Tourette Syndrome (TS) is characterized primarily by multiple motor and vocal tics. Additionally cognitive deficits, such as problems with attention, may also exist, in those both with and without co-morbid Attention Deficit/Hyperactivity Disorder (ADHD). Although neuroleptics, which block dopamine receptors, are often the treatment of choice for TS, insufficient symptomatic control often requires the use of increased doses. In addition, undesirable side effects can occur at high doses of neuroleptics, including detrimental effects on attention and concentration. Nicotine has been reported to effectively potentiate neuroleptic-induced catalepsy in rats and, when combined with neuroleptics, to reduce motor and vocal tics in TS patients. However, reported acute and sustained (i.e. up to 8 weeks) nicotine-induced improvements in tic symptomatology in TS patients have come from case reports, open and single blind studies. Nicotine alone has been shown to improve attention and cognition in both normal and neuropsychiatric populations. This double-blind, placebo-controlled, crossover design study investigated the comparative efficacy, both acute and sustained, of placebo and a single test dose of transdermal nicotine patch (TNP) on clinical symptoms of TS (i.e. tics), evaluative ratings (by parents) of attention and maladaptive behaviours, as well as event-related potential (ERP) and behavioural performance measures extracted from a degraded stimulus continuous performance task (DS-CPT) of sustained attention. Twenty-three children and adolescents with TS (with and without co-morbid ADHD), aged 8--17, who were taking conventional neuroleptics (i.e. dopamine D-2 receptor antagonists) were entered into the study. Adjunctive nicotine, relative to placebo, failed to significantly alter tic symptomatology in either the acute (i.e. 4 hours post-treatment) or follow-up (i.e. 1 week post treatment) conditions. At follow-up but not at acute assessment, parents reported non-specific improvements in attention, and performance was found to have improved on Coding, a visuomotor task measuring freedom from distractibility, following nicotine treatment. Nicotine had a limited effect on area measures of the P300 component of the ERP, by preventing area decrements seen following placebo treatment. However, other performance measures on the DS-CPT, including accuracy and speed of responding, and P300 amplitude and latency measures, failed to identify any significant effects of nicotine relative to placebo. Given the lack of initial significant effects of a single dose challenge of nicotine and the side effect profile of the TNP, the clinical use of adjunctive nicotine in neuroleptically treated children and adolescents with TS appears premature.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/9338 |
| Date | January 2001 |
| Creators | Howson, Anne L. |
| Contributors | Knott, Verner J., |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Detected Language | English |
| Type | Thesis |
| Format | 246 p. |
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