Balance impairments and neuromuscular changes in breast cancer patients with chemotherapy-induced peripheral neuropathy.
OBJECTIVE
Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment. Resulting sensory and motor dysfunctions often lead to functional impairments like gait or balance disorders. As the underlying neuromuscular mechanisms are not fully understood, we compared balance performance of CIPN patients with healthy controls (CON) to specify differences responsible for postural instability.


METHODS
20 breast cancer patients with CIPN (PAT) and 16 matched CONs were monitored regarding centre of pressure displacement (COP) and electromyographic activity of M. soleus, gastrocnemius, tibialis anterior, rectus femoris and biceps femoris. We calculated antagonistic co-contraction indices (CCI) and elicited soleus H-reflexes to evaluate changes in the elicitability and sensitivity of spinal reflex circuitry.


RESULTS
PAT's COP displacement was greater than CON's (p=.013) and correlated significantly with the level of CCIs and self-reported CIPN symptoms. PAT revealed prolonged H-wave latency (p=.021), decreased H-reflex elicitability (p=.001), and increased H-reflex sensitivity from bi- to monopedal stance (p=.004).


CONCLUSIONS
We summarise that CIPN causes balance impairments and leads to changes in elicitability and sensitivity of spinal reflex circuitry associated with postural instability. We assume that increased simultaneous antagonistic muscle activation may be used as a safety strategy for joint stiffness to compensate for neuromuscular degradation.


CONCLUSIONS
Sensorimotor training has the potential to influence neuromuscular mechanisms in order to improve balance performance. Therefore, this training modality should be evaluated as a possible treatment strategy for CIPN.
Department Medicine I, Haematology, Oncology and Stem Cell Transplantation, University Medical Centre Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany; Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117 Freiburg, Germany. Electronic address: sarah.kneis@uniklinik-freiburg.de.
Sarah
S
Kneis
Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117 Freiburg, Germany; Institute for Exercise- and Occupational Medicine, Department of Internal Medicine, University Medical Centre Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
Anja
A
Wehrle
Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117 Freiburg, Germany.
Kathrin
K
Freyler
Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117 Freiburg, Germany.
Katrin
K
Lehmann
Tumour Biology Centre Freiburg, Breisacher Str. 117, 79106 Freiburg, Germany.
Britta
B
Rudolphi
Tumour Biology Centre Freiburg, Breisacher Str. 117, 79106 Freiburg, Germany.
Bernd
B
Hildenbrand
Tumour Biology Centre Freiburg, Breisacher Str. 117, 79106 Freiburg, Germany.
Hans Helge
HH
Bartsch
Department Medicine I, Haematology, Oncology and Stem Cell Transplantation, University Medical Centre Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
Hartmut
H
Bertz
Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117 Freiburg, Germany.
Albert
A
Gollhofer
Institute of Sport and Sport Science, University of Freiburg, Schwarzwaldstr. 175, 79117 Freiburg, Germany.
Ramona
R
Ritzmann
D000328:Adult; D000970:Antineoplastic Agents / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000453:epidemiology*; D004576:Electromyography / Q000379:methods; D005260:Female; D006181:H-Reflex / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology*; D004856:Postural Balance / Q000187:drug effects / Q000502:physiology*; D012678:Sensation Disorders / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology*
D000970:Antineoplastic Agents
Co-contraction; H-reflex; Latency; Motor control; Postural stability