Patients with breast cancer experience psychosocial distress such as anxiety, depression,
fatigue, and cognitive disturbances. Both fatigue and cognitive dysfunction have been
observed as post-treatment outcomes of chemotherapy and/or radiotherapy.
The PPI test represents an operational measure of information-protective pre-attentional
mechanisms. PPI is a neurological phenomenon in which a weaker acoustic pre-pulse
(delivered via headphones) inhibits the reaction to a subsequent strong startling
pulse. The reduction of the response amplitude (measured by electromyographic activity
from the orbicularis oculi muscle) reflects the ability of the nervous system to temporarily
adapt to a strong sensory stimulus when a preceding weaker signal is given. PPI is
an objective tool for fatigue evaluation.
In a randomized, double blind, IBR-approved study, 57 female patients who underwent
chemotherapy and adjuvant whole breast radiation in the radiation department at Sheba
Medical Centre, and who gave written consent for participation, were included in the
study: 38 received homeopathic treatment and 19 received placebo.
All patients were evaluated at the beginning, during, end and one month after completing
radiotherapy for: (i) fatigue level, utilizing the Fatigue Symptom Inventory (FSI);
(ii) attention performance, utilizing the Pre-Pulse Inhibition (PPI) task; and (iii)
anxiety level, utilizing both the startle response test and examining the Galvanic
Skin Response (GSR) differences.
At baseline, both treated and placebo groups showed similar impaired level of auditory-sustained
attention (ASAT; measured by pre-pulse inhibition), probably as a consequence of recent
chemotherapy.
One-month after radiotherapy completion, while the placebo ASAT performance further
deteriorated, a significant improvement (to normal performance) was observed in the
homeopathic treatment group.
Keywords: Homeopathy, breast cancer, fatigue, radiotherapy
