Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
A brain lesion describes damage or destruction to any part of the brain. It
may be due to trauma or any other disease that can cause inflammation,
malfunction, or destruction of a brain cells or brain tissue. A lesion may be
localized to one part of the brain or they may be widespread. The initial damage
may be so small as to not produce any initial symptoms, but progresses over
time to cause obvious physical and mental changes.
A brain lesion may affect the neuron directly or one of the glial cells
thereby indirectly affecting neuron functions.
Trauma is the most widely recognized cause of an
acute brain injury. Bleeding
or swelling within the skull can directly damage brain cells or the pressure
that can build within the skull can compress the brain and compromise its
ability to function. Trauma can also damage the brain on a microscopic level.
Shear injuries describe damage to the synapse connections between brain cells
decreasing their ability to communicate with each other. Recent reports have
linked concussions to the gradual destruction of brain cells that can affect
personality and thinking.
Inflammation within brain tissue can affect function. This
inflammation may be due to infections that cause
meningitis and encephalitis. Other infections may
cause discrete changes within the brain tissue. Neurocysticercosis, for example,
is the most common cause of epilepsy in the developing world; the parasite
causes small calcifications that are scattered throughout the brain. Infections may also form
abscesses within the brain that can lead to symptoms.
Certain diseases affect only specific cells within the brain. For example, the
symptoms of multiple sclerosis are caused by damage to the glial cells that
manufacture and maintain the myelin sheath that insulates axons. Without this
normal nerve covering, electrical transmission is compromised and symptoms may
occur. Alzheimer's disease and other
dementias occur when neuron cells are
affected and die prematurely.
Stroke or cerebral infarction (cerebral=brain + infarction=loss of blood
supply) describes the condition where blood supply to part of the brain is lost
and and the brain stops functioning. There are numerous reasons for blood supply to decrease.
There may be gradual narrowing of an artery to part of the brain, blockage may
occur should debris from a diseased carotid artery break loose, or a clot may
travel or embolize from the heart.
Tumors that originate from brain cells or those that metastasize from other
organs can affect brain function in two ways. The
tumor can destroy brain cells
so that their function is lost, or the tumor can take up space and cause pressure
and swelling that affects brain cell function. This may occur with benign or
cancerous tumors. Common tumors that arise from the brain include meningiomas,
adenomas, and gliomas.
Pituitary adenomas are common benign tumors that grow in the sella tursica,
where the pituitary gland sits and near where the optic nerves travel from
the eyes to the occiput in the back of the brain. As the tumor grows it can
push on the optic nerve and cause visual changes and
Glioblastoma multiforme, a malignant tumor is the most common type of
astrocytoma that arises from astrocytes and is a glioma. Victims of this tumor
include Senator Ted Kennedy, George Gershwin, and Ethel Merman.
Cerebral palsy describes the
condition where a developing infant's brain is
deprived of oxygen and fails to develop normally. This may occur in the uterus
before birth or may be due to an injury or illness that happens within the first
couple of years of life. Often it is an infection or bleeding that is the cause,
though many times the reason for cerebral palsy is never found.
Reviewed by Charles Patrick Davis, MD, PhD on 6/30/2011