In chemotherapy-induced neuropathy, different pain patterns might help to identify subgroups with predominant neuropathic or musculoskeletal pain and thereby allow a more specific treatment.
Chemotherapy-induced neuropathy (CIN) is an adverse effect of chemotherapy. Pain in CIN might comprise neuropathic and nonneuropathic (ie, musculoskeletal) pain components, which might be characterized by pain patterns, electrophysiology, and somatosensory profiling. Included were 146 patients (100 female, 46 male; aged 56 ± 0.8 years) with CIN arising from different chemotherapy regimens. Patients were characterized clinically through nerve conduction studies (NCS) and quantitative sensory testing (QST). Questionnaires for pain (McGill) and anxiety/depression (Hospital Anxiety and Depression Scale) were supplied. Patients were followed-up after 17 days. Large- (61%) and mixed- (35%) fibre neuropathies were more frequent than small-fibre neuropathy (1.4%). The 5 major chemotherapeutic regimens impacted differently on large- but not on small-fibre function and did not predict painfulness. Chronic pain associated with CIN was reported in 41.7%. Painless and painful CIN did not differ in QST profiles or electrophysiological findings, but different somatosensory patterns were found in CIN subgroups (pain at rest [RestP], n = 25; movement-associated pain [MovP], n = 15; both pain characteristics [MovP+RestP], n = 21; or no pain [NonP], n = 85): small-fibre function (cold-detection threshold, CDT: z score: −1.46 ± 0.21, P < 0.01) was most impaired in RestP; mechanical hyperalgesia was exclusively found in MovP (z score: +0.81 ± 0.30, P < 0.05). “Anxiety” discriminated between painful and painless CIN; “CDT” and “anxiety” discriminated between patients with ongoing (RestP) and movement-associated pain (MovP) or pain components (MovP+RestP). The detrimental effect of chemotherapy on large fibres failed to differentiate painful from painless CIN. Patients stratified for musculoskeletal or neuropathic pain, however, differed in psychological and somatosensory parameters. This stratification might allow for the application of a more specific therapy.
aKlinik und Poliklinik für Neurologie, Universitätsmedizin der Johannes Gutenberg-Universität, Mainz, Germany
bRehaklinik Nahetal, Bad Kreuznach, Germany
cZentrum für Biomedizin und Medizintechnik (CBTM), Medizinische Fakultät Mannheim, Universität Heidelberg, Mannheim, Germany
dMurdoch University, Perth, Australia
*Corresponding author. Address: Klinik und Poliklinik für Neurologie, Universitätsmedizin der Johannes Gutenberg-Universität Mainz (KöR), Langenbeckstr. 1, Mainz 55101, Germany. Tel.: +49 6131 17 5486; fax: +49 6131 17 5620.
1These authors shared senior authorship.
Submitted March 17, 2013; revised July 16, 2013; accepted August 26, 2013.