Characteristics of hypotonia in children: a consensus opinion of pediatric occupational and physical therapists

Identifying and Evaluating Young Children with Developmental Central Hypotonia: An Overview of Systematic Reviews and Tools

Children with developmental central hypotonia have reduced muscle tone secondary to non-progressive damage to the brain or brainstem. Children may have transient delays, mild or global functional impairments, and the lack of a clear understanding of this diagnosis makes evaluating appropriate interventions challenging. This overview aimed to systematically describe the best available evidence for tools to identify and evaluate children with developmental central hypotonia aged 2 months to 6 years. A systematic review of systematic reviews or syntheses was conducted with electronic searches in PubMed, Medline, CINAHL, Scopus, Cochrane Database of Systematic Reviews, Google Scholar, and PEDro and supplemented with hand-searching. Methodological quality and risk-of-bias were evaluated, and included reviews and tools were compared and contrasted. Three systematic reviews, an evidence-based clinical assessment algorithm, three measurement protocols, and two additional measurement tools were identified. For children aged 2 months to 2 years, the Hammersmith Infant Neurological Examination has the strongest measurement properties and contains a subset of items that may be useful for quantifying the severity of hypotonia. For children aged 2-6 years, a clinical algorithm and individual tools provide guidance. Further research is required to develop and validate all evaluative tools for children with developmental central hypotonia.

Neurodevelopmental outcome in children with congenital cytomegalovirus infection: A prospective multicenter cohort study

BACKGROUND

Congenital cytomegalovirus infection (cCMV) is the most common congenital infection worldwide and is a major cause of neurodevelopmental impairment in children. At this point there are insufficient data on neurodevelopmental outcome of children with cCMV, both symptomatic and asymptomatic.

AIM

This study aimed to describe the neurodevelopmental outcome in a large prospective cohort of children with cCMV.

METHODS

All children with cCMV, included in the Flemish cCMV register, were eligible for this study. Data on neurodevelopmental outcome was available in 753 children. Data on neuromotor, cognitive, behavioral, audiological and ophthalmological outcome were analyzed.

RESULTS

Neurodevelopmental outcome was normal in 530/753 (70,4 %) at any age of last follow-up. Mild, moderate and severe neurodevelopmental impairment was found in 128/753 (16,9 %), 56/753 (7,4 %) and 39/753 (5,2 %), respectively. Adverse outcome is found both in the symptomatic and asymptomatic children (53,5 % versus 17,8 %). Autism spectrum disorder (ASD) was diagnosed more often than in the general population in Flanders (2,5 % versus 0,7 %). Speech and language impairment was found in 2 %, even in absence of hearing loss.

CONCLUSION

Both symptomatic and asymptomatic cCMV children are at risk of sequelae, with higher risk in case of first trimester infection. During follow-up of this population, special attention should be given to the audiological follow-up, the presence of hypotonia at young age, the possible higher risk of ASD and the risk of speech and language impairment even in absence of hearing loss. Our results emphasize the need for multidisciplinary neurodevelopmental follow-up of all cCMV infected children.

Hypotonia: Is It a Clear Term and an Objective Diagnosis? An Exploratory Systematic Review

BACKGROUND

Hypotonia is considered a determinant factor in multiple developmental disorders and is associated with various characteristics and morbidities. It is necessary to perform a systematic review to know which characteristics are described as associated with hypotonia in children and which methods are used for its diagnosis.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used to develop the systematic review protocol. A search of databases (Pubmed, Cochrane, Web of Knowledge, among others) was performed in May 2021 to identify relevant studies. Those describing characteristics or tests of hypotonia assessment were included, excluding those that exclusively addressed peripheral hypotonia. Two reviewers evaluated the articles and collected the data in a table, noting the authors, date of publication, type of study, and characteristics or tests described in relation to hypotonia. The quality of the studies was also assessed, and data were extracted.

RESULTS

A total of 8778 studies were identified and analyzed, of which 45 met the inclusion criteria. Fifty-three characteristics associated with hypotonia and tests used for its evaluation were located, with pull to sit and vertical suspension being the most frequently referenced.

CONCLUSIONS

The characteristics associated with hypotonia, more highly debated by authors are muscle strength, hypermobility, or the maintenance of antigravity postures. The most used test in the diagnosis of hypotonia is observation, followed by the pull-to-sit test, and adoption of frog posture. A unanimous understanding of the term hypotonia would favor further research.

Pathophysiological Heterogeneity of the BBSOA Neurodevelopmental Syndrome

The formation and maturation of the human brain is regulated by highly coordinated developmental events, such as neural cell proliferation, migration and differentiation. Any impairment of these interconnected multi-factorial processes can affect brain structure and function and lead to distinctive neurodevelopmental disorders. Here, we review the pathophysiology of the Bosch–Boonstra–Schaaf Optic Atrophy Syndrome (BBSOAS; OMIM 615722; ORPHA 401777), a recently described monogenic neurodevelopmental syndrome caused by the haploinsufficiency of NR2F1 gene, a key transcriptional regulator of brain development. Although intellectual disability, developmental delay and visual impairment are arguably the most common symptoms affecting BBSOAS patients, multiple additional features are often reported, including epilepsy, autistic traits and hypotonia. The presence of specific symptoms and their variable level of severity might depend on still poorly characterized genotype–phenotype correlations. We begin with an overview of the several mutations of NR2F1 identified to date, then further focuses on the main pathological features of BBSOAS patients, providing evidence—whenever possible—for the existing genotype–phenotype correlations. On the clinical side, we lay out an up-to-date list of clinical examinations and therapeutic interventions recommended for children with BBSOAS. On the experimental side, we describe state-of-the-art in vivo and in vitro studies aiming at deciphering the role of mouse Nr2f1, in physiological conditions and in pathological contexts, underlying the BBSOAS features. Furthermore, by modeling distinct NR2F1 genetic alterations in terms of dimer formation and nuclear receptor binding efficiencies, we attempt to estimate the total amounts of functional NR2F1 acting in developing brain cells in normal and pathological conditions. Finally, using the NR2F1 gene and BBSOAS as a paradigm of monogenic rare neurodevelopmental disorder, we aim to set the path for future explorations of causative links between impaired brain development and the appearance of symptoms in human neurological syndromes.

Systematic Review of Instrumented Measures of Skeletal Muscle Mechanical Properties: Evidence for the Application of Shear Wave Elastography with Children

The aim of this review was to identify instrumented devices that quantify skeletal muscle mechanical properties and to evaluate their potential clinical utility and clinimetric evidence with respect to children. Four databases were searched to identify articles reporting original clinimetric data for devices measuring muscle stiffness or elastic modulus, along a muscle's main fibre direction. Clinimetric evidence was rated using the Consensus-Based Standard for the Selection of Measurement Instruments (COSMIN) checklist. Sixty-five articles provided clinimetric data for two devices meeting our criteria: the Aixplorer and the Acuson. Both are shear wave elastography devices that determine the shear modulus of muscle tissue. The Aixplorer had strong construct validity and reliability, and the Acuson, moderate construct validity and reliability. Both devices have sound clinical utility with non-invasive application at various joint positions and data acquisition in real time, minimizing fatigue. Further research is warranted to evaluate utility for children with specific disorders of abnormal muscle structure or function.

Psychometric Properties of Segmental Assessment of Trunk Control in Infants and Toddlers With Down Syndrome

PURPOSE

This study investigated infants and toddlers with Down syndrome (DS) to determine: reliability of the Segmental Assessment of Trunk Control (SATCo), concurrent validity of the SATCo with the Gross Motor Function Measure (GMFM), and whether age and SATCo score predict GMFM score.

METHODS

Eighteen infants and toddlers with DS were tested on the SATCo by 2 physical therapist (PT) raters. One PT rater administered the GMFM. After 2 weeks, PT raters rescored their recorded SATCo sessions. A third PT rater also scored the SATCo videos.

RESULTS

Interrater reliability of the SATCo was moderate to good and intrarater reliability was good to excellent. The SATCo and the GMFM had good to excellent significant correlations. Age and SATCo score were significant predictors of the GMFM.

CONCLUSIONS

Trunk control appears to play a central role in gross motor function of infants and toddlers with DS. The SATCo has good psychometric properties in this population.

WHAT THIS ADDS TO THE EVIDENCE

This study contributes to the literature on the psychometric properties of the SATCo and supports its use to measure trunk control in infants and toddlers with DS between the ages of 6 and 24 months.

White Paper: Movement System Diagnoses in Neurologic Physical Therapy

BACKGROUND AND PURPOSE

The APTA recently established a vision for physical therapists to transform society by optimizing movement to promote health and wellness, mitigate impairments, and prevent disability. An important element of this vision entails the integration of the movement system into the profession, and necessitates the development of movement system diagnoses by physical therapists. At this point in time, the profession as a whole has not agreed upon diagnostic classifications or guidelines to assist in developing movement system diagnoses that will consistently capture an individual's movement problems. We propose that, going forward, diagnostic classifications of movement system problems need to be developed, tested, and validated. The Academy of Neurologic Physical Therapy's Movement System Task Force was convened to address these issues with respect to management of movement system problems in patients with neurologic conditions. The purpose of this article is to report on the work and recommendations of the Task Force.

SUMMARY OF KEY FINDINGS

The Task Force identified 4 essential elements necessary to develop and implement movement system diagnoses for patients with primarily neurologic involvement from existing movement system classifications. The Task Force considered the potential impact of using movement system diagnoses on clinical practice, education and, research. Recommendations were developed and provided recommendations for potential next steps to broaden this discussion and foster the development of movement system diagnostic classifications.

RECOMMENDATIONS FOR CLINICAL PRACTICE

The Task Force proposes that diagnostic classifications of movement system problems need to be developed, tested, and validated with the long-range goal to reach consensus on and adoption of a movement system diagnostic framework for clients with neurologic injury or disease states.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A198).

Muscle tone assessments for children aged 0 to 12 years: a systematic review

AIM

The aim of this study was to identify and examine the psychometric properties of muscle tone assessments for children aged 0 to 12 years.

METHOD

Four electronic databases were searched to identify studies that included assessments of resting and/or active muscle tone. Methodological quality and overall psychometric evidence of studies were rated using the COnsensus-based Standards for the selection of health Measurement INstruments checklist.

RESULTS

Twenty-one assessments were identified from 97 included studies. All assessments were broad developmental assessments that included muscle tone items or subscales. Most assessments (16/21) were designed for young children (<2y). Four assessments measured resting and active tone and demonstrated at least moderate validity or reliability: the Amiel-Tison Neurological Assessment (ATNA) at term, Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS), Premie-Neuro for newborn infants, and the Hammersmith Infant Neurological Examination (HINE) for infants aged 2 months to 2 years. For children over 2 years, the Neurological Sensory Motor Developmental Assessment (NSMDA) assesses resting and active tone but has limited validity.

INTERPRETATION

The ATNA at term, NNNS, Premie-Neuro, HINE, and NSMDA can assess resting and active tone in infants and/or children. Further psychometric research is required to extend reliability, validity, and responsiveness data, particularly for older children.

WHAT THIS PAPER ADDS

This is the first review of muscle tone assessments for children aged 0 to 12 years. Twenty-one assessments contain muscle tone items and 16 are for children under 2 years. Four assessments are reliable or valid to measure both resting and active tone.

Evidence-Based Clinical Algorithm for Hypotonia Assessment: To Pardon the Errs

Despite the many advances in diagnostics, the clinical assessment of children with hypotonia presents a diagnostic challenge for clinicians due to the current subjectivity of the initial clinical assessment. The aim of this paper is to report on an evidence-based clinical algorithm (EBCA) that was developed for the clinical assessment of hypotonia in children as part of the output of a multiphased study towards assisting clinicians in more accurate assessments. This study formed part of a larger advanced mixed methods design. The preceding phases of the study included a systematic review, a survey amongst clinicians, a consensus process (Delphi technique), and a qualitative critique with multiple focus groups. Samples were drawn from three professional groups (occupational therapists, physiotherapists, and paediatricians). Data were analysed at each stage and merged in the development of the EBCA. The EBCA followed a rigorous process of development and critique. The methods for formulating changes in the revision and development of the EBCA are presented together with a description and presentation of the final algorithm for practice. The overarching concepts that guided the development and refinement of the EBCA are described, taking into consideration knowledge translation, evidence-based practice, and the value of EBCAs in addition to recommendations for stakeholder uptake. The EBCA is envisaged to be useful in practice for clinicians who are faced with the assessment of a child that is suspected as having hypotonia via a systematic process in identifying specific characteristics that are associated with low muscle tone.

Interventions to improve sensory and motor outcomes for young children with central hypotonia: A systematic review

OBJECTIVE

To evaluate evidence supporting physical and occupational therapy interventions used to improve sensory and motor outcomes for children 0-6 years with central hypotonia.

METHODS

Four electronic databases were searched from 1996 to March 2017. Level of evidence and study conduct was evaluated using American Academy of Cerebral Palsy and Developmental Medicine criteria. Traffic lighting classification identified interventions that were green (proven effective), yellow (possibly effective) or red (proven ineffective or contraindicated).

RESULTS

Thirty-seven articles were included. Nine studies measured orthotic interventions while four distinct studies published over nine articles measured treadmill interventions. Remaining studies measured impact of compression garments, massage, motor and sensori-motor interventions, positioning and mobility interventions.

CONCLUSIONS

Green light evidence supports treadmill training (to promote ambulation and gait characteristics) and massage (to positively affect muscle tone, motor development and use of vision) for infants with Down syndrome. These interventions are considered Yellow (possibly effective) for other populations. Green light evidence supports impact of orthoses on foot alignment for ambulatory children with hypotonia, while impact on gait characteristics is Yellow light and motor development may be negatively impacted (Red light) in pre-ambulatory children. All other interventions rated Yellow (possibly effective) and therapists should monitor using sensitive outcome measures.

Temple syndrome: comprehensive molecular and clinical findings in 32 Japanese patients

Purpose

Temple syndrome (TS14) is a rare imprinting disorder caused by aberrations at the 14q32.2 imprinted region. Here, we report comprehensive molecular and clinical findings in 32 Japanese patients with TS14.

Methods

We performed molecular studies for TS14 in 356 patients with variable phenotypes, and clinical studies in all TS14 patients, including 13 previously reported.

Results

We identified 19 new patients with TS14, and the total of 32 patients was made up of 23 patients with maternal uniparental disomy (UPD(14)mat), six patients with epimutations, and three patients with microdeletions. Clinical studies revealed both Prader-Willi syndrome (PWS)-like marked hypotonia and Silver-Russell syndrome (SRS)-like phenotype in 50% of patients, PWS-like hypotonia alone in 20% of patients, SRS-like phenotype alone in 20% of patients, and nonsyndromic growth failure in the remaining 10% of patients in infancy, and gonadotropin-dependent precocious puberty in 76% of patients who were pubescent or older.

Conclusion

These results suggest that TS14 is not only a genetically diagnosed entity but also a clinically recognizable disorder. Genetic testing for TS14 should be considered in patients with growth failure plus both PWS-like hypotonia and SRS-like phenotypes in infancy, and/or precocious puberty, as well as a familial history of Kagami-Ogata syndrome due to maternal microdeletion at 14q32.2.

'Toning' up hypotonia assessment: A proposal and critique

Background

Clinical assessment of hypotonia is challenging due to the subjective nature of the initial clinical evaluation. This poses dilemmas for practitioners in gaining accuracy, given that the presentation of hypotonia can be either a non-threatening or malevolent sign. The research question posed was how clinical assessment can be improved, given the current contentions expressed in the scientific literature.

Objectives

This paper describes the development and critique of a clinical algorithm to aid the assessment of hypotonia.

Methods

An initial exploratory sequential phase, consisting of a systematic review, a survey amongst clinicians and a Delphi process, assisted in the development of the algorithm, which is presented within the framework of the International Classification of Functioning, Disability and Health. The ensuing critique followed a qualitative emergent–systematic focus group design with a purposive sample of 59 clinicians. Data were analysed using semantical content analysis and are presented thematically with analytical considerations.

Results

This study culminated in the development of an evidence-based clinical algorithm for practice. The qualitative critique of the algorithm considered aspects such as inadequacies, misconceptions and omissions; strengths; clinical use; resource implications; and recommendations.

Conclusions

The first prototype and critique of a clinical algorithm to assist the clinical assessment of hypotonia in children has been described. Barriers highlighted include aspects related to knowledge gaps of clinicians, issues around user-friendliness and formatting concerns. Strengths identified by the critique included aspects related to the evidence-based nature of the criteria within the algorithm, the suitability of the algorithm in being merged or extending current practice, the potential of the algorithm in aiding more accurate decision-making, the suitability of the algorithm across age groups and the logical flow. These findings provide a starting point towards ascertaining the clinical utility of the algorithm as an essential step towards evidence-based praxis.

A pilot study for evaluation of hypotonia in children with neurofibromatosis type 1

There are currently no objective criteria to evaluate pediatric hypotonia. The purpose of this pilot study was to identify diagnostic criteria for assessing hypotonia in children with neurofibromatosis type 1. Fifty-five subjects between the ages of 1 and 7 years with a diagnosis of neurofibromatosis type 1 were evaluated. A physical therapist recorded a subjective tone assessment and objective tone metrics, including ankle dorsiflexion, knee extension, hip abduction, triceps fat percentage, grip strength, and head lag during a pull-to-sit test. Multivariate logistic regression analysis showed the presence of head lag paired with increased hip range of motion was a significant predictor of hypotonia. The presence of head lag on a pull-to-sit test paired with increased hip range of motion is an accurate predictor of hypotonia in children with neurofibromatosis type 1. These objective measures should be prospectively evaluated in other pediatric populations for their ability to predict hypotonia.

Development of an evidence-based clinical algorithm for practice in hypotonia assessment: a proposal

Background

Assessing muscle tone in children is essential during the neurological assessment and is often essential in ensuring a more accurate diagnosis for appropriate management. While there have been advances in child neurology, there remains much contention around the subjectivity of the clinical assessment of hypotonia, which is often the first step in the diagnostic process.

Objective

In response to this challenge, the objective of the study is to develop and validate a prototype of a decision making process in the form of a clinical algorithm that will guide clinicians during this assessment process.

Methods

Design research within a pragmatic stance will be employed in this study. Multi-phase stages of assessment, prototyping and evaluation will occur. These will include processes that include a systematic review, processes of reflection and action as well as validation methods. Given the mixed methods nature of this study, use of NVIVO or ATLAS-ti will be used in the analysis of qualitative data and SPSS for quantitative data.

Results

Initial results from the systematic review revealed a paucity of scientific literature that documented the objective assessment of hypotonia in children. The review identified the need for more studies with greater methodological rigor in order to determine best practice with respect to the methods used in the assessment of low muscle tone in the paediatric population.

Conclusions

It is envisaged that this proposal will contribute to a more accurate clinical diagnosis of children with low muscle tone in the absence of a gold standard. We anticipate that the use of this tool will ultimately assist clinicians towards moving to evidenced based practice whilst upholding best practice in the care of children with hypotonia.

Efficacy of orthoses for children with hypotonia: a systematic review

PURPOSE

The purpose of this systematic review of the literature was to determine the efficacy of orthoses for children with hypotonia and provide a concise summary of the state of the evidence in this area.

METHODS

Fifteen search terms were used to find articles addressing children with hypotonia, orthotic use, and physical therapy.

RESULTS

Ten articles met the inclusion criteria, but no level I evidence was found. Data were reported for body structure and activity components, but not participation outcomes. Current evidence suggests that foot orthoses and supramalleolar orthoses may benefit children with hypotonia; however, the evidence is low level.

CONCLUSION

The evidence for efficacy of orthoses for children with hypotonia continues to have gaps with the following questions still unanswered: When is the optimal time to introduce orthoses? Are foot orthoses or supramalleolar orthoses more efficacious? Should orthoses be combined with physical therapy?

"The problem with running"--comparing the propulsion strategy of children with developmental coordination disorder and typically developing children

Children with Developmental Coordination Disorder (DCD) often have difficulties running. This study compared strategies of propulsion and power generation at the ankle during late stance/early swing in both walking and running in children with and without DCD. Eleven children (six male) aged nine to 12 years with DCD were matched by sex and age with 11 typically developing (TD) children. Gait kinematics and kinetics were measured during 4 gait types; normal walking, fast walking, jogging and sprinting using three-dimensional motion analysis. Propulsion strategy during gait was calculated as ankle power divided by the sum of ankle and hip power (A2/A2+H3). The children with DCD ran slower than the TD children (mean difference [MD] when jogging 0.3m/s and sprinting 0.8m/s). Adjusting for speed, those with DCD had smaller propulsion strategy values during jogging (p=0.001) and sprinting (p=0.012), explained by reduced ankle power generation at push off (A2) (jogging, MD 2.5 W/kg, p<0.001) and greater hip flexor power generation at pull off (H3) (jogging, MD 0.75 W/kg, p=0.013). Similar findings were observed during sprinting. Children with DCD ran with a slow and less efficient running style compared with TD children. Physiotherapy targeting running-specific needs in relation to ankle muscle strength and coordination could enable more participation in running activities.

Consensus on hypotonia via Delphi process

OBJECTIVES

To generate consensus on the assessment of hypotonia in the pediatric population, more specifically with respect to the clinical characteristics and first line tests and methods to be used to assess these characteristics.

METHODS

Consensus methodology was used. A sample of experts was recruited based on specific inclusion criteria. A two-round Delphi process was conducted electronically, which was based on a prior literature appraisal and survey amongst a cohort of clinicians. An a priori threshold margin error of 70 ± 5 % was pre-determined, with Cronbach's α measuring the level of internal consistency.

RESULTS

The 2-round iteration was useful in establishing consensus on clinical characteristics and tests /methods in the assessment of low muscle tone in the pediatric population (2-5 y age band). Twenty-four clinical characteristics, organized into 11 clusters were determined as relevant for inclusion. For each characteristic, one test (as a first line assessment method) had been identified with consensus after two rounds. Additionally, consensus on the importance of collateral sources was determined. The ranking order of importance of characteristics however revealed variations.

CONCLUSIONS

The results of this study have displayed that Delphi, if executed with available guidelines, may be a useful technique in moving towards consensus on issues that may be contentious and have assisted in providing initial data to move towards consensus on the assessment of hypotonia in children.

Clinical decision making in hypotonia and gross motor delay: a case report of type 1 spinal muscular atrophy in an infant

BACKGROUND AND PURPOSE

Children often are referred for physical therapy with the diagnosis of hypotonia when the definitive cause of hypotonia is unknown. The purpose of this case report is to describe the clinical decision-making process using the Hypothesis-Oriented Algorithm for Clinicians II (HOAC II) for an infant with hypotonia and gross motor delay.

CASE DESCRIPTION

The patient was a 5-month-old infant who had been evaluated by a neurologist and then referred for physical therapy by his pediatrician. Physical therapist evaluation results and clinical observations of marked hypotonia, significant gross motor delay, tongue fasciculations, feeding difficulties, and respiratory abnormalities prompted necessary referral to specialists. Recognition of developmental, neurologic, and respiratory abnormalities facilitated clinical decision making for determining the appropriate physical therapy plan of care.

OUTCOMES

During the brief episode of physical therapy care, the patient was referred to a feeding specialist and diagnosed with pharyngeal-phase dysphasia and mild aspiration. Continued global weakness, signs and symptoms of type 1 spinal muscular atrophy (SMA), and concerns about increased work of breathing and respiratory compromise were discussed with the referring physician. After inconclusive laboratory testing for metabolic etiologies of hypotonia, a genetics consult was recommended and confirmed the diagnosis of type 1 SMA at 9 months of age.

DISCUSSION

Physical therapists use clinical decision making to determine whether to treat patients or to refer them to other medical professionals. Accurate and timely referral to appropriate specialists may assist families in obtaining a diagnosis for their child and guide necessary interventions. In the case of type 1 SMA, early diagnosis may affect outcomes and survival rate in this pediatric population.

Diagnosis dialog for pediatric physical therapists: hypotonia, developmental coordination disorder, and pediatric obesity as examples

PURPOSE

To clarify what diagnosis means for pediatric physical therapists, to provide several examples of human movement dysfunction syndromes, and to offer guidance for how pediatric physical therapists may continue this work in any clinical setting.

KEY POINTS

The importance of diagnosis in pediatric physical therapy is presented along with examples of 3 different processes used to develop diagnostic labels. These processes included surveys to identify consensus opinion of clinicians, a literature review, and a combination of these 2. Hypotonia, developmental coordination disorder, and pediatric obesity are presented as examples.

SUMMARY

The 3 diagnoses serve as a basis for ongoing dialogue, discussion, and development of diagnostic labels for human movement syndromes identified by pediatric physical therapists.

The floppy infant: evaluation of hypotonia

Hypotonia is characterized by reduced resistance to passive range of motion in joints versus weakness, which is a reduction in the maximum muscle power that can be generated. (Dubowitz, 1985; Crawford, 1992; Martin, 2005) Based on strong research evidence, central hypotonia accounts for 60% to 80% of cases of hypotonia, whereas peripheral hypotonia is the cause in about 15% to 30% of cases. Disorders causing hypotonia often are associated with a depressed level of consciousness, predominantly axial weakness, normal strength accompanying the hypotonia, and hyperactive or normal reflexes. (Martin, 2005; Igarashi, 2004; Richer, 2001; Miller, 1992; Crawford, 1992; Bergen, 1985; Dubowitz, 1985) Based on some research evidence, 50% of patients who have hypotonia are diagnosed by history and physical examination alone. (Paro-Panjan, 2004) Based on some research evidence, an appropriate medical and genetic evaluation of hypotonia in infants includes a karyotype, DNA-based diagnostic tests, and cranial imaging. (Battaglia, 2008; Laugel, 2008; Birdi, 2005; Paro-Panjan, 2004; Prasad, 2003; Richer, 2001; Dimario, 1989) Based on strong research evidence, infant botulism should be suspected in an acute or subacute presentation of hypotonia in an infant younger than 6 months of age who has signs and symptoms such as constipation, listlessness, poor feeding, weak cry, and a decreased gag reflex. (Francisco, 2007; Muensterer, 2000)

Clinical characteristics of hypotonia: a survey of pediatric physical and occupational therapists

PURPOSE

This study extended previous work on defining characteristics of children with hypotonia.

METHODS

A survey regarding previously identified characteristics of hypotonia, examination tools, interventions, and prognosis was sent to a random sample of 500 physical therapists and 500 occupational therapists.

RESULTS

A total of 268 surveys were returned, for a response rate of 26.8%. Characteristics most frequently observed in children with hypotonia included decreased strength, hypermobile joints, and increased flexibility. Observation was the most commonly cited assessment tool and 85% of those surveyed believe that characteristics of hypotonia improve with therapy.

CONCLUSIONS

Despite agreement among physical and occupational therapists on characteristics of hypotonia and potential for improvement, clear clinical guidelines for the diagnosis and quantification of hypotonia have yet to be determined. Research is needed to develop an operational definition of hypotonia, develop valid tests and assess effectiveness of intervention.

Outcomes of infants with idiopathic hypotonia

PURPOSE

To describe the outcomes of children diagnosed before the age of two with idiopathic hypotonia.

METHODS

A total of 105 parents of children who were diagnosed with hypotonia returned a questionnaire. Medical records were reviewed.

RESULTS

A transient impairment group (10.5%) reported no problems. A minimal impairment group (32.4%) had mild problems such as learning disability or language delay but no major developmental diagnosis. A globally impaired group (40.9%) had mental retardation or a recognizable genetic/developmental diagnosis. More than 50% of the minimal impairment group had poor coordination, language delay, and learning difficulties. The mean walking age (minimal group) was 22 months. Initial fine motor and cognitive, but not gross motor, developmental quotients were significantly greater in the minimal compared with global impairment group.

CONCLUSION

Deficits in motor coordination, language, and learning difficulties were common problems that persisted in the minimal and global impairment groups.