Prognosis: Implications for Long-Term Recovery and Disability
The science of predicting long-term recovery and disability following TBI is anything but precise.Sometimes–for reasons not well understood—an individual with MTBI will develop permanent and profound disabilities while another person with a seemingly serious TBI will appear to recover fully. When most people think of TBI, they think of it as just that—an acute injury, something that they can eventually “get over”—as opposed to a disease with long-term sequelae. TBI, though, is formally recognized as a progressive disease involving injury to the neuronal cell bodies –the brain’s “gray matter”—and the axonal processes, the white matter controlling the biochemical and electrical conveyance of messages from one neuron to the next (http://www.tbims.org/combi).
Prognosis during the Early Stages of TBI
Understandably, patients with TBI and their families are anxious for a prognosis during the early stages of recovery. Clinicians are often reluctant to provide a definitive answer, especially since complications of TBI often do not emerge for months or even years following brain injury. (A contemporary example involves the retired football players who have filed suit against the NFL for injuries sustained 20-30 years prior leading to their development of CTE.) Nonetheless, a few early indicators of a poor prognosis include:
- Duration of coma.
- Severity of coma.
- Duration of post-traumatic amnesia.
- Location and size of contusions and hemorrhages in the brain.
- Severity of injuries to other body systems sustained at the time of TBI.
Other generalizations that can be shared are:
- The more severe the injury, the longer the recovery period, and the greater the impairment once recovery has plateaued (sometimes a period of 2-3 years post-TBI).
- Recovery from diffuse axonal injury takes longer than recovery from focal contusion.
- Recovery from TBI with hypoxia (oxygen deprivation to the tissues) is less complete than TBI without hypoxia.
- Need for surgery does not necessarily spell a worse outcome.
Long-term and profound disabilities frequently accompany moderate to severe TBI. Problems with cognition (thinking, memory and reasoning) and behavior/mental health (depression, anxiety, personality changes, aggression, lack of inhibition and acting out) are among the most frequent sequelae following TBI. Recent research has established a highly significant correlation between penetrating head injury and long-term cognitive disability. Severe TBI is strongly linked to long-term cognitive deficits, and it appears that moderate TBI is too (http://www.ninds.nih.gov/disorders/tbi/detail_tbi.htm).
At this point, the connection between MTBI and long-term cognitive disability remains unclear; however, researchers have found evidence of metabolic changes in the concussed brain up to four months following MTBI,even when there is a total absence of symptoms (http://www.neurology.org/content/early/2013/11/20/01.wnl.0000437302.36064.b1.short?rss=1).
TBI is significantly linked with several neurologic disorders six months after injury. These include a high rate of seizures among moderate and severe TBI patients as well as a preponderance of neurodegenerative diseases, such as Alzheimer’s type (DAT), Parkinsonism and Chronic Traumatic Encephalopathy (CTE). To wit: patients diagnosed with moderate TBI have a 2.32 times greater risk of developing DAT than a person who has not suffered a TBI.
Language and communication problems are common among TBI patients. Aphasia—the inability to understand speech and to read and write—occurs in approximately 20% of moderate and severe TBI cases; dysarthria, a condition in which speech is disrupted due to poor motor control of the mouth, face and sometimes respiratory system—manifests in 30% of patients; dysphagia, or difficulty swallowing, occurs in about 17% of cases. Some people with TBI develop problems with the more subtle aspects of language, such as exhibiting inappropriate body language and emotional, non-verbal communication signals.
TBI is also associated with heterotopic ossification (HO), a condition which causes extra bone to form around the soft tissue surrounding big joints. HO causes restrictions in range of motion, pain, swelling, vascular flow issues and rash and exacerbates TBI. Incidence of HO in TBI ranges between 8% and 76% and is related to the severity of brain injury. Length of coma, diffuse axonal injury, spasticity (rigidity of muscles) and systemic infections are among the primary factors that increase the risk of developing HO.
Social functioning—which involves numerous brain functions, including cognitive, emotional/behavioral, language, motor and sensory—is commonly impacted by brain injury. Various studies have attempted to assess which patients are most likely to suffer long-term problems in regaining pre-injury social function, integration and productivity. Based on findings, it appears that the strongest predictors for projecting the likelihood of experiencing problems with social functioning include factors of:
- Older age
- TBI initially diagnosed as moderate to severe
- Pre-injury unemployment
- Pre-injury substance abuse
- Severe disability at rehabilitation discharge
- Posttraumatic amnesia
- Greater disability at rehabilitation admission
The Craig Handicap Assessment and Reporting Technique (CHART) was designed to provide a simple, objective measure of the degree to which impairments and disabilities result in handicaps in the years after initial rehabilitation. The original CHART, developed in 1992, includes domains to assess five dimensions of handicap:
- Physical Independence: Ability to sustain a customarily effective independent existence.
- Mobility: Ability to move about effectively in his/her surroundings.
- Occupation: Ability to occupy time in the manner customary to that person’s sex, age, and culture.
- Social Integration: Ability to participate in and maintain customary social relationships.
- Economic Self-Sufficiency: Ability to sustain customary socio-economic activity and independence.
Even though the mortality associated with TBI has decreased substantially in recent years, the associated disability outcomes have not been appreciably reduced.
The impact of a moderate to severe brain injury can include these daily life difficulties:
- Speed of Processing
- Language Processing
- “Executive functions”
Speech and Language:
- Not understanding the spoken word (receptive aphasia)
- Difficulty speaking and being understood (expressive aphasia)
- Slurred speech
- Speaking very fast or very slow
- Problems reading
- Problems writing
- Difficulties with interpretation of touch, temperature, movement, and limb position
- Partial or total loss of vision
- Weakness of eye muscles and double vision (diplopia)
- Blurred vision
- Problems judging distance
- Involuntary eye movements (nystagmus)
- Intolerance of light (photophobia)
- Decrease or loss of hearing
- Ringing in the ears (tinnitus)
- Increased sensitivity to sounds
- Loss or diminished sense of smell (anosmia)
- Loss or diminished sense of taste
- Physical paralysis/spasticity
- Chronic pain
- Control of bowel and bladder
- Sleep disorders
- Loss of stamina
- Appetite changes
- Regulation of body temperature
- Menstrual difficulties
- Dependent behaviors
- Emotional ability
- Lack of motivation
- Lack of normal inhibition