Joint distraction for thumb carpometacarpal osteoarthritis: a feasibility study with 1-year follow-up

Objective: The purpose of this pilot study was to evaluate the feasibility of joint distraction of the first carpometacarpal (CMC1) joint in patients with CMC1 osteoarthritis (OA).

Methods: An external joint distractor was placed over the CMC1 joint by K-wire fixation in the trapezium and the metacarpal. The joint was distracted 3?mm during surgery. The device was then kept in place for 8 weeks. Disabilities of the Arm, Shoulder, and Hand (DASH) score, Michigan Hand Outcome Questionnaire (MHQ), Visual Analogue Scale (VAS), and grip strength were recorded preoperatively and at set postoperative intervals.

Results: Five female patients with an average age of 53 years (range?=?41–61) were included. One year postoperatively, average DASH, MHQ, and VAS scores improved compared to preoperative values; DASH 53 to 27, MHQ 48 to 76, and VAS pain 48 to 14. There were no technical problems associated with the device. One patient had a local pin site infection treated successfully with oral antibiotics.

Conclusions: This study concludes that joint distraction of the osteoarthritic CMC1 joint is technically feasible. In this small, prospective pilot study the majority of the results were favourable during short-term follow-up.     

Acute tryptophan depletion in healthy males attenuates phasic cardiac slowing but does not affect electro-cortical response to negative feedback

RATIONALE: Recent studies have shown that serotonin might be involved in performance monitoring, although the results have been inconclusive. Inconsistent results might be related to the type of pharmacological manipulation and the used behavioral and physiological measures. OBJECTIVES: The present study aimed at further specifying the role of serotonin in performance monitoring. MATERIALS AND METHODS: The effect of serotonin on performance monitoring was studied by using acute tryptophan depletion (ATD), a well-known method to transiently lower central serotonin levels. Twenty healthy male volunteers performed a time-estimation task and their event-related brain potential (ERP), behavioral, and cardiac responses to feedback stimuli were measured. Furthermore, subjective mood and amino-acid levels were determined. RESULTS: As expected, ATD did not affect mood and lowered tryptophan levels. ATD attenuated cardiac slowing to negative feedback but did not affect responses to positive feedback, ERPs, and performance measures. CONCLUSIONS: The data point in the direction of a dissociation between cardiac and electro-cortical responses. Cardiac responses appear to be more sensitive to changes in serotonin metabolism and appear to reflect different aspects of the feedback stimulus. The phasic cardiac response appears to be an important measure that provides additional information about the impact of feedback stimuli and serotonergic functioning.     

The hand injury severity scoring system and workers' compensation cases in Wisconsin, USA.

The Hand Injury Severity Score was retrospectively applied to a group of workers' compensation cases in Wisconsin, USA. A statistically significant correlation was found between the score and the time interval between injury and the end of healing. These results are comparable to the findings in the original study of Campbell and Kay (1996). We provide some suggestions for further development of this scoring system.     

Stimulation of the subthalamic region facilitates the selection and inhibition of motor responses in Parkinson's disease

The aim of the present study was to specify the involvement of the basal ganglia in motor response selection and response inhibition. Two samples were studied. The first sample consisted of patients diagnosed with Parkinson's disease (PD) who received deep-brain stimulation (DBS) of the subthalamic nucleus (STN). The second sample consisted of patients who received DBS for the treatment of PD or essential tremor (ET) in the ventral intermediate nucleus of the thalamus (Vim). Stop-signal task and go/no-go task performances were studied in both groups. Both groups performed these tasks with (on stimulation) and without (off stimulation) DBS to address the question of whether stimulation is effective in improving choice reaction time (RT) and stop-signal RT. The results show that DBS of the STN was associated with significantly enhanced inhibitory control, as indicated by shorter stop-signal RTs. An additional finding is that DBS of the STN led to significantly shorter choice RT. The effects of DBS on responding and response inhibition were functionally independent. Although DBS of the Vim did not systematically affect task performance in patients with ET, a subgroup of Vim-stimulated PD patients showed enhanced stop-signal RTs in on stimulation versus off stimulation. This result suggests that the change in performance to stop signals may not be directly related to STN function, but rather results from a change in PD function due to DBS in general. The findings are discussed in terms of current functional and neurobiological models that relate basal ganglia function to the selection and inhibition of motor responses.