'Thumb localizing test' for detecting a lesion in the posterior column-medical lemniscal system

Multisensory Integration in Stroke Patients: A Theoretical Approach to Reinterpret Upper-Limb Proprioceptive Deficits and Visual Compensation

For reaching and grasping, as well as for manipulating objects, optimal hand motor control arises from the integration of multiple sources of sensory information, such as proprioception and vision. For this reason, proprioceptive deficits often observed in stroke patients have a significant impact on the integrity of motor functions. The present targeted review attempts to reanalyze previous findings about proprioceptive upper-limb deficits in stroke patients, as well as their ability to compensate for these deficits using vision. Our theoretical approach is based on two concepts: first, the description of multi-sensory integration using statistical optimization models; second, on the insight that sensory information is not only encoded in the reference frame of origin (e.g., retinal and joint space for vision and proprioception, respectively), but also in higher-order sensory spaces. Combining these two concepts within a single framework appears to account for the heterogeneity of experimental findings reported in the literature. The present analysis suggests that functional upper limb post-stroke deficits could not only be due to an impairment of the proprioceptive system per se, but also due to deficiencies of cross-references processing; that is of the ability to encode proprioceptive information in a non-joint space. The distinction between purely proprioceptive or cross-reference-related deficits can account for two experimental observations: first, one and the same patient can perform differently depending on specific proprioceptive assessments; and a given behavioral assessment results in large variability across patients. The distinction between sensory and cross-reference deficits is also supported by a targeted literature review on the relation between cerebral structure and proprioceptive function. This theoretical framework has the potential to lead to a new stratification of patients with proprioceptive deficits, and may offer a novel approach to post-stroke rehabilitation.

Contracture preventive positioning of the hemiplegic arm in subacute stroke patients: a pilot randomized controlled trial

Objective: To investigate the effectiveness of a contracture preventive positioning procedure for the hemiplegic arm in subacute stroke patients in addition to conventional physio and occupational therapy.

Design: A single-blind pilot randomized controlled trial.

Setting: Inpatient neurological units from three rehabilitation centres in the Netherlands.

Subjects: Nineteen subacute stroke patients (minus two drop-outs) with a severe motor deficit of the arm.

Interventions: All subjects underwent conventional rehabilitation care. Nine subjects additionally received a positioning procedure for two 30-min sessions a day, five days a week, for five weeks.

Main measures: Passive range of motion of five arm movements using a hydrogoniometer and resistance to passive movement at the elbow using the Ashworth Scale. Secondary outcome measures were pain at the end range of passive motions, the arm section of the Fugl-Meyer Assessment and Barthel Index scores for ADL-independence. Outcome measures were taken after five weeks and additional measurements after 10 weeks by two assessors blinded to group allocation.

Results: Comparison of the experimental ( n = 9) with the control subjects ( n = 8) after five weeks showed that additional positioning significantly slowed down development of shoulder abduction contracture ( P = 0.042, −5.3 degrees versus −23 degrees). No other differences were found between the groups.

Conclusions: Applying a contracture preventive positioning procedure for the hemiplegic arm slowed down the development of shoulder abduction contracture. Positioning did not show significant additional value on other outcome measures. Since the sample size was small, results of this study need future verification.

The hemiplegic arm: Interrater reliability and concurrent validity of passive range of motion measurements

PURPOSE

To assess whether our measurement protocol using two raters simultaneously yielded reliable passive range of motion measurements of the hemiplegic arm. Additionally, motion ranges were correlated to several factors to examine the concurrent validity of these measurements.

METHOD

Two raters simultaneously assessed five arm motions at baseline, after five and ten weeks in respectively 18, 13 and 12 stroke patients. One tester made the passive movement and the other read the hydrogoniometer. Raters then switched roles.

RESULTS

Intraclass correlation coefficients revealed high agreement between the raters with intraclass correlation coefficients (ICCs) ranging between 0.84 and 0.99. Standard errors of measurement and smallest detectable differences were large for shoulder abduction. Significant correlations were found between shoulder external rotation and flexion. All arm motions correlated negatively to pain at the end range of these motions. Shoulder external rotation and flexion were significantly correlated to the time post stroke. Concurrent validity with Ashworth Scale, Fugl-Meyer Assessment and Barthel Index was limited.

CONCLUSIONS

The current measurement protocol yielded high reliability indices and seems useful for further use. However, standard error of measurement and smallest detectable difference for shoulder abduction were high, implying the necessity to include a large sample size in future studies. Correlations revealed that restricted range of arm motions relate to the time post-stroke and coincide with pain.