disorders of consciousness: individualized assessment methods john whyte, md, phd moss...
TRANSCRIPT
Disorders of Consciousness:Individualized Assessment Methods
John Whyte, MD, PhDMoss Rehabilitation Research Institute
&
Thomas Jefferson University
Topics to be Covered
Challenges to reaching accurate diagnoses and assessing recovery in VS/MCS
The role of standardized assessment procedures
The role of individualized assessment procedures
Case examples of individualized assessment protocols
Assessment:Challenges to Accurate Assessment
Behavior is highly variable from hour to hour and day to day
Available indicators are generally very simple behaviors that may not be indicators of consciousness (e.g., blinking, eye movements)
Clinicians and caregivers are not objective “integrators” of a set of observations: memory limitations and emotional factors
Case Examples of Assessment Difficulties:
Record review for medical legal purposes of a patient in treatment for over a year
Assessment of a patient living at home: VS, MCS, or higher level?
Standardized Assessment Approaches
“Macro” assessment scales: FIM DRS GOS/ GOS-E All require an inference about level of
consciousness but do not specify how to arrive at that inference
Considerable recovery is possible without major impact on scores
Standardized Assessment Approaches (cont.)Standardized assessment scales appropriate for
VS/MCS patients Coma Recovery Scale-Revised (CRS-R) Coma Near Coma Scale Western Neuro Sensory Stimulation Profile (WNSSP) Disorders of Consciousness Scale (DOCs)
All are more fine-grained, sensitive to changeThey vary in terms of how well indicators of
consciousness are operationalizedCan a single assessment provide a diagnosis?
Role of Standardized Assessment
“Macro” scales: for use in the acute stage when significant recovery is likely; useful for program evaluation, discharge and therapy planning, research
“Micro” scales: acutely, for use in conjunction with “macro” scales; post-acute for stand-alone use for diagnosis (particularly in the absence of promising behaviors), program evaluation, therapy planning
Quantitative Individualized Assessment (QIA)
Based on the principles of single subject experimental design
Intended to answer specific clinical questions and clarify the meaning of particular behaviors that may be controversial (like those discussed in the case examples)
May provide a diagnosis (VS vs. MCS in the process)Useful for monitoring the progress in those behaviorsUseful for guiding treatment approaches
How Does QIA Address the Challenges to Accurate Assessment?
Variability Standardize the assessment conditions Increase the “sample size”
Simple behaviors of ambiguous significance Develop appropriate experimental controls for
non-conscious possibilitiesObserver bias, memory limitations
Operationalize assessment conditions and response scoring
Check inter-rater reliability
The QIA Process used in the MossRehab Responsiveness Program
Initial general clinical evaluation and observation of behaviors, elicit family beliefs
Team meeting to identify questions and clinical priorities
Develop individualized assessment protocol in pilot form
Revise the protocol if necessaryFormal data collection by all disciplinesPeriodic data review, team discussion,
termination or modification of protocol
An Introductory Example
Does the patient make arm movements in response to verbal commands?
The patient appears to move his arm to command inconsistently.
Hypothesis: The patient’s arm movements will occur more often after verbal commands than after silence or contrasting commands.
Define “arm movement”, standardize commands, positioning, initial arousal interventions
Arm Movements to Verbal Command
COMMAND RESPONSE
Moves Arm None
Move Arm 40% (34/84) 60% (50/84)
Hold Still 43% (36/84) 57% (48/84)
Observe 29% (24/84) 71% (60/84)
How Do We Select the Question(s)?
Perceived importance by family and team members
Logical sequenceCurrently available behaviors
How Do We Select the Specific Behaviors and Design the Control Conditions?
Review injury history, neuroimaging, other relevant studies (e.g., ERPs, EMGs, etc.)
Observe for behaviors that occur with some frequency but not extremely frequently
Consider possible reasons for failure other than unconsciousness (e.g., deafness, blindness, aphasia)
Types of Evaluations Successfully Conducted
Patterns of alertness and sleep Patterns of restlessness and agitation Visual statusLanguage comprehension and ability to
follow commandsAbility to engage in simple communication
tasks
Successful Evaluations (cont.)
Types of cuing that result in the best performance
Ability to persist in tasks and whether specific types of cues can promote persistence
Whether certain types of grimacing or moaning are indications of pain
Whether patients recognize family members and/or respond to emotional themes
Some Additional Case Examples
Is the patient’s kicking spontaneous or related to the environment?
The patient had spontaneous kicking of both legs.
Hypothesis: The patient’s kicking is volitional and related to visual recognition of objects that can be kicked.
Responding to Environmental Cues
Response STIMULUS None Left
Kick Right Kick
None 90% (47/52)
8% (4/52)
2% (1/52)
Left Ball 26% (14/54)
47% (25.5/54)
7% (14.5/54)
Right Ball
29% (16/55)
4% (2/55)
67% (37/55)
(Total) 77 31.5 52.5
Can the patient see?
The patient appears to intermittently fixate and track visual stimuli.
Hypothesis: If the patient can see, she should orient to a visual stimulus more often than to nothing, and should orient more often to a complex visual stimulus than a simple one.
Visual Assessment
Stimulus Looks L Looks R No Resp. P/- 9 2 9 -/P 1 12 7 C/- 6 1 13 -/C 0 10 10 P/C 2 7 11 C/P 0 8 12
Can the patient use finger and thumb movements for Yes/No communication?
The patient can flex R thumb and index finger independently, reasonably consistently on command to “Show me a Yes” or “Show me a No”
Hypothesis: If the patient can use these finger movements to communicate, there should be a relationship between yes/no finger movements, and correct answers to yes/no questions
Yes/No Communication
RESPONSE
QUESTION Yes No NR
Yes 26 2 12
No 13 11 16
Evaluation of Treatment Effects
No treatments are proven to enhance recovery.
Can we use the RP assessment methods to prove the value of treatments for individual patients?
We hoped to use the same single subject assessment methods to answer these questions about whether a drug or other treatment improves performance.
Challenges to Individualized Assessment of Treatment
Variability of performanceSpontaneous recoveryTime taken for certain treatments to
workShort length of stay
Three Basic Assessment Designs
A-BA-B-AA-B-A-B-A-B-A-B-A…
(where A = no treatment; B = treatment of interest)
A-B Design
TIME (DAYS)
PERFORMANCE
A-B-A Design
TIME (DAYS)
PERFORMANCE
A-B-A-B-A-B Design
TIME (DAYS)
PERFORMANCE
How Successfully Can We Evaluate Treatment Effects?
A-B: almost neverA-B-A: rarely done and rarely
conclusiveA-B-A-B-A-B…: strongest design, but
not feasible with most treatments; many treatment reversals may be needed if there is great variability
Meta-Analysis of a Set of QIA Assessments in VS/MCS Patients
R. Martin, J. Whyte (in press)
A-B-A-B:Methylphenidate & Responding
RRDIFSC
.31.25.19.13.060.00-.06-.13-.19-.25
8
6
4
2
0
Std. Dev = .11
Mean = .02
N = 23.00
A-B-A-B:Methylphenidate and Accuracy
ACCDIFSC
.38.31.25.19.13.060.00-.06-.13-.19
8
6
4
2
0
Std. Dev = .13
Mean = .02
N = 23.00
Management Structure
Typical interdisciplinary team responsible for patient treatment (including many other medical and physical priorities)
Assessment support team: specially trained Neuropsychologist, data clerk, working in collaboration with JW.
QAI team leads protocol design in collaboration with clinical team; all team members collect data
Reporting back to team with group decisions about next steps
ConclusionQIA methods are highly successful in assessmentQIA methods, within the reality constraints of the
inpatient unit, and LOS, rarely produce definitive results re: treatment
QIA methods can answer specific questions of clinical concern, not answered by standardized scales; may be used in conjunction with those scales
We must rely on traditional group studies to advance our knowledge of treatment efficacy for this patient population
References
Whyte J, DiPasquale M: Assessment of vision and visual attention in minimally responsive brain injured patients. Arch Phys Med Rehabil 76(9):804-810, 1995
Phipps E, DiPasquale M, Blitz C, Whyte J: Interpreting responsiveness in persons with severe traumatic brain injury: beliefs in families and quantitative evaluations. J Head Trauma Rehabil 12(4):52-67, 1997
Laborde A, Whyte J: Update on Pharmacology. Two dimensional, quantitative data analysis: its role in assessing the functional utility of psychostimulants in minimally conscious patients. J Head Trauma Rehabil 12(4):90-92, 1997
Whyte J, Laborde A, DiPasquale MC: Assessment and treatment of the vegetative and minimally conscious patient. In Rosenthal M, Griffith ER, Kreutzer JS, Pentland B (eds.), Rehabilitation of the Adult and Child With Traumatic Brain Injury (3rd Ed.), Philadelphia: F.A. Davis, 25:435-452, 1999
Phipps E, Whyte J: Medical decision-making with persons who are minimally conscious. Am J Phys Med Rehabil 78(1):77-82, 1999
Whyte J, DiPasquale M., Vaccaro M: Assessment of command-following in minimally conscious brain injured patients. Arch Phys Med Rehabil 80:1-8, 1999
References (cont.) Giacino J, Ashwal S, Childs N, Cranford R, Jennett B, Katz D, Kelly J, Rosenberg J,
Whyte J, Zafonte R, Zasler N: The minimally conscious state: Definition and diagnostic criteria. Neurology 12;58(3):349-353, 2002
Whyte J: Valutazione quantitative dei pazienti in stato vegetativo o minimamente responsive “Quantitative assessment of vegetative and minimally conscious patients”. MR Giornale Italiano Di Medicina Riabilitativa, 17(4):31-37, 2003
Giacino JT, Kalmar K, Whyte J: The JFK coma recovery scale-revised: measurement characteristics and diagnostic utility. Arch Phys Med Rehabil, 85(12):2020-2029, 2004
Giacino J, Whyte J: The vegetative and minimally conscious states: current knowledge and remaining questions. The J Head Trauma Rehabil, 20;(1):30-50, 2005
Whyte J, Katz D, Long D, DiPasquale MC, Polansky M, Kalmar K, Giacino J, Childs N, Mercer W, Novak P, Maurer P, Eifert B: Predictors of outcome and effect of psychoactive medications in prolonged posttraumatic disorders of consciousness: A multicenter study. Arch Phys Med Rehabil, 86;(3):453-462, 2005
Martin RT, Whyte J: The effects of methyphenidate on command following and yes/no communication in persons with severe disorders of consciousness: a meta-analysis of n-of-1 studies. Am J Phys Med Rehabil (in press)
General Discussion
A Multicenter Prospective Randomized Controlled Trial of the Effectiveness of Amantadine Hydrochloride in Promoting Recovery of Function Following Severe Traumatic Brain Injury:
“The Amantadine Study”
Study Participants
Participants: patients with traumatic brain injuries resulting in severe disorders of consciousness
180 participants, across 8 facilities in the United States and Europe.
Aims of the study
To determine whether amantadine improves functional recovery in patients with severe disorders of consciousness
To determine whether any amantadine-related gains in function are maintained after the drug is discontinued