Impaired performance of patients with writer's cramp in complex fine motor tasks

Alterations in dexterity and manual function in patients with focal hand dystonia

INTRODUCTION

Focal hand dystonia is a movement disorder whose symptoms cause alterations in the performance of tasks requiring a high level of dexterity. Currently, there is no model for interpreting the disease and few studies have identified the difficulties of patients with dystonia in carrying out activities of daily living (ADL). This study aims to describe manipulative dexterity and its influence on ADLs in patients with focal hand dystonia.

MATERIALS AND METHODS

We performed an observational, cross-sectional, case-control study including 24 participants (12 patients with focal hand dystonia and 12 controls). The patients were referred by the neurology department of Hospital Ramón y Cajal. We gathered sociodemographic data, as well as retrospective clinical data for patients. We subsequently administered evaluation tests, in the following order: Nine-Hole Peg Test (NHPT), Box and Blocks Test (BBT), Purdue Pegboard Test (PPT), and Jebsen-Taylor Test of Hand Function (JTTHF).

RESULTS

The study sample included a total of 24 participants, 7 women and 17 men, with a mean age (standard deviation) of 50.79 (14.40) years. In the patient group, neuromuscular involvement or psycho-emotional problems were not detected in half of cases; smaller numbers of patients presented difficulties associated with the right shoulder (25%) and anxious state (33.3%).

CONCLUSIONS

Our results indicate that focal hand dystonia affects manipulative dexterity in these patients, who showed poorer performance and required more time to complete the tasks.

Never too little: Grip and lift forces following probabilistic weight cues in patients with writer's cramp

OBJECTIVE

Planning of voluntary object-related movements requires the estimation of the most probable object properties. We investigated how 14 writer's cramp (WC) patients compared to 14 controls use probabilistic weight cues in a serial grip-lift task.

METHODS

In every grip-lift trial, an object of either light, medium or heavy weight had to be grasped and lifted after a visual cue gave a probabilistic prediction of the object weights (e.g. 32.5% light, 67.5% medium, 0 % heavy). We determined peak (1) grip force GF, (2) load force LF, (3) grip force rate GFR, (4) load force rate LFR, while we registered brain activity with functional magnetic resonance imaging.

RESULTS

In both groups, GFR, LFR and GF increased when a higher probability of heavy weights was announced. When a higher probability of light weights was indicated, controls reduced GFR, LFR and GF, while WC patients did not downscale their forces. There were no inter-group differences in blood oxygenation level dependent activation.

CONCLUSIONS

WC patients could not utilize the decision range in motor planning and adjust their force in a probabilistic cued fine motor task.

SIGNIFICANCE

The results support the pathophysiological model of a hyperfunctional dopamine dependent direct basal ganglia pathway in WC.

Alterations in dexterity and manual function in patients with focal hand dystonia

INTRODUCTION

Focal hand dystonia is a movement disorder whose symptoms cause alterations in the performance of tasks requiring a high level of dexterity. Currently, there is no model for interpreting the disease and few studies have identified the difficulties of patients with dystonia in carrying out activities of daily living (ADL). This study aims to describe manipulative dexterity and its influence on ADLs in patients with focal hand dystonia.

MATERIALS AND METHODS

We performed an observational, cross-sectional, case-control study including 24 participants (12 patients with focal hand dystonia and 12 controls). The patients were referred by the neurology department of Hospital Ramón y Cajal. We gathered sociodemographic data, as well as retrospective clinical data for patients. We subsequently administered evaluation tests, in the following order: Nine-Hole Peg Test (NHPT), Box and Blocks Test (BBT), Purdue Pegboard Test (PPT), and Jebsen-Taylor Test of Hand Function (JTTHF).

RESULTS

The study sample included a total of 24 participants, 7 women and 17 men, with a mean age (standard deviation) of 50.79 (14.40) years. In the patient group, neuromuscular involvement or psycho-emotional problems were not detected in half of cases; smaller numbers of patients presented difficulties associated with the right shoulder (25%) and anxious state (33.3%).

CONCLUSIONS

Our results indicate that focal hand dystonia affects manipulative dexterity in these patients, who showed poorer performance and required more time to complete the tasks.