UK study finds misdiagnosis in some ADHD.
A case study examining motor activity of children during neurocognitive testing has revealed instances of attention-deficit/hyperactivity disorder (ADHD) being diagnosed and stimulant medication prescribed for increased activity which was subsequently attributed to posture weakness by occupational therapists.
"Overactive behavior is often represented as a function of cognitive deficits such as problems of executive or higher-order control functions or delay aversion. The under emphasis on motor control (eg, overflow movements) and motor timing in recent ADHD assessment may seem surprising and are often overlooked in the assessment of children with ADHD," indicated study author, Carsten Vogt, MD, Child and Adolescent Mental Health Services, Berkshire Healthcare Foundation Trust, Reading, United Kingdom.
Although there are an increasing number of continuous performance test () systems incorporating infrared measure of motion to facilitate clinical assessment of ADHD, including the QbTest, the Quotient ADHD System, and the McLean Motion and Attention Test, Vogt's study finds that these could evidence increased motor activity that is unrelated to ADHD.
The retrospective study of cases of children diagnosed with ADHD included those who had been assessed with the QbTest in addition to the Conners questionnaire, and for whom there was an available occupational therapist (OT) report.
Vogt found that all those with high motor activity levels during the QbTest had also scored high for hyperactivity/impulsivity on the parent rating of the Conners questionnaire. Several were later distinguished by OT report for having abnormal posture, however, and two cases with high motor activity in the QbTest were without evidence of attention or impulse control deficits.
In one case, a 13-year-old boy had been diagnosed with ADHD at the age of seven years, and an initial apparent improvement after receiving stimulant medication proved temporary. In his reassessment, a QBTest indicated high activity but with attention and impulse control parameters within the normal range, and he was referred to OT.
The OT report indicated that he was double-jointed and exhibited low energy levels; and had experienced two left ankle sprains and two fractures on his left ankle during a one-year period, as well as frequent dislocation of his left shoulder. He had also presented with a slumped posture and "winging" scapulae, which indicated lowered muscle tone. At this assessment, it was concluded that his hyperactivity during the QbTest was related to weak posture, and that medication was not indicated.
In a second case, OT assessment determined weakness in sustaining postural responses and static balance and provided exercises to improve capacity for sitting in a more controlled manner than had been evidenced on the QbTest. These included half press-ups and hand and wall press exercises. Subsequent testing found that motor activity levels were reduced, to meet the average scoring that had also been found with attention and impulse control.
Vogt points out that the manual of the widely applied Conner questionnaire highlights the importance of integrating information from different sources in determining a diagnosis of ADHD. He notes that it states that is particularly useful for assessing attention problems.
Vogt adds, however, "emphasis should also be given to the posture of the child...and data from the combined infrared motion analysis should not be integrated purely on quantitative information."
The case study examining posture weakness as a possible source for misdiagnosing ADHD, "The Risk of Misdiagnosing Posture Weakness as Hyperactivity in ADHD: A Case Study," was published on-line March 4 in Attention Deficit Hyperactivity Disorder.