Cerebral atrophy is a common feature of many of the diseases that affect the brain.
Atrophy 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 neurons and the connections between them.
Atrophy can be generalized, which means that all of the brain has shrunk; or it can be
focal, affecting only a limited area of the brain and resulting in a decrease of the functions
that area of the brain controls.
If the cerebral hemispheres are affected, conscious thought and voluntary processes
may be impaired.
Some degree of cerebral shrinkage occurs naturally with age; after the brain completes growth
and attains its maximum mass at around age 25, it gradually loses mass with each decade
of life, although the rate of loss is comparatively tiny until the age of 60, when approximately
.5 to 1% of brain volume is lost per year.
By age 75, the brain is an average of 15% smaller than it was at 25.
Some areas of the brain such as short-term memory are affected more than others and men
lose more brain mass overall than women.
Cerebral atrophy greatly increases in elderly persons and especially causes a diminution
of functions such as judgement and social appropriateness.
Possible Causes and Associated Diseases and Disorders
The pattern and rate of progression of cerebral atrophy depends on the disease involved.
Injury Stroke, loss of brain function due to a sudden
interruption of blood supply in the brain Traumatic brain injury
Steroid Use Diseases/Disorders
Alzheimer's disease Cerebral palsy, in which lesions may impair
motor coordination Senile dementia, fronto-temporal dementia,
and vascular dementia Pick’s disease, causes progressive destruction
of nerve cells in the brain Huntington's disease, and other genetic disorders
that cause build-up of toxic levels of proteins in neurons
Leukodystrophies, such as Krabbe disease, which destroy the myelin sheath that protects
axons Multiple sclerosis, which causes inflammation,
myelin damage, and lesions in cerebral tissue Epilepsy, in which lesions cause abnormal
electrochemical discharges that result in seizures
Anorexia nervosa, bulimia nervosa, and other eating disorders
Malnutrition, caused by lack or excess of nutrition from foods
Type II Diabetes, where the body does not use insulin properly resulting in high blood
sugar Mitochondrial encephalomyopathies, such as
Kearns-Sayre syndrome, which interfere with the basic functions of neurons
Infections Where an infectious agent or the inflammatory
reaction to it destroys neurons and their axons, these include...
Encephalitis, acute inflammation in the brain Neurosyphilis, an infection in the brain or
spinal chord AIDS, disease of the immune system
Symptoms Many diseases that cause cerebral atrophy
are associated with dementia, seizures, and a group of language disorders called the aphasias.
Dementia 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 causes impaired comprehension.
Expressive aphasia is reflected in odd choices of words, the use of partial phrases, disjointed
clauses, and incomplete sentences.
Reducing the Risk and Treatment Unfortunately, cerebral atrophy is not usually
preventable, however there are steps that can be taken to reduce the risks such as controlling
your blood pressure, eating a healthy balanced diet including omega-3's and antioxidants,
and staying active mentally, physically, and socially.
While most cerebral atrophy is said to be irreversible there are some recent studies
that show this is not always the case.
A child who was treated for ACTH originally showed atrophy, but four months after treatment
the brain was seemingly normal again.
References