1. OVERVIEW AND DESCRIPTION
Brain injuries cause a spectrum of deficits in cognitive functioning, ranging in severity and presentation from profound to subtle. Deficits may be diffuse or isolated to specific cognitive or structural domains. While some deficits are readily apparent, some may not be immediately evident post-injury. Identifying cognitive deficits, strengths, and weaknesses
Comprehensive cognitive, behavioral, and neuropsychological testing can assist in identifying specific structural or functional areas in cognition on which to focus treatment. It can provide information helpful for prognostication and highlight potential barriers to community reintegration post-acute rehabilitation. It may offer insight into capacity-related decision making, as well as information on individual factors which can significantly impact treatment outcomes, such as the emotional state and personal resilience of the patient.1-3
Cognitive, behavioral, and neuropsychological testing can be accomplished by a cognitive bedside evaluation, a formalized neuropsychologic test battery, and observation of patient behaviors. Understanding the scope of each type of assessment is important for the timing of administration of any test of cognitive functioning. It may also be useful in establishing a baseline at the beginning of the rehabilitation process, from which serial measurements may then document progress and be used to assess treatment effectiveness.
Cognitive testing in an acute hospital setting or rehabilitation unit setting is done by the physician, rehabilitation nurse, neuropsychologist, speech and language pathologist, and physical and occupational therapists. Standardized tests are available in nonproprietary formats for testing many of the cognitive variables in the therapeutic environment. While the domains listed below are commonly covered in basic standardized cognitive tests, it may also be useful to do serial testing of specific limited categories deemed relevant to the individual patient and this can be done informally during bedside interviews.
- Alertness and orientation describe ability to pay attention, level of sensory awareness, and awareness of time, place, and person. Significant alterations in these dimensions are more common in the immediate postinjury phase. The first step in determining the cognitive status of a patient is observation of alertness. Impaired alertness may be the result of brain injury, or may be related to medical interventions (induced coma, medication side effects). Impaired alertness limits thorough cognitive testing, and tests should be prioritized to maximize observation during alert periods. Orientation to self, place, date, time, and situation are commonly asked at the bedside by all brain injury rehabilitation professionals, and consistent orientation signals the end of posttraumatic amnesia, a powerful predictor for prognosticating recovery.4 Families can be engaged in reorientation of the patient during posttraumatic amnesia.
- Attention is the ability to focus on a task at hand, and it is a necessary precursor to engagement in cognitive testing. Focused or selective attention describes the ability to focus on some aspect of the environment. Sustained attention or vigilance is the length of time one can focus on a task in the face of distracting variables. Divided attention or cognitive flexibility is the ability to shift back and forth between tasks.
- Memory is the ability to process or the act of remembering or recalling, and the ability to reproduce what has been learned or experienced.5 Memory impairments are extremely common after brain injury. Retrograde amnesia describes loss of memory preceding an injury. Anterograde amnesia describes loss of memory for events after an injury. Both verbal and visual memory can be formally tested. Registration of events with recall of the information tests immediate memory. Delayed recall of information is described as recent or episodic memory. Semantic memory is the general store of conceptual and factual knowledge.6 Procedural memory is the ability to learn behavioral and cognitive skills and algorithms at an automatic, unconscious level.6 Working memory retains information while concentrating on another task, and utilizes that information in a functional environment.5 Remote memory is typically well preserved following brain injury.
- Executive functioning is the ability of a patient to perform problem-solving or task planning from beginning to end. Major areas of executive functioning include: judgment, reasoning, concept formation, abstraction, initiation and fluency, planning and organization, set maintenance and mental flexibility, and disinhibition and impulse control.5
- Speech and language assessment describes fluency, repetition, naming, verbal comprehension, reading, and writing. Note that the presence of aphasia can make interpretation of other cognitive spheres challenging and can lead to misconceptions about a patient’s orientation, command following, and executive functioning. Offering choices and using nonverbal means of testing can help differentiate whether cognitive deficits exist in the setting of aphasia.
Neuropsychologic testing is formalized, validated testing performed by a neuropsychologist. Formal evaluation typically occurs in the outpatient setting after emergence from posttraumatic amnesia. This comprehensive assessment of cognitive functioning allows clinicians to target therapies to aid outpatient therapy, home, school, and work transitions. The exam includes a diagnostic interview, gathering of medical information, emotional history and current stressors, developmental and social history, and patient’s perceived deficits or concerns. As baseline neuropsychologic testing is rarely available, this may allow an understanding of an individual’s premorbid level of functioning.
After description of the testing structure and consent, a battery of standardized (usually proprietary) tests is administered. The battery typically includes tests measuring patient motivation, malingering, emotional functioning, attention and concentration, generalized intellectual ability, verbal and visual memory, executive functioning, speech and language, and visuospatial and visuoconstructional skills. Basic motor screening, including measures of grip strength, handedness, visual dominance, and manual dexterity, are typically performed. Tests are validated and offer aged- and education-matched norms, and results are typically reported as impaired, borderline, low average, average, above average, or superior when compared with demographic peers. Conclusions are drawn based on the location of any known lesions, as well as the individual’s relative strengths and weaknesses. Focal lesions can cause profound deficits in specific areas. Diffuse brain injuries generally lead to global deficits across categories. Visual memory can be more impaired in patients with oculomotor dysfunction or occipital lesions. Executive functioning deficits are more common with frontal lobe injuries.
A neuropsychologist should be present during the test battery to alter the battery based on the subject’s performance, to provide continuous feedback as to participation, and to observe the process by which the subject reaches conclusions. The neuropsychologist’s interpretation of the process to getting to the same wrong answer can be important. Performance should reflect an individual’s best performance; therefore, fatigue and diminished attention may require testing to be split over multiple sessions.
Interpretation of neuropsychologic testing can be helpful. It can offer more information about cognitive functioning and areas of relative strength and weaknesses that can help direct therapeutic interventions across therapy disciplines. Identification of weaknesses can target improvement strategies and guide reasonable accommodations in school or work environments to ensure success of the brain injured individual.
Computerized neuropsychologic testing is available, especially for patients who have experienced concussion. The advantages of computerized testing include lower cost, easier access to both baseline and subsequent testing, standardized administration, and less learning effect than traditional pen and paper testing. Disadvantages include decreased breadth of scope, inability to tailor the testing environment based on performance, and lack of information regarding the process a testing subject goes through in reaching an answer. It provides useful but incomplete information about recovery from concussion.
Recovery after brain injury can involve periods of confusion, restlessness, agitation, and/or socially inappropriate behaviors. Behavior is an outward observation of action, and is a complex manifestation of an individual’s emotional state, their conception of the surrounding environment, and their understanding of social norms. Undesired behaviors are common in early recovery, but are typically short lived. Undesired behavior is often the result of altered perception or interpretation of the surrounding environment.
In some patients, undesired behaviors are persistent or disruptive to the rehabilitation process and may even be potentially dangerous to the patient or to others.. Assessing insight into and awareness of physical and cognitive deficits helps team members to formulate approaches to behavioral intervention. Careful observation and codification of behavior can lead to development of treatment plans to minimize aberrant and encourage appropriate behavior through identification of undesirable behavior, analysis of environmental factors, behavioral antecedents, and concurrent behaviors. Goals of behavioral treatment are to minimize undesirable behavior and to encourage socially acceptable behaviors.
Contingency management strategies for addressing the targeted behavior incorporate positive and negative reinforcement, with the former most common in a rehabilitation setting. Extinction is non-acknowledgement of an undesirable behavior and is often used in conjunction with positive reinforcement of alternative behaviors.7 Reinforcement of desired behaviors can be accomplished with varying the frequency of positive reinforcement. In an acute rehabilitation setting, reinforcement plans may not be best, and behavior plans focus on team consistency in modifying behavior. Patient behavior is evaluated, environmental changes implemented, and any medical modifications that can reduce agitation/restlessness are accomplished (e.g., removal of safety restraints, tracheostomy). Low frequency behaviors that are undesirable can be diminished by positively reinforcing their lack of occurrence. All reinforcement must be tailored to the individual with brain injury and their ability to understand the relationship between their action and a positive reinforcement. Examples are errorless learning for patients with severe cognitive deficits and modeling of desired behaviors with positive reinforcement to encourage imitation of desired behaviors by patients.
Environmental factors consistently contribute to undesirable behavior, and when identified, they can be modified (e.g., decrease stimulation in environment, minimize nursing cares as able). Consistency of behavior and intervention among staff is important to achieve a uniform response to identified behaviors. Staff education and environmental modification to remove noxious stimuli need to be quickly identified and managed with consistency, regardless of timing or setting.
When environmental modifications are ineffective in deescalating a patient’s behaviors, medications are usually the next intervention. Mood stabilizers are most commonly used, but have potential for significant side effects. Common agents used to control agitation include atypical antipsychotics, antiepileptics, and antidepressants. Brain injury recovery may be affected by medication intervention, and medication trials need to be done to clarify best practices.
2. RELEVANCE TO CLINICAL PRACTICE
Formal neuropyschologic testing is an important part of defining cognitive deficits following brain injury. Its advantages over thorough clinical examination include the following: standardization, comparison with age- and education-matched controls, more comprehensive than clinical examination, identification of areas of relative deficits and strengths, helping to guide the rehabilitation team in maximizing a patient’s recovery, and ability to repeat yearly to document recovery of brain function. In certain cases, the results can help to guide cognitive rehabilitation therapy, working to incorporate consistent strategies to augment deficits and utilize relative strengths of the individual in an effort to maximize their overall cognitive function. When conducted early in the rehabilitation process, it can aid in identifying patient factors such as resiliency or emotional disorders that may significantly impact patient engagement and treatment outcomes.2,3 Interventions can then be aimed at building on resiliency or addressing psychiatric comorbidities to maximize success. This formal testing has also been shown to potentially offer information on prognostics and future productivity when conducted in the early weeks to months following brain injury.8,9
Some patients are poor candidates for formal neuropsychologic testing for various reasons, including, for example, being unable to complete such a lengthy battery of tests. A briefer battery of cognitive tests has been found to still have some predictive value for functional outcomes a year out in patients with traumatic brain injury.10 In fact, a simple test cognitive test of recall of three words following a 24-hour delay has been shown to have some predictive value of variables such as psychosocial distress and return to productivity following brain injury.11
Agitation, aggression, disinhibition, and impulsivity can pose challenges for care providers and for the patient’s loved ones. These behaviors can also interfere with compliance, successful engagement in treatment, and thus outcomes. Effective behavioral assessment involves ongoing monitoring for the effectiveness of interventions and can facilitate collaboration. It can also be helpful to the family, identifying triggers of the problem behavior and education on responses to it.1
Evidence for specific standardized tests
Brain injury is a broad category with a vast array of etiologies and disease processes. There is a growing body of research comparing the various standardized tests of cognition in their ability to detect deficits and assess function in patients with a variety of brain injuries, ranging from stroke to concussion to subarachnoid hemorrhage. The O-Log and Cog-Log are brief bedside instruments that have been shown to have utility as serial assessment tools to track cognitive recovery or decline in the neurologic rehabilitation setting.12 Additionally, numerous studies have compared the Mini-Mental State Examination (MMSE) with the Montreal Cognitive Assessment (MoCA) in assessing the neurologic rehabilitation population. While there has been variation in results, some studies have suggested that the MoCA may be better suited than the MMSE in identifying cognitive deficits in the first month post-stroke,13 while others have found them roughly equivalent in the same population 3-6 months post-stroke.14 In patients post-subarachnoid hemorrhage, the MoCA was found to be more sensitive for detecting cognitive impairment and to correlate to a greater degree than the MMSE with lengthier neurocognitive testing findings.15 In terms of predicting functional outcomes, the portion of the MoCA specifically assessing the visuoexecutive domain has also been shown to have greater association with functional outcomes in persons post-stroke than the total scores of either the MMSE or MoCA.16
Concomitant disorders can create challenges with neuropsychological testing. For example, in patients with stroke and early dementia, it may be difficult to decipher which disease process is contributing to any deficits noted. Please refer to the “Dementia and Delirium” chapter for more details on testing for these conditions.
Brain injury in the developing pediatric brain also poses unique challenges. Many factors play a role in cognitive development, such as biological age, developmental age, and environment. Children injured at an early age may have more challenges acquiring new cognitive skills, in spite of neuroplasticity. It is important to select tests that are appropriate for biological age as well developmental age and interpretation of results is based on age-matched norms. Repeat testing is warranted at times of transition, particularly when there is an increase in cognitive expectation in school and during early teenage years when abstract reasoning and executive functions are developing.
3. CUTTING EDGE/UNIQUE CONCEPTS/EMERGING ISSUES
For management of concussion, computerized neuropsychologic tests are comercially available, including the ImPACT, Concussion Sentinel, and Headminder Concussion Resolution Index tests. These can be administered anywhere there is access to a computer, mouse, and a quiet testing environment. They are administered by qualified trainers, nurses, neuropsychologists, or physicians, and have many advantages over previously used pencil and paper tests, most importantly, decreased practice effect from repeated administration of the tests. They use standardized batteries to measure verbal and visual memory, visual motor speed, reaction time, and overall symptoms. Baseline preinjury testing can establish a baseline for the individual; therefore, postconcussion testing can help to identify changes. Because altered performance on neuropsychologic tests can persist without adverse symptoms in children, waiting for neuropsychologic testing to normalize can help prevent releasing children back to playing before they have fully recovered.17 However, variability of performance in testing of non-concussed individuals over time has called the validity of these tests into question.18
Another area of technological advancement in neurophysiological testing is in the growing availability of teleconferencing. There is increasing literature suggesting that administering a battery of neuropsychological testing via video teleconference is a both feasible and reliable means of conducting assessment with populations that would otherwise lack access due to remote location or difficulties with traveling.19
4. GAPS IN KNOWLEDGE/EVIDENCE BASE
- Pastorek NJ, Proto DA, Sander AM, Clark AN. Psychological assessment and intervention in rehabilitation. In: Cifu DX, Kaelin DL, Kowalske KJ, Lew HL, Miller MA, Ragnarsson KT, Worsowicz GM, eds. Braddom’s Physical Medicine and Rehabilitation. 5th Philadelphia, PA: Elsevier; 2016: 71-83.
- Scott, KL, Strong C-AH, Gorter B, Donders J. Predictors of Post-concussion Rehabilitation Outcomes at Three-month Follow-up. The Clinical Neuropsychologist. 2016; 30(1): 66-81.
- McCauley SR, Wilde EA, Miller ER, Frisby ML, Garza HM, Varghese R, Levin HS, Robertson CS, McCarthy JJ. Preinjury Resilience and Mood as Predictors of Early Outcome Following Mild Traumatic Brain Injury. Journal of Neurotrauma. 2013; 30: 642-652.
- Kothari S. Prognosis after severe TBI: A practical, evidence-based approach. In: Zasler ND, Katz DI, Zafonte RD, eds. Brain Injury Medicine, Principles and Practice. 1st New York, NY: Demos; 2007:178.
- Pelham MF, Lovell MR. Issues in neuropsychological assessment. In: Silver JM, McAllister TW, Yudofsky SC, eds. Textbook of Traumatic Brain Injury. 1st Arlington, VA: American Psychiatric Publishing; 2005:159-174.
- Budson AE, Price BH. Memory dysfunction. New England Journal of Medicine. 2005; 352: 692-699.
- Karol RL. Principles of behavioral analysis and modification. In: Zasler ND, Katz DI, Zafonte RD, eds. Brain Injury Medicine, Principles and Practice. 1st New York, NY: Demos; 2007:818.
- Green RE, Colella B, Hebert DA, et al. Prediction of Return to Productivity After Severe Traumatic Brain Injury: Investigations of Optimal Neuropsychological Tests and Timing of Assessments. Archives of Physical Medicine and Rehabilitation. 2008; 89(12): pp. S51-S60
- Sherer M, Novack TA, Sander AM, et al. Neuropsychological assessment and employment outcome after traumatic brain injury: a review. The Clinical Neuropsychologist. 2002; 16(2): 157-178
- Hanks RA, Millis SR, Ricker JH, et al. The predictive validity of a brief inpatient neuropsychologic battery for persons with traumatic brain injury. Archives of Physical Medicine and Rehabilitation. 2008; 89: 950-957
- Dawson DR, Levine B, Schwartz ML, et al. Acute predictors of real-word outcomes following traumatic brain injury: a prospective study. Brain Injury. 2004; 18: 221-238.
- Penna S, and Novack TA. Further validation of the orientation and cognitive logs: their relationship to the mini-mental state examination. Archives of Physical Medicine and Rehabilitation, 2007; 88: 1360-1361
- Van Heugten, CM, Walton L, Hentschel U. Can we forget the Mini-Mental State Examination? A systematic review of the validity of cognitive screening instruments within one month after stroke. Clinical Rehabilitation. 2015; 29(7): 694-704.
- Dong, Y, Slavin MJ, Chan BP, Venketasubramanian N, Sharma VK, Collinson SL, Sachdev PS, Chen CL. Improving screening for vascular cognitive impairment at three to six months after mild ischemic stroke and transient ischemic attack. International psychogeriatrics. 2014; 26(5): 787-793.
- Schwizer, TA, Al-Khindi T, Macdonald RL. Mini-Mental State Examination versus Montreal Cognitive Assessment: Rapid assessment tools for cognitive and functional outcome after aneurysm subarachnoid hemorrhage. Journal of the Neurological Sciences. 2012; 316: 137-140.
- Toglia J, Fitzgerald KA, O’Dell MW, Mastrogiovanni AR, Lin CD. The Mini-Mental State Examination and Montreal Cognitive Assessment in Persons with mild subacute stroke: Relationship to functional outcome. Archives of Physical Medicine and Rehabilitation. 2011; 92: 792-798.
- Moser RS, Iverson GL, Echemendia RJ, et al. Neuropsychological evaluation in the diagnosis and management of sports-related concussion. Archives of Clinical Neuropsychology. 2007; 22: 909-916.
- Broglio SP, Ferrara MS, Maccioccci SN, Baumgartner TA, Elliot R. Test-retest reliability of computerized concussion assessment programs. Journal of Athletic Training. 2007; 42: 509-514.
- Wadsworth, HE, Galusha-Glasscock JM, Womack KB, Quiceno M, Weiner MF, Hynan LS, Shore J, Cullum CM. Remote neuropsychological assessment in rural American Indians with and without cognitive impairment. Archives of Clinical Neuropsychology. 2016; 31: 420-425.
- Khan, F and Tandros G. Complexity in cognitive assessment of elderly British minority ethnic groups: Cultural perspective. Dementia. 2014; 13(4): 467-482.
Original Version of the Topic
Brian T. Kucer, MD, Todd Lewis, PhD. Cognitive / behavioral / neuropsychological testing. 09/20/2013.
Kimberly Hartman, MD
Nothing to Disclose
Allison Blough, MD
Nothing to Disclose