Complexity analysis of spontaneous brain activity in attention-deficit/hyperactivity disorder: diagnostic implications.
BACKGROUND
Attention-deficit/hyperactivity disorder (ADHD) is defined as the most common neurobehavioral disorder of childhood, but an objective diagnostic test is not available yet to date. Neurophychological, neuroimaging, and neurophysiological research offer ample evidence of brain and behavioral dysfunctions in ADHD, but these findings have not been useful as a diagnostic test.


METHODS
Whole-head magnetoencephalographic recordings were obtained from 14 diagnosed ADHD patients and 14 healthy children during resting conditions. Lempel-Ziv complexity (LZC) values were obtained for each channel and child and averaged in five sensor groups: anterior, central, left lateral, right lateral, and posterior.


RESULTS
Lempel-Ziv complexity scores were significantly higher in control subjects, with the maximum value in anterior region. Combining age and anterior complexity values allowed the correct classification of ADHD patients and control subjects with a 93% sensitivity and 79% specificity. Control subjects showed an age-related monotonic increase of LZC scores in all sensor groups, while children with ADHD exhibited a nonsignificant tendency toward decreased LZC scores. The age-related divergence resulted in a 100% specificity in children older than 9 years.


CONCLUSIONS
Results support the role of a frontal hypoactivity in the diagnosis of ADHD. Moreover, the age-related divergence of complexity scores between ADHD patients and control subjects might reflect distinctive developmental trajectories. This interpretation of our results is in agreement with recent investigations reporting a delay of cortical maturation in the prefrontal cortex.
Fernández
Alberto
A
Departamento de Psiquiatría, Universidad Complutense de Madrid, Madrid, Spain. aferlucas@med.ucm.es
Quintero
Javier
J
Hornero
Roberto
R
Zuluaga
Pilar
P
Navas
Marta
M
Gómez
Carlos
C
Escudero
Javier
J
García-Campos
Natalia
N
Biederman
Joseph
J
Ortiz
Tomás
T
D000375:Aging; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000503:physiopathology*; D001921:Brain / Q000254:growth & development / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D012680:Sensitivity and Specificity