NASHVILLE—One of the underlying principles of neurology—that a patient's signs and symptoms reflect the location of neurologic damage or dysfunction—also applies to interpreting psychopathology. "For example, most of us know that lesions in the frontal lobe will be associated with abulia or dysinhibition," noted Roger Kurlan, MD. Similarly, dysfunction of the basal ganglia results in a broad but characteristic spectrum of psychopathology, which Dr. Kurlan outlined at the 28th Annual Meeting of the Child Neurology Society.

Over the past decade, Dr. Kurlan and colleagues have described and refined the diagnostic criteria for an entity they termed "developmental basal ganglia syndrome" (DBGS), which often resembles Tourette syndrome but—given the interconnections between the circuitry of the limbic system and the basal ganglia—encompasses an array of problems in regulating movement, thought, and affect. While the syndrome's motor hallmarks are tics, dystonia, or chorea, there may also be stuttering or other speech articulation disorders, delays in reaching motor milestones, and clumsiness that manifests as poor handwriting.

Moreover, Dr. Kurlan noted that DBGS is also associated with a variety of psychosocial and behavioral problems, including obsessive-compulsive symptoms, attention difficulties, executive dysfunction, learning disabilities, and social and emotional problems (eg, aggression). "It is important that if you see a child with one of these features to [remember] that they may in fact be an example of the basal ganglia syndrome," said Dr. Kurlan, who is Professor of Neurology at the University of Rochester and Chief of the Cognitive and Behavioral Neurology Unit at the University of Rochester Medical Center. "Have a high index of suspicion for the other features that go along with the syndrome."

THE LINK WITH TOURETTE

It is likely, Dr. Kurlan said, that DBGS is in many cases caused by the genetic defect responsible for Tourette syndrome, one of the most common childhood disorders in which basal ganglia dysfunction has been implicated. Indeed, the psychological manifestations of the two disorders may overlap considerably. "It is very clear that Tourette syndrome is a spectrum disorder that includes significant behavioral problems," Dr. Kurlan noted, adding that tics, obsessive-compulsive symptoms, and attention-deficit/hyperactivity disorder—all common features of DBGS—make up the classic triad of Tourette features.

Despite the similarities between Tourette syndrome and DBGS, Dr. Kurlan and colleagues now believe that "a wide variety of insults that interfere with normal basal ganglia development will all produce" DBGS; these include fetal alcohol syndrome, perinatal asphyxia, head trauma, stroke, and encephalitis. The syndrome, he suggested, is part of a clinical spectrum that encompasses a range of functional impairments, reflecting various degrees of abnormality in basal ganglia development. The mildest form includes largely subclinical features; in some cases, children exhibit attentional disturbances, tics, or obsessive-compulsive behavior on a temporary basis. Further along the spectrum are children who have mild to moderate academic and behavioral problems, and at the extreme end of the spectrum are children with severe and disabling symptoms.

The neurologic basis for the symptoms is becoming increasingly clear. For example, disruption of the areas that mediate cognitive function, including the frontal lobes and basal ganglia, is thought to underlie problems in attention. Researchers have also identified the basal ganglia as the mediating site for the generation of goal-oriented behavior, the expression of emotions in an appropriate manner, and the suppression or inhibition of inappropriate responses, suggesting that dysfunction of this region plays a role in the pathogenesis of obsessive-compulsive behaviors.

DETECTING OBSESSIONS AND OTHER PSYCHOPATHOLOGY

Although neither attention problems nor obsessive-compulsive symptoms are part of the standard diagnostic criteria for Tourette syndrome or DBGS, a significant proportion of patients exhibit these symptoms, Dr. Kurlan noted. He emphasized that while obsessions in Tourette patients may include repetitive thoughts or impulses, they may also manifest as religious obsessions or persistent images, such as perceptions of harm coming to a family member. Compulsions, Dr. Kurlan continued, are defined as repetitive behaviors that a patient feels driven to perform, often in response to an obsession. Typically, they are carried out according to rigid rules; they may be performed only at a certain time of day, in a particular order, or for a certain number of times. One example is a behavior known as "evening up," in which the child must get both sides of the body to feel or look the same, Dr. Kurlan explained. He or she may spend a great deal of time on such activities as tying both sneakers to the exact same degree of tightness.

While such behavior might seem readily apparent, Dr. Kurlan noted that obsessive-compulsive symptoms are often overlooked, particularly in Tourette patients. He recommended using the Leyton Obsessional Inventory and the Yale-Brown Obsessive-Compulsive Scale, which systematically review examples of pathologic behavior. It is unproductive to ask patients generic questions—such as "Do you have any peculiar behaviors?"—according to Dr. Kurlan. "Many times, the parent or child has no idea that what the child does is actually abnormal behavior."

Other psychological manifestations of DBGS can include anxiety, depression, and oppositional defiant disorder. One approach that can help uncover pediatric anxiety problems, Dr. Kurlan suggested, is to ask whether the patient has any school phobias, as well as frequent stomachaches or other somatic complaints. Childhood depression can be signaled by poor school performance, loss of interest in usual activities, irritability, weight changes, and substance abuse, he continued; family history may also provide clues about the possibility of childhood anxiety and depression. Children with oppositional defiant disorder express hostile or defiant behaviors that persist over a period of at least six months; examples include loss of temper, defying rules set by adults, deliberately annoying others, and blaming others for problems.

TREATMENT TIPS

"Treating psychopathology [in Tourette syndrome and DBGS] has relatively low risk but a very high gain potential," Dr. Kurlan emphasized. "Some of the most satisfied patients (and parents) are not those who had their tics treated successfully but those whose behavior problems have been treated." Compulsions are one behavior that may respond to treatment, although it can be virtually impossible to differentiate some compulsions from tics, Dr. Kurlan said, since they commonly coexist. He noted, however, that compulsions typically respond to selective serotonin reuptake inhibitors (SSRIs), while tics tend to respond to neuroleptics.

A number of clinical trials have documented the efficacy of SSRIs for treating childhood behavioral problems. Paroxetine and fluoxetine are among the most popular choices for children because they are available in low-dose tablets, as well as oral suspension. When considering these or other options, the physician should consider whether the medication is activating or sedating. "If you have a child who is particularly hyperactive, not sleeping at night, and so on, you might want to try a more sedating drug first," Dr. Kurlan suggested. Conversely, an activating drug may be appropriate for a withdrawn, lethargic, and depressed child.

The standard practice, Dr. Kurlan noted, is to start with the minimum possible dose and then make gradual upward adjustments as necessary; the goal is to identify the lowest effective dose while avoiding side effects. With SSRIs, this may take eight to 12 weeks. "So don't give up after three or four weeks," Dr. Kurlan advised. He added that pharmacotherapy should not be abandoned before clomipramine is tried, since it may be effective for patients unresponsive to other agents.

Pharmacotherapy can also markedly improve childhood anxiety disorders, particularly in conjunction with cognitive/behavioral therapy. The most effective agents are the longer-acting benzodiazepines and sedating SSRIs, according to Dr. Kurlan. Buspirone has also shown promise except in cases of panic disorder.

Potentially effective medications for oppositional defiant disorder include clonidine, SSRIs, risperidone, and clonazepam. Unfortunately, however, most of the data are anecdotal. "But at least this gives some therapeutic options to think about," Dr. Kurlan concluded.

-Timothy Begany
Contributing Writer

Suggested Reading
Palumbo D, Maughan A, Kurlan R. Hypothesis III. Tourette syndrome is only one of several causes of a developmental basal ganglia syndrome. Arch Neurol. 1997;54:475-483.

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