Memory
loss, attention deficits, difficulty learning, and mood changes are commonly reported side effects of
chemotherapy. Direct neurotoxic effects of
chemo agents (or the metabolites), and hormonal changes induced by
the treatment may all play a role.
Dose and dose timing, age, genetic factors, and the specific chemo agents may also influence the extent,
duration, and the type of side effects each person will experience.
"Within one year of treatment, many people find these difficulties greatly improve or no longer exist. However, for some people,
"chemobrain" can continue for years following completion of treatment."
cancercare.org
pdf
Here we provide resources
and links to articles on "chemo brain" - a
reported side effect of chemotherapy. It appears that
additional studies
will be needed to better measure and understand chemo-induced damage to
cognitive and psychological brain function.
Are there tests to
measure damage to the brain from chemo?
We anticipate that baseline tests (cognitive and imaging) prior to
treatment would be required in order to objectively measure injury,
and that tests to definitively measure chemotherapy-induced damage
do not exist at this time.
It is also possible that stress, anxiety, and
depression - often associated with the diagnosis of a cancer and
treatments - plays a role in these effects.

Resources
 |
Chemotherapy and Cognitive Function: Maybe It Is All in Their
Heads? Medscape
(free login)
|
 |
Memory Problems Following
Chemotherapy WebMD
|
 |
Prednisone PAL
|
 |
|
 |
Doctor, Can We Talk About Chemobrain? Cancercare.org
PDF
|
 |
Depression self-assessment test mayoclinic.com
|

Related Articles
 | Review: Renaming
"chemobrain". Cancer Invest. 2007 Sep;25(6):373-7. Review.
PMID: 17882646
For some, a fear of this side effect enters into their decision
regarding therapy. Our review of the literature reveals that
so-called "chemobrain" is complex and that factors other
than chemotherapy may affect cognitive function, including the
impact of surgery and anesthesia, hormonal therapy, menopause,
anxiety, depression, fatigue, supportive care medications, genetic
predisposition, comorbid medical conditions, or possibly
paraneoplastic phenomenon. Studies to date have differed in their
assessment and definition of cognitive impairment, thus, making
comparisons between studies difficult.
We propose that the phenomenon commonly referred to as "chemobrain"
would be more accurately labeled "cancer- or
cancer-therapy-associated cognitive change."
|
 | Cognitive function recovers after stem cell
transplant oncolink.org
To investigate, the researchers initially studied 286 patients
who were randomized to be tested pre-transplant and 6 and 12
months, and another 124 were tested at 6 and 12 months.
Eighty-three patients who were tested at 12 months only were not
included in the analysis.
|
 | Neuropsychological changes from pretransplant
to one year in patients receiving
myeloablative allogeneic hematopoietic cell transplant bloodjournal.org
(2006)
|
 | ADD Drug Shows Effectiveness Against
"Chemobrain" nci.nih.gov
Also see Focalin, a refined formulation of Ritalin (d,l-methylphenidate
HCl) centerwatch.com
TOPIC SEARCH: ClinicalTrials.gov
| Outcomes: Web
|
 | Mechanisms of chemotherapy-induced
cognitive disorders: neuropsychological, pathophysiological,
and neuroimaging perspectives. Semin Clin Neuropsychiatry.
2003 Oct;8(4):201-16. PMID:
14613048 or Readable version | Related
articles
|
 | Cognitive performance and magnetic
resonance imaging findings after high-dose systemic and
intraventricular chemotherapy for primary central nervous
system lymphoma.
Arch Neurol. 2003 Apr;60(4):563-8. PMID:
12707070 | Related
articles
|

Readable Abstract
Semin Clin Neuropsychiatry. 2003 Oct;8(4):201-16.
Mechanisms of chemotherapy-induced cognitive disorders: neuropsychological, pathophysiological, and neuroimaging perspectives.
Saykin AJ, Ahles TA, McDonald BC.
Brain Imaging Laboratory, Dartmouth Medical School, Lebanon, NH 03756, USA. saykin@dartmouth.edu
Recent studies have indicated the frequent occurrence of neuropsychologic
(psychological) deficits and cognitive (thinking) complaints after systemic
(not local) cancer chemotherapy. Most early reports were retrospective, but prospective longitudinal studies are underway.
Although the available evidence suggests a fairly diffuse pattern of changes, memory and executive functions could be preferentially affected. Preliminary data also suggest that some individuals might be more vulnerable than others, leading to investigation of genetic and other risk factors.
The greatest gap in our knowledge regarding chemotherapy-related cognitive changes is a lack of understanding of the mechanism or mechanisms that account for the observed changes.
Several pathophysiological candidates include direct neurotoxic effects leading to atrophy
(death) of cerebral gray matter (GM) and/or demyelination (Progressive
destruction of the myelin sheath that protects the nerves and allows
for uninterrupted transmission of nerve impulses) of white matter (WM) fibers, secondary immunologic responses causing inflammatory reactions, and microvascular
small blood vessel) injury. Altered neurotransmitter levels and metabolites
(compounds produced by the chemotherapy) could constitute an additional mechanism related to neurotoxic
(toxic to brain) effects.
Advanced brain imaging techniques can directly or indirectly assess many of these mechanisms, but to date there has been very limited application of these tools.
Morphometric magnetic resonance imaging (MRI), functional MRI (fMRI), diffusion tensor imaging (DTI), and MR spectroscopy (MRS) are noninvasive techniques that could yield important complementary data regarding the nature of neural changes after chemotherapy.
Electrophysiological studies and targeted molecular imaging with positron emission tomography (PET) could also provide unique information.
We review the minimal imaging data available at present and also note studies of other brain disorders or treatment effects that might serve as a model for imaging chemotherapy-induced changes.
Large-scale prospective studies are needed to help isolate the pathophysiological
mechanisms underlying the cognitive deficits associated with chemotherapy.
PMID: 12707070
|