Post-chemotherapy cognitive impairment
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Fahimeh Shojaei, M.D., Maria Fernanda Villarreal, M.D. [2]
Synonyms and keywords: Chemotherapy-induced cognitive dysfunction; Chemo brain; Chemo fog; Chemobrain; PCCI
Overview
Post-chemotherapy cognitive impairment (also known as chemotherapy-induced cognitive dysfunction) is defined as the cognitive impairment that can result from chemotherapy treatment. Post-chemotherapy cognitive impairment was first discovered and described in 1980. Post-chemotherapy cognitive impairment is characterized by changes in memory, fluency, and other cognitive abilities that impeded their ability to function as they had pre-chemotherapy. Approximately 20-30% of patients that undergo chemotherapy experience some level of post-chemotherapy cognitive impairment. The exact pathogenesis of post-chemotherapy cognitive impairment is not fully understood. However, the underlying mechanisms of the disease are believed to be caused by direct neurotoxicity. Genes involved the development of post-chemotherapy cognitive impairment, include COMT nucleotide polymorphism, Apolipoprotein E gene, and BDNF gene mutations. Post-chemotherapy cognitive impairment is more commonly observed among middle aged and elderly patients. The median age at diagnosis ranges between 40-70 years old. There are no specific imaging findings associated with post-chemotherapy cognitive impairment. However, in some cases MRI may detect accurate measurement of therapy-induced changes in grey and white matter volumes. Recent studies suggest further investigation on the underlying mechanisms of cognitive impairment.
Historical Perspective
Post-chemotherapy cognitive impairment was first discovered and described in 1980 following the increasing number of breast cancer survivors.[1]
Classification
There is no classification system for post-chemotherapy cognitive impairment.[1]
Pathophysiology
- The pathogenesis of post-chemotherapy cognitive impairment is not fully understood.[1]
- However, the underlying pathophysiology is believed to be caused by direct neurotoxicity.
- Genes involved the development of post-chemotherapy cognitive impairment, include:[2][3]
- COMT nucleotide polymorphism
- Apolipoprotein E
- Brain-derived neurotropic factor (BDNF) gene
Causes
- Common chemotherapeutic agents causing post-chemotherapy cognitive impairment, include:[4]
Differentiating Post-Chemotherapy Cognitive Impairment from Other Diseases
- Post-chemotherapy cognitive impairment must be differentiated from other diseases that cause cognitive impairment (such as, lack of attention, orientation to time and space), such as:[1]
Epidemiology and Demographics
Prevalnce
- The prevalence of post-chemotherapy cognitive impairment remains unknown but approximately 20-30% of patients that undergo chemotherapy experience some level of post-chemotherapy cognitive impairment.[5]
Age
- Post-chemotherapy cognitive impairment is more commonly observed among patients aged 40-70 years old.
Gender
- Females are slightly more commonly affected with post-chemotherapy cognitive impairment than males.
Race
- There is no racial predilection for post-chemotherapy cognitive impairment.
Risk Factors
The most common risk factor in the development of post-chemotherapy cognitive impairment include:
- High number of cycles of chemotherapy.[4]
- Smoking[3]
Screening
There is insufficient evidence to recommend routine screening for Post-chemotherapy cognitive impairment.
Natural History, Complications and Prognosis
- The majority of patients with post-chemotherapy cognitive impairment are initially asymptomatic.[1]
- Early clinical features, include:
- Lack of attention
- Memory loss
- Problems to recall
- Lack of orientation
- If left untreated, patients with post-chemotherapy cognitive impairment may progress to develop severe cognitive impairment.
- Common complications of post-chemotherapy cognitive impairment, include:[4]
- Decreased executive function
- Cerebrovascular disorders
- Focal neurological deficits
- Prognosis is generally good, and symptoms of post-chemotherapy cognitive impairment typically disappear in about four years.
Diagnosis
Diagnostic Study of Choice
There are no established criteria for the diagnosis of post-chemotherapy cognitive impairment. The diagnosis of post-chemotherapy cognitive impairment is based on the history and symptoms.
History and Symptoms
- Patients with post-chemotherapy cognitive impairment may have aggravating factors such as:
- Post-chemotherapy cognitive impairment is usually asymptomatic at diagnosis.
- Symptoms of post-chemotherapy cognitive impairment may include the following:[1]
- Memory loss
- Lack of attention
- Difficult language fluency
- Poor calculation and recall
- Loss of appetite
- Irritability or constant mood swings
- Hopelessness
Physical Examination
- Patients with post-chemotherapy cognitive impairment usually appear malnourished and pale.
- Physical examination shows no remarkable findings for patients with post-chemotherapy cognitive impairment.[4]
Laboratory Findings
- There are no specific laboratory findings associated with post-chemotherapy cognitive impairment.[1][6]
- In some cases, elevated levels of apolipoprotein (APOE) allele may be seen in patients with post-chemotherapy cognitive impairment
Electrocardiogram
There are no ECG findings associated with post-chemotherapy cognitive impairment.
X-ray
There are no x-ray findings associated with post-chemotherapy cognitive impairment.
Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with post-chemotherapy cognitive impairment.
CT scan
There are no CT scan findings associated with post-chemotherapy cognitive impairment.
MRI
There are no MRI findings associated with post-chemotherapy cognitive impairment.
Other Imaging Findings
There are no other imaging findings associated with post-chemotherapy cognitive impairment.
Other Diagnostic Studies
There are no other diagnostic studies associated with post-chemotherapy cognitive impairment.
Treatment
Medical Therapy
- The majority of cases of post-chemotherapy cognitive impairment are self-limited and require only supportive care including:
- Behavioral interventions
- Relaxation
- Exercise
- Group therapy
- Brain-training programs
- Pharmacologic interventions
- Behavioral interventions
Surgery
Surgery is not recommended for patients with post-chemotherapy cognitive impairment.
Primary Prevention
There are no primary preventive measures available for post-chemotherapy cognitive impairment.
Secondary Prevention
There are no secondary prevention measures available for post-chemotherapy cognitive impairment.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Janelsins MC, Kohli S, Mohile SG, Usuki K, Ahles TA, Morrow GR (2011). "An update on cancer- and chemotherapy-related cognitive dysfunction: current status". Semin. Oncol. 38 (3): 431–8. doi:10.1053/j.seminoncol.2011.03.014. PMC 3120018. PMID 21600374.
- ↑ Ng, Terence; Lee, Ying Yun; Chae, Jung-woo; Yeo, Angie Hui Ling; Shwe, Maung; Gan, Yan Xiang; Ng, Raymond C. H.; Chu, Pat Pak Yan; Khor, Chiea Chuen; Ho, Han Kiat; Chan, Alexandre (2017). "Evaluation of plasma brain-derived neurotrophic factor levels and self-perceived cognitive impairment post-chemotherapy: a longitudinal study". BMC Cancer. 17 (1). doi:10.1186/s12885-017-3861-9. ISSN 1471-2407.
- ↑ 3.0 3.1 Ahles, Tim A.; Li, Yuelin; McDonald, Brenna C.; Schwartz, Gary N.; Kaufman, Peter A.; Tsongalis, Gregory J.; Moore, Jason H.; Saykin, Andrew J. (2014). "Longitudinal assessment of cognitive changes associated with adjuvant treatment for breast cancer: the impact ofAPOEand smoking". Psycho-Oncology. 23 (12): 1382–1390. doi:10.1002/pon.3545. ISSN 1057-9249.
- ↑ 4.0 4.1 4.2 4.3 Aleah J. McHenry, MSN, RN. Management of Chemotherapy Induced Cognitive Impairment. http://www.oncolink.org/resources/article.cfm?id=1057 Accesed on May 18, 2016
- ↑ Janelsins, Michelle C.; Kesler, Shelli R.; Ahles, Tim A.; Morrow, Gary R. (2014). "Prevalence, mechanisms, and management of cancer-related cognitive impairment". International Review of Psychiatry. 26 (1): 102–113. doi:10.3109/09540261.2013.864260. ISSN 0954-0261.
- ↑ Ahles, Tim A.; Li, Yuelin; McDonald, Brenna C.; Schwartz, Gary N.; Kaufman, Peter A.; Tsongalis, Gregory J.; Moore, Jason H.; Saykin, Andrew J. (2014). "Longitudinal assessment of cognitive changes associated with adjuvant treatment for breast cancer: the impact ofAPOEand smoking". Psycho-Oncology. 23 (12): 1382–1390. doi:10.1002/pon.3545. ISSN 1057-9249.