Prevalence of Spasticity and Postural Patterns in the Upper Extremity Post Stroke

INTRODUCTION

A high number of patients with stroke develop upper extremity spasticity, causing abnormal postures and patterns. These alterations limit the use of arm in functional activities and affect social participation.

AIM

To determine the prevalence of spasticity and postural patterns of the upper extremity post stroke.

MATERIALS AND METHODS

A cross-sectional descriptive design was used with a prospective follow-up. The sample included 136 patients. The study included 3 measuring times; at 10 days (T1), applying a record with sociodemographic-clinical data, the evaluation of muscle tone in the elbow and wrist and the postural patterns of the UE, and at 3 months (T2) and 12 months (T3) post stroke, re-evaluating tone and patterns. Prevalence was calculated through the one-sample chi-squared (χ2) test followed by inspection of the standardized residuals (z) in each cell. The Kappa coefficient evaluated the degree of agreement in elbow and wrist tone.

RESULTS

The prevalence of spasticity in the elbow was 37.5% at T1, 57.4% at T2, and 57.4% at T3. At each time there was a high degree of agreement between elbow and wrist tone. Patients developed increased elbow tone between T1 and T2, with maintained tone between T2 and T3. Postural pattern III was the most prevalent according to Hefter's classification.

CONCLUSION

The prevalence of spasticity in the elbow and wrist increases between 10 days and 3 months post stroke, and is maintained between 3 and 12 months. The onset of spasticity occurs in almost half of patients during the first 10 days post stroke. Postural pattern III according to Hefter's classification presented the greatest prevalence in the spastic UE.

Is floral diversification associated with pollinator divergence? Flower shape, flower colour and pollinator preference in Chilean Mimulus

BACKGROUND AND AIMS

Adaptation to different pollinators is thought to drive divergence in flower colour and morphology, and may lead to interspecific reproductive isolation. Floral diversity was tested for association with divergent pollinator preferences in a group of four closely related wildflower species: the yellow-flowered Mimulus luteus var. luteus and the red-pigmented M. l. variegatus, M. naiandinus and M. cupreus.

METHODS

Patterns of pollinator visitation were evaluated in natural plant populations in central Chile, including both single-species and mixed-species sites. Floral anthocyanin pigments were identified, and floral morphology and nectar variation were quantified in a common garden experiment using seeds collected from the study sites.

KEY RESULTS

Mimulus l. luteus, M. l. variegatus and M. naiandinus are morphologically similar and share a single generalist bumblebee pollinator, Bombus dahlbomii. Mimulus cupreus differs significantly from the first three taxa in corolla shape as well as nectar characteristics, and had far fewer pollinator visits.

CONCLUSIONS

This system shows limited potential for pollinator-mediated restriction of gene flow as a function of flower colour, and no evidence of transition to a novel pollinator. Mimulus cupreus may experience reduced interspecific gene flow due to a lack of bumblebee visitation, but not because of its red pigmentation: rare yellow morphs are equally undervisited by pollinators. Overall, the results suggest that factors other than pollinator shifts may contribute to the maintenance of floral diversity in these Chilean Mimulus species.