|Year : 2016 | Volume
| Issue : 1 | Page : 19-22
Continuous performance task in attention deficit hyperactivity disorder children
Ann A Abdel Kader1, Nagwa A Mohamed2, Basma B El Sayed1, Omnia R Amin3, Islam F Halawa2
1 Clinical Neurophysiology Unit, Faculty of Medicine, Cairo University, Cairo, Egypt
2 Department of Human Genetics, National Research Center, Cairo, Egypt
3 Department of Psychiatry, Faculty of Medicine, Cairo University, Cairo, Egypt
|Date of Submission||03-Jun-2015|
|Date of Acceptance||03-Aug-2015|
|Date of Web Publication||15-Feb-2016|
Basma B El Sayed
MD, 4th Mahmoud Samy El Baroudy Street, Haram, Giza, 12111
Source of Support: None, Conflict of Interest: None
Poor behavioural inhibition is the central impairment in attention deficit hyperactivity disorder (ADHD). At present, there is no reliable objective measure to detect ADHD. A proper pinpointing evaluation for ADHD depends mainly on the history from parents, family members as well as teachers and schoolmates, by means of questionnaires and conduct rating scales.
The aim of this study was to detect continuous performance task (CPT) (test of variants of attention) changes in children suffering from ADHD compared with normal children.
Patients and methods
CPT, Conners' parent rating scale and Wechsler intelligence scale were done for two groups of children each containing 39 children, a group of ADHD children and the other a normal control group.
We found a significant difference between the mean total IQ score among the ADHD patients group compared with control group. Comparing both groups revealed statistically significant increase in omission, commission and reaction time among patients. A significant negative correlation was found between age on one side and IQ, hyperactivity and psychosomatic subscales, hyperactivity and total DSM-IV scores on the other hand and between commission and opposition, restlessness subscales and ADHD index and also between reaction time and restlessness and emotional index. There was a significant positive correlation between omission and hyperactivity and anxiety subscales, restlessness and emotional indices and DSM-IV hyperactive and total scores. In addition, there was a significant positive correlation between perfectionism and commission and also between reaction time and inattention and social problems subscales.
CPT can have a substantial role in objective identification of ADHD.
Keywords: Attention deficit hyperactivity disorder, continuous performance task, test of variants of attention
|How to cite this article:|
Abdel Kader AA, Mohamed NA, El Sayed BB, Amin OR, Halawa IF. Continuous performance task in attention deficit hyperactivity disorder children. Egypt J Neurol Psychiatry Neurosurg 2016;53:19-22
|How to cite this URL:|
Abdel Kader AA, Mohamed NA, El Sayed BB, Amin OR, Halawa IF. Continuous performance task in attention deficit hyperactivity disorder children. Egypt J Neurol Psychiatry Neurosurg [serial online] 2016 [cited 2021 Apr 21];53:19-22. Available from: http://www.ejnpn.eg.net/text.asp?2016/53/1/19/176340
| Introduction|| |
Noncommunicable diseases in children have taken the upper hand in children disorders and may even replace the communicable ones and malnourishment because of recent prosperity. However, those common noncommunicable diseases, particularly behavioural troubles in children as attention deficit hyperactivity disorder (ADHD), have been less recognized in the Middle East compared with the West .
An accurate diagnostic assessment for ADHD, along with other psychiatric diseases, encompasses gathering of data through detailed history taking of the course and duration of symptoms, from parents, family members as well as teachers and schoolmates, by means of questionnaires and conduct rating scales. However, there is no particular diagnostic test specific for ADHD.
As inattention occurs almost in all psychiatric diseases occurring in children, this makes differentiating among psychiatric diseases as learning disabilities, autism or anxiety disorders on one hand and ADHD on the other hand very challenging .
Functional brain imaging studies of ADHD patients show hypofunction of the anterior cingulate cortex while doing errands requiring inhibitory control . Scientists have suggested that the main impairment in this disease was reduced behavioural inhibition .
Behavioural inhibition means the capability to suppress or disrupt an ongoing response, and recently its occurrence has been related to the presence of a neuronal linkage among brain frontostriatal regions .
The aim of this study is to detect whether there are significant changes in continuous performance task (CPT) results in children suffering from ADHD compared with normal children.
| Patients and methods|| |
We prospectively enrolled 39 male patients with the diagnosis of ADHD (according to DSM-IV-TR), referred from outpatient clinic of child psychiatry of center of social and preventive medicine (Abo-El Reesh Hospital) and special needs clinic in National Research Centre (NRC). Thirty-nine normal control children, age and sex matched, were included. The studied groups' age ranged from 8 to 12 years.
- Children with ADHD on medication.
- Children with any neurologic, cardiac or any other condition that may delay mental development.
- Intelligence quotient less than 80.
This study was approved by Cairo University research committee. A written informed consent was taken from the parents or caregivers of all patients and controls included in the study.
Evaluation of patients
- Detailed history and full general examination.
- Psychiatric assessment:
- Every child was tested individually by a well-trained psychologist.
- Conners' parent rating scale-revised, long version including 80 questions with an average administration time of 30 min . The version used in this study was the Arabic version that was translated into Arabic language and had the reliability and validity tests .
- Wechsler intelligence scale for children , psychometric tests used to assess the level of cognitive abilities (thinking and reasoning), commonly used when evaluating a person's innate intelligence. We used the Arabic version of this test .
Continuous positive task: The GO/NOGO task [test of variants of attention (TOVA)] is a simple GO/NOGO paradigm. The examined child sat 1.5 m in front of a 19-inch monitor where the stimuli were shown through the Psytask (Mistar, Ltd., Arizona, USA) software. He was told to push a button as soon as a square appears on the top of the screen (GO trial) and to ignore squares appearing on the bottom of the screen (NO GO trial). The TOVA test takes 10 min to complete. Behavioural data are registered; errors as omission and commission, variability of response and reaction time, in both groups .
Continuous variables were summarized using mean, SD. Quantitative independent variables were compared using Student's t-test. Pearson's correlation equation was used to find correlation between different variables. A probability value (P value) less than 0.05 was counted statistically significant. SPSS (Statistical Package for the Social Science; SPSS Inc., Chicago, Illinois, USA) version 18 for Microsoft Windows 7® platform was used to calculate all statistical results.
| Results|| |
Age of study population ranged between 8 and 12 years where the mean age of patients was 9.77 ± 1.15 years and mean age of control group was 10.08 ± 1.12 years. No statistically significant difference in age was found between both groups (P > 0.05).
There was statistically significant difference between the mean total IQ score of Wechsler intelligence scale among the ADHD patients group (92.2 ± 3.73), compared with the control group (103.62 ± 4.36) where P value was less than 0.0001.
As regards the severity of ADHD symptoms in the sampled ADHD group measured by Conner's parents rating scale, the mean values were 80.76 ± 6.08 for hyperactivity, 80.31 ± 12.42 for social problems, 78.77 ± 6 for inattention, 78.7 ± 5.44 for opposition, 73.38 ± 12.61 for psychosomatic, 68.31 ± 10.76 for anxiety-shyness and 67.54 ± 6.39 for perfectionism.
Among Conner's indices, the restless-impulsive index was the highest index with a mean of 88.38 ± 2.43. The mean of emotional liability index was 80.77 ± 7.07. The mean of ADHD index was 74.38 ± 4.02 and the total score mean was 86.69 ± 4.43.
Comparing both groups, the ADHD group showed higher statistically significant values as regards CPT errors; omission (P < 0.0001), commission (P < 0.0001), reaction time (P < 0.0001) and reaction time SD (P < 0.0001), as shown in [Table 1].
|Table 1: Comparison of mean ± SD of TOVA CPT in patients and control participants|
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There was a significant negative correlation between age and hyperactivity (r = −0.6503, P < 0.001), and psychosomatic Conner's (r = −0.3716, P = 0.0199) subscale results.
In addition, there was significant negative correlation between age and DSM-IV hyperactivity (r = −0.5169, P = 0.0008), and total score (r = −0.3446, P = 0.0317) subscales.
A significant negative correlation was found between commission and opposition, (r = −0.4568, P = 0.0035), restlessness (r = −0.4974, P = 0.0013), subscales, and ADHD index (r = −0.3582, P = 0.0251).
In addition, there was a significant negative correlation between reaction time and restlessness (r = −0.3831, P = 0.0161), and emotional index (r = −0.4594, P = 0.0033).
There was a significant positive correlation between omission error in CPT results and hyperactivity (r = 0.3799, P = 0.0171), and anxiety Conner's (r = 0.6825, P < 0.001) subscales.
There was also a significant positive correlation between omission and restlessness (r = 0.3495, P = 0.0292), and emotional Conner's indices (r = 0.3565, P = 0.0259).
There was a significant positive correlation between omission error and DSM-IV hyperactive (r = 0.6219, P < 0.001), and total scores (r = 0.3499, P = 0.029).
In addition, there was a significant positive correlation between perfectionism and commission (r = 0.4266, P = 0.0068), and between reaction time and inattention (r = 0.3705, P = 0.0202),, and social problems (r = 0.4216, P = 0.0075) subscales.
There was no statistically significant correlation between total IQ (Wechsler) and CPT results (P > 0.05).
| Discussion|| |
Since our sample was age and sex matched from the beginning, there were no age and sex significant differences. This denotes that the studied samples were homogenous as the mean age in ADHD patients was 9.77 ± 1.15 years while in control group it was 10.08 ± 1.12 years.
In addition, we selected only males in both ADHD patient group and control group. This is in agreement with Greene et al.  and Kytja  who reported that the prevalence of ADHD among boys to girls ratio was 3-6 : 1 respectively.
Our study aimed at exploring the relation between TOVA results, ADHD symptoms severity as reported by Conners' parents rating scale and Wechsler intelligence quotient (IQ) results.
Concerning the total IQ score, measured by Wechsler intelligence scale for children, we found highly significant difference in patients scores compared with normative values. In agreement with Benikos and Johnstone  who reported a difference in IQ between ADHD patients and control groups, with the clinical group showing a significantly lower mean IQ. They concluded that this may not be due to intellectual insufficiencies but may be due to inattention during IQ test administration. This may clarify IQ amendments after stimulant drug treatment, which were probably due to increased attention and not signifying changes in basic intellect.
In our study, as regards the severity of ADHD symptoms in the sampled group measured by Conner's parents rating scale, the subscale that was the highest among all participants was the hyperactivity index, which signifies that the patient group is mostly of the hyperactive ADHD subtype .
The TOVA CPT findings show significantly greater number of errors in ADHD patients compared with control group. In addition, there was a significant positive relation between CPT errors that depend on attention and Conners subscales that assess the attention and behavioural inhibition in patients, disclosing that ADHD patients might have cognitive disorder, or reduced behavioural inhibition. Scientists have suggested that the main impairment in ADHD disease was reduced behavioural inhibition .
This cognitive disorder and reduced behavioural inhibition may be related to cortical hypoarousal, which is thought to be one of the confounding factors in the development of ADHD.
A limitation of this study is related to the CPT circumstance. Though the different versions of the CPT are commonly regarded as attentional tasks, the TOVA dares contributors in the fields of response preparation, expectation and execution or inhibition of motor reactions and not only attention.
| Conclusion|| |
The CPT could play a role in diagnosis of ADHD. Aiming at identifying specific patterns of these findings can help develop a credible objective diagnostic test for ADHD.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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