Cerebral atrophy is a common feature of many of the diseases that affect the brain.

Atrophy Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply t ...

of any tissue means a decrement in the size of the cell, which can be due to progressive loss of cytoplasmic proteins. In brain tissue, atrophy describes a loss of

neuron A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...

s and the connections between them. Brain atrophy can be classified into two main categories: generalized and focal atrophy. Generalized atrophy occurs across the entire brain whereas focal atrophy affects cells in a specific location. If the

cerebral hemispheres The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres ...

(the two lobes of the brain that form the

cerebrum The cerebrum, telencephalon or endbrain is the largest part of the brain containing the cerebral cortex (of the two cerebral hemispheres), as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In ...

) are affected, conscious thought and voluntary processes may be impaired. Some degree of cerebral shrinkage occurs naturally with the dynamic process of

aging Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In ...

. Structural changes continue during adulthood as brain shrinkage commences after the age of 35, at a rate of 0.2% per year. The rate of decline is accelerated when individuals reach 70 years old. By the age of 90, the human brain will have experienced a 15% loss of its initial peak weight. Besides brain atrophy, aging has also been associated with cerebral microbleeds.

Symptoms

Many diseases that cause cerebral atrophy are associated with dementia,

seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

s, and a group of language disorders called the

aphasia Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. The major causes are stroke and head trauma; prevalence is hard to determine but aphasia due to stroke is estimated to be 0.1–0.4% in th ...

Dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

is characterized by a progressive impairment of memory and intellectual function that is severe enough to interfere with social and work skills. Memory, orientation, abstraction, ability to learn, visual-spatial perception, and higher executive functions such as planning, organizing and sequencing may also be impaired. Seizures can take different forms, appearing as disorientation, strange repetitive movements, loss of consciousness, or convulsions. Aphasias are a group of disorders characterized by disturbances in speaking and understanding language.

Receptive aphasia Wernicke's aphasia, also known as receptive aphasia, sensory aphasia or posterior aphasia, is a type of aphasia in which individuals have difficulty understanding written and spoken language. Patients with Wernicke's aphasia demonstrate fluent s ...

causes impaired comprehension.

Expressive aphasia Expressive aphasia, also known as Broca's aphasia, is a type of aphasia characterized by partial loss of the ability to produce language ( spoken, manual, or written), although comprehension generally remains intact. A person with expressive apha ...

is reflected in odd choices of words, the use of partial phrases, disjointed clauses, and incomplete sentences.

Causes

The pattern and rate of progression of cerebral atrophy depends on the disease involved.

Injury

Stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

, loss of brain function due to a sudden interruption of blood supply in the brain * Moderate-to-severe traumatic brain injury

Diseases and disorders

Alzheimer's disease Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...

(High resolution MRI scans have shown the progression of cerebral atrophy in Alzheimer's disease) *

Cerebral palsy Cerebral palsy (CP) is a group of movement disorders that appear in early childhood. Signs and symptoms vary among people and over time, but include poor coordination, stiff muscles, weak muscles, and tremors. There may be problems with sensa ...

, in which lesions (damaged areas) may impair

motor coordination Motor coordination is the orchestrated movement of multiple body parts as required to accomplish intended actions, like walking. This coordination is achieved by adjusting kinematic and kinetic parameters associated with each body part involved in t ...

* Senile

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

, fronto-temporal dementia, and

vascular dementia Vascular dementia (VaD) is dementia caused by problems in the supply of blood to the brain, typically a series of minor strokes, leading to worsening cognitive abilities, the decline occurring piecemeal. The term refers to a syndrome consisting ...

Pick's disease Frontotemporal dementia (FTD), or frontotemporal degeneration disease, or frontotemporal neurocognitive disorder, encompasses several types of dementia involving the progressive degeneration of frontal and temporal lobes. FTDs broadly present as ...

, causes progressive destruction of nerve cells in the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

Huntington's disease Huntington's disease (HD), also known as Huntington's chorea, is a neurodegenerative disease that is mostly inherited. The earliest symptoms are often subtle problems with mood or mental abilities. A general lack of coordination and an unst ...

, and other

genetic disorders A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders ...

that cause build-up of toxic levels of proteins in neurons * Leukodystrophies, such as

Krabbe disease Krabbe disease (KD) (also known as globoid cell leukodystrophy or galactosylceramide lipidosis) is a rare and often fatal lysosomal storage disease that results in progressive damage to the nervous system. KD involves dysfunctional metabolism of ...

, which destroy the

myelin Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be ...

sheath that protects

axon An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action po ...

s *

Multiple sclerosis Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...

, which causes inflammation, myelin damage, and lesions in cerebral tissue *

Epilepsy Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrical ...

, in which lesions cause abnormal electrochemical discharges that result in seizures *

Anorexia nervosa Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gr ...

bulimia nervosa Bulimia nervosa, also known as simply bulimia, is an eating disorder characterized by binge eating followed by purging or fasting, and excessive concern with body shape and weight. The aim of this activity is to expel the body of calories eate ...

, and other

eating disorders An eating disorder is a mental disorder defined by abnormal eating behaviors that negatively affect a person's physical or mental health. Only one eating disorder can be diagnosed at a given time. Types of eating disorders include binge eating ...

Malnutrition Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is "a deficiency, excess, or imbalance of energy, protein and other nutrients" which adversely affects the body's tissues a ...

, caused by lack or excess of nutrition from foods *

Type II diabetes Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urination, ...

, where the body does not use insulin properly resulting in high blood sugar *

Bipolar disorder Bipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that last from days to weeks each. If the elevated mood is severe or associated with ...

, significant loss of brain tissue during manic episodes; however it's not verified whether the episodes cause brain tissue loss or vice versa *

Schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...

* Mitochondrial encephalomyopathies, such as

Kearns–Sayre syndrome Kearns–Sayre syndrome (KSS), oculocraniosomatic disorder or oculocranionsomatic neuromuscular disorder with ragged red fibers is a mitochondrial myopathy with a typical onset before 20 years of age. KSS is a more severe syndromic variant of chron ...

, which interfere with the basic functions of neurons *

Posterior cortical atrophy Posterior cortical atrophy (PCA), also called Benson's syndrome, is a rare form of dementia which is considered a visual variant or an atypical variant of Alzheimer's disease (AD). The disease causes atrophy of the posterior part of the cerebral ...

: In the most posterior area of the brain lies the

visual cortex The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and ...

, the area of the brain where visual information is received and processed. When cortical atrophy occurs in this brain area due to

neurodegeneration A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic ...

, the first symptom is impairment in vision. A common vision impairment seen in patients with posterior cortical atrophy is

simultanagnosia Simultanagnosia (or simultagnosia) is a rare neurological disorder characterized by the inability of an individual to perceive more than a single object at a time. This type of visual attention problem is one of three major components (the others ...

, where a person is unable to see multiple locations at once or to quickly shift attention between these locations. When looking at images of a brain with posterior cortical atrophy, one can see a loss in volume of the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

and

ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

visual pathways, where visual stimuli is brought to the visual cortex and integrated information is sent back out to other areas of the brain. Because this disorder results in visual impairments, there is often a missed or delayed diagnosis, as the assumption is that there is a problem is in the eyes when the reality is that the problem is all the way in the back of the brain. *

Prion diseases Prions are Proteinopathy, misfolded proteins that have the ability to transmit their misfolded shape onto normal variants of the same protein. They characterize several fatal and transmissible neurodegenerative diseases in humans and many othe ...

, a group of invariably fatal encephalopathies that cause the progressive death of neurons.

Infections

Where an infectious agent or the inflammatory reaction to it destroys neurons and their axons, these include... *

Encephalitis Encephalitis is inflammation of the brain. The severity can be variable with symptoms including reduction or alteration in consciousness, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations, ...

, acute inflammation in the brain *

Neurosyphilis Neurosyphilis refers to infection of the central nervous system in a patient with syphilis. In the era of modern antibiotics the majority of neurosyphilis cases have been reported in HIV-infected patients. Meningitis is the most common neurologic ...

, an infection in the brain or spinal chord *

AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual m ...

, disease of the immune system

Drug-induced

Alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

(partially reversible): Standardized

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...

evidence suggest chronic

alcoholism Alcoholism is, broadly, any drinking of alcohol (drug), alcohol that results in significant Mental health, mental or physical health problems. Because there is disagreement on the definition of the word ''alcoholism'', it is not a recognize ...

(alcohol use disorder) is associated with widespread cortical atrophy and major brain changes. In contrast to healthy controls, macrostructural findings indicate alcoholic brains are smaller in mass and volume.

Neuroimaging Neuroimaging is the use of quantitative (computational) techniques to study the structure and function of the central nervous system, developed as an objective way of scientifically studying the healthy human brain in a non-invasive manner. Incre ...

studies also show that cortical shrinkage in "uncomplicated alcoholism" is most severe in the

frontal lobe The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a groove betwe ...

in comparison to the other divisions of the cerebral cortex. In addition,

neurological diseases A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weak ...

that co-occur with excessive alcohol consumption—such as Wernicke-Korsakoff syndrome (WKS)—are characterized by substantial volume deficits of the diencephalon structures. In comparison to unaffected, non-alcoholic participants, tissue degeneration in WKS patients is found in specific

white matter White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribution ...

structures including the corpus callosum, the hippocampus, the subcortical

basal ganglia The basal ganglia (BG), or basal nuclei, are a group of subcortical nuclei, of varied origin, in the brains of vertebrates. In humans, and some primates, there are some differences, mainly in the division of the globus pallidus into an extern ...

(hypothalamus, thalamus, putamen), and the

mammillary bodies The mammillary bodies are a pair of small round bodies, located on the undersurface of the brain that, as part of the diencephalon, form part of the limbic system. They are located at the ends of the anterior arches of the fornix. They consist o ...

. *

Antipsychotic Antipsychotics, also known as neuroleptics, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but ...

Corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involv ...

use (There appears to be correlations between degree of dosing with corticosteroids and cerebral atrophy)

Diagnosis

Neurofilament light chain

Cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...

(CSF) is a fluid that is found exclusively in the brain and spinal cord that circulates between sections of the brain offering an extra layer of protection. Studies have shown that

biomarker In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, ...

s in the CSF and

plasma Plasma or plasm may refer to: Science * Plasma (physics), one of the four fundamental states of matter * Plasma (mineral), a green translucent silica mineral * Quark–gluon plasma, a state of matter in quantum chromodynamics Biology * Blood pla ...

can be tracked for their presence in different parts of the brain—and their presence can tell us about cerebral atrophy. One study took advantage of

s, namely one called

neurofilament light chain Neurofilament light polypeptide, also known as neurofilament light chain, is a neurofilament protein that in humans is encoded by the ''NEFL'' gene. Neurofilament light chain is a biomarker that can be measured with immunoassays in cerebrospinal f ...

(NFL), in patients with

Alzheimer's Disease Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...

. Neurofilament light chain is a protein that is important in the growth and branching of neurons—cells found in the brain. In Alzheimer's Disease, neurons will stop working or die in a process called

. By tracking NFL, researchers can see this neurodegeneration, which this study showed was associated with brain atrophy and later cognitive decline in Alzheimer's patients. Other biomarkers like Ng – a protein important in long-term potentiation and memory – have been tracked for their associations with brain atrophy as well, but NFL had the greatest association.

Measures

CT of medial temporal lobe (MTA), posterior atrophy (PA) and frontal cortical atrophy (fGCA)

CT and

are most commonly used to observe the brain for cerebral atrophy. A CT scan takes cross sectional images of the brain using

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

s, while an MRI uses a magnetic field. With both measures, multiple images can be compared to see if there is a loss in brain volume over time.

Difference from hydrocephalus

Cerebral atrophy can be hard to distinguish from

hydrocephalus Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased intracranial pressure, pressure inside the skull. Older people may have headaches, double vision, poor ...

because both cerebral atrophy and hydrocephalus involve an increase in cerebrospinal fluid (CSF) volume. In cerebral atrophy, this increase in CSF volume comes as a result of the decrease in cortical volume. In hydrocephalus, the increase in volume happens due to the CSF itself.

Treatment

Cerebral atrophy is not usually preventable. However, there are steps that can be taken to reduce the risk: * controlling blood pressure * a healthy balanced diet including

omega-3 Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chem ...

's and antioxidants * staying active mentally, physically, and socially.

Reversibility of cerebral atrophy

While most cerebral atrophy is said to be irreversible, recent studies that show this is not always the case. A child who was treated with

ACTH Adrenocorticotropic hormone (ACTH; also adrenocorticotropin, corticotropin) is a polypeptide tropic hormone produced by and secreted by the anterior pituitary gland. It is also used as a medication and diagnostic agent. ACTH is an important co ...

originally showed atrophy, but four months after treatment the brain was seemingly normal again. As previously mentioned,

chronic alcoholism Alcoholism is, broadly, any drinking of alcohol that results in significant mental or physical health problems. Because there is disagreement on the definition of the word ''alcoholism'', it is not a recognized diagnostic entity. Predomina ...

is known to be associated with significant brain damage. The pronounced shrinkage in the frontal lobes and cerebellum of alcoholics correlates with serious impairments in

executive Executive ( exe., exec., execu.) may refer to: Role or title * Executive, a senior management role in an organization ** Chief executive officer (CEO), one of the highest-ranking corporate officers (executives) or administrators ** Executive dir ...

and psychomotor functions. However,

longitudinal Longitudinal is a geometric term of location which may refer to: * Longitude ** Line of longitude, also called a meridian * Longitudinal engine, an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicle, ...

studies suggest that some of these brain damages are partially reversible with

abstinence Abstinence is a self-enforced restraint from indulging in bodily activities that are widely experienced as giving pleasure. Most frequently, the term refers to sexual abstinence, but it can also mean abstinence from alcohol, drugs, food, etc. ...

''.'' In response to drinking cessation, bodies of gray and white matter including the

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of ...

, the

limbic system The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain.Schacter, Daniel L. 2012. ''Ps ...

(amygdala, hippocampus, thalamus), the

cerebellum The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...

, and the

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is cont ...

all showed a general increase in brain volume. Similarly, ventricular enlargement—which reflects atrophy of surrounding brain regions—is also reduced in abstinent alcoholics. Following extended

sobriety Sobriety is the condition of not having any measurable levels or effects from alcohol or drugs. Sobriety is also considered to be the natural state of a human being at birth. A person in a state of sobriety is considered sober. Organizations o ...

, the volume of the

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

and

third Third or 3rd may refer to: Numbers * 3rd, the ordinal form of the cardinal number 3 * , a fraction of one third * Second#Sexagesimal divisions of calendar time and day, 1⁄60 of a ''second'', or 1⁄3600 of a ''minute'' Places * 3rd Street (d ...

ventricles was decreased, and abstainers showed an improvement in working memory and balance. Finally, evidence for the recovery of brain volume with continued sobriety is supported by the improvement in neuropsychological performance. Compared to the control participants, abstinent alcoholic patients scored significantly better on tests measuring cognitive, sensory, and motor functions including

abstract reasoning Abstraction in its main sense is a conceptual process wherein general rule of inference, rules and concepts are derived from the usage and classification of specific examples, literal ("real" or "Abstract and concrete, concrete") signifiers, firs ...

, memory, visuospatial ability, and

gait Gait is the pattern of movement of the limbs of animals, including humans, during locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on speed, terrain, the need to maneuver, and energetic efficiency. Di ...

and balance. That being said, while short-term abstinence suffices to produce structural and functional recovery, some alcohol-induced brain changes may persist even after long-term sobriety.

References

{{DEFAULTSORT:Cerebral Atrophy Gross pathology