Diagnosis and management of attention deficit disorder: a pediatric perspective

A Preliminary Study of Motor Problems in Children with Attention-Deficit/Hyperactivity Disorder

Although many children with Attention-Deficit/Hyperactivity Disorder (ADHD) are described as “clumsy,” there is relatively little research on problems in motor development in this population. We used a survey method to assess retrospectively developmental histories of 25 children with ADHD and 27 control children (ages 8–15 years). Children with ADHD reportedly had more difficulty than control children with both learning and performing a variety of motor skills, e.g., tying shoes, printing letters, playing sports. In contrast, parents reported few problems in their children's language development. Severity of motor problems was related to performance on specific IQ indices and reading and spelling tests. Given previous research on adverse consequences of clumsiness in children with attention deficits, results of this preliminary study indicate that further research on motor development can shed light on the developmental psychopathology of ADHD.

The quantified EEG characteristics of responders and non-responders to long-term treatment with atomoxetine in children with attention deficit hyperactivity disorders

OBJECTIVE

The aim of our study is to examine quantitative Electroencephalogram (QEEG) differences between ADHD patients that are responders and non-responders to long-term treatment with Atomoxetine at baseline and after 6 and 12months of treatment. Patients with attention deficit hyperactivity disorder (ADHD) received atomoxetine titrated, over 7days, from 0.5 to 1.2mg/kg/day. QEEG and Swanson, Nolan, and Pelham-IV Questionnaire (SNAP-IV) scores were recorded before treatment and after therapy.

METHODS

Twenty minutes of eyes closed resting EEG was recorded from 19 electrodes referenced to linked earlobes. Full frequency and narrow band spectra of two minutes of artifact-free EEG were computed as well as source localization using Variable Resolution Electrical Tomography (VARETA). Abnormalities were identified using Z-spectra relative to normative values.

RESULTS

Patients were classified as responders, non-responders and partial responders based upon the SNAP-IV findings. At baseline, the responders showed increased absolute power in alpha and delta in frontal and temporal regions, whereas, non-responders showed increased absolute power in all frequency bands that was widely distributed. With treatment responders' absolute power values moved toward normal values, whereas, non-responders remained at baseline values.

CONCLUSIONS

Patients with increased power in the alpha band with no evidence of alterations in the beta or theta range, might be responders to treatment with atomoxetine. Increased power in the beta band coupled with increased alpha seems to be related to non-responders and one should consider atomoxetine withdrawal, especially if there is persistence of increased alpha and beta accompanied by an increase of theta.

Motor flexibility problems as a marker for genetic susceptibility to attention-deficit/hyperactivity disorder

BACKGROUND

Since many children with attention-deficit/hyperactivity disorder (ADHD) have fine visuomotor problems that are already evident at a young age, motor dysfunctioning is investigated in family-genetic perspective. We hypothesized that if fine motor problems may be a marker for genetic susceptibility to ADHD, nonaffected siblings of ADHD probands would experience motor problems similar to those of their ADHD siblings.

METHODS

Twenty-five carefully phenotyped ADHD probands with a family history of ADHD, their nonaffected siblings (n = 25), and 48 normal control subjects (aged 6 to 17) completed a motor fluency task and a motor flexibility task. The motor fluency task involved completion of a familiar, automatized trajectory, whereas the motor flexibility task required continuous adjustment of movement to complete an unpredictable random trajectory.

RESULTS

On the motor fluency task, the performance of the nonaffected children was significantly better than that of the ADHD probands; strikingly, on the motor flexibility task, they performed as well as their ADHD siblings.

CONCLUSIONS

Nonaffected siblings experience complex motor problems similar to their ADHD siblings but only in nonautomatized movements that require controlled processing. The results suggest that higher-order controlled motor deficits in ADHD may be associated with genetic susceptibility for ADHD.

Sensory-motor deficits in children with developmental coordination disorder, attention deficit hyperactivity disorder and autistic disorder

Children who have been diagnosed with any one developmental disorder are very likely to meet diagnostic criteria for some other developmental disorder. Although comorbidity has long been acknowledged in childhood disorders, little is understood about the mechanisms that are responsible for the high level of comorbidity. In a series of studies, we have investigated the link between sensory-motor deficits and developmental disorders. Poor sensory-motor integration has long been implicated as a cause of motor problems in developmental disorders such as developmental coordination disorder (DCD), and our recent research has also investigated sensory-motor deficits in children with attention deficit hyperactivity disorder (ADHD) and autistic disorder. Based on a critical examination of relevant literature and some of our recent research findings, we argue that the importance of poor sensory-motor functioning in discriminating children with different disorders has been underestimated. Poor sensory-motor coordination appears to be linked to DCD, but not ADHD. Also, sensory-motor deficits in children with DCD and autistic disorder may provide insight into some of the social difficulties found in these groups of children. This research will increase our understanding of why children with one developmental disorder typically also have problems in other areas.

Fine and gross motor ability in males with ADHD

In the this study, both fine and gross motor ability of males with attention-deficit-hyperactivity disorder (ADHD) were compared with a group of control children. Three groups of males with the following ADHD subtypes: predominantly inattentive (ADHD-PI; n = 50), hyperactive/impulsive (ADHD-HI; n = 16), or combined (ADHD-C; n = 38) were compared with 39 control males. Mean ages for the control group were 10 years 4 months (SD 1 year 4 months, range 7 years 8 months to 12 years 11 months); for the ADHD-PI group, 10 years (SD 1 year 2 months, range 7 years 10 months to 13 years); for the ADHD-HI group, 9 years 11 months (SD 1 year 2 months), range 7 years 11 months to 12 years 6 months); and for the ADHD-C group 10 years 2 months (SD 1 year 4 months, range 8 to 13 years). The Australian Disruptive Behaviours Scale and Connors' Parent Rating Scale-Revised were used to assess ADHD symptomatology. Verbal IQ was estimated using two verbal subtests of the Wechsler Intelligence Scale for Children, and movement ability was assessed using the Movement Assessment Battery for Children (MABC) and the Purdue Pegboard test. Findings demonstrated that the children with ADHD had significantly poorer movement ability than control children. A high percentage of these children displayed movement difficulties consistent with developmental coordination disorder (DCD). In addition, the current study found that the type and degree of movement difficulty differed between subtypes. The Total Impairment score, as derived from the MABC, was less severe for the ADHD-HI group than the other two ADHD groups, but more severe than for the control group. Males with ADHD-PI and ADHD-C had significantly poorer fine motor ability (p < 0.001) than control males, whereas the ADHD-HI group did not differ significantly from any of the other groups. As children with ADHD only and the control group did not differ significantly on fine motor ability but were significantly better than children categorized with both ADHD and DCD, it was argued that poorer fine motor ability found in children with ADHD could not be attributed to deficits in attention and concentration, but rather to factors relating to their motor ability.

Attention shifts and anticipatory mechanisms in hyperactive children: an ERP study using the Posner paradigm

BACKGROUND

The aim of this study was to assess attentional, decisional, and motor processing stages during the performance of an attention shifting paradigm, both in normal children and children with attention-deficit/hyperactivity disorder (ADHD).

METHODS

We recorded event-related potentials (ERPs) and performance measures during a variant of the Posner paradigm in 13 control subjects and 24 ADHD children. Subjects responded with a spatially concordant motor response to left or right visual targets, which could be either preceded by a spatial cue ("valid" = same side; "invalid" = opposite side) or presented uncued.

RESULTS

Patients made significantly more errors than control subjects, with predominance of the anticipatory type. As compared to control subjects, ADHD children had faster reaction times, as well as a shortened interval between the N2 and P3 ERPs and the motor response. Patients also showed a decreased attentional priming effect on early sensory responses (P1). Finally, the slow negativity (contingent negative variation/readiness potential) that preceded the target in the "no cue" condition was absent in ADHD patients.

CONCLUSIONS

The combined analysis of electrophysiological and behavioral data suggest a characteristic mode of response of ADHD in attention shifting tasks, characterized by "motor impulsivity" with release of motor responses before stimulus processing is adequately completed, as well as a lack of strategic planning/anticipatory mechanisms in the absence of warning stimulus. These deficits may be partly attributed to dysmaturation of executive frontal functions. In addition, a minor deficit in early attentional priming was also observed in ERPs, with no apparent behavioral counterparts.

Abnormal presynaptic catecholamine regulation in a hyperactive SNAP-25-deficient mouse mutant

The consequences of a reduction in the presynaptic protein, SNAP-25, were investigated to determine the neurochemical basis of the marked hyperlocomotor activity in coloboma (Cm/+) mice. SNAP-25 is part of the minimal presynaptic machinery necessary for exocytotic neurotransmitter release. Reserpine treatment was used to deplete vesicular stores of catecholamines. Coloboma mice were more sensitive to the effects of reserpine than control mice. However, presynaptic regulation of dopamine (DA) release, as assessed by low-dose apomorphine challenge, was intact. There were region-specific reductions in in vivo tyrosine hydroxylation and the DA metabolites homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the striatum and nucleus accumbens of Cm/+ mice. While hyperactivity is often associated with changes in DA concentration, norepinephrine (NE) concentration was significantly increased in the striatum and nucleus accumbens of the hyperactive mutant. The increase in NE may regulate the hyperactivity in these mice, as suggested by current hypotheses of the mechanisms underlying attention-deficit hyperactivity disorder (ADHD) and Tourette's syndrome.

Visuomotor perception in children with attention deficit hyperactivity disorder--combined type

Children with Attention Deficit Hyperactivity Disorder--Combined Type (ADHD-CT) defined by behavioral characteristics of inattention, impulsivity, and hyperactivity including weaknesses in fine motor coordination and poor motor inhibition frequently exhibit poor handwriting and penmanship. Performance of children on visuomotor tasks is further complicated, as most studies have not excluded children with specific learning disabilities who are known to do poorly on these tests. This study was designed to examine the performance of children diagnosed with this disorder, without learning disabilities on visuomotor tasks. 26 preadolescent patients were administered a battery of tests that included the Bender-Gestalt, Conners' Parent Rating Scale, Continuous Performance Task, and Wide Range Achievement Test-Third Edition Scores on the Bender-Gestalt test averaged significantly lower than Koppitz normative data. This study lends support to the hypothesis that ADHD-CT children without learning disabilities exhibit deficits on tasks requiring visuomotor perception.

Do hyperactive children have motor organization and/or execution deficits?

Hyperactive children have been described as motorically clumsy. To explore the validity of this assertion, an experiment using the additive factor method was designed to examine motor organization and execution in hyperactive children. Four groups of boys aged 7 to 8 years took part in the study: (1) a pure hyperactive (HA) group, N=20; (2) a pure conduct-disordered (CD) group, N=18; (3) a mixed hyperactive/conduct-disordered (HA+CD) group, N=12; (4) a normal (N) control group, N=22. While the small sample size precluded a definitive conclusion, the results indicated that neither HA nor CD children showed any motor organization or execution deficit in a simple sequential key-tapping task. Given previous findings indicating that hyperactive children show deficits in more complex motor coordination skills, the generalizability of our negative results needs to be examined on other more complex tasks.

Kinaesthetic acuity and fine motor skills in children with attention deficit hyperactivity disorder: a preliminary report

Two groups of 9-year-old children (24 children with attention deficit hyperactivity disorder [ADHD] and 24 controls) were assessed for kinaesthetic acuity and fine motor skills with medication withdrawn. Results showed significantly poorer performance on both tasks for children with ADHD, but only a weak association between fine motor and kinaesthetic performance. The implications are discussed, particularly the role of attention to proprioceptive signals in children with the diagnosis of ADHD.

Persistent school dysfunction: unrecognized comorbidity and suboptimal therapy

To determine reasons for continued school dysfunction in children previously diagnosed as having attention deficit hyperactivity disorder (ADHD) or enrolled in a special education program (spec. ed.), a retrospective chart review of patients referred for interdisciplinary evaluations at a tertiary center for hyperactivity and learning problems was completed. Interdisciplinary clinical recommendations were used to define reasons for treatment failure in 116 children with prior diagnosis of ADHD or spec. ed. placement. Results showed 45% of children enrolled in spec. ed. had previously undiagnosed ADHD. Thirty-one percent of those with ADHD, 55% of those in spec. ed., and 55% of those diagnosed with ADHD and in spec. ed. (Both) received a new educationally handicapping diagnosis. Psychiatric comorbidity was present in 28% of those with ADHD, 18% of those in spec. ed., and 23% of Both subjects. Thirteen percent of those in spec. ed. had significant coexisting medical conditions. Special education services were insufficient in 55% of children in spec. ed. and 55% of Both subjects. A significant difference (P < 0.01) in medication use was noted between the groups with 56% of the ADHD group, 55% of the Both group, and none of the spec. ed. group treated with medication. Of all subjects with ADHD, 76% were receiving insufficient or no medication. This review suggests the following: (1) Comorbidity in children with school dysfunction is frequently not recognized. (2) Educational therapy alone may not be sufficient treatment for school dysfunction, and in cases where the treatment program is failing, the appropriateness of the program should be reviewed. (3) ADHD is commonly seen in conjunction with other educationally handicapping conditions. Therefore, in cases of continuing school dysfunction, children previously diagnosed has having ADHD should be assessed for other educationally handicapping conditions; those previously diagnosed as educationally handicapped should be assessed for ADHD. (4) Suboptimal medication use may be associated with treatment failure.

Mouse model of hyperkinesis implicates SNAP-25 in behavioral regulation

Although hyperkinesis is expressed in several neurological disorders, the biological basis of this phenotype is unknown. The mouse mutant coloboma (Cml+) exhibits profound spontaneous locomotor hyperactivity resulting from a deletion mutation. This deletion encompasses several genes including Snap, which encodes SNAP-25, a nerve terminal protein involved in neurotransmitter release. Administration of amphetamine, a drug that acts presynaptically, markedly reduced the locomotor activity in coloboma mice but increased the activity of control mice implicating presynaptic function in the behavioral abnormality. In contrast, the psychostimulant methylphenidate increased locomotor activity in both coloboma and control mice. When a transgene encoding SNAP-25 was bred into the coloboma strain to complement the Snap deletion, the hyperactivity expressed by these mice was rescued, returning these corrected mice to normal levels of locomotor activity. These results demonstrate that the hyperactivity exhibited by these mice is the result of abnormalities in presynaptic function specifically attributable to deficits in SNAP-25 expression.

Coloboma contiguous gene deletion encompassing Snap alters hippocampal plasticity

Mice heterozygous for the semidominant mutation coloboma (Cm/+) display several distinct pathologies including head bobbing, ophthalmic deformation, and locomotor hyperactivity. The Cm/+ mutation comprises a contiguous gene defect which encompasses deletion of the gene Snap encoding the presynaptic nerve terminal protein SNAP-25 that is an integral component of the synaptic vesicle docking and fusion complex. Indeed, SNAP-25 is required for axonal growth and for the regulated release of neurotransmitters at the synaptic cleft. As an extension of our studies on the behavioral deficits exhibited by these mutants, including evaluation of the hyperkinesis and dopamine-related behavioral pharmacology that might be related to attention-deficit hyperactivity disorder in humans, we have studied spontaneous electroencephalographic and evoked potential recordings in the dentate gyrus of halothane-anesthetized Cm/+ and normal (+/+) littermates to evaluate potential physiological abnormalities of synaptic function in these mice. While sensory activation elicited by brief (10 sec) tail-pinch produced 1-2 min of theta rhythmic activity in +/+ mice, theta induction was markedly reduced in Cm/+ mice. There were no significant differences in dentate afferent-evoked population excitatory postsynaptic potential (pEPSP) slopes, pEPSP facilitation, or population spike (PS) amplitudes; however, paired-pulse inhibition of dentate PS amplitudes was significantly increased in Cm/+ mice. Furthermore, although brief high-frequency stimulation of the perforant path produced robust long-term potentiation (LTP) of synaptic responses in the dentate gyrus of +/+ mice, LTP was attenuated in Cm /+ mice. It has been previously demonstrated that dopamine (DA) neurotransmission is essential for induction of one type of hippocampal theta rhythm and also may modulate hippocampal LTP, suggesting that alterations in DA synaptic transmission may underlie the behavioral abnormalities, in particular the hyperactivity, associated with Cm/+ mutant mice.

Developmental dyscalculia: prevalence and demographic features

One hundred and forty-three 11-year-old children with development dyscalculia, from a cohort of 3029 students, were studied to determine demographic features and prevalence of this primary cognitive disorder. They were evaluated for gender, IQ, linguistic and perceptual skills, symptoms of attention-deficit hyperactivity disorder (ADHD), socio-economic status and associated learned disabilities. The IQs of the 140 children (75 girls and 65 boys) retained in the study group (three were excluded because of low IQs) ranged from 80 to 129 (mean 98.2, SD 9.9). 26 per cent of the children had symptoms of ADHD, and 17 per cent had dyslexia. Their socio-economic status was significantly lower than that of the rest of the cohort, and 42 per cent had first-degree relatives with learning disabilities. The prevalence of dyscalculia in the original cohort was 6.5 per cent, similar to that of dyslexia and ADHD. However, unlike these other learning disabilities, dyscalculia affected the two sexes in about the same proportions.

Developmental dyscalculia behavioral and attentional aspects: a research note

Behavioral characteristics of 140 children with developmental dyscalculia (DC) were evaluated using the Child Behavior Checklist. DC children demonstrated more behavior problems than normal children but significantly fewer problems than children psychiatrically referred. DC children had significantly more attentional problems although they had normal levels of anxiety/depression. Significantly higher scores on all syndrome scales were found for DC children who had attentional problems in the clinical range. When associated with dyslexia and a low verbal IQ, DC children had more attentional problems and externalizing syndromes. The implications of the behavioral characteristics of DC are discussed.

Attention deficit disorder during adolescence: a review

Attention deficit disorder (ADD) in adolescents has received scant attention when compared with that given to children. With or without hyperactivity, ADD does not disappear at puberty and is an important factor in scholastic and social failure in adolescents. As a condition associated with decreased metabolism in the premotor and prefrontal superior cerebral cortex, ADD in adolescents responds well to treatment with stimulants, tricyclic antidepressants and monoamine oxidase inhibitors. Nonpharmacologic modalities such as behavior modification, individual and family therapy, and cognitive therapy are useful adjuncts to psychopharmacologic management. Without effective treatment, ADD often results in increased risk of trauma, substance abuse and conduct and affective disorders during adolescence, and marital disharmony, family dysfunction, divorce, and incarceration in adulthood. Properly treated with medication and counseling, adolescents with ADD succeed as well as their peers.

Attention deficit disorder in college students: facts, fallacies, and treatment

Attention deficit disorder (ADD), with or without hyperactivity, is a common but highly misunderstood and frequently underdiagnosed condition in college students. It affects students' academic and social success and emotional development. ADD is an invisible impairment of cortical regulation of activity and impulse control that is often hereditary, is as common in women as in men, and does not subside or disappear at puberty. ADD increases the risk of drug abuse, delinquency, incarceration, job failure, marital discord, and divorce. In college students, ADD is amenable to treatment in a multimodal program combining medication; individual, family, and group psychotherapy; career counseling; and cognitive control, together with electronic prostheses and special accommodations in the college classroom.

Non-Hodgkin's lymphoma during pregnancy

A rare case of non-Hodgkin's lymphoma stage IE complicating pregnancy is presented. The diagnosis was made by biopsy at 28 weeks gestation and treated with 2635 rad of external radiotherapy with abdominal and pelvic shielding beginning at 30 weeks gestation. Following delivery, the patient received combination chemotherapy and is disease-free 6 years later. The baby, weighing 2015 g, was delivered by cesarean section at term. The effects of radiotherapy on a fetus are reviewed and the factors that were considered in the treatment of this patient are discussed. Radiotherapy with protective shielding can be an effective initial modality of treatment in this setting.

Attention deficit disorder: association with familial-genetic factors

The etiology of attention deficit disorder and hyperactivity (ADDH) is controversial because both biologic and social factors have been postulated. To study such factors, we undertook a referral study based on an entire cohort (N = 6,950) of children born in Jerusalem in 1976. Of 479 children referred for learning disabilities, hyperactivity, and behavioral problems, 381 were available for study. Information regarding obstetric, developmental, and family histories was obtained by a detailed, structured interview. A DSM-III-based questionnaire for ADDH was completed by parents and teachers. Each child underwent neurologic examination and 133 had IQ testing. Of these children, 145 fulfilled the criteria for ADDH. Our results revealed a number of significant familial-genetic factors: boys outnumbered girls by 3:1, 30% of ADDH children had siblings with learning disabilities (P less than .001); and ADDH children clustered within families of North African descent (P less than .001). The only significant developmental factor was delayed language development. Of numerous pre- and peri-natal factors investigated, only intrauterine growth retardation was significantly associated with ADDH. No correlation was found between ADDH and IQ, parental age, years of education, profession, and language spoken at home. Our study supports the hypothesis that familial-genetic factors are contributory to ADDH.

Management of attention deficit hyperactivity disorder (ADHD). A continuing dilemma for physicians and educators

The American Academy of Pediatrics (AAP) has recommended that the initial treatment of attention deficit hyperactivity disorder (ADHD) should be educational and behavioral. The authors surveyed the directors of special education in the United States to determine whether these services are available to children with ADHD. They determined that the diagnosis of ADHD qualifies a child for services in only 1 out of 51 departments of special education surveyed. ADHD and classroom underachievement qualifies a child for special education services in 2 out of 51 departments. Thus, in most areas of the United States, special educational services are not available to meet the guidelines of the AAP.

Clinical aspects of mental retardation. The chief complaint

The charts of 101 mentally retarded children were studied to determine how their retardation first came to the attention of their pediatrician. It was found that Speech Delay, Developmental Delay, and School Failure were the three most common parental concerns. Speech Delay accounted for over 50 percent of all referrals of children age 2 to 6 years. A first step to improve accurate evaluation and treatment of mental retardation is to recognize how children ultimately diagnosed as retarded are initially brought to the attention of the pediatrician.

Acute leukemia. Learning disabilities following CNS irradiation

Thirteen elementary school age children with acute leukemia who had received cranial irradiation with dosages between 1,800 and 4,800 rads a mean of 6.3 years earlier were evaluated for the presence of learning disorders. The authors utilized both psychometric and educational tests. The results were analyzed according to a graduated regressed standard score procedure and yielded the following diagnoses: mental retardation, two (15%); learning disability in reading and mathematics, two (15%); learning disability in mathematics, five (39%); no psychoeducational diagnosis, four (31%). Of the nine children (69%) who qualified for a specific psychoeducational diagnosis, only three were receiving any special educational services. The failure of a previous assessment of this same group of children at our center and of other research reports to uncover a similarly high incidence of neurodevelopmental pathology may be due to the specific tests employed or to the later onset of measurable difficulties in these patients.

Catecholamines and attention. I: Animal and clinical studies

One important function of the catecholamine innervation of the cerebral cortex may be the control of attention. Of particular interest are the catecholamine projections to the cerebral cortex from the reticular formation, namely the dopamine neurons of the ventral tegmentum of the midbrain and the noradrenergic neurons of the locus coeruleus in the upper pons. Animal studies implicate noradrenaline and dopamine in a wide range of attention-related behaviours involving search and exploratory activity, distractibility, response rate, discriminability and the switching of attention. Most human studies come from the clinical literature relating to schizophrenia, Parkinson's disease and attention deficit disorder. An association has been claimed in each of these conditions between abnormal catecholamine activity (in particular dopamine) and attentional dysfunction. In particular, difficulty with the attachment of appropriate responses to environmental stimuli, akin to those observed in animals with lesions to central dopamine pathways, indicates a role for dopamine in response selection processes. Overall, the animal and human studies reviewed indicate a role for central noradrenaline and dopamine in the early and late processing of information, respectively.