and NIPA1 genes but identified a missense mutation (c.1082C>T) in the coiled-coil coding region of the KIF5A gene. CONCLUSIONS: This finding enlarges the phenotypic spectrum of ADHSP linked to KIF5A and enhances the role of that gene in the epidemiology of this disease. We propose that the KIF5A gene should be routinely analyzed in patients with hereditary spastic paraplegia negative for spastin and atlastin mutations.

Two novel mutations in the spastin gene (SPG4) found by DHPLC mutation analysis.

The most common form of autosomal dominant hereditary spastic paraplegia is caused by mutations in the gene encoding spastin (SPG4), a member of the AAA family of ATPases. In the current study, we designed a denaturing high-performance liquid chromatography based protocol for the analysis of the SPG4 gene. Using this method, we detected two novel missense mutations, 1375A > G (R459G) and 1378C > T (R460C), one previously described five bases deletion (1215_1219del) and three polymorphic changes. This study suggests that denaturing high-performance liquid chromatography would be a fast and reliable tool in the investigation of the molecular defects in the SPG4 gene.