Marjorie A. Garvey

Developing constructs for psychopathology research: Research domain criteria.

There exists a divide between findings from integrative neuroscience and clinical research focused on mechanisms of psychopathology. Specifically, a clear correspondence does not emerge between clusters of complex clinical symptoms and dysregulated neurobiological systems, with many apparent redundancies. For instance, many mental disorders involve multiple disruptions in putative mechanistic factors (e.g., excessive fear, deficient impulse control), and different disrupted mechanisms appear to play major roles in many disorders. The Research Domain Criteria (RDoC) framework is a heuristic to facilitate the incorporation of behavioral neuroscience in the study of psychopathology. Such integration might be achieved by shifting the central research focus of the field away from clinical description to more squarely examine aberrant mechanisms. RDoC first aims to identify reliable and valid psychological and biological mechanisms and their disruptions, with an eventual goal of understanding how anomalies in these mechanisms drive psychiatric symptoms. This approach will require new methods to ascertain samples, relying on hypothesized psychopathological mechanisms to define experimental groups instead of traditional diagnostic categories. RDoC, by design, uncouples research efforts from clinically familiar categories to focus directly on fundamental mechanisms of psychopathology. RDoC proposes a matrix of domains and levels of analyses and invites the field to test and refine the framework. If RDoC is successful, the domains will ultimately relate to familiar psychopathologies in ways that promote new knowledge regarding etiology and more efficient development of new preventive and treatment interventions.

A pilot study of penicillin prophylaxis for neuropsychiatric exacerbations triggered by streptococcal infections

BACKGROUND Some children with obsessive-compulsive disorder (OCD) and tic disorders appear to have symptom exacerbations triggered by group A beta-hemolytic streptococcal infections in a manner that is similar to rheumatic fever and its neurologic variant, Sydenhams chorea. Because penicillin prophylaxis has proven to be effective in preventing recurrences of rheumatic fever, it was postulated that it might also prevent streptococcal-triggered neuropsychiatric symptom exacerbations in children with Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS). These children are identified by five clinical characteristics: presence of OCD or tic disorder, prepubertal onset, episodic symptom course, neurologic abnormalities (i.e., choreiform movements) and streptococcal-triggered symptom exacerbations. METHODS Thirty-seven children with PANDAS were enrolled in an 8 month, double-blind, balanced cross-over study. Patients were randomized to receive either 4 months of the active compound (twice daily oral 250 mg penicillin V) followed by 4 months of placebo, or placebo followed by penicillin V. Tic, OCD, and other psychiatric symptoms were monitored monthly. Throat cultures and streptococcal antibody titers were also obtained. RESULTS There were an equal number of infections in both the active and placebo phases of the study. There was no significant change seen in either the obsessive-compulsive or tic symptom severity between the two phases. CONCLUSIONS Because of the failure to achieve an acceptable level of streptococcal prophylaxis, no conclusions can be drawn from this study regarding the efficacy of penicillin prophylaxis in preventing tic or OCD symptom exacerbations. Future studies should employ a more effective prophylactic agent, and include a larger sample size.

Definition and Classification of Negative Motor Signs in Childhood

In this report we describe the outcome of a consensus meeting that occurred at the National Institutes of Health in Bethesda, Maryland, March 12 through 14, 2005. The meeting brought together 39 specialists from multiple clinical and research disciplines including developmental pediatrics, neurology, neurosurgery, orthopedic surgery, physical therapy, occupational therapy, physical medicine and rehabilitation, neurophysiology, muscle physiology, motor control, and biomechanics. The purpose of the meeting was to establish terminology and definitions for 4 aspects of motor disorders that occur in children: weakness, reduced selective motor control, ataxia, and deficits of praxis. The purpose of the definitions is to assist communication between clinicians, select homogeneous groups of children for clinical research trials, facilitate the development of rating scales to assess improvement or deterioration with time, and eventually to better match individual children with specific therapies. “Weakness” is defined as the inability to generate normal voluntary force in a muscle or normal voluntary torque about a joint. “Reduced selective motor control” is defined as the impaired ability to isolate the activation of muscles in a selected pattern in response to demands of a voluntary posture or movement. “Ataxia” is defined as an inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints. “Apraxia” is defined as an impairment in the ability to accomplish previously learned and performed complex motor actions that is not explained by ataxia, reduced selective motor control, weakness, or involuntary motor activity. “Developmental dyspraxia” is defined as a failure to have ever acquired the ability to perform age-appropriate complex motor actions that is not explained by the presence of inadequate demonstration or practice, ataxia, reduced selective motor control, weakness, or involuntary motor activity.

Treatment of Sydenham's Chorea with Intravenous Immunoglobulin, Plasma Exchange, or Prednisone

Sydenhams chorea has been established as a postinfectious autoimmune neuropsychiatric disorder. Corticosteroids have been used to treat patients with severe disease but are not always effective, and relapses are frequent after cessation. Eighteen subjects were entered into this randomized-entry controlled trial designed to determine if intravenous immunoglobulin or plasma exchange would be superior to prednisone in decreasing the severity of chorea. Mean chorea severity for the entire group was significantly lower at the 1-month follow-up evaluation (overall 48% improvement). Although the between-group differences were not statistically significant, clinical improvements appeared to be more rapid and robust in the intravenous immunoglobulin and plasma exchange groups than in the prednisone group (mean chorea severity scores decreased by 72% in the intravenous immunoglobulin group, 50% in the plasma exchange group, and 29% in the prednisone group). Larger studies are required to confirm these clinical observations and to determine if these treatments are cost-effective for this disorder. (J Child Neurol 2005;20:424—429).

Cortical correlates of neuromotor development in healthy children

OBJECTIVE To examine the relationship between acquisition of fine motor skills in childhood and development of the motor cortex. METHODS We measured finger tapping speed and mirror movements in 43 healthy right-handed subjects (6-26 years of age). While recording surface electromyographic activity from right and left first dorsal interosseus, we delivered focal transcranial magnetic stimulation (TMS) over the hand areas of each motor cortex. We measured motor evoked potential (MEP) threshold, and ipsilateral (iSP) and contralateral (CSP) silent periods. RESULTS As children got older, finger speeds got faster, MEP threshold decreased, iSP duration increased and latency decreased. Finger tapping speed got faster as motor thresholds and iSP latency decreased, but was unrelated to CSP duration. In all subjects right hemisphere MEP thresholds were higher than those on the left and duration of right hemisphere CSP was longer than that on the left. Children under 10 years of age had higher left hand mirror movement scores, and fewer left hemisphere iSPs which were of longer duration. CONCLUSIONS Maturation of finger tapping skills is closely related to developmental changes in the motor threshold and iSP latency. Studies are warranted to explore the relationship between these measures and other neuromotor skills in children with motor disorders. SIGNIFICANCE TMS can provide important insights into certain functional aspects of neurodevelopment in children.

Psychiatric disorders in first-degree relatives of children with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS).

OBJECTIVE To determine the rates of psychiatric disorders in the first-degree relatives of children with infection-triggered obsessive-compulsive disorder (OCD) and/or tics (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections; PANDAS). METHOD The probands of this study were 54 children with PANDAS (n = 24 with a primary diagnosis of OCD; n = 30 with a primary diagnosis of a tic disorder). One hundred fifty-seven first-degree relatives (100 parents [93%] and 57 siblings [100%]) were evaluated for the presence of a tic disorder. One hundred thirty-nine first-degree relatives (100 parents [93%] and 39 of 41 siblings over the age of 6 [95%]) were evaluated with clinical and structured psychiatric interviews to determine the presence of subclinical OCD, OCD, and other DSM-IV Axis I disorders. RESULTS Twenty-one probands (39%) had at least one first-degree relative with a history of a motor or vocal tic; 6 mothers (11%), 9 fathers (19%), and 8 siblings (16%) received this diagnosis. Fourteen probands (26%) had at least one first-degree relative with OCD; 10 mothers (19%), 5 fathers (11%), and 2 siblings (5%), received this diagnosis. An additional 8 parents (8%) and 3 siblings (8%) met criteria for subclinical OCD. Eleven parents (11%) had obsessive-compulsive personality disorder. CONCLUSIONS The rates of tic disorders and OCD in first-degree relatives of pediatric probands with PANDAS are higher than those reported in the general population and are similar to those reported previously for tic disorders and OCD. Further study is warranted to determine the nature of the relationship between genetic and environmental factors in PANDAS.

Topical Review: PANDAS: The Search for Environmental Triggers of Pediatric Neuropsychiatric Disorders. Lessons from Rheumatic Fever:

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) is a relatively new diagnostic construct applied to children or adolescents who develop, and have repeated exacerbations of, tic disorders and/or obsessive-compulsive disorder following group A beta-hemolytic streptococcal infections. The proposed pathophysiology is that the group A beta-hemolytic streptococcal bacteria trigger antibodies that cross-react with the basal ganglia of genetically susceptible hosts leading to obsessive-compulsive disorder and/or tics. This is similar to the etiologic mechanisms proposed for Sydenhams chorea, in which group A beta-hemolytic streptococcal antibodies cross-react with the basal ganglia and result in abnormal behavior and involuntary movements. When first proposed, there was much controversy about the idea that streptococcal infections were etiologically related to rheumatic fever. In a like manner, discussion has arisen about the concept of infection-triggered obsessive-compulsive disorder and tic disorders. We review the historical background to these controversies, give an update on the findings provided by research on PANDAS, and address areas of future study. (J Child Neurol 1998; 13:413-423).

Should transcranial magnetic stimulation research in children be considered minimal risk

OBJECTIVE Transcranial magnetic stimulation (TMS) is a neurophysiologic technique with research applications. Institutional Review Boards (IRBs) must carefully consider potential risks and possible benefits in research involving children. The purpose of this study is to provide concise information for investigators and IRBs about the safety of single and paired pulse TMS research in children. METHODS This paper has 4 sections: (I) Regulations governing research in children are reviewed and applied to the use of TMS. (II) Energy imparted by TMS is assessed in terms of theoretical biological risks to human subjects. (III) Through MEDLINE review, the empirical evidence of risk from TMS is assessed. Reported adverse events, including issues related to risk of seizures and of hearing loss, are summarized. (IV) Safety data are presented from a study of TMS in children with Tourette Syndrome. RESULTS No published or empirical evidence was found to suggest that single or paired pulse TMS is associated with more than minimal risk in children. CONCLUSIONS IRBs may consider well-designed studies using single and paired pulse TMS protocols similar to those described in this study as bearing minimal risk to children. SIGNIFICANCE This manuscript may be useful as a reference to IRBs and TMS investigators.

Subjective Reactions of Children to Single-Pulse Transcranial Magnetic Stimulation

Single-pulse transcranial magnetic stimulation is a useful tool to investigate cortical function in childhood neuropsychiatric disorders. Magnetic stimulation is associated with a shock-like sensation that is considered painless in adults. Little is known about how children perceive the procedure. We used a self-report questionnaire to assess childrens subjective experience with transcranial magnetic stimulation. Normal children and children with attention-deficit hyperactivity disorder (ADHD) underwent transcranial magnetic stimulation in a study of cortical function in ADHD. Subjects were asked to rate transcranial magnetic stimulation on a 1 to 10 scale (most disagreeable = 1, most enjoyable = 10) and to rank it among common childhood events. Thirty-eight subjects completed transcranial magnetic stimulation; 34 said that they would repeat it. The overall rating for transcranial magnetic stimulation was 6.13, and transcranial magnetic stimulation was ranked fourth highest among the common childhood events. These results suggest that although a few children find transcranial magnetic stimulation uncomfortable, most consider transcranial magnetic stimulation painless. Further studies are necessary to confirm these findings. (J Child Neurol 2001;16:891-894).

Obsessive-compulsive symptoms among patients with Sydenham chorea

BACKGROUND Among patients with tic disorders, a distinctive clinical profile of obsessive-compulsive symptomatology has been described. The present investigation was designed to document the phenomenology of obsessive-compulsive symptoms (OCS) among patients with Sydenham chorea (SC), the neurologic variant of rheumatic fever. We hypothesized that OCS occurring in association with SC would be similar to those among patients with tic disorders. METHODS The authors studied the presence of OCS in 73 patients with SC by using the Yale-Brown Obsessive-Compulsive Scale at the Pediatric Clinics of the University of Sao Paulo Medical Center in Sao Paulo, Brazil (n = 45) and at the National Institute of Mental Health in Bethesda, Maryland (n = 28). RESULTS The most frequent symptoms observed among subjects with comorbid SC and OCS were aggressive, contamination, and somatic obsessions and checking, cleaning, and repeating compulsions. A principal component factor analysis yielded a five-factor solution (accounting for 64.5% of the total variance), with contamination and symmetry obsessions and cleaning compulsions loading highly. CONCLUSIONS The symptoms observed among the SC patients were different from those reported by patients with tic disorders but were similar to those previously noted among samples of pediatric patients with primary obsessive-compulsive disorder.