Traumatic and progressive neurological injuries

Traumatic brain injuries are caused by a blow or jolt to the head. They may be limited to a particular section of the brain or may result in generalized neurologic damage. Injuries can range from a mild concussion to severe injury, coma, and death. A minor concussion usually has no long-term side effects; however, a moderate to severe brain injury can result in headaches, amnesia, confusion, personality changes, and seizures. Spinal cord injuries usually result from severe, accidental trauma to the back or neck. These injuries are most common in the 16- to 30-year-old age group and are associated with automobile and sports accidents. The higher the damage to the spinal cord, the more serious the injury.

The extent of CNS injury can be limited with the proper use of child car seats, adult safety belts, helmets in childhood sports and activities, and by reducing the frequency of drinking and driving. Several types of brain injuries can occur, depending on the type and amount of force with which the head is struck.

Signs of a concussion

Signs of a concussion that occur seconds to minutes after a head injury include:

• Possible loss of consciousness
• Difficulty focusing, with slowed responses
• Slurred speech
• Nausea and vomiting
• Headache
• Blurred vision
• Confusion and disorientation or amnesia

The patient should be seen immediately if he or she reports any of the following signs and symptoms days or weeks after a head injury:

• Persistent headache
• Vertigo (dizziness)
• Inability to concentrate
• Repeated problems with memory
• Nausea or vomiting (especially if vomiting is projectile)
• Unusual anger, irritability, anxiety, or depression
• Sleep disorders
• Seizures

Cerebral concussion and contusion

A concussion is the mildest and most common type of brain injury. Trauma from an impact or a sudden change in motion can cause a concussion with loss of consciousness, which may last seconds to several minutes and may be followed by a period of disorientation that lasts up to 24 hours. A single concussion may disrupt the normal electrical activity in the brain, but the brain usually is not injured permanently. However, research has shown that the damage from multiple concussions may be cumulative. No one knows how many concussions are too many before permanent damage occurs. The medical assistant should help gather a comprehensive head injury history so that the provider is aware of all previous concussions, including those that occurred outside of playing sports, to determine when or if a child should return to sports activities. A more serious injury to the brain can cause the formation of a contusion, or bruised area, usually because of a skull fracture. Symptoms can include headache, nausea, vomiting, vision disturbances, and sensitivity to light. Talking with the patient may reveal reduced levels of concentration, irritability, or periods of amnesia. The Glasgow Coma Scale (GCS) is one of the most commonly used severity scoring systems for assessing coma and impaired consciousness. The Glasgow Coma Scale (GCS) is a neurological assessment tool used to objectively describe a patient’s level of consciousness, primarily after a traumatic brain injury, by evaluating their eye opening, verbal, and motor responses, with scores ranging from 3 to 15.

Open and closed head injuries

In a closed head injury, a brain injury occurs but the skull is not fractured. A more serious brain injury can occur with an open head injury because the skull is fractured or displaced. A serious head injury can cause life-threatening damage to the intracerebral structures. Subarachnoid hemorrhage may occur when the delicate meningeal blood vessels are ruptured, resulting in the collection of blood in the subarachnoid space. This causes a rapid increase in intracranial pressure, which may give rise to sudden, severe headache; nausea and severe projectile vomiting; motor disturbances; visual disturbances; and seizures. In addition to trauma, other predisposing factors that can cause subarachnoid hemorrhage include hypertension, a family history of the condition, and congenital malformations of cranial blood vessels. Treatment is designed to reduce the intracranial pressure, sometimes surgically.

A subdural hematoma develops when blood collects in the space between the dura mater and the arachnoid layers of the meninges, usually as a result of head trauma that has caused slow bleeding from ruptured blood vessels in the meningeal layers. Symptoms of increased intracranial pressure occur over several days as the hematoma increases in size. Signs and symptoms build over time and include headache, motor disturbances, speech abnormalities, nausea and vomiting, seizures, and a decreased level of consciousness. Treatment requires surgery to stop the bleeding and reduce the pressure inside the skull. People age 75 or older are at the greatest risk of developing a subdural hematoma after a minor fall.

Shaken baby syndrome

Shaken baby syndrome is the most common reason for serious head injury in infants. It is caused by violently shaking the infant back and forth, forcing the brain against opposite ends of the skull. Shaking is so dangerous for babies because of their small size compared to their relatively large head size, in addition to their undeveloped neck muscles. The typical presentation is a child approximately 6 months old who is brought to the clinic or emergency department because of difficulty breathing or marked lethargy. Usually, little or no external bruising or trauma is seen. Physical findings on examination or autopsy include a subdural hematoma and retinal hemorrhages. The history given by the caregiver usually indicates that the baby “fell” from the sofa, coffee table, or bed or was “dropped.” Approximately one-fourth of these infants die of their injuries.

Spinal cord injuries

If a traumatic accident completely transects the spinal cord, all CNS stimulation to nerves distal to the injury stops, resulting in paralysis of the areas below the injury. The most common causes of spinal cord injuries in the United States are car or motorcycle accidents, falls, especially in those over age 65; violence, sports injuries, and diseases that cause inflammation of the spinal cord, including arthritis and cancer. Paralysis from spinal cord transection is classified into one of two categories. In paraplegia, transection occurs below the midpoint of the spinal cord, causing paralysis of both legs; loss of function below the level of injury, including loss of bladder and bowel control; and sexual dysfunction in males. In quadriplegia, transection occurs in the upper thoracic or cervical region of the spinal cord, causing paralysis of all four limbs, respiratory difficulty, and loss of function to all muscles below the injury point. Hemiplegia is unrelated to spinal cord injury and occurs when a CVA, a vascular injury such as a ruptured aneurysm, or a tumor occurs on one side of the brain, resulting in paralysis on the opposite side of the body. No surgery or treatment can restore a transected cord, although much research is currently underway, including electrical stimulation of nerves and medications to promote nerve cell regeneration or improve the function of the nerves that remain after a spinal cord injury. Treatment also includes surgical stabilization of the spine, physical and occupational therapy, and the use of assistive devices. If the spinal cord is injured but not completely transected, the degree of paralysis depends on the degree of injury. Such patients usually respond well to physical therapy, and their ability to restore motor function is good, although they may always have some functional limitations.

Additional central nervous system pathologies

Parkinson’s disease

Parkinson’s disease (PD) is a chronic, progressive, debilitating disease that affects about 1% of individuals over age 60; more than 50,000 new cases are reported annually in the United States. PD is slightly more common in men than in women. The four primary symptoms of PD are tremors of the hands, arms, legs, jaw, and face; rigidity of the limbs and trunk; bradykinesia, or slowness of movement; and postural instability with impaired balance and coordination. The typical presentation of PD includes a unilateral, pill-rolling tremor; a high-pitched, monotone voice; difficulty swallowing; a mask-like facial expression; and bowed head and forward-bent posture. Tremors and rigidity increase in severity over time. Currently, there are no laboratory tests specific for PD; therefore, the diagnosis is based on a comprehensive medical history and neurologic examination.

Parkinson’s disease is believed to be caused by a combination of genetic and environmental factors that result in a deficiency of the neurotransmitter dopamine in the brain. It is diagnosed with a comprehensive neurologic examination to determine symptoms and their severity. There is no test that clearly identifies the disease. PD has no cure, but the most common medication prescribed for symptomatic relief is carbidopa-levodopa (Sinemet). Levodopa enters the brain and is converted to dopamine; carbidopa increases levodopa’s effectiveness and prevents or decreases many of the side effects of levodopa. Dopamine agonists, which mimic the effects of dopamine, are also prescribed; these include pramipexole (Mirapex) and ropinirole (Requip). Although the initial response to medical treatment can reflect dramatic relief of symptoms, over time, the body’s response to Parkinsonian medications declines. Surgical destruction of the most affected area of the brain may produce some relief of symptoms.

Another treatment option is deep brain stimulation (DBS), in which a surgically implanted device similar to a cardiac pacemaker delivers electrical stimulation to specific areas in the brain that control movement; this also blocks the abnormal nerve signals that cause PD symptoms.

Tumors

The symptoms of a brain tumor depend on the type and location of the mass, but generally, the initial symptoms are headaches, vomiting, dizziness, diplopia, and alterations in muscle strength and coordination. Changes in personality and mental function, seizures, progressive paralysis, loss of speech, and sensory disorders appear as the tumor enlarges.

CNS tumors can be diagnosed by means of CT, MRI, EEG, or lumbar puncture. Ophthalmoscopic examination may reveal papil­ledema. Accurate diagnosis of a brain tumor includes determining its precise location in the brain and whether it is benign or malignant. Approximately half of all brain tumors are metastatic growths from other primary cancer sites in the body. Lung cancer, breast cancer, and melanoma frequently spread to the brain by metastasis. Regardless of whether the mass is benign or malignant, as brain tumors grow, they cause serious problems and complications for the patient because of the limited space inside the skull. Treatment of brain tumors can include surgery, chemotherapy, and radiation in any combination.