Impact of co-morbid attention-deficit and hyperactivity disorder on cognitive function in male children with Tourette syndrome: A controlled study

Abstract

Tourette syndrome (TS) and attention-deficit and hyperactivity disorder (ADHD) are co-morbid neurodevelopmental conditions affecting more commonly male patients. We set out to determine the impact of co-morbid ADHD on cognitive function in male children with TS by conducting a controlled study. Participants included four matched groups of unmedicated children (age range 6-15 years): TS (n=13), TS+ADHD (n=8), ADHD (n=39), healthy controls (n=66). Following clinical assessment, each participant completed a battery of tests from the Wechsler Intelligence Scale for Children-III, the Italian Battery for ADHD, the Tower of London test, the Corsi test, and the Digit Span test. All patient groups reported significantly lower scores than healthy controls across the neuropsychological tests involving executive functions. The TS+ADHD group was the most severely affected, followed by the ADHD group and the TS group, particularly in the tests assessing planning ability, inhibitory function, working memory and visual attention, but not auditory attention. Problems in executive functions are more common in patients with neurodevelopmental disorders than controls. Deficits in planning ability, inhibitory function, working memory and visual attention reported by children with TS appear to be more strongly related to the presence of co-morbid ADHD symptoms than core TS symptoms.

A Review of the Neuropsychological Dimensions of Tourette Syndrome

“…However, normal performance has been reported on the Corsi span [ 92 ], the Benton visual retention test [ 92 ], the delayed matching to sample task [ 67 ], the self-ordered pointing task [ 92 ], and the finger windows (a subtest of the wide range assessment of memory and learning) [ 61 ]. Comorbid ADHD could lead to some deficits here again, since Termine et al [ 87 ] found impaired forward and backward Corsi span in TS + ADHD but not in TS-only children.…”

“…In children and adolescents with TS, good verbal working memory was often reported, as proven by normal forward and backward digit span [ 61 , 86 , 87 ] and good n -back performance [ 88 ]. The presence of ADHD could impair working memory capacities, since worse forward and backward digit span was found in TS + ADHD children, when compared to TS children without comorbidities [ 89 ].…”

Trichotillomania is more related to Tourette disorder than to obsessive-compulsive disorder

“…Second, altered flexibility was found in adults with OCD 12 (but not in children 13 ) and in TS, 15 but not in TTM 93,95,[97][98][99] (except in one study, which found a deficit in the Object Alternation task, but not in the Wisconsin Card Sorting Test [WCST] 100 ). Attention deficits are found in all three disorders, 12,101 but more mixed results are found in TS (some studies found a deficit, [102][103][104] whereas others did not [105][106][107] ). However, one must keep in mind that attention deficit/hyperactivity disorder (ADHD) is a frequent comorbidity in TS and that the attention deficit results mentioned above seem linked only to comorbid ADHD.…”

Gilles-de-la-Tourette-Syndrom

“…Durch Faktorenanalyse in epidemiologischen Studien mit GTS-Patienten hat sich gezeigt, dass Patienten mit GTS + ADHS eine höhere Wahrscheinlichkeit für einen früheren Krankheitsbeginn, weitere psychiatrische Komorbiditäten und damit eine höhere Krankheitsschwere haben. Darüber hinaus geht das GTS + ADHS im Vergleich zu GTS ohne ADHS mit mehr kognitiven Störungen wie dysexekutiven Defiziten einher [30].…”