Neurologic injury has many forms resulting from several causes. These broad categories include:
Traumatic Brain Injury (TBI): Damage to living brain tissue caused by an external, mechanical force. It is usually characterized by a period of altered consciousness (amnesia or coma) that can be very brief (minutes) or very long (months/indefinitely). The specific disabling condition(s) may be orthopedic, visual, aural, neurologic, perceptive/cognitive, or mental/emotional in nature. The term does not include brain injuries that are caused by insufficient blood supply, toxic substances, malignancy, disease producing organisms, congenital disorders, birth trauma or degenerative processes.TBI may result from:
Closed Head Injury (CHI)): A subset of a traumatic brain injury in which the skull is not breeched. Occurs when the head accelerates and then rapidly decelerates or collides with another object (for example the windshield of a car) and brain tissue is damaged, not by the presence of a foreign object within the brain, but by violent smashing, stretching, and twisting, of brain tissue. Closed brain injuries typically cause diffuse tissue damage that result in disabilities which are generalized and highly variable.
Acquired Brain Injury (ABI): The implication of this term is that the individual experienced normal growth and development from conception through birth, until sustaining an insult to the brain at some later time which resulted in impairment of brain function.Types of acquired brain injury:
An abscess is a collection of pus in a pocket formed by an infectious process. This infectious process is usually caused by bacteria or parasites.
An aneurysm is a ballooning of a section of blood vessel usually at a juncture point. This becomes susceptible to breaking or leaking. When this occurs in the brain, it will cause damage from the blood interacting with the brain cells, and the increased pressure in the skull.
Anoxic brain injury
An anoxic/hypoxic brain injury occurs when a person is without oxygen for a period of time. This can occur due to various causes such as cardiopulmonary arrest, carbon monoxide poisoning, or drowning. The effects of an anoxic/hypoxic injury tend to be diffuse and global though some portions of the brain are more impacted by the lack of oxygen than others.
Arterioveneous Malformation (AVM)
Arterioveneous Malformation (AVM) occurs when the capillaries from the arteries and veins connect in a nonstandard manner. An AVM causes an increase in the size of the blood vessels and is often thin increasing the potential for a bleed in the brain.
A stroke occurs when blood flow to a portion of the brain becomes disrupted. This can occur due to a blood clot becoming lodged in the blood vessel, an embolism (such as plaque from cholesterol) becoming lodged in the blood vessel, or the blood vessel leaking from a tear. Strokes tend to be circumscribed and to impact a specific area of functioning such as language production, or motor movement.
Encephalitis refers to an infection of the brain causing swelling and disruption of the neuron communications. The cause of the infection can be viral, bacterial, or fungal.
Encephalopathy is a general term that refers to damage to the brain and is usually preceded by the cause of the damage such as anoxic encephalopathy.
An epidural hemorrhage occurs when the bleed occurs between the dura matter and the skull. This will cause increased pressure within the skull and can cause the brain to shift in the skull away from the area of bleed.
Fetal Alcohol Syndrome (FAS)
Fetal Alcohol Syndrome (FAS) occurs when a female drinks excessive amounts of alcohol during her pregnancy. The child with FAS is born with specific physical defects and neurologic delays that impact their ability to succeed in school and society.
An intraventricular hemorrhage occurs when there is bleeding into the ventricles of the brain. This can occur following a traumatic brain injury when the blood vessels are damaged. This can lead to blockages in the ventricles and increased pressure in the brain.
Meningitis refers to the swelling of the tissues that cover the brain and form the blood brain barrier. This swelling tends to be caused by infection from a bacterium or a virus.
Metabolic encephalopathy occurs when an individual suffers an imbalance in the chemistry and/or hormone levels in the body which cause the individual to suffer from an insult that will affect the brain. Metabolic encephalopathy can occur from insulin shock, acute renal failure, and liver disease.
Seizure disorders occur when the brain’s electrical signals are misfired causing convulsions and cognitive confusion. Seizures can result from several different causes such as epilepsy, electrolyte imbalance, and drug overdose.
A subdural hematoma occurs when there is bleeding below the dura matter, which encases the brain. When this occurs, the blood can potentially be reabsorbed or continue to increase pressure within the skull. If the pressure in the skull continues to increase, the skull would have to be opened to remove the excess blood.
A subarachnoid hemorrhage refers to a bleed below the arachnoid layer of the dura matter enclosing the brain. This will cause increased pressure within the skull and can require surgical intervention to remove the excess blood.
Torrette Syndrome refers to a motor/vocal tic disorder that includes stereotypical motor movements and verbalizations. This is associated with neurologic issues and obsessive compulsive types of symptoms.
Toxic exposure can result from in utero exposure to substances such as alcohol, cocaine, or other drugs and medication. Other forms of toxic exposure would include solvents such as gasoline.
Tumors can occur in any point in the brain. The tumors can form from the tissues of the brain itself, the surrounding membranes, or can result from metastatic spread from another primary area of occurrence. The tumors cause damage in two possible ways, by displacing the brain tissue and increasing pressure in the skull, or by invading and destroying the brain tissues.