Tics have been reported to occur in association with numerous different acquired and congenital neurologic and neuropsychiatric disorders or on exposure to a variety of drugs (Table 1). The terms secondary tics or tourettism have been applied to these disorders.<sup>159 Sacks O.W. Acquired Tourettism in adult life Gilles de la Tourette Syndrome, Advances in Neurology New York: Raven Press (1982).  89-92

Haga clic aquí para ir a la sección de Referencias</sup> Although association does not imply causation, many of these disorders and drugs have been consistently associated with tics and clearly affect basal ganglia function; furthermore, abnormalities of basal ganglia structure and function have been demonstrated on imaging studies and immunohistochemical analysis of postmortem tissue in the commonest cause of idiopathic tics, Tourette syndrome (TS).<sup>68 Haber S.N., Kowall N.W., Vonsattel J.P. , y al. Gilles de la Tourette's syndrome: A postmortem neuropathological and immunohistochemical study J Neurol Sci 1986 ;  75 : 225-241  [cross-ref]

Haga clic aquí para ir a la sección de Referencias, 69 Haber S.N., Wolfer D. Basal ganglia peptidergic staining in Tourette syndrome: A follow-up study Advances in Neurology New York: Raven Press (1992).  145-150

Haga clic aquí para ir a la sección de Referencias, 80 Hyde T.M., Stacey M.E., Coppola R. , y al. Cerebral morphometric abnormalities in Tourette's syndrome: A quantitative MRI study of monozygotic twins Neurology 1995 ;  45 : 1176-1182

Haga clic aquí para ir a la sección de Referencias, 151 Peterson B., Riddle M.A., Cohen D.J. , y al. Reduced basal ganglia volumes in Tourette's syndrome using three-dimensional reconstruction techniques from magnetic resonance images Neurology 1993 ;  43 : 941-949

Haga clic aquí para ir a la sección de Referencias, 172 Singer H.S., Reiss A.L., Brown J.E. , y al. Volumetric MRI changes in basal ganglia of children with Tourette's syndrome Neurology 1993 ;  43 : 950-956

Haga clic aquí para ir a la sección de Referencias</sup> In addition, basal ganglia lesions (from a variety of causes) may result in obsessive-compulsive symptomatology (OCS), which commonly coexists with TS or may be an alternative expression of a genetic predisposition to TS.<sup>28 Comings D.E. A controlled study of Tourette syndrome. VII. Summary: A common genetic disorder causing disinhibition of the limbic system Am J Hum Genet 1987 ;  41 : 839-866

Haga clic aquí para ir a la sección de Referencias, 103 Kurlan R. Hypothesis II: Tourette's syndrome is part of a clinical spectrum that includes normal brain development Arch Neurol 1994 ;  51 : 1145-1150

Haga clic aquí para ir a la sección de Referencias, 110 Laplane D., Levasseur M., Pillon B. , y al. Obsessive-compulsive and other behavioural changes with bilateral basal ganglia lesions Brain 1989 ;  112 : 699-725

Haga clic aquí para ir a la sección de Referencias, 119 Leonard H.L., Swedo S.E., Rapoport J.L. , y al. Tourette syndrome and obsessive-compulsive disorder Advances in Neurology New York: Raven Press, Ltd. (1992).  83-93

Haga clic aquí para ir a la sección de Referencias, 150 Pauls D.L., Leckman J.F. The inheritance of Gilles de la Tourette's syndrome and associated behaviours: Evidence for autosomal dominant transmission N Engl J Med 1986 ;  315 : 993-997  [cross-ref]

Haga clic aquí para ir a la sección de Referencias, 204 Williams A.C., Owen C., Heath D.A. A compulsive movement disorder with cavitation of caudate nucleus J Neurol Neurosurg Psychiatry 1988 ;  57 : 447-448  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> Recognition and careful study of secondary tic disorders may aid our understanding of the pathogenesis of TS.

One important problem with the literature cited is the inconsistent use of the term tics. In many cases, what has been labeled tics may have been another movement disorder, including chorea, myoclonus, stereotypies, or even psychogenic movements. Such features as urge, distractibility, suppressibility, and suggestibility are rarely described in case reports of secondary tics. Thus, all such case reports must be reviewed critically before cause and effect can be accepted and conclusions drawn regarding the pathogenic mechanisms of tics in general.