Brain Health & Dysfunction
The Role of Cerebellar Atrophy
CHRIS D. MELETIS, ND
Mind-body medicine is the ability of the brain to improve the health of the body. However, if cognitive function is not operating at peak capacity, the brain will not be able to impact bodily health. In this article, I will address the importance of brain health and show how the relationship between the mind and the body is bidirectional. Keeping the body healthy can also affect the health of the brain. Specifically, it’s important to address the underappreciated role of the cerebellum relative to concentration, thinking, focus, cognitive function, and so much more.
What Is the Cerebellum?
Before addressing the effects of cerebellar atrophy on brain health, we must attend a lesson in brain anatomy 101 to refresh our minds on what the cerebellum is and what it does. The cerebellum (Latin for “little brain”) is the largest structure of the hindbrain. It is located at the back of the skull under the hemispheres of the cerebral cortex.
The cerebellum comprises about 10% of brain volume1 but contains over half of its neurons.2 The cerebellum is best known for coordinating voluntary movements. The cerebellum is also involved in how the brain processes thinking, language, and mood, and regulates attention span. The cerebellum has several lobules, each controlling different aspects of cognitive health. The lobules include:
- Vermis: involved in affective processes
- Posterior lobules: involved in complex cognitive operations
- Right cerebellar hemisphere: regulates linguistic tasks
- Left cerebellar hemisphere: controls visual-spatial tasks1
Cerebellar Atrophy: An Underrecognized Threat
Cerebellar atrophy is the loss of neurons and synapses of the cerebellum leading to brain shrinkage. It is an important cause of impaired cognitive function but is rarely recognized or treated in clinical practice. Typical symptoms of cerebellar pathology include ataxia symptoms such as stumbling, slurred speech, falling, and lack of coordination. However, there is a growing appreciation among scientists for the role of cerebellar atrophy in neurodegenerative conditions, including:1,3
- Alzheimer’s disease
- Frontotemporal dementia
- Amyotrophic lateral sclerosis
- Multiple system atrophy
- Progressive supranuclear palsy
- Multiple sclerosis
Cerebellar atrophy can be caused by several factors such as severe traumatic head injury and chronic high cortisol levels such as those seen in Cushing’s disease. In other cases, such as Parkinson’s or Alzheimer’s disease, we don’t know if the cerebellar atrophy plays a role in causing a particular condition or is an effect of the disease. More than likely, it’s a vicious circle whereby cerebral atrophy plays a role in the development of neurodegenerative disorders, and those disorders exacerbate cerebral atrophy, which subsequently worsens neurodegeneration.
Severe Traumatic Head Injury
In traumatic brain injury, the cerebellum has fewer studies than the cortical areas and hippocampus. There is limited evidence from structural and functional imaging that the cerebellum is vulnerable to damage.4 The cerebellum communicates with the cerebral cortex. A possible explanation for the cerebellar atrophy that occurs in traumatic head injury is that there is an interruption in communication between these regions of the brain.5 In a study of 13 children with severe traumatic head injuries, 6 of them had cerebellar subcortical atrophy.5 The researchers observed reduced scores in verbal, performance, and IQ tests in 3 of those children.
Chronic High Cortisol Levels
We live in a stressful world filled with deadlines and responsibilities and provocative national headlines. Unsurprisingly, most patients have imbalanced cortisol levels, which may affect brain health. Long-term elevated cortisol levels, such as those seen in Cushing’s disease, are associated with cerebellar atrophy. 6 Exposure to chronic high cortisol levels in Cushing’s disease leads to atrophy of the brain, with certain regions being more impacted than others. The cerebellum is particularly susceptible to atrophy from elevated cortisol levels.6 Patients with untreated Cushing’s disease have a pronounced decline in the gray matter of the cerebellum and the hippocampus.6
Aging is associated with cerebellar atrophy. A study used computed tomography to detect cerebellar atrophy in the brains of 2 102 healthy subjects of varying ages who did not have any neurological disorders.7 The study divided the subjects into 10 different age groups: 3 age groups comprising the first decade of life, an age group per decade thereafter through the seventh decade, and the last for all subjects over the age of 70. The study confirmed that the incidence of cerebellar atrophy increased gradually with age in subjects aged 20 and older. It was especially noteworthy in subjects over the age of 60.
Autism Spectrum Disorders and ADHD
The majority of autism spectrum disorder (ASD) patients have cerebellar abnormalities. A neuroinflammatory response has also been detected in the cerebellum of people with ASD. Autistic patients have significantly smaller vermis sizes in their cerebellum compared to controls.8 There’s also evidence that some of the behavioral impairments that occur in autism may be related to dysfunction of the frontal lobe of the cerebellum.8
Evidence implicates cerebellar atrophy in attention-deficit hyperactivity disorder (ADHD). Researchers have observed reduced volume in the cerebellar network in ADHD. A meta-analysis found that the cerebellum was among several brain regions that suffered reductions in volume in ADHD.9
Many neurodegenerative disorders are associated with cerebellar atrophy. A meta-analysis detected the presence of cerebellar gray matter atrophy in Alzheimer’s disease, frontotemporal dementia, amyotrophic lateral sclerosis, multiple system atrophy, and progressive supranuclear palsy.3 In this review, cerebellar atrophy was not observed in Parkinson’s disease and Huntington’s disease. However, other research supports the role of cerebellar atrophy in Parkinson’s disease. A study found that cerebellar alterations are involved in Parkinson’s and that cerebellar atrophy plays a role in the depression and anxiety that occur in Parkinson’s.10
In multiple sclerosis patients, cerebellar atrophy leads to certain clinical aspects of the disease. A study of 61 patients with relapse-onset multiple sclerosis found that MS patients with depression or fatigue had significantly lower volume in specific cerebellar lobules compared to patients without depression or fatigue.1
Other Disorders Linked to Cerebellar Atrophy
A surprising number of conditions have been associated with cerebellar atrophy.8,11,12 These include:
- Anorexia nervosa
- Major depressive disorder
- Bipolar disorders
- Post-traumatic stress disorder
- Panic attacks
- Obsessive-compulsive disorder
Neuroinflammation is a driving force behind many neurodegenerative disorders. In patients who have suffered a stroke, significant neurodegeneration that involves the progressive death of neurons can occur even in patients who outwardly seem to be recovering.13 Neuroinflammation due to the release of proinflammatory cytokines plays a key role in this post-stroke neurodegeneration.13 There is an indication that a prolonged neuroinflammatory response continues long after the initial stroke, resulting in worse long-term outcomes, especially the development of dementia.13
Neuroinflammation is also involved in the progression of Alzheimer’s disease through the production of proinflammatory cytokines and the activation of microglia and astrocytes.14 Microglia are cells located in the brain and spinal cord. They make up 10-15% of all cells in the brain and are a part of the central nervous system’s immune defense. Astrocytes are the most common type of cell in the central nervous system. They perform various tasks, including maintaining the integrity of the blood-brain barrier and supporting healthy synapses.
Solutions for Keeping the Brain Healthy
Cognitive decline is not inevitable; no matter what a patient’s age, supporting a healthy brain will also maintain a healthy body and vice versa. Here are some approaches I frequently recommend to patients who want to keep their brains sharp and focused.
One of the best examples of how physical health can impact mental health is the effect of exercise on the brain. Several large studies have found that older people who are more physically active have a significantly lower risk of developing Alzheimer’s disease and cognitive impairment.15-18 A meta-analysis evaluating 18 studies concluded that aerobic exercise enhances cognitive function in the elderly.19 Research in the elderly has also found that resistance exercise is as protective to cognitive function as aerobic exercise.20 Furthermore, the brains of even low-mobility seniors can benefit from exercise.21
Zing Coordination Training
In clinical practice and for my benefit I use a computer-based program called Zing that identifies your brain’s weak spots and customizes exercises for the individual. The Zing Performance program trains the cerebellum and takes the burden off the processing capacity of the cerebral cortex.22 When well trained, the cerebellum can help complete rote memory functions.
Research supports the use of coordinative exercises for improving brain function, which is the concept behind Zing. For example, in a study of 40 participants with a mean age of 79 years, an 8-week coordination training program led to a significant improvement in dementia rating scale scores.21 In another study of 52 adolescents, coordinative exercises led to greater improvements in attention and concentration compared to regular physical exercise.23
One of the most effective ways to counteract neuroinflammation is to supplement with nicotinamide riboside, a precursor to nicotinamide adenine dinucleotide (NAD+). NAD+ is a cofactor for several enzymes involved in cellular energy metabolism. Cell culture research indicates that by boosting NAD+, nicotinamide riboside can suppress neuroinflammation, while rodent research indicates it can reduce ataxia and improve motor function.24 A double-blind, phase 1 clinical trial used 1 000 mg/day of nicotinamide riboside or a placebo on newly diagnosed, untreated Parkinson’s disease patients for 30 days.25 The study found that the patients treated with nicotinamide riboside had mild clinical improvement. In contrast, the placebo group experienced a slight decline. Patients given nicotinamide riboside also had reduced inflammatory cytokines in the serum and cerebrospinal fluid.
More than likely, as time unfolds, more and more ways to support brain health will be discovered. Science continues to uncover new and novel functions of the human body and mind. As we see from the research, the body’s physical health contributes to the brain’s health. Our predecessors in functional and naturopathic medicine were pioneers in creating methods to protect brain health. Since “necessity is the mother of invention” and more strategies are needed as we learn more about the brain, let’s continue their spirit of innovation for the health of all people.[REFS]
- Lazzarotto A, Margoni M, Franciotta S, et al. Selective Cerebellar Atrophy Associates with Depression and Fatigue in the Early Phases of Relapse-Onset Multiple Sclerosis. Cerebellum. 2020;19(2):192-200.
- Li WK, Hausknecht MJ, Stone P, et al. Using a million cell simulation of the cerebellum: network scaling and task generality. Neural Netw. 2013;47:95-102.
- Gellersen HM, Guo CC, O’Callaghan C, et al. Cerebellar atrophy in neurodegeneration-a meta-analysis. J Neurol Neurosurg Psychiatry. 2017;88(9):780-788.
- Spanos GK, Wilde EA, Bigler ED, et al. Cerebellar atrophy after moderate-to-severe pediatric traumatic brain injury. AJNR Am J Neuroradiol. 2007;28(3):537-542.
- Soto-Ares G, Vinchon M, Delmaire C, et al. Cerebellar atrophy after severe traumatic head injury in children. Childs Nerv Syst. 2001;17(4-5):263-269.
- Burkhardt T, Lüdecke D, Spies L, et al. Hippocampal and cerebellar atrophy in patients with Cushing’s disease. Neurosurg Focus. 2015;39(5):E5.
- Nishimiya J. [CT evaluation of cerebellar atrophy with aging in healthy persons]. No To Shinkei. 1988;40(6):585-591.
- Hoppenbrouwers SS, Schutter DJ, Fitzgerald PB, et al. The role of the cerebellum in the pathophysiology and treatment of neuropsychiatric disorders: a review. Brain Res Rev. 2008;59(1):185-200.
- Valera EM, Faraone SV, Murray KE, et al. Meta-analysis of structural imaging findings in attention-deficit/hyperactivity disorder. Biol Psychiatry. 2007;61(12):1361-1369.
- Ma X, Su W, Li S, et al. Cerebellar atrophy in different subtypes of Parkinson’s disease. J Neurol Sci. 2018;392:105-112.
- Addolorato G, Taranto C, Capristo E, et al. A case of marked cerebellar atrophy in a woman with anorexia nervosa and cerebral atrophy and a review of the literature. Int J Eat Disord. 1998;24(4):443-447.
- de la Monte SM, Kril JJ. Human alcohol-related neuropathology. Acta Neuropathol. 2014;127(1):71-90.
- Stuckey SM, Ong LK, Collins-Praino LE, et al. Neuroinflammation as a Key Driver of Secondary Neurodegeneration Following Stroke? Int J Mol Sci. 2021;22(23).
- Hou Y, Lautrup S, Cordonnier S, et al. NAD(+) supplementation normalizes key Alzheimer’s features and DNA damage responses in a new AD mouse model with introduced DNA repair deficiency. Proc Natl Acad Sci U S A. 2018;115(8):E1876-e1885.
- Etgen T, Sander D, Huntgeburth U, et al. Physical activity and incident cognitive impairment in elderly persons: the INVADE study. Arch Intern Med. 2010;170(2):186-193.
- Geda YE, Roberts RO, Knopman DS, et al. Physical exercise, aging, and mild cognitive impairment: a population-based study. Arch Neurol. 2010;67(1):80-86.
- Laurin D, Verreault R, Lindsay J, et al. Physical activity and risk of cognitive impairment and dementia in elderly persons. Arch Neurol. 2001;58(3):498-504.
- Yaffe K, Barnes D, Nevitt M, et al. A prospective study of physical activity and cognitive decline in elderly women: women who walk. Arch Intern Med. 2001;161(14):1703-1708.
- Colcombe S, Kramer AF. Fitness effects on the cognitive function of older adults: a meta-analytic study. Psychol Sci. 2003;14(2):125-130.
- Cassilhas RC, Viana VA, Grassmann V, et al. The impact of resistance exercise on the cognitive function of the elderly. Med Sci Sports Exerc. 2007;39(8):1401-1407.
- Kwok TC, Lam KC, Wong PS, et al. Effectiveness of coordination exercise in improving cognitive function in older adults: a prospective study. Clin Interv Aging. 2011;6:261-267.
- What Is Zing Performance? https://www.zingperformance.com/the-science/. Accessed May 9, 2022.
- Budde H, Voelcker-Rehage C, Pietrabyk-Kendziorra S, et al. Acute coordinative exercise improves attentional performance in adolescents. Neurosci Lett. 2008;441(2):219-223.
- Yang B, Dan X, Hou Y, et al. NAD(+) supplementation prevents STING-induced senescence in ataxia telangiectasia by improving mitophagy. Aging Cell. 2021;20(4):e13329.
- Brakedal B, Dölle C, Riemer F, et al. The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson’s disease. Cell Metab. 2022;34(3):396-407.e396.
Dr. Chris D. Meletis is an educator, international author and lecturer. His personal mission is “Changing World’s Health One Person at a Time.” He believes that when people become educated about their body is the moment when change begins. He has authored 16 books and over 200 national scientific articles in such journals and magazines as Natural Health, Alternative and Complementary Therapies, Townsend Letter for Doctors and Patients, Life Extension and Natural Pharmacy. Dr. Meletis served as Dean of Naturopathic Medicine and Chief Medical Officer for 7 years and was awarded the 2003 physician of the year by the American Association of Naturopathic Physicians.