Release Date: April 17, 2008
BUFFALO, N.Y. -- Tourette syndrome(TS), which in childhood is more severe in boys than girls, appears in adulthood to be more severe in women than men, a study by a University at Buffalo neurologist has shown.
David G. Lichter, M.D., professor of clinical neurology in the UB School of Medicine and Biomedical Sciences, who conducted the study, also found that those whose tics were severe as children were likely to have severe tics as adults.
Results of the study were presented today at a poster session at the 60th annual meeting of the American Academy of Neurology in Chicago.
"Contrary to the association of tic prevalence and severity with the male gender in childhood TS, female gender independently may predict greater adult tic severity," said Lichter. "This suggests the possibility of gender-related differences in the long-term natural history of tics in TS.
"In addition to any genetic influences, epigenetic factors [processes that affects a cell without directly affecting its DNA] or environmental factors may play an important role in tic expression over one's lifetime, and these factors also may be influenced by gender," he said.
"In addition, this study found that development and long-term expression of tics and comorbid conditions in TS appear to be influenced separately.
"If these results are confirmed, this research will identify both age and gender as significant influences that may interact with genetic and environmental factors to affect the severity of tics over the course of an individual's lifetime," said Lichter. "This may reflect gender-related differences that have been observed in various brain systems, including dopaminergic neurons, in response to aging."
Childhood Tourette's Syndrome is three-to-four times more frequent in boys than girls and often is more severe in boys, research into the syndrome has shown. However, much less is known about the syndrome in adulthood, the relationship of the severity of adult TS with TS family history, or the relationship of Tourette's with other conditions, such as obsessive compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD).
Lichter addressed these questions in a study of 15 female and 35 male adult TS patients, ranging in age from 20 to 80. The current severity of tics, presence of OCD or ADHD and overall functioning were assessed using standard tests.
Information on childhood and adolescence severity of tics plus coexistence of ADHD and OCD was collected from participants' clinical records.
While results showed a gender difference in adult tic severity, Lichter found no relationship between gender and the coexistence of OCD in adults. Nor was there an association of tic severity in adults with scores measuring overall functioning, distress, or use of selective serotonin reuptake inhibitors (SSRIs), which are prescribed primarily for anxiety and depression.
Adult tic severity in these participants also was not affected by a family history of tics or OCD.
Lichter plans to replicate the study in a larger sample that will include more female subjects.
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