Tic Disorders: Diagnosis

Diagnosis

Clinical Presentation

Before the 1980s, only people with the most severe and clini-cally obvious tics were diagnosed with Tourette’s disorder. The majority of these patients were adults who pursued care and were correctly diagnosed only when their tic symptoms were disabling and when classic symptoms such as coprolalia were present. Adults with milder tics generally did not pursue care and may have been stigmatized without the awareness of the cause of their movements. Children with tics were not identified at all or were identified as having other behavioral or psychiatric difficulties. Increasingly, as medical professionals and the public became more knowledgeable about tic disorders, psychiatrists began to see children at younger ages and with milder symptoms. Today, psychiatrists sometimes become involved even when the tics themselves are not obvious or even disabling. In today’s clinical practice, the challenge is often not the treatment of the tics but identification of cooccurring and often more disabling psychiat-ric, behavioral, family and school problems.

More than half of families who finally pursue expert con-sultation find out about tic disorders from news articles or televi-sion. Many parents describe as their worst fear that their child’s mild tic disorder is the beginning of a permanent neuropsychiatric disorder with a deteriorating course. Other children are identified during evaluation for other problems, such as ADHD. When the diagnosis of Tourette’s disorder is made as part of an evaluation for other problems, it can be particularly difficult for the fam-ily and the patient to cope with the additional and unexpected diagnosis. Clearly, at the time of the evaluation, the patient and family are often frightened and require considerable psychologi-cal support.

Some children with tics, who present directly to a neurolo-gist or a psychiatrist for an evaluation, may have a parent who has been diagnosed with a tic disorder. In this context, children can present early in the course of their disorder, often before a clear diagnosis can be made. The parents of these children were often diagnosed with tics late in their life or experienced significant duress from their symptoms and want their child to have a better experience.

Assessment

Tic Severity

Clinical assessment of the tic disorders begins with identifica-tion of the specific movements and sounds. It is also important to identify the severity of and impairment caused by the tics. A number of structured and semistructured instruments are avail-able for the identification of tics and the rating of tic. Knowledge of the basic clinical parameters of tics and the course of illness dictates the evaluation. Questioning patients and their families about the presence of simple and complex movements in muscle groups from head to toe is a good beginning. Because vocal tics usually follow the development of motor tics, questions about the presence of simple sounds is next. Inquiring about the presence of complex vocal tics completes the tic inventory. It is helpful to elu-cidate other aspects of tic severity, such as the absolute number of tics; the frequency, forcefulness and intrusiveness of the symp-toms; the ability of the patient successfully to suppress the tics; and how noticeable the tics are to others. It is also important to know whether premonitory sensory or cognitive experiences are a component of specific tics because these intrusive experiences may disrupt functioning more than the tics themselves. Although the waxing and waning nature of the tics and the replacement of one tic with another do not directly affect severity, identify-ing the characteristic course of illness is important for diagnostic confidence.

 Last, it is important to assess the impairment due to the tics themselves. Whereas tic severity is frequently correlated with overall impairment, it is not uncommon to identify patients in whom tic severity and impairment are not correlated. Patients who experience more impairment than their tic symptoms ap-parently warrant are a particular clinical challenge. A number of clinical features of tics are associated with impairment:

·           Large, disruptive, or painful motor movements;

·           Vocalizations that call attention to the patient;

·           Premonitory sensations or cognitions that intrude into consciousness;

·           Tics that are socially unacceptable.

Associated Cooccurring Conditions

Whereas tic severity and impairment are often correlated, many patients with mild tics are most impaired by the comorbid condi-tions ADHD, OCD and Learning Disorders. An adequate assess-ment of these conditions is part of any comprehensive evaluation. The assessment of tic-related obsessive–compulsive symptoms, for example, touching, tapping, rubbing, “evening up”, repeating actions, stereotypical self-mutilation, staring, echolalia and pali-lalia, although often omitted from the traditional psychiatric and neurological review of symptoms, should always be part of the routine evaluation of patients with tics, OCD, or ADHD.

Psychosocial Issues

Psychosocial issues can play a role in tic severity and in over-all adaptation and impairment. Assessment of family, peer and school support for the youngster (adequate protection) along with assessment for the presence of opportunities to be intellec-tually, physically and socially challenged is important. The bal-ance between protection and challenge in children is critical for long-term development. An environment that is too protective decreases opportunities for building skills. An environment that is too challenging can lead to frustration, anger and maladaptive coping.

Physical Examination Findings

Tic assessment requires a careful evaluation of observable tic symptoms. Interestingly, the absence of tic symptoms during an evaluation, in spite of parent’s or patient’s report, is not uncommon and should not necessarily lead to clinical doubt. Occasionally, an additional clinical observer (e.g. nurse or medi-cal student) may identify tics more readily than the psychiatrist conducting the evaluation. Other than the observation of tics in the interview, there are no pathognomonic physical examina-tion findings. Patients with Tourette’s disorder have been noted to have nonfocal and nonspecific subtle neurological findings (“soft” signs). If tic suppression  the with neuroleptic agents is con-sidered, a more structured method of documenting the complex movements that are part of the pretreatment baseline evaluation is useful for following the progression of the disease and for sub-sequent assessment for neuroleptic-induced movements.