Down syndrome and Physiotherapy Management

This presentation contains detailed knowledge about Down's Syndrome its types, clinical presentation, diagnosis, medical and physio therapeutic management of the condition.

Down syndrome is a condition in which a person has an extra chromosome. Chromosomes are small “packages” of genes in the body. They determine how a baby’s body forms and functions as it grows during pregnancy and after birth. Typically, a baby is born with 46 chromosomes. Babies with Down syndrome have an extra copy of one of these chromosomes, chromosome 21. A medical term for having an extra copy of a chromosome is ‘trisomy.’ Down syndrome is also referred to as Trisomy 21. This extra copy changes how the baby’s body and brain develop, which can cause both mental and physical challenges for the baby.

1. By – Anumeha Sharma MPT (Neurology)

2. Introduction Named after a physician, “John Langdon Down” in 18 th century. Down syndrome is the most common chromosomal abnormality. The estimated global incidence of this of this chromosopathy is around 0.1% in live birth. In 1959 a French doctor, named “Jerome Lejeune” , discovered it was caused by the inheritance of an extra chromosome 21.

3. It is an chromosomal disorder caused by an error in cell division resulting in the presence of an additional third chromosome 21 or 21 trisomy. A ‘syndrome’ means a group of recognisable characteristics occurring together. A ‘congenital’ syndrome is one present at birth. Down syndrome is one of the most leading causes of intellectual disability and various health issues.

4. Standard trisomy 21 In this type of aberration, the carrier has 47 chromosomes, including three chromosomes 21. It accounts for nearly 90% to 95% of DS cases. The majority of free trisomy 21 cases (85-90%) originates from errors in maternal meiosis. In particular, maternal meiosis I is the most frequently affected stage of nondisjunction (>75%), whereas maternal meiosis II errors account for >20%. In 5% of free trisomy 21, paternal meiotic errors can be observed, here meiosis II nondisjunction is more frequent than meiosis I errors.

5. Nondisjunction  is the failure of homologous chromosomes or sister chromatids to separate properly during cell division.

6. T ranslocations Translocation occurs before fertilisation where a part of an extra copy of chromosome 21 breaks off during cell division and becomes translocated (attached) to another chromosome in the egg or sperm cell . Affected individuals have two normal copies of chromosome 21, in addition to an extra attached chromosome 21.

7. DS due to translocation is the only variant that occurs independent of maternal age and may be inherited from either parent . Approximately 4% of people with DS have translocation, which may either be reciprocal or Robertsonian .  Reciprocal translocations are the most common type and involve an exchange of chromosome between any of the different types, for example, between chromosome 1 and chromosome 9.

8. Robertsonian translocations only involve exchanges among chromosome numbers 13, 14, 15, 21 and 22.

9. M osaic variant The mosaic variant is the least common pattern of transmission of DS, occurring in 1% – 2% of people with DS, and the error in cell division occurs after fertilisation. Affected individuals have some cells with an extra chromosome 21 and others with the normal number, and this results in some body cells containing 47 chromosomes and others having the usual 46 chromosomes.

10. The greater the number of normal cells in DS, the higher the chances of higher cognitive functions, with a possibility of less intellectual impairment.

11. Risk Factors Advancing maternal age – usually women of age 35 or above. Mothers who already have child affected with down syndrome. Being carriers of the genetic translocation for Down syndrome .

12. Habitual risk factor Maternal cigarette smoking U se of oral contraceptive P eri-conceptional alcohol consumption by mother E xposure to radiation L ow socio-economic status

13. Clinical Features DS is a multisystem disorder that affects the individual physically, medically and psychologically . These patients have a wide array of signs and symptoms like – intellectual and developmental disabilities or neurological features congenital heart defects gastrointestinal (GI) abnormalities characteristic facial features, and abnormalities. 

14. Physical appearance  B rachycephaly (disproportionately shorter or small head or skull shape) U nusually round face S hort neck S mall ears F lat nasal bridge Microgenia (an abnormally small chin) M acroglossia (protruding or oversized tongue) due to small oral cavity, small chin.

15. Almond shape to the eyes caused by an epicanthic fold of the eyelid and oblique palpebral fissures. Other features include shorter limbs A single transverse palmar crease (a single instead of a double crease across one or both palms) L ax ligaments, excessive space between great toe and second toe D ry skin, muscle hypotonia (poor muscle tone) and brachydactyly (shorter fingers and toes).

16. Ocular and visual features High refractive errors (when the eye cannot clearly focus image from the outside world) A mblyopia (lazy eye) and strabismus (crossed eye) A ccommodative and vergence anomalies, ptosis, blepharitis (eye lid inflammation), nasolacrimal duct obstruction N ystagmus

17. Keratoconus (conical cornea) Brushfield’s spots ( speckling of the iris) Cataracts G laucoma and retinovascular anomalies

18. Neurological disorders R educed brain volume especially hippocampus and cerebellum Hypotonia ( defined as low resting muscle tone, has been reported in nearly 80% of new-borns with DS) Because of hypotonia Down syndrome patients have joint laxity that causes decreased gait stability and increased energy requirement for physical exertion . Five percent to 13% of children with Down syndrome have seizures

19. Forty percent of patients with Down syndrome develop  tonic - clonic or myoclonic seizures in their first 3 decades. Lennox - Gestaut syndrome is also seen to be more prevalent in children with Down syndrome. Dementia occurs more commonly in patients older than 45 years of age with Down syndrome.

20. The risk of developing early-onset Alzheimer disease is significantly high in patients with Down syndrome with 50% to 70% of patients developing dementia by the age of 60 years . Nearly all the patients with Down syndrome have mild to moderate learning disability.

21. Diagnosis

22. Diagnosis S creening and diagnostic tests . The prenatal screenings do not give definite results but provide the probability of a foetus having DS If screening test gives a positive finding for DS, a pregnancy may have DS, a diagnostic test is performed to confirm if the baby actually has DS.

23. There are different methods used for the prenatal diagnosis of Down syndrome. Ultrasound between 14 and 24 weeks of gestation Amniocentesis and chorionic villus sampling FISH(fluorescent in situ hybridization), QF-PCR (quantitative fluorescence PCR), and MLPA(multiplex probe ligation assay)- also used for prenatal diagnosis.

24. A relatively new method called as P aralogue S equence Q uantification (PSQ) uses the paralogue sequence on Hsa21 copy number. It is a PCR based method that uses the paralogue genes to detect the targeted chromosome number abnormalities which are known as paralogue sequence quantification.

25. There are non-invasive prenatal diagnostic methods which are being studied to be used for the diagnosis of Down syndrome  prenatally. These are based on the presence of foetal cells in the maternal blood and the presence of cell-free foetal DNA in the maternal serum.

26. Few other recent methods like digital PCR and next-generation sequencing (NGS) are also being developed for the diagnosis of Down syndrome

27. Management

28. American Academy of Paediatrics (AAP)

29. Management The management of patients with Down syndrome is multidisciplinary. New-born with suspicion of Down syndrome, should have a karyotyping done to confirm the diagnosis. The family needs to be referred to the clinical geneticist for the genetic testing and counselling of both the parents.

30. Parental education is one of the foremost aspects regarding the management of Down syndrome, as parents need to be aware of the different possible conditions associated with it so that they can be diagnosed and treated appropriately. Treatment is basically symtomatic and complete recovery is not possible.

31. These patients should have their hearing and vision assessed and as they are more prone to have a cataract, therefore timely surgery is required. Thyroid function tests should be done on a yearly basis and if deranged should be managed accordingly.

32. A balanced diet, regular exercise , and physical therapy are needed for the optimum growth and weight gain, although feeding problems do improve after the surgery . Cardiac referral should be sent for all the patients regardless of the clinical signs of congenital heart disease which if present should be corrected within the first 6 months of life to ensure optimum growth and development of the child.

33. Clinical geneticist - Referral to a genetics counselling program is highly desirable Developmental pediatrician Cardiologist - Early cardiologic evaluation is crucial for diagnosing and treating congenital heart defects, which occur in as many as 60% of these patients Pediatric pneumonologist -Recurrent respiratory tract infections are common in patients with DS.

34. Ophthalmologist Neurologist/Neurosurgeon – As many as 10% of patients with DS have epilepsy; therefore, neurologic evaluation may be needed Orthopedic specialist Child psychiatrist - A child psychiatrist should lead liaison interventions, family therapies, and psychometric evaluations Physical and occupational therapist Speech-language pathologist Audiologist

35. Assessment When recording history from parents, the clinician should include the following Parental concern about hearing, vision, developmental delay, respiratory infections, and other problems Feeding history to ensure adequate caloric intake Prenatal diagnosis of Down syndrome Vomiting secondary to GI tract blockage by duodenal web or atresia (closed or absent orifice)

36. Absence of stools secondary to Hirschsprung disease(nerve cells in the colon don’t form completely). Delay in cognitive abilities, motor development, language development (specifically expressive skills), and social competence Arrhythmia, fainting episodes, palpitations, or chest pain secondary to heart lesion Symptoms of sleep apnea, including snoring, restlessness during sleep, difficulty awaking, daytime somnolence, behavioral changes, and school problems

37. Symptoms of atlanto-axial instability include the following: About 13-14% of patients have radiographic evidence of atlanto-axial instability but no symptoms Only 1-2% of patients have symptoms that require treatment Symptoms include easy fatigability, neck pain, limited neck mobility or head tilt, torticollis, difficulty walking, change in gait pattern, loss of motor skills, incoordination, clumsiness, sensory deficits, spasticity .

38. Hyperreflexia , clonus, extensor-plantar reflex, loss of upper-body strength, abnormal neurologic reflexes, change in bowel and bladder function, increased muscle tone in the legs, and changes in sensation in the hands and feet Physical Examination Clinical Features

39. Assessment tools Test of infant motor performance Alberta infant motor scales Peabody development scales Gross Motor Function Measure Pediatric Evaluation of Disability Index Pediatric Balance Scale

40. Motor Development

41. Physiotherapy Management

42. Some of the common issues that physiotherapists will address are : Delayed developmental milestones Impaired Balance Decreased strength Reduced levels of physical activity Sensory Deficits Reduced mental health and emotional well-being

43. Major Goal The general goal is to maintain alignment and encourage normal movement forces to promote optimal biomechanical forces for best musculoskeletal development and prevention of anticipated malalignment and instabilities.

44. Learning Differences Generally, children with intellectual disabilities such as Down syndrome have been found to: B e capable of learning B enefit from frequent repetitions in order to learn H ave difficulty generalizing skill N eed more frequent practice sessions in order to maintain learned skills N eed extended time to respond, and H ave a more limited repertoire of responses

45. Intervention must include an understanding from a functional, dynamic systems perspective The general goal is to anticipate gross and fine motor delay and provide interventions to minimize it by : T eaching the caregivers appropriate positioning and handling activities to use throughout early infancy and childhood to promote antigravity control and weight bearing.

46. D esigning activities to encourage the development of antigravity muscle strength in all positions, E mphasizing trunk extension and extremity loading, which tend to increase axial muscle tone, E ncouraging the emergence of righting and postural reactions through use of rotation within and during movement , E ncouraging dynamic rather than static exploration of movement ,

47. F acilitating the emergence of developmental milestones when chronologically appropriate, including supported sitting and standing, when trunk control and alignment are able to be established A nticipating the delay in postural control responses and providing functional opportunities to enhance development in areas of cognition, language, and socialization,

48. T eaching parents and other team members activities and position choices that will enhance the child’s overall development. Suggestions include: Use of aligned compression or weight-bearing forces to stimulate longitudinal bone growth as well as thickness and density of the bone and shaft.

49. Aligned , supported weight bearing to promote joint stability. F acilitation of muscular co-contraction , force production, and increased muscle tone . Therapists should avoid exaggerated neck flexion, extension, rotation, and positions or movements that may cause twisting or undue forces .

50. With caution, joint approximation or compression of the cervical spine should be performed gently but these activities are contraindicated in children with identified atlantoaxial instability . Extreme caution must be taken, and any activity that may result in cervical spine injury should be avoided.

51. Motor Learning Considerations Reduce hands-on support when safe, to avoid dependence. Practice new skill in new environment. Provide visual and tactile cues.

52. Sensory Integration Therapy

53. Sensory Integration Therapy

54. Neuro Developmental Technique NDT is an approach which focuses on the quality of movement and coordination rather than individual muscle group function This hands-on approach is achieved by the physiotherapist having several ‘key points of control’, including the head, shoulders, trunk and/or pelvis to guide and alter movement

55. Neuro Developmental Technique

56. Perceptual Motor Training PMT incorporates activities which help to explore balance, coordination and body awareness and is not skills-based. So , rather than being taught a certain skill, individuals are provided with an environment in which to explore and determine what their bodies can do 

57. Other Interventions Treadmill Training Two-Wheeled Bicycle Training Balance training Gait Training Strengthening exercise Aerobic Exercise Endurance Training Post-surgical Management