Brain injury: A primary-care perspective
When a patient presents with traumatic head injury, or when you take over the care of one who has had hospital care, here’s what you should know.
When an individual experiences a sudden, violent blow to the head, the brain is launched on a collision course with the skull. The result is a traumatic brain injury (TBI). If the skull is able to withstand the impact without fracturing, this TBI is known as a closed-head injury. When a projectile such as a bullet, rock, or skull fragment punctures the skull, the result is a penetrating head injury.
Each year in the United States, 1.4 million individuals suffer a TBI, according to the CDC. Following an injury, patients can experience a wide variety of symptoms, some of which include spinal-fluid leakage from the ears or nose, dilated or unequal-sized pupils, vision changes, dizziness, respiratory failure, ringing in the ears, body numbness or tingling, loss of bowel or bladder control, loss of consciousness, coma, and even death.
The severity of TBI varies greatly depending on the part of the brain affected and the amount of damage sustained. Recovery from TBI may take months or even years, and coping with the consequences of severe TBI can be challenging for patients, families, health-care providers, and society at large.
Although approximately 52,000 people die of TBI annually, recent medical and surgical advances have improved patients’ chances of survival. Some patients may present shortly after receiving a blow to the head, but primary-care clinicians will usually see TBI victims weeks later—after they have returned home from the hospital to try and move on with their lives only to find that they are experiencing problems they may or may not realize are connected to TBI.
Determining neurologic status
When a patient presents with symptoms suggestive of TBI, it’s important to take a careful history. First, ask whether a head injury has been sustained (this might not be mentioned otherwise). Some patients may not realize that their symptoms are connected to a prior event. They may have been briefly unconscious at the time of the incident or may assume their symptoms are related to a more severe injury that occurred at the same time. Others may be reluctant to mention such symptoms as memory problems, incontinence, or sexual dysfunction. If the patient is unable to answer questions because of confusion or forgetfulness, try to obtain the history from a family member or friend.
If the patient or caretaker confirms a recent head injury, inquire about physical and mental symptoms, recent changes in ability to perform activities of daily living, gait abnormalities, change in balance or coordination, falls, difficulty swallowing, seizures, tremors, and use of medications that affect coordination or mental status. Imaging tests are crucial in determining the extent of injury. If you suspect TBI and the patient has not undergone inpatient evaluation, arrange for imaging.
Skull and neck x-rays can reveal bone fractures or spinal instability. CT scans can uncover evidence x-rays cannot (e.g., bleeding in the brain, large blood clots, bruised tissue, and brain swelling). A complete neurologic examination should be performed whenever a patient presents with possible TBI. The neurologic exam is organized into a number of areas:
Mental status. A patient’s mental status is the total expression of his emotional responses, mood, cognitive function, and personality. A baseline mental status exam of the TBI patient will aid the clinician in planning and monitoring the patient’s care. Assess mental status by evaluating the patient’s level of awareness, orientation, cognitive ability, and affect. Observe physical appearance, grooming, and body language. Poor hygiene, lack of concern with appearance, or inappropriateness of dress for the season can be red flags.
The patient should be oriented to time, place, and person and able to appropriately respond to questions and environmental stimuli. To assess cognitive function, ask him to explain simple and then more complex analogies, such as “How is an apple like an orange?” and “How is the brain like a computer?” Ask the meanings of proverbs such as “A rolling stone gathers no moss.” Signs of possible impairment include significant memory loss, confusion, impaired communication, hazardous behavior, agitation, and suspiciousness. Note mood swings or behaviors indicating the patient’s pattern of thinking, especially the appropriateness of sequence, logic, coherence, and relevance to topics discussed. You should be able to follow the patient’s thought processes, and the ideas expressed should be logical and goal-directed.
Cranial nerves. An evaluation of the cranial nerves is an integral part of the neurologic examination. Generally, clinicians test the function of the 12 cranial nerves, which are connected directly to the brain. The number of nerves tested depends on what type of injury is suspected. Ordinarily, taste and smell are not evaluated unless a problem is expected. Quite often, patients will not recognize a loss of hearing in some ranges, certain taste sensations, or some visual aspects.
When a sensory loss is suspected, determine the extent of loss while testing the relevant cranial nerves. Unexpected findings indicate trauma or a lesion in the cerebral hemisphere or local injury to the specific nerve. For more information on cranial-nerve testing, see the Merck Manual’s online library listing at www.merck.com/mmhe. Accessed June 4, 2007.
Sensory system. Test the patient’s ability to localize sensations. Stimuli should be random but symmetrical (test proximal and distal first). Have the patient identify light touch, sharp touch, dull pain, vibration, and tactile discrimination.
Motor system. Examine muscle size, tone, and movement. Test strength and ability to execute voluntary movements.
Proprioception and cerebellar function. Assess coordination of the upper extremities by having the patient extend his arms and touch his nose, heel, and shin. Perform the Romberg test, which entails asking the patient to stand with his feet together and eyes closed (be sure to remain close by in case the patient begins to sway or fall). With eyes open, three sensory systems provide input to the cerebellum to maintain truncal stability. If there is a mild lesion in the vestibular or proprioception systems, the patient is usually able to compensate with eyes open. With eyes closed, however, visual input is removed and instability can ensue. If there is a more severe proprioceptive or vestibular lesion or if there is a midline cerebellar lesion causing truncal instability, the patient will be unable to maintain this position even with his eyes open.
Reflexes. Test reflexes to determine whether the sensory nerve to the spinal cord, the nerve connections in the spinal cord, and the motor nerves back to the muscle are functioning.
Managing TBI symptoms
Here are the most common post-TBI symptoms seen in primary care, along with suggested management strategies:
Headache. Headaches following TBI may fit the pattern typical for migraine with or without aura. They may resemble tension headaches or occur in conjunction with disorders of the cervical spine sustained along with the head injury.
Treatment for migraine-type TBI headaches may include prophylactic medications, such as beta-adrenergic blockers (propranolol), antidepressants (amitriptyline, nortriptyline), calcium channel blockers (verapamil), and anticonvulsants (valproic acid). Treatment for tension-type TBI headaches may include antidepressant medication (amitriptyline, nortriptyline, trazodone) for prophylaxis and nonsteroidal anti-inflammatory drugs (NSAIDs) (ibuprofen or naproxen) for pain relief. Cervicogenic headache often responds well to physical therapy or biofeedback plus NSAIDs.
Painkillers should be prescribed with caution to avoid addiction or rebound-type headaches. Muscle relaxants are not usually beneficial and often cause lethargy or drowsiness that may worsen other post TBI-symptoms. Dizziness. Post-TBI dizziness is common and may be accompanied by diplopia, nausea, and vomiting. Medical management of dizziness can be tricky.
Anxiolytic drugs, such as benzodiazepines, are sometimes used, but somnolence and low efficacy are big problems with these medications. Of the benzodiazepines that can be tried, clonazepam is the most useful. To avoid sedative side effects, start with a low dose (0.5 mg) at bedtime, and carefully increase dosage to 0.5 mg twice a day if needed. Starting the medication at bedtime helps the patient build tolerance to the sedative side effect. Post-traumatic dizziness tends to undergo gradual spontaneous improvement. These patients need to gain confidence by working on gait and balance initially with a physical therapist and later with a home-exercise program. Exercises that involve moving the head and body to stimulate the vestibular system can be effective. For examples, go to the Acoustic Neuroma Patient Archive at www.anarchive.org/exercises. Accessed June 4, 2007.
Post-TBI epilepsy. About 10% of TBI patients develop post-traumatic epilepsy. Even if the patient is unaware of any interruptions in the conscious state, family, friends, or other observers may report episodes of inattention, staring spells, or strange automatisms. Often, a simple electroencephalogram will show little evidence of abnormality in TBI patients.
In cases of frontal-lobe localization in TBI epilepsy, typical associated symptoms include pre-seizure postural changes, speech arrest, or vocalizations. Seizures associated with TBI are usually simple partial or complex partial with or without secondary generalization. Medication options include carbamazepine, phenytoin, or gabapentin. When anticonvulsants are used to treat post-TBI seizures, patients need to be closely monitored for potential drug interactions. Monitoring anticonvulsant levels in the serum is very useful in seizure management.
Hearing impairment and tinnitus.
These problems are relatively common following TBI and may not present until several weeks post-injury. Hearing impairment is typically persistent and not amenable to augmentation. The patient may report a subjective hearing impairment that audiometric testing fails to identify. This suggests central auditory processing problems. In patients with tinnitus, masking with a low-intensity, pure auditory tone can be helpful. Medications are generally ineffective against tinnitus or other post-TBI auditory disorders. In some situations, anxiolytic medications, such as benzodiazepines, are effective in reducing associated anxiety and thereby lessening awareness of tinnitus.
Intention tremor. TBI has also been associated with the development of intention tremor. The amplitude is usually low, generally affecting the upper extremities and/or the head. Some myoclonic-type jerking may also be present. Clonazepam 0.5 mg twice a day can be helpful. Some patients respond to treatment with propranolol. Unfortunately, post-TBI tremor is often a permanent residual symptom.
Depression and emotional lability.
Pathologic expression of laughter, crying, or smiling are fairly common after TBI. Symptoms develop gradually and tend to be more severe when the patient’s functional capacity is more gravely disrupted. Irritability and emotional lability may be accompanied by fatigue or feelings of detachment. Patients may also report sleep disorders, which can further impair overall functioning.
Treatment for these symptoms typically consists of reassurance, education, and support. If depression or emotional lability are interfering with ordinary activities at work or at home, consider treatment with antidepressant medications (e.g., fluoxetine, sertraline, or paroxetine). Serotonergic antidepressants are most effective for patients who have prominent inanition or withdrawal symptomatology. Be aware, however, that these medications may induce hyperexcitability syndrome, and monitor patients accordingly. Tricyclic antidepressants (e.g., amitriptyline, nortriptyline, or doxepin) may be more effective for patients with accompanying sleep disorder, such as prominent insomnia, or poor appetite and attendant weight loss. When depression is associated with headache or spinal pain, tricyclics are preferred.
Psychosocial issues. TBI often causes significant stress, not only for patients themselves but also for family members and health-care providers. During rehabilitation, caregivers may benefit greatly from peer support programs, which provide practical information as well as emotional support.