Characteristics of pain and the burden it causes in patients with amyotrophic lateral sclerosis - a longitudinal study

OBJECTIVE

Pain currently plays a subordinate role in the clinical care of patients with ALS. We aim to examine epidemiological and clinical characteristics of pain as well as its impact throughout the disease course.

METHODS

During a longitudinal follow-up at three time points, 151 ALS patients from three German outpatient clinics completed the Brief Pain Inventory, ALS-Functional Rating Scale-Extension and ALS Depression Inventory. Analysis of variance and covariance with repeated measures were performed.

RESULTS

Pain was prevalent in 56% of the 151 patients at baseline and in 70% of the remaining 40 patients at the third survey. Of the 28 patients with pain who participated in all three surveys, about two thirds suffered from an average pain intensity corresponding to at least moderate pain on the numerical rating scale (NRS ≥ 4). Patients reported different pain qualities and localized the pain most frequently in the extremities, back and neck. Pain moderately impaired the functions of daily living. Pain intensity, pain quality and pain-related impairment did not significantly change over time. One third of the patients suffered from clinically relevant depressive symptoms. However, there was no conclusive evidence of a link between pain intensity and depressive symptoms.

CONCLUSION

Pain is frequent and constitutes an additional strain on ALS patients who have to endure a rapidly progressive and severely debilitating disease. This study contributes to better understanding of the characteristics of pain and its impact on ALS patients throughout the disease course and may thus help to more effectively address this symptom.

Expression of dachshund in wild-type and Distal-less mutant Tribolium corroborates serial homologies in insect appendages

We isolated the homologue of the Drosophila gene dachshund (dac) from the beetle Tribolium castaneum. Tc'dac is expressed in all appendages except urogomphi and pleuropodia. Tc'dac is also active in the head lobes, in the ventral nervous system, in the primordia of the Malpighian tubules and in bilateral stripes corresponding to the presumptive dorsal midline. Expression of Tc'dac in the labrum lends support to the interpretation that the insect labrum is derived from a metameric appendage. The legs of Tribolium accommodate two Tc'dac domains, of which the more distal one corresponds to the single dac domain described for Drosophila leg discs. In contrast to Drosophila, where this domain is thought to intercalate between the homothorax (hth) and the Distal-less (Dll) domains, in Tribolium it arises from within the Dll domain. In embryos mutant for the Tc'Dll gene we find that the distal Tc'dac domain in the legs, as well as the expression in the labrum, are deleted while the proximal leg domain and the mandibular expression are unaffected. Based on Tc'dac expression in wild-type and mutant embryos, we demonstrate serial homology of the complete mandible with the coxa of the thoracic legs, which affirms the gnathobasic nature of the insect mandible.