Closed Head Traumatic Brain Injury (TBI)
Closed head traumatic brain injury (TBI) is physical harm to the brain caused by the brain's rapid acceleration and deceleration within the skull. It occurs when the head is subjected to a sudden and violent external force such as a baseball striking the head of a spectator at a baseball game or impact with a steering wheel or windshield during an car wreck. A closed head injury can also occur if the head is violently shaken; tragically, this sometimes affects babies who are shaken by angry caregivers (shaken baby syndrome). Closed head injury is also common among American soldiers in Iraq whose heads come into close contact with improvised explosive devices (IEDs).
Many closed head injuries, which can have costly and lifelong consequences, are caused or worsened by someone's negligence. When head injuries are caused by another party, people harmed are often eligible for compensation for medical bills and pain and suffering. If you think your closed head injury was someone else's fault, contact a personal injury attorney who can help evaluate your specific situation, provide you with examples of settlements, determine your legal rights and help you file an injury claim.
In this article you will learn about the causes and types of closed head TBI, how they are diagnosed and treated and, finally, what to expect in terms of a prognosis.
Closed Head TBI's Distinguishing Characteristics
The term closed head traumatic brain injury refers only to injuries that occur while the brain and meninges (surrounding layers of membrane) remain physically intact, even though the skull may be fractured. A traumatic brain injury that involves open wounds caused by penetrating objects such as bullets, knives or shrapnel is called an open head injury.
Multi-focal (spread across several parts of the brain) or diffuse (spread across the entire brain) closed head TBI affects a wide range of bodily functions and, consequently, produces a wide variety of symptoms.
Causes of Closed head TBI
A closed head injury is caused by three mechanisms: tearing, compressing, and stretching or straining. Common causes of closed head TBI include:
- Motor vehicle accidents (Read about the consequences of DWI charges)
- Sports accidents
- Industrial accidents
- Child abuse
- Military accidents
Types of Closed Head TBI
There are two types of closed head injury: initial and ensuing. An initial (primary) injury consists of a temporary or permanent interruption to normal brain function or damage done to the structure of the brain that occurs at the moment of impact to or jolting of the head. An ensuing (secondary) injury occurs when harmful conditions develop subsequent to the initial injury.
Initial (primary) Injuries
Concussion. A concussion is a temporary change in brain function. The distinguishing symptoms of a concussion are temporary loss of consciousness, confusion and amnesia (memory loss). Headache, dizziness, blurred vision, nausea, vomiting, shock, anxiety and increased pulse rate may also be present. Grave symptoms include persistent confusion or drowsiness, amnesia, difficulty speaking, partial paralysis, dilation of a pupil, and coma (persistent unconsciousness).
Contusion. A contusion is a localized bruise of brain tissue. A bruise is a well-defined area of broken blood vessels that can cause brain tissue to swell and neurons (nerve cells) to be damaged. Merging of two or more bruises can produce an intracranial hematoma (blood collecting within the brain).
Two types of brain contusions can occur as a result of a closed head injury: coup and contracoup. A coup contusion occurs directly below the point of impact to the skull. A contracoup contusion occurs at the spot on the brain directly across from the point of impact to the skull.
Symptoms of a brain contusion vary depending on the size of the bruise and the area of the brain where the bruise occurs. Tiny bruises in areas of the brain that are not responsible for specific bodily functions may not exhibit symptoms. However, extensive bruising over an area or areas of the brain that do govern one or more bodily function may cause noticeable and permanent damage, interfering with the ability to think, see, remember, and/or coordinate. In a worst-case scenario, a contusion can lead to coma and death.
Epidural Hematoma. An epidural hematoma (also called extradural hematoma) is an accumulation of blood between the dura mater (outer layer of membrane sheathing the brain) and the skull caused by laceration of the middle meningeal artery or other superficial blood vessels as a result of hard contact against the rough inside of the skull.
A common characteristic of an epidural hematoma is a conscious interval followed by unconsciousness. Early symptoms of epidural hematoma during the period of consciousness include dizziness, nausea, headache, vomiting, back pain and weakness in the limbs. As the epidural hematoma expands, causing the brain to compress, symptoms broaden to include numbness, difficulty seeing, difficulty speaking, difficulty coordinating, confusion, seizures, drowsiness, loss of consciousness and coma.
Subdural hematoma. A subdural hematoma is a collection of blood between the arachnoid (middle layer of membrane sheathing the brain) and the dura mater (outer layer of membrane sheathing the brain) caused by the tearing of delicate tissue as a result of the brain moving within the skull in response to an external force. Symptoms of a subdural hematoma include headache, nausea, vomiting, memory loss, confusion, loss of consciousness, numbness and/or weakness in one or more limbs, and difficulty walking, seeing and coordinating.
Intraventricular hemorrhage. An intraventricular hemorrhage is a bleeding into the brain's inner ventricles (chambers), where cerebrospinal fluid (a water-like fluid) is manufactured. Among others, symptoms include chronic headache, difficulty walking, difficulty thinking and loss of bladder control.
Subarachnoid hemorrhage.A subarachnoid hemorrhage is bleeding on the surface of the brain that is confined between the brain and the arachnoid membrane (middle of three membranes surrounding the brain), an area ordinarily filled with cerebrospinal fluid. Symptoms include headache, nausea, vomiting, lapse of consciousness, lack of concentration, confusion, difficulty coordinating, numbness and difficulty seeing.
Diffuse axonal injury.A diffuse axonal injury refers to torn axons (nerve fibers) spread over most of the brain as a result of the brain moving back and forth and twisting inside the skull. This type of injury, which is often permanent, causes unconsciousness and can lead to coma and death.
Ensuing (secondary) Injuries
Among others, secondary injuries can include the following:
- Hemorrhage, or abnormal flow of blood out of blood vessels
- Ischemia, or insufficient blood flow to the tissues of the brain
- Edema, or swelling of brain tissues caused by an accumulation of fluid
- Increased intracranial pressure (ICP), or pressure inside the skull building in response to brain tissue swelling or fluid accumulating
- Vasospasm, or involuntary contracting or narrowing of blood vessels
- Infection, a detrimental invasion of a foreign microorganism (i.e., bacteria, virus)
- Epilepsy, a fit characterized by uncontrollable tremors and/or loss of consciousness
- Hydrocephalus, or too much buildup of fluid within the brain
To prevent or mitigate secondary injuries, patients are carefully monitored for ventilation and oxygenation and proper circulation of blood to the brain. Other secondary conditions are constantly watched for and managed.
Diagnosing and Treating a Closed Head TBI
Diagnosing and treating closed head injuries go hand-in-hand. Diagnosing a closed head injury involves using, among others, the following techniques:/p>
- Blood tests
- Evaluation, using the Glasgow Coma Scale (GCS) test or The Rancho Los Amigos Scale test (of these, the GCS is probably most used)
- Physical/neurological exams
- Electroencephalogram (EEG)
- Imaging (X-ray, CT scan, MRI, Angiography)
Mild head injuries may require nothing more than plenty of bed rest and good nutrition. However, when contusions, hematomas, skull fractures, diffuse axonal injuries and/or constricted blood vessels are identified, various treatments are considered. This may include surgery or administration of anti-coagulants to reduce immediate threats. Afterward, depending on the severity of the injuries, rehabilitation may be prescribed (i.e., speech therapy, physical therapy, occupational therapy and psychological therapy). In severe cases, long-term, full-time care may be in order. Patients with severe closed head injuries caused by another person's negligence may be eligible for compensation in the form of a settlement or court award. Contact a personal injury attorney to learn more.
The outcomes of the Glasgow Coma Scale are good indicators of whether or not a closed head TBI patient will recover and to what extent. The possible outcomes include:
- Mild disability, indicated by brief or no period of unconsciousness, promises a good chance for full recovery.
- Moderate disability, indicated by a loss of consciousness exceeding 30 minutes, promises good recovery after a period of rehabilitation.
- Severe disability, indicated by a coma, lowers the chance of full recovery, but does not eliminate it. The extent of recovery from a coma often depends upon the duration of the coma. In some cases, but not all, the need for perpetual outside care is the final outcome.
- Vegetative state (no cognitive brain function present)
On average, 1.5 million Americans suffer traumatic brain injuries every year. Of these, 50,000 die and 230,000 are hospitalized and survive, with 80,000-90,000 left permanently disabled.
Source: U.S. Department of Health & Human Services. Traumatic Brain Injury in the United States: A Report to Congress. 1999.