Memory function after resolution of post-traumatic amnesia

Duration of post-traumatic amnesia is uniquely associated with memory functioning in chronic moderate-to-severe traumatic brain injury

BACKGROUND

Disrupted memory circuitry may contribute to post-traumatic amnesia (PTA) after traumatic brain injury (TBI). It is unclear whether duration of PTA (doPTA) uniquely impacts memory functioning in the chronic post-injury stage.

OBJECTIVE

To examine the relationship between doPTA and memory functioning, independent of other cognitive abilities, in chronic moderate-to-severe TBI.

METHODS

Participants were 82 individuals (median chronicity = 10.5 years) with available doPTA estimates and neuropsychological data. Composite memory, processing speed (PS), and executive functioning (EF) performance scores, as well as data on subjective memory (SM) beliefs, were extracted. DoPTA-memory associations were evaluated via linear modeling of doPTA with memory performance and clinical memory status (impaired/unimpaired), controlling for PS, EF and demographic covariates. Interrelationships between doPTA, objective memory functioning, and SM were assessed.

RESULTS

DoPTA was significantly related to memory performance, even after covariate adjustment. Impairment in memory, but not PS or EF, was associated with a history of longer doPTA. SM was associated with memory performance, but unrelated to doPTA.

CONCLUSIONS

Findings suggest a specific association between doPTA-an acute injury phenomenon-and chronic memory deficits after TBI. Prospective studies are needed to understand how underlying mechanisms of PTA shape distinct outcome trajectories, particularly functional abilities related to memory processing.

Is the Weigl Colour-Form Sorting Test Specific to Frontal Lobe Damage?

OBJECTIVE

The Weigl Colour-Form Sorting Test is a brief, widely used test of executive function. So far, it is unknown whether this test is specific to frontal lobe damage. Our aim was to investigate Weigl performance in patients with focal, unilateral, left or right, frontal, or non-frontal lesions.

METHOD

We retrospectively analysed data from patients with focal, unilateral, left or right, frontal (n = 37), or non-frontal (n = 46) lesions who had completed the Weigl. Pass/failure (two correct solutions/less than two correct solutions) and errors were analysed.

RESULTS

A greater proportion of frontal patients failed the Weigl than non-frontal patients, which was highly significant (p < 0.001). In patients who failed the test, a significantly greater proportion of frontal patients provided the same solution twice. No significant differences in Weigl performance were found between patients with left versus right hemisphere lesions or left versus right frontal lesions. There was no significant correlation between performance on the Weigl and tests tapping fluid intelligence.

CONCLUSIONS

The Weigl is specific to frontal lobe lesions and not underpinned by fluid intelligence. Both pass/failure on this test and error types are informative. Hence, the Weigl is suitable for assessing frontal lobe dysfunction.

Post-traumatic Confusional State: A Case Definition and Diagnostic Criteria

In response to the need to better define the natural history of emerging consciousness after traumatic brain injury and to better describe the characteristics of the condition commonly labeled posttraumatic amnesia, a case definition and diagnostic criteria for the posttraumatic confusional state (PTCS) were developed. This project was completed by the Confusion Workgroup of the American Congress of Rehabilitation Medicine Brain Injury Interdisciplinary Special Interest group. The case definition was informed by an exhaustive literature review and expert opinion of workgroup members from multiple disciplines. The workgroup reviewed 2466 abstracts and extracted evidence from 44 articles. Consensus was reached through teleconferences, face-to-face meetings, and 3 rounds of modified Delphi voting. The case definition provides detailed description of PTCS (1) core neurobehavioral features, (2) associated neurobehavioral features, (3) functional implications, (4) exclusion criteria, (5) lower boundary, and (6) criteria for emergence. Core neurobehavioral features include disturbances of attention, orientation, and memory as well as excessive fluctuation. Associated neurobehavioral features include emotional and behavioral disturbances, sleep-wake cycle disturbance, delusions, perceptual disturbances, and confabulation. The lower boundary distinguishes PTCS from the minimally conscious state, while upper boundary is marked by significant improvement in the 4 core and 5 associated features. Key research goals are establishment of cutoffs on assessment instruments and determination of levels of behavioral function that distinguish persons in PTCS from those who have emerged to the period of continued recovery.

Fatores associados à amnésia pós-traumática de longa duração

OBJETIVO: Identificar fatores relacionados à amnésia pós-traumática de longa duração. MÉTODO: Estudo prospectivo, longitudinal, com 187 vítimas de trauma cranioencefálico contuso, idade >14 anos, atendidos em hospital de referência para trauma. As variáveis independentes foram: idade, sexo, gravidade do trauma cranioencefálico, local e tipo de lesão, número de lesões encefálicas e uso de medicação com atividade em sistema nervoso central ou corticoides. RESULTADO: O modelo de regressão logística múltipla ajustado pela variável área de lesão (intra/extra axial) evidenciou: Escala de Coma de Glasgow inicial <12 (OR=20,17); Maximum Abbreviated Injury Scale/cabeça >3 (OR=2,80) e uso de Fenitoína (OR=2,60), Midazolan (OR=2,83) ou ambas as drogas (OR=3,83). CONCLUSÃO: O uso do Midazolan e da Fenitoína, além da gravidade do trauma cranioencefálico, destacaram-se como fatores relacionados à amnésia de longa duração.

Galveston Orientation Amnesia Test (GOAT)

O trauma crânio-encefálico contuso (TCEC) é freqüentemente seguido pela amnésia pós-traumática (APT), caracterizada como um estado transitório de confusão e desorientação. Sua duração tem sido utilizada para quantificar a gravidade do TCEC e prever distúrbios nas funções cognitivas, assim como para antever as alterações na capacidade funcional das vítimas pós-trauma. O Galveston Orientation Amnesia Test (GOAT) é o primeiro instrumento sistematizado criado e o mais amplamente utilizado para avaliar a APT. Este artigo apresenta esse instrumento, as bases conceituais para seu desenvolvimento e a adaptação e validação do GOAT para cultura brasileira. Além disso, descreve sua aplicação e comenta as restrições do seu uso. Resultados de pesquisas realizadas em nosso meio contribuíram para as evidências sobre a validade do GOAT. Também apontaram os indicadores do momento pós-trauma em que o GOAT deve ser aplicado e destacaram as dificuldades no uso desse instrumento.

Comparison of the O-Log and GOAT as measures of posttraumatic amnesia

PRIMARY OBJECTIVE

To compare PTA severity and duration assessments made by Orientation Log (O-Log) and the Galveston Orientation and Amnesia Test (GOAT) and the relationship of data yielded by these assessments to rehabilitation outcomes.

RESEARCH DESIGN

Retrospective study.

METHODS AND PROCEDURES

O-Log, GOAT, demographic, length of stay, and Functional Independence Measure (FIM) data among 83 inpatient subjects with recent TBI requiring inpatient care were reviewed.

MAIN OUTCOMES AND RESULTS

PTA severity and duration as assessed by the O-Log and the GOAT are statistically similar and correlate similarly with rehabilitation LOS and discharge total FIM score. Simple linear regression models suggest that O-Log scores better predict rehabilitation outcomes than GOAT scores.

CONCLUSIONS

Although the O-Log and GOAT perform similarly as measures of PTA severity and duration, PTA assessments using the O-Log offers better prediction of rehabilitation outcomes. Further study of the O-Log as an alternate assessment of PTA is warranted.

"Galveston Orientation and Amnesia Test": tradução e validação

OBJETIVO: Traduzir e validar o Galveston Orientation and Amnesia Test para uso em nosso meio. MÉTODOS: Esse teste foi traduzido para o português e retro-traduzido para o inglês por diferentes especialistas na língua e por fim, feita a avaliação da equivalência entre o instrumento original e a versão retro-traduzida. Sua aplicação em 73 vítimas de trauma crânio-encefálico contuso e a indicação da gravidade dessa lesão, estabelecida pela Escala de Coma de Glasgow, permitiram verificar as propriedades de medida do instrumento. RESULTADOS: A confiabilidade verificada pelo Alfa de Cronbach resultou em 0,76. Houve indicação de validade convergente e discriminante do instrumento quando os resultados de aplicação do Galveston Orientation and Amnésia Test foram analisados perante a gravidade do trauma crânio-encefálico. CONCLUSÃO: Os resultados observados dão suporte para a aplicação do Galveston Orientation and Amnesia Test em nosso meio como indicador do término da amnésia pós-traumática.