Imaging as a Means of Studying Chemotherapy-Related Cognitive Impairment

Abstract

T he chemotherapy-related cognitive impairment (chemo fog/chemo brain) that is reported by many cancer patients is supported to varying degrees primarily by evidence from prospective and retrospective clinical studies. However, the inherent difficulty in conducting such trials (including ethical issues of placebo-controlled designs), the fact that the cognitive impairment is characteristically subtle and that the patients might be able to compensate for their deficits during testing, gives rise to questions about the degree and the extent of the problem-and indeed even if there is a problem. Neuroimaging techniques might offer additional insight. This chapter is a succinct summary of a more expanded review of the relatively few such studies.

A systemic literature review of neuroimaging studies in women with breast cancer treated with adjuvant chemotherapy

“…Based on the studies carried out using neuroimaging methods, it is possible to describe the cognitive deficits caused by adjuvant chemotherapy [72]. Specific, albeit small, structural changes and functional changes within the central nervous system are associated with the minor specific impairments of cognitive functions described in literature [72].…”

“…Specific, albeit small, structural changes and functional changes within the central nervous system are associated with the minor specific impairments of cognitive functions described in literature [72]. …”

“…A greater expenditure of energy on mental activities can lead to increased fatigue and be associated with the deterioration in cognitive effectiveness and quality of life suffered by the patients [63]. Even though neuroimaging methods are not free from limitations, using them in CRCI studies in combination with self-descriptive and neuropsychological methods may yield a broader image of the described phenomenon [72]. …”

Opening up the Window into “Chemobrain”: A Neuroimaging Review

“…Additionally, the neural structures and/or circuits that are being affected by chemotherapy treatment are still relatively unknown. In an attempt to provide empirical evidence for chemotherapy-related CRCI, neuro-imaging tools are increasingly being used to examine the effects of chemotherapy on the brain and cognition [33,35,36]. Application of such tools could help uncover a neural basis for the subtle cognitive deficits in affected patients.…”

A proposed mechanism for chemotherapy-related cognitive impairment (‘chemo-fog’)

“…A postulated adverse effect associated with adjuvant cancer chemotherapy is a mild cognitive impairment (variously called ‘chemo-fog’, ‘chemo-brain’ or similar term) (1, 2). The cognitive domains that are most often detected as being impaired include verbal and visual memory, attention, concentration, language, motor skills, multitasking and ability to organize information.…”