Table I. Demographic and clinical characteristics of TBI patients (n = 22). |
|||
Demographic characteristics |
Women |
3 (14%) |
|
Age (years) |
Mean ± SD |
34.1 ± 10.3 |
|
Range |
19-56 |
||
Education (years) a |
Mean ± SD |
13 ± 4.2 |
|
Range |
6-22 |
||
Laterality |
Right-handed |
20 (91%) |
|
Clinical characteristics |
GCS (median) |
Prehospitalization b |
13 (IR: 8) |
At hospitalization |
6 (IR: 10) |
||
Days from injury to acute assessment c |
Mean ± SD |
24.4 ± 16.3 |
|
Range |
8-69 |
||
Non-evaluable days d |
Mean ± SD |
7 ± 7.6 |
|
Range |
0-25 |
||
Days from acute to subacute assessment |
Mean ± SD |
146 ± 47.2 |
|
Range |
46-218 |
||
GCS: Glasgow Coma Scale; IR: interquartile range; SD: standard deviation. a Years of schooling completed; b GCS score before hospitalization; c GCS score at hospitalization; d Days during which the evaluation of the patient could not be carried out during the acute phase. |
Table II. Demographic and clinical characteristics of the different patient subsamples included in each analysis. Mean ± standard deviation scores are presented (median in GCS). |
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|
TMT |
Stroop |
DS, SS, DF, DB, Memory |
Verbal Fluency |
Women |
3 |
3 |
3 |
3 |
Mean age (years) |
33.3 ± 10 |
32.3 ± 8.8 |
34.1 ± 10.3 |
33.4 ± 9.4 |
Years of education (mean) |
13.4 ± 3.7 |
12.9 ± 3.7 |
13.1 ± 4.2 |
12.8 ± 3.8 |
Right-handed/left-handed |
16 / 1 |
18 / 2 |
20 / 2 |
18 / 2 |
Prehospitalization GCS (median) |
13 (IR: 8) |
13 (IR: 8) |
13 (IR: 8) |
14 (IR: 8) |
Days from acute to subacute assessment (mean) |
163.5 ± 41.2 |
165.8 ± 40.7 |
170.6 ± 41.9 |
169.3 ± 40.9 |
DB: Digits Backward; DF: Digits Forward; DS: Digits Symbol-Coding; GCS: Glasgow Coma Scale; IR: interquartile range; SS: Symbol Search; TMT: Trail Making Test. |
Table III. Score changes between the two assessments (gain) presented as standard deviations (SD) and percentage of change. The change attributed to practice and recovery is shown separately. |
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|
Change (SD) |
% of change |
||||
Total |
Practice |
Recovery |
Practice |
Recovery |
||
TMT |
A |
0.47 |
0.26 |
0.21 |
56.1% |
43.9% |
B |
0.88 |
0.32 |
0.56 |
36.3% |
63.7% |
|
B-A |
0.88 |
0.26 |
0.62 |
29.2% |
70.8% |
|
B/A |
0.66 |
0.05 |
0.60 |
8.2% |
91.8% |
|
Stroop |
Stroop W |
0.46 |
0.23 |
0.24 |
48.9% |
51.1% |
Stroop C |
0.38 |
0.23 |
0.15 |
59.7% |
40.3% |
|
Stroop CW |
0.53 |
0.21 |
0.32 |
40% |
60% |
|
Stroop Int |
0.44 |
0.12 |
0.31 |
28.5% |
71.5% |
|
IPS |
DS |
0.71 |
0.32 |
0.39 |
44.6% |
55.4% |
SS |
0.65 |
0.22 |
0.43 |
33.5% |
66.5% |
|
Digits Forward |
Series |
0.31 |
–0.05 |
0.36 |
–16.4% |
116.4% |
Span |
0.45 |
–0.05 |
0.50 |
–11.1% |
111.1% |
|
Digits Backward |
Series |
0.64 |
–0.05 |
0.69 |
–7.8% |
107.8% |
Span |
0.67 |
–0.05 |
0.72 |
–7.4% |
107.4% |
|
Verbal Fluency |
F |
0.61 |
0.23 |
0.38 |
38.3% |
61.7% |
A |
0.42 |
0.23 |
0.19 |
55.2% |
44.8% |
|
Animals |
0.96 |
0.23 |
0.72 |
24.3% |
75.7% |
|
Memory |
Recall |
0.56 |
0.20 |
0.35 |
36.6% |
63.4% |
Recognition |
0.50 |
0.20 |
0.29 |
41% |
59% |
|
DS: Digits Symbol-Coding; IPS: information process speed; SS: Symbol Search; Stroop Int: Stroop Interference; TMT: Trail Making Test. |
Figure. Percentage of total change attributed to practice and spontaneous recovery of patients. B-A: derived score resulting from subtracting TMT A from TMT B; B/A: derived score resulting from dividing n TMT B by TMT A; Stroop Int: Stroop Interference score; DS: Digit Symbol-Coding; SS: Symbol Search; DF: Digits Forward; DB: Digits Backward; VF: Verbal Fluency.
Table IV. Mean scores (standard deviation), significance, effect size and contrast power obtained in t-tests comparing the performance of patients in the acute and subacute stage of TBI in each of the neuropsychological tests. Results calculated before and after correcting practice effects are shown. |
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|
|
Without practice effects correction |
With practice effects corrected |
|||||||
Acute stage |
Subacute stage |
Significance |
d |
Power |
Subacute stage |
Significance |
d |
Power |
||
TMT |
A |
52.6 ± 34.3 |
36.5 ± 9.4 |
0.036 c |
0.56 |
0.58 |
45.5 ± 9.2 |
0.331 d |
0.24 |
0.16 |
B |
136.9 ± 69.3 |
76.3 ± 22 |
0.001 a |
1.01 |
0.97 |
98.3 ± 22.8 |
0.017 c |
0.64 |
0.70 |
|
B-A |
84.4 ± 50.8 |
39.8 ± 18 |
0.001 a |
0.98 |
0.98 |
52.8 ± 19.3 |
0.011 c |
0.70 |
0.77 |
|
B/A |
2.9 ± 1.2 |
2.1 ± 0.5 |
0.012 c |
0.69 |
0.76 |
2.2 ± 0.4 |
0.019 c |
0.64 |
0.69 |
|
Stroop |
Stroop W |
85.9 ± 19 |
94.7 ± 18.7 |
0.039 c |
0.50 |
0.56 |
90.3 ± 18.7 |
0.270 d |
0.25 |
0.19 |
Stroop C |
60.7 ± 15.4 |
66.5 ± 14.8 |
0.016 c |
0.59 |
0.71 |
63 ± 14.7 |
0.297 d |
0.24 |
0.17 |
|
Stroop CW |
33.9 ± 15.6 |
42.1 ± 12.7 |
< 0.001 a |
1.02 |
0.99 |
38.8 ± 12.7 |
0.014 c |
0.60 |
0.72 |
|
Stroop Int |
–1.6 ± 10.8 |
3.1 ± 9.5 |
0.032 c |
0.52 |
0.59 |
1.8 ± 9.6 |
0.117 d |
0.37 |
0.35 |
|
IPS |
DS |
44.7 ± 22.2 |
60.4 ± 18.5 |
< 0.001 a |
0.99 |
0.99 |
53.4 ± 18.3 |
0.019 c |
0.54 |
0.68 |
SS |
24.7 ± 11.1 |
32 ± 9.6 |
< 0.001 a |
0.94 |
0.99 |
29.5 ± 9.6 |
0.008 b |
0.62 |
0.80 |
|
Digits Forward |
Series |
7.3 ± 1.6 |
7.8 ± 1.5 |
0.149 d |
0.32 |
0.30 |
7.9 ± 1.6 |
0.095 d |
0.37 |
0.39 |
Span |
5.2 ± 0.9 |
5.6 ± 0.9 |
0.119 d |
0.35 |
0.34 |
5.6 ± 0.9 |
0.086 d |
0.38 |
0.41 |
|
Digits Backward |
Series |
4.4 ± 1.8 |
5.5 ± 1.6 |
< 0.001 a |
0.91 |
0.98 |
5.6 ± 1.6 |
< 0.001 a |
0.99 |
0.99 |
Span |
3.5 ± 1 |
4.2 ± 1.3 |
0.010 c |
0.6 |
0.77 |
4.3 ± 1.3 |
0.007 b |
0.64 |
0.81 |
|
Verbal Fluency |
F |
7.3 ± 4 |
9.8 ± 2.7 |
0.010 c |
0.64 |
0.77 |
8.8 ± 2.7 |
0.095 d |
0.39 |
0.39 |
A |
7.9 ± 4 |
9.6 ± 2.8 |
0.032 c |
0.52 |
0.60 |
8.6 ± 2.8 |
0.312 d |
0.23 |
0.17 |
|
Animals |
13.7 ± 6.1 |
19.5 ± 5.1 |
0.001 b |
0.85 |
0.95 |
18 ± 5.1 |
0.010 b |
0.64 |
0.78 |
|
Memory |
Recall |
7.7 ± 3.1 |
11.5 ± 3.1 |
0.020 c |
0.54 |
0.67 |
8.8 ± 3.3 |
0.126 d |
0.34 |
0.33 |
Recognition |
9.5 ± 2.1 |
10.9 ± 1.1 |
0.006 b |
0.64 |
0.82 |
10 ± 1.4 |
0.087 d |
0.38 |
0.40 |
|
d: effect size; DS: Digits Symbol-Coding; IPS: information process speed; SS: Symbol Search; Stroop Int: Stroop Interference; TMT: Trail Making Test. a p < 0.001; b p < 0.01; c p < 0.05; d Non-significant difference (p > 0.05). |
Evolución de las alteraciones cognitivas tras un traumatismo craneoencefálico: ¿hay mejoría tras controlar el efecto de la práctica? Introducción. La importancia de conocer el patrón de evolución de los déficits cognitivos en los primeros meses tras un traumatismo craneoencefálico (TCE) ha fomentado el desarrollo de numerosos estudios longitudinales. Sin embargo, los resultados de la mayoría de ellos deberían tomarse con cautela debido a la falta de un control adecuado del efecto de la práctica, que puede llevar a sobreestimar la recuperación genuina de los procesos cognitivos. Objetivo. Describir los cambios cognitivos entre las fases aguda y subaguda del TCE controlando el efecto de la práctica. Pacientes y métodos. Veintidós pacientes realizaron dos evaluaciones neuropsicológicas tras el TCE (inmediata y tras seis meses) mediante los siguientes tests: Trail Making Test (A, B, B/A y B-A), test de Stroop (P, C, PC e interferencia), clave de números, búsqueda de símbolos, dígitos directos e inversos, fluidez verbal y memoria inmediata. Para controlar el efecto de la práctica se realizó una transformación de las puntuaciones aplicando el procedimiento propuesto por Calamia et al. Resultados. Antes de controlar el efecto de la práctica, se evidenció una mejoría en las puntuaciones de todos los tests (p > 0,001). Sin embargo, tras él, la mejoría permaneció sólo en el Trail Making Test B, B/A y B-A, la clave de números, la búsqueda de símbolos, el test de Stroop PC y los dígitos inversos. Conclusiones. La falta de control del efecto de la práctica en estudios longitudinales puede generar interpretaciones erróneas sobre el perfil de evolución de los déficits cognitivos. El patrón de recuperación tras un TCE varía en función del proceso cognitivo. Palabras clave. Diseño longitudinal. Evolución. Práctica. Recuperación. Rendimiento cognitivo. Traumatismo craneoencefálico. |