Pediatrics and Research BOARD REVIEW Question • On examination, a 3-month-old girl still has a Moro reflex, asymmetric tonic neck reflex, and plantar grasp reflex. She does not have any protective extension. You advise her parents that • (a) further diagnostic evaluation is indicated. • (b) she requires a physical therapy evaluation. • (c) she needs a neurology evaluation. • (d) these reflexes are normal reflexes. Answer • (d) These are normal reflexes in a 3month-old child. The Moro and asymmetric tonic neck reflexes (ATNR) usually are integrated by approximately 6 months. The plantar grasp reflex is integrated by 12 to 14 months after walking has begun. Protective extension in sitting is seen anteriorly at 5 to 7 months, lateral at 6 to 8 months, and posterior at 7 to 8 months. Question • A 2-month-old infant presents to you for evaluation of delayed development. He was the product of a normal term pregnancy, labor, and delivery. Birth weight was 3500 grams. He has had difficulty feeding since birth. Family history is negative for developmental problems. On physical examination, he is awake, but not alert. Weight is 3600 grams. Respiration is unlabored. He has poor head control and decreased tone throughout. Deep tendon reflexes are absent. What is the most likely diagnosis? • (a) Kugelberg Welander syndrome • (b) Duchenne muscular dystrophy • (c) Infantile botulism • (d) Tetraplegic cerebral palsy Answer • (d) This patient illustrates the diagnostic dilemma of the floppy infant. Causes of this problem include central nervous system lesions (both brain and spinal cord), myopathies, neuropathies, and neuromuscular junction problems. This infant has had abnormalities since birth, which argues against infantile botulism. Kugelberg Welander syndrome (also known as spinal muscular atrophy type 3) has onset during childhood, as does Duchenne muscular dystrophy. Tetraplegic cerebral palsy often presents in infancy with floppiness and hyporeflexia, which later change to spasticity and hyperreflexia. Question • Professionalism is the basis of medicine’s contract with society. Which item is a fundamental principle of medical professionalism? • (a) Social justice • (b) Physician paternalism • (c) Patient disclosure • (d) Free enterprise Answer • (a) According to the Charter on Medical Professionalism, there are 3 fundamental principles of medical professionalism. They are (1) the primacy of patient welfare, (2) patient autonomy, and (3) social justice. Question • Your co-resident presents an article in journal club on a new medication and its impact on outcomes following traumatic brain injury. On which point would you NOT need assurance before you decide to use this medication in your clinical practice? • (a) That the research study results are clinically significant • (b) That bias was eliminated from the study • (c) That the research study results are statistically significant • (d) That research investigators used valid outcome measures Answer • (b) When critically evaluating the medical literature, it is important to consider if the results of the study are both clinically and statistically significant. It is also important to consider whether the outcome assessment tools have been validated for both accuracy and reliability. While biases that may impact the outcome of the study also must be considered, it is often impossible to completely eliminate bias from the study. Question • Which statement accurately characterizes a metaanalysis? • (a) It summarizes the results of randomized controlled trials. • (b) It summarizes the findings of an expert panel. • (c) It groups research on a particular topic area into 3 tiers. • (d) It summarizes findings of a single research protocol that is carried out a multiple centers. Answer • (a) A meta-analysis summarizes the results of randomized controlled trials on a particular topic or research question. A consensus statement summarizes the findings of an expert panel. In developing a consensus statement and reviewing the literature, research studies are typically divided into 3 tiers based on the type of research performed. A multi-center study implements a particular research protocol at multiple centers at different institutions. Question • Investigators must address ethical considerations when designing and implementing research studies. One such consideration requires investigators to design protocols that will provide generalizable knowledge and ensure that the benefits of the research are proportionate to the risks assumed by the subjects. This ethical consideration is referred to as • (a) respect. • (b) beneficence. • (c) justice. • (d) autonomy. Answer • (b) Beneficence requires investigators to design protocols that will provide generalizable knowledge and ensure that the benefits of the research are proportionate to the risks assumed by the subjects. Question • In instances where a researcher has financial investments in a company and is researching the effectiveness of one of the company’s products, the researcher is obligated to • (a) terminate the investigation if the investigational agent is found to be not effective. • (b) disclose this involvement in writing to subjects that are being enrolled in the study. • (c) end financial involvement in the company before the results of the research are revealed to the public. • (d) disclose this involvement to the investigator's medical center, to funding organizations, and to journals publishing the results. Answer • (d) Conflicts of interest in biomedical research are becoming more apparent as private companies increasingly develop relationships with academic research scientists. Avoidance of real or perceived conflicts of interest in clinical research is necessary if the medical community is to ensure objectivity and maintain individual and institutional integrity. Financial investments should only transpire outside of the time that the investigator is involved in any research activity and the results of the research are known to the public. If conflicts of interest exist, the investigator is obligated to disclose this involvement in writing to the investigator's medical center, organizations funding the research, and anytime that the research is presented or published. Question • 149. A 6-month-old infant presents to you with hypotonia. You perform an electrodiagnostic study which shows normal motor conduction velocity, normal sensory conduction velocity and amplitude, normal motor units, and occasional fibrillations and positive waves. The most likely cause of these findings is • (a) congenital myotonic dystrophy. • (b) spinal muscular atrophy. • (c) metachromatic leukodystrophy. • (d) infantile botulism. Answer • 149. (a) Hypotonia in infants can be caused by many abnormalities, including cerebral lesions, spinal cord pathology, polyneuropathies, and myopathies. These electrodiagnostic findings are most consistent with congenital myotonic dystrophy. Question • In children with spastic cerebral palsy, which intervention strengthens weak muscles? • (a) Ankle-foot orthotics • (b) Tendon transfer surgery • (c) Intrathecal baclofen • (d) Functional training program Answer (d) Children with cerebral palsy often have weakness as part of their disorder. Treatments such as bracing, tendon lengthening or transfers, and medications such as botulinum toxin or intrathecal baclofen add to this weakness. Strengthening programs or functional training programs can help to strengthen weak muscles. Question • One of your 4-year-old patients exhibits the following characteristics: distress over minor changes in environment, echolalia, lack of awareness of the existence of feelings in others, nonparticipation in simple games. The most likely diagnosis is • (a) autism. • (b) cerebral palsy. • (c) hearing impairment. • (d) mental retardation. Answer • (a) Autism is characterized by echolalia, inability to play reciprocally, and abnormal relationships with people. While children with mental retardation, cerebral palsy, and hearing impairment may have some of these features, they do not have all of them in the absence of autism. Question • A 17-year-old boy from India presents with a longstanding history of areflexia and asymmetric muscular atrophy after a febrile illness as a child. The likeliest site of neurologic pathology is • • (a) myelin sheath of peripheral nerves. • (b) axons of peripheral nerves. • (c) anterior horn cells. • (d) muscle membrane. Answer • (c) Poliomyelitis involves the anterior horn cells. During an acute infection, the virus is transported to the anterior horn cells followed by inflammation and loss of spinal and bulbar motor neurons. Question • Which finding is normal in newborn infants? • (a) Extensor tone predominates • (b) Hands are kept fisted • (c) Spine is straight when held in sitting position • (d) Unable to turn head to side in prone position Answer • (b) In normal newborn infants flexor tone predominates and hands are kept fisted. In prone position a normal newborn is able to turn the head to either side. The newborn has a rounded spine when placed in supported sitting. Question • A 10-year-old child with L4-5 myelodysplasia and shunted hydrocephalus develops spasticity in her legs. The most likely cause of this spasticity is • (a) shunt malfunction. • (b) symptomatic Chiari malformation. • (c) growth. • (d) tethered cord. Answer • (d) Tethered cord is the most common cause of new onset spasticity in patients with myelodysplasia. Linear growth does not cause new spasticity. Symptoms of Chiari malformation include cranial nerve disorders and respiratory problems. Shunt malfunction may be associated with headaches, vomiting, eye muscle abnormalities, and sometimes abdominal symptoms. Question • Which positive effect of ankle-foot orthotics has been proven beneficial in the treatment of children with cerebral palsy? • (a) Improved gait efficiency as measured by gait analysis • (b) Prevention of contractures • (c) Improved knee extensor strength • (d) Decreased plantar flexor posture Answer • (a) There are no large, randomized, controlled studies that show the long-term effects of any type of Ankle-Foot Orthosis (AFO) on function or contracture formation. Small studies have shown that both rigid and hinged AFOs improve gait efficiency by preventing plantar flexion. Question • • • • • • • A 5-year-old boy is brought to your office with pain in his left groin for the last 2 months. He has an antalgic gait and favors his left leg. He has been unable to play with his siblings because of pain and reports increased severity of the pain at night. There is no history of trauma. Passive range of motion of the left hip is extremely painful. Which of the following is most likely? (a) The child is not telling the truth about the trauma for fear of being punished by his parents. (b) A simple radiograph will demonstrate this problem to be a benign syndrome that only requires monitoring. (c) This child is at risk for permanent disability and treatment requires the use of an abduction brace. (d) You are very concerned about physical abuse by the parents, since the child is very quiet when the parents are in the examination room. Answer • (c) This child has Legg-Calvé-Perthes disease. This is avascular necrosis of the femoral head (also known as idiopathic osteonecrosis of the femoral head) and typically affects children between the ages of 4 and 8 years. Boys are affected 4 times more than girls are, and it is unilateral in 90% of children. It is uncommon in African American children. The bone dies and loses its structural integrity, leading to collapse of the femoral head with deformity and arthritis. Question • What condition casues the typical “myopathic gait” seen in a young boy with Duchenne muscular dystrophy with accentuated lumbar lordosis and toe walking? • (a) Hip and knee extensor weakness • (b) Hip flexion and ankle plantar flexion contractures • (c) Hip extensor weakness and plantar flexion contracture • (d) Hip flexion contracture and knee extensor weakness Answer • (a) The typical “myopathic gait” seen in early Duchenne muscular dystrophy is caused by weakness of the gluteus maximus and quadriceps muscles. In order to maintain upright posture the child assumes the hyperlordotic stance. Contractures of the gastrocsoleus and iliopsoas muscles occur later in the disorder. Question The most useful clinical criterion to distinguish Becker muscular dystrophy from Duchenne muscular dystrophy is ? • (a) creatine kinase values at the time of diagnosis. • (b) walking ability during the teen-age years. • (c) Gowers’ sign and calf enlargement. • (d) age at onset of diagnosis. Answer • (b) The most useful clinical criterion to distinguish Becker muscular dystrophy (BMD) from Duchenne muscular dystrophy (DMD) is the continued ability of the patient to walk into late teen-age years. Persons with BMD will typically remain ambulatory beyond 16 years. Outlier DMD cases generally stop ambulating between 13 and 16 years of age. Creatine kinase values cannot be used to differentiate DMD from BMD. Calf enlargement and the presence of Gowers’ sign are a nonspecific findings. Studies have shown significant overlap in the observed age at onset between DMD and BMD. Question The leading cause of childhood disability is • (a) traumatic brain injury. • (b) spinal muscular atrophy. • (c) spina bifida. • (d) cerebral palsy. Answer • (d) Cerebral palsy is the leading cause of childhood disability. The reported incidence is approximately 2-3 per 1,000 live births. The incidence of spina bifida is .5 per 1,000, of spinal muscular atrophy 1 in 25,000. The annual incidence for traumatic brain injury in children is 12 per 1,000. However, the great majority of cases are minor and result in no long-term disability. Approximately 15% of brain-injured children have moderate and severe injuries resulting in permanent impairment. Question • The earliest weakness seen in skeletal muscle in Duchenne muscular dystrophy is located in • (a) knee extensors. • (b) hip flexors. • (c) neck flexors. • (d) ankle plantar flexors. Answer • c. neck flexors Question The most common complication after amputation in the immature child is • (a) phantom limb pain. • (b) diffuse edema. • (c) terminal overgrowth. • (d) painful neuroma. Answer • (c) Terminal overgrowth at the transected end of a long bone is the most common complication after amputation in the skeletally immature child. It occurs most frequently in the humerus, fibula, tibia, and femur, in that order. The oppositional growth may be so vigorous that the bone pierces the skin. The treatment of choice is surgical revision. Question • The earliest marker of abnormal central nervous system maturation is ? • (a) diffuse fasciculations. • (b) gross motor delay. • (c) delay of postural responses. • (d) persistence of primitive reflexes. Answer • (d) In neonates and young infants, motor behavior is influenced by primitive reflexes because of the immature central nervous system. These reflexes gradually become suppressed. Concurrently, more sophisticated postural responses emerge. Obligatory persistent primitive reflexes are the earliest markers of abnormal neurologic maturation. Question A parent of an 18-month-old child reports that the child babbled as an infant but became much quieter after about 8 months of age. She has no true words, though she will wave bye-bye. She follows no verbal commands but will follow occasional pantomime commands. Her gross and fine motor skills have been normal. The most likely diagnosis is ? • (a) autism. • (b) mental retardation. • (c) hearing impairment. • (d) oral motor apraxia. Answer • (c) A history of delay in communication development raises several diagnostic possibilities, including true language dysfunction or a motor dysfunction or significant hearing loss. Infants with hearing loss start to fall behind after 6-8 months of age, when learning of auditory-dependent vocalization begins. Oral motor dysfunction is often associated with cerebral palsy, most often spastic quadriparesis. Difficulty with drinking from a cup and difficulty with the introduction of solid food are early symptoms of oral motor dysfunction. Autism is a spectrum disorder with qualitative abnormalities in communication and in social and behavioral realms. Question The most severe form of mental retardation in cerebral palsy occurs in association with • (a) spastic diplegia. • (b) ataxia. • (c) spastic quadriplegia. • (d) athetosis. Answer • (c) Mental retardation is the most common serious associated disability in cerebral palsy. The overall incidence of mental retardation is approximately 30%-50%. Severe mental retardation is present in about one-half of the retarded group. Approximately one-third of cases have mild cognitive deficits. The greatest retardation is seen in rigid, atonic, and severe spastic quadriplegic cerebral palsy. Question A 7-year-old boy is referred for evaluation and management of gradually progressive pain located in the right medial thigh and knee, a limp, and limited painful hip motion. There was a similar episode 3 months before which resolved spontaneously. Of the following conditions, the most likely diagnosis is • (a) congenital hip dysplasia. • (b) slipped capital femoral epiphysis. • (c) Legg-Calvé-Perthes disease. • (d) epiphyseal fracture. Answer • (c) Legg-Calvé-Perthes disease, avascular necrosis of the femoral head, occurs most commonly in boys between the ages of 4 and 8 years. It is characterized by medial thigh, groin, and knee pain, is associated with a limp, and is often preceded by a transient episode of hip synovitis. Congenital hip displasia is usually apparent much earlier; slipped capital femoral epiphysis occurs during periods of rapid growth, typically in adolescent boys, and may be preceded by trauma. Question In evaluating a hypotonic infant with electromyography you find low-amplitude, shortduration motor units with early recruitment. Based on these findings, the LEAST likely diagnosis would be • • • • (a) central core disease. (b) nemaline myopathy. (c) type II glycogenosis (acid maltase deficiency). (d) infantile spinal muscular atrophy. Answer • (d) The motor unit changes noted are typically seen in myopathies. Spinal muscular atrophy is an anterior horn cell disease. Question • In traumatic brain injury in children, outcome is primarily related to • (a) severity of original injury. • (b) location of injury. • (c) age at time of injury. • (d) associated injuries. Answer • (a) Although there is considerable variability from case to case, outcome is primarily related to the severity of the injury. Question Which reflex is typically NOT seen in a normal 4month-old infant? • (a) Extremities extend on the face side as the head is turned to the side. • (b) Fingers flex when the palm is touched. • (c) Extremities extend to the direction of displacement when center of gravity is displaced. • (d) Shoulder abduction, and shoulder, elbow, and finger extension occur when the neck is suddenly extended. Answer • (c) These options all describe reflexes. (a) asymmetric tonic neck reflex, (b) palmar grasp, and (d) Moroare seen until a baby is about 6 months old. Protective extension or parachute reaction (c) does not appear until after 6 months. Question Which statement is true regarding spinal cord injury without obvious radiologic abnormality in children? • • • • (a) It most commonly occurs in lumbar rather than cervical injuries. (b) There is a lower incidence in younger children. (c) It is associated with larger head size and relatively weak neck muscles. (d) Neurologic impairmen, if it occurs, is usually apparent within 2 to 4 hours post-injury. Answer • (c) Spinal cord injury without obvious radiologic abnormality (SCIWORA) usually occurs in young children, is thought to be due to the relatively large head size and weak neck muscles, and motor abnormalities may not be apparent for up to several days. SCIWORA most commonly occurs in the cervical region. Question • Which is the following represents the best description a cohort study? a) A group examined at one point in time b) 2 groups selected based on the presence or absence of an outcome. c) A group followed over time d) A group that is divided into an intervention versus a placebo. • C: A group followed over time Question • True or false: A case control study, the investigator makes all of the measurements on a single occasion or within a short period of time. –? Answer • False: • In a case control study, the investigator works backwards. They began by choosing one sample from a population of patient’s with the outcome (but cases) and another from a population without outcome (the control); then they compare the distribution levels of the predictor variables in the 2 samples to see which ones are associated with and might cause the outcome. • It is the cross sectional study where the investigator makes all of the measurements on a single occasion or within a short period of time. Question Acquired subluxation or dislocation of the hips in spastic cerebral palsy is usually due to muscular imbalance and pull of the • • • • (a) hip flexors and tensor fascia lata. (b) hip flexors and hip adductors. (c) rectus femoris and hip abductors. (d) tensor fascia lata and hip extensors. Answer • (b) Strong hip flexor and adductor muscles can overpower weak extensors and abductors. Acquired hip dislocation can be prevented in some cases by release of spastic hip flexors and adductors. Question Your 15-year-old patient with Duchenne muscular dystrophy complains of new onset morning headaches. What is the most likely cause? • (a) Neck extensor tightness • (b) Hypercarbia • (c) Migraines • (d) Vision changes Answer • (b) Migraines do not typically occur only in the morning. Neck extensor tightness usually occurs before the loss of ambulation in boys with Duchenne muscular dystrophy, which usually occurs before the age of 15 years. Vision changes usually do not cause morning headaches. Hypercarbia results from hypoventilation during sleep and is an early sign of impending respiratory failure. Question Which insult is the most likely cause of spastic diplegic cerebral palsy? • (a) Intrauterine stroke • (b) Hyperbilirubinemia in the neonatal period • (c) Postnatal intraventricular hemorrhage • (d) Perinatal asphyxia Answer • (c) Spastic diplegic cerebral palsy occurs most commonly in premature infants who have had an intraventricular hemorrhage during the neonatal period. Intrauterine stroke causes hemiplegia. Neonatal hyperbilirubinemia most commonly causes athetosis. Birth asphyxia is more commonly associated with spastic quadriplegic cerebral palsy. Question A 6-month-old child presents in your office for rehabilitation assessment. She was born at full term. There was mild transient respiratory distress at birth. The patient was noted to be diffusely hypotonic at birth except for normal cranial nerves. There were no feeding issues once the respiratory distress resolved within 24 hours. The baby has remained relatively hypotonic since birth. However, she has become very socially alert and aware and attempts to use her arms to reach for toys and pick up lightweight objects. She doesn’t roll. She cannot sit except very briefly when propped and bearing weight through both arms with elbows extended. On examination, head circumference is normal, length is normal, as is weight. There is a pronounced head lag. Arms, while in the supine position, maintain a “jughandle” posture. Reflexes are present but dimished There is no spasticity. The cranial nerves are normal except for fine fasciculations of the tongue.The most likely diagnosis is • • • • (a) myotonic muscular dystrophy. (b) cerebral palsy. (c) infantile botulism. (d) spinal muscular atrophy. Answer • (d) Spinal muscular atrophy (SMA)is a term used to describe a group of inherited disorders characterized by weakness and muscle wasting due to degeneration of anterior horn cells of the spinal cord and brainstem motor nuclei. Three subtypes of autosomal recessive predominantly proximal SMA have been linked to chromosome 5q. The majority of cases of SMA type I present within the first 2 months of life with generalized hypotonia and symmetric weakness. Children typically sit only with support. Tongue fasciculations have been reported in 56%-61% of patients. Proximal muscles are weaker than distal. Question What is the most common cause of traumatic brain injury in a child under the age of 1 year? • (a) Motor vehicle crash • (b) Near drowning in bath • (c) Inflicted injuries • (d) Fall from changing table Answer • (d) For infants, more than two-thirds of all traumatic brain injuries result from falls; only 8% of these result in moderate or severe injuries. For preschool children, falls account for 51% of TBI and motor vehicle crashes for 22%. For children 8 to 9 years of age, etiology of TBI is evenly divided between falls, sports, and recreational activities, and motor vehicle crashes. Question Secondary injury in pediatric brain trauma is caused by • (a) hypotension, hypoxia, and hydrocephalus. • (b) growing skull fractures. • (c) coup and contrecoup cerebral contusions. • (d) diffuse axonal injuries and punctate hemorrhages Answer • (a) Any disorder that interferes with cerebral perfusion or oxygenation can cause further damage following traumatic brain injury. This includes hypotension, hypoxia, increased intracranial pressure because of cerebral edema, acute hydrocephalus, or space-occupying lesions. Midline shift or herniation may lead to infarction because of pressure or traction on cerebral vessels. Therefore, efforts are made to control intracranial pressure through fluid and electrolyte management, hyperventilation, and maintenance of normal blood pressure and oxygenation. Growing skull fractures result from the arachnoid protruding through a dural tear, producing a cyst that can contribute to a widening skull deficit, which usually requires operative repair. This is a complication of traumatic brain injury but not a secondary injury. Coup and contrecoup cerebral contusions and diffuse axonal injuries are examples of primary injury. Question To prevent contractures, which position is the correct placement for children with major burns? • (a) Shoulder in external rotation • (b) Wrist in extension • (c) Hip in flexion • (d) Metacarpophalangeal joints in hyperextension Answer • (b) Children with major burn injuries should be placed in positions that tend to prevent contractures. These include neck extension (no pillows); shoulders at 90° abduction and neutral rotation with elbows, wrists, hips, and knees extended; feet at neutral dorsiflexion, metacarpophalangeal joints at 70° to 90° flexion and finger interphalangeal joints in full extension. Question Bracing for curves developing after age 3, but before puberty onset (juvenile idiopathic scoliosis) should commence when the curve reaches approximately how many degrees? • (a) 15° • (b) 25° • (c) 40° • (d) 60° Answer • (b) Unlike infantile idiopathic scoliosis, the juvenile type almost never spontaneously resolves, and owing to the many years of growth during which progression can take place, extremely severe curves can develop. Because of the very poor prognosis of this scoliosis, and the great desire to avoid fusion at a young age, bracing becomes an extremely important method of management. Therefore, the standard of care is to begin bracing when the curve reaches approximately 25°. It is not necessary to brace curves less than 20°, and curves as high as 60° can still respond to a brace. This is a much higher value than for successful bracing of adolescent idiopathic scoliosis where the upper limit is 40° to 45°. Question In children with spastic cerebral palsy, which intervention strengthens weak muscles? • (a) Ankle-foot orthotics • (b) Tendon transfer surgery • (c) Intrathecal baclofen • (d) Functional training program Answer • (d) Children with cerebral palsy often have weakness as part of their disorder. Treatments such as bracing, tendon lengthening or transfers, and medications such as botulinum toxin or intrathecal baclofen add to this weakness. Strengthening programs or functional training programs can help to strengthen weak muscles. Question One of your 4-year-old patients exhibits the following characteristics: distress over minor changes in environment, echolalia, lack of awareness of the existence of feelings in others, nonparticipation in simple games. The most likely diagnosis is • (a) autism. • (b) cerebral palsy. • (c) hearing impairment. • (d) mental retardation. Answer • (a) Autism is characterized by echolalia, inability to play reciprocally, and abnormal relationships with people. While children with mental retardation, cerebral palsy, and hearing impairment may have some of these features, they do not have all of them in the absence of autism. Question • During discussion with the parents of a 2year-old leukemic patient, you inform them that significant brain irradiation almost uniformly produces • (a) attention deficits. • (b) focal motor weakness. • (c) ataxia. • (d) anosmia. Answer • (a) An adverse sequela of intensive pediatric anticancer therapy is learning difficulty. Impaired learning can exert a deleterious long-term impact. Whole brain irradiation for leukemic prophylaxis results in enlarged cerebral sulci and ventriculomegaly on cranial imaging.Clinical symptomatology roughly correlates with scan findings. Virtually all patients in whom a substantial portion of the brain is radiated complain of memory loss and attentional deficits. Question A 17-year-old boy from India presents with a longstanding history of areflexia and asymmetric muscular atrophy after a febrile illness as a child. The likeliest site of neurologic pathology is • • • • (a) myelin sheath of peripheral nerves. (b) axons of peripheral nerves. (c) anterior horn cells. (d) muscle membrane. Answer • (c) Poliomyelitis involves the anterior horn cells. During an acute infection, the virus is transported to the anterior horn cells followed by inflammation and loss of spinal and bulbar motor neurons. Question Which finding is normal in newborn infants? • (a) Extensor tone predominates • (b) Hands are kept fisted • (c) Spine is straight when held in sitting position • (d) Unable to turn head to side in prone position Answer • (b) In normal newborn infants flexor tone predominates and hands are kept fisted. In prone position a normal newborn is able to turn the head to either side. The newborn has a rounded spine when placed in supported sitting. Question Which measure is the first sign of respiratory muscle dysfunction in boys with Duchenne muscular dystrophy? • (a) Vital capacity • (b) Oxygen saturation • (c) Maximal expiratory force • (d) Negative inspiratory force Answer • (c) Recent studies by McDonald and by Bach showed that reduction of maximal expiratory force (MEF) to 40%–60% of normal in the 7- to 14-year-old age group was the first sign of respiratory muscle dysfunction in boys with Duchenne muscular dystrophy (DMD). The earlier and more severe decreases of MEF that are greater than the decreases in maximal inspiratory force, correspond to the clinically observed weakness of abdominal muscles, which like coughing are important in forced expiration. Vital capacity was not found to decrease until an average of 15–16 years. Low oxygen saturation is a late manifestation in DMD, developing after hypercapnia. • Question A 10-year-old child with L4-5 myelodysplasia and shunted hydrocephalus develops spasticity in her legs. The most likely cause of this spasticity is • (a) shunt malfunction. • (b) symptomatic Chiari malformation. • (c) growth. • (d) tethered cord. Answer • (d) Tethered cord is the most common cause of new onset spasticity in patients with myelodysplasia. Linear growth does not cause new spasticity. Symptoms of Chiari malformation include cranial nerve disorders and respiratory problems. Shunt malfunction may be associated with headaches, vomiting, eye muscle abnormalities, and sometimes abdominal symptoms. Question Juvenile rheumatoid arthritis (JRA) differs from adult onset rheumatoid arthritis: in JRA • (a) joint destruction occurs earlier. • (b) large joint involvement is less frequent. • (c) the cervical spine is involved less frequently. • (d) systemic features are more common. Answer • (d) Children with juvenile rheumatoid arthritis are more likely to have systemic features, have large joints involved, and have cervical spine involvement. Adults with rheumatoid arthritis have joint destruction earlier. Question Children with which physical disorder tend to have higher verbal skills compared to overall cognitive ability? • (a) Muscular dystrophy • (b) Myelodysplasia • (c) Cerebral palsy • (d) Autism Answer • (b) Children with myelodysplasia have deceptively good verbal facility that creates the impression of higher intellectual functioning than is found on formal testing (“cocktail party syndrome”). Children with cerebral palsy, autism, and muscular dystrophy do not typically demonstrate this finding. Question A 5-year-old boy is brought to your office with pain in his left groin for the last 2 months. He has an antalgic gait and favors his left leg. He has been unable to play with his siblings because of pain and reports increased severity of the pain at night. There is no history of trauma. Passive range of motion of the left hip is extremely painful. Which of the following is most likely? • • • • (a) The child is not telling the truth about the trauma for fear of being punished by his parents. (b) A simple radiograph will demonstrate this problem to be a benign syndrome that only requires monitoring. (c) This child is at risk for permanent disability and treatment requires the use of an abduction brace. (d) You are very concerned about physical abuse by the parents, since the child is very quiet when the parents are in the examination room. Answer • This child has Legg-Calvé-Perthes disease. This is avascular necrosis of the femoral head (also known as idiopathic osteonecrosis of the femoral head) and typically affects children between the ages of 4 and 8 years. Boys are affected 4 times more than girls are, and it is unilateral in 90% of children. It is uncommon in African American children. The bone dies and loses its structural integrity, leading to collapse of the femoral head with deformity and arthritis. An abduction brace is worn all day in an attempt to position the femoral head in the acetabulum. This will hopefully lead to a more spherical head of the femur. The femoral head can revascularize and remodel, but this occurs over several months. Osteotomy is usually reserved for older children. Question What condition casues the typical “myopathic gait” seen in a young boy with Duchenne muscular dystrophy with accentuated lumbar lordosis and toe walking? • (a) Hip and knee extensor weakness • (b) Hip flexion and ankle plantar flexion contractures • (c) Hip extensor weakness and plantar flexion contracture • (d) Hip flexion contracture and knee extensor weakness Answer • (a) The typical “myopathic gait” seen in early Duchenne muscular dystrophy is caused by weakness of the gluteus maximus and quadriceps muscles. In order to maintain upright posture the child assumes the hyperlordotic stance. Contractures of the gastrocsoleus and iliopsoas muscles occur later in the disorder. Question The most common spinal problem seen with achondroplasia during childhood is • (a) kyphosis. • (b) scoliosis. • (c) spinal stenosis. • (d) low back pain. Answer • (a) While scoliosis may occur in children with achondroplasia, it is less common than kyphosis, which begins in infancy. Spinal stenosis occurs frequently in individuals with achondroplasia, with 38 years being the average age of symptom onset. Low back pain is extremely frequent in adults with achondroplasia, but rare in children. Progressive kyphosis that occurs in infants and young children with achondroplasia is treated with a spinal orthosis. Question What is the pathophysiology of Duchenne muscular dystrophy? • (a) merosin deficiency • (b) abnormally low levels of dysferlin • (c) absence of dystrophin • (d) mutations of alpha-sarcoglycan Answer • (c) The absence of dystrophin is the basis of the pathophysiology of Duchenne muscular dystrophy (DMD). Most genes in the affected area of the X chromosome encode for components of the dystrophin-glycoprotein complex (DGC), an assembly of transmembrane and membraneassociated proteins that form a structural linkage between the F-actin cytoskeleton and the extracellular matrix in muscle. The proteins that comprise the DGC are organized into 3 subcomponents, the cytoskeletal proteins, the sarcoglycans and the sarcospan. Many of the different types of muscular dystrophies arise from primary mutations in genes encoding components of this complex. However, the other choices noted above are not involved in DMD or Becker MD. Deficiencies in those proteins are associated with forms of limb girdle muscular dystrophy. Question Your 6-month-old patient had burns to his head and both arms in a house fire. What approximate percent of his total body surface area (TBSA) was burned? • (a) 37 • (b) 18 • (c) 27 • (d) 49 Answer • (a) An infant’s head is approximately 19% and each arm constitutes 9% of the total body surface area (TBSA). In adults and older children the head is approximately 9% of the TBSA. Question Which joints are most commonly involved in juvenile rheumatoid arthritis? • (a) Shoulder, hip, fingers • (b) Atlantoaxial, costomanubrum, hip • (c) Sternomanubrum, shoulder, sacroiliac • (d) Elbow, hip, temporomandibular Answer • (d) The elbow is involved 90% of the time in juvenile rheumatoid arthritis (JRA), the temporomandibular and hip 50% each. The shoulder is involved about 8% of the time in early JRA and about 33% later. Question You are asked to evaluate an 8-month-old child with developmental delay. On exam you find low tone, but brisk deep tendon reflexes at the knees and biceps, full passive range of motion, and poor head and trunk control. This child’s diagnosis is likely • (a) myotonic dystrophy. • (b) cerebral palsy. • (c) spinal muscular atrophy. • (d) Hunter’s syndrome. Answer • (b) This patient presents with hypotonia, weakness, and hyperreflexia, a combination most commonly seen in central nervous system lesions such as cerebral palsy. A child with a neuromuscular disorder would not have hyperreflexia with the hypotonia and weakness. In severe cerebral palsy it is common to see early hypotonia with brisk reflexes that changes to hypertonia as the child gets older. Question Which endocrine abnormality is most likely to occur 5 years after severe traumatic brain injury in a 2-year-old girl? • (a) Diabetes insipidus • (b) Precocious puberty • (c) Hypothyroidism • (d) Hyperparathyroidism Answer • (b) Precocious puberty occurs in up to 50% of girls who sustain a severe traumatic brain injury (TBI) in early childhood. Diabetes insipidus is an early complication of TBI. While other endocrine abnormalities may occur, they are less common. Question What percentage of American children with myelomeningocele requires a shunt to manage hydrocephalus? • (a) 10–20 • (b) 25–50 • (c) 60–70 • (d) 80–90 Answer • (d) Seventy-five percent of lesions in spina bifida cystica (myelomeningocele) affect the lumbosacral spine. Ninety percent of children with spina bifida have hydrocephalus that requires a shunt for management. Question A 16-year-old with Duchenne muscular dystrophy presents to your office with a 3-month history of worsening shortness of breath and pressure-like chest pain. His pulmonary function testing has not changed significantly. The most likely cause for his complaints is • • • • (a) decreased cardiac output. (b) bacterial pneumonia. (c) pulmonary embolus. (d) aspiration pneumonia. Answer • (a) Given that his pulmonary function has not changed, the most likely cause for his shortness of breath is cardiac decompensation due to cardiomyopathy. Respiratory failure due to neuromuscular weakness would typically correspond to worsening of pulmonary function testing. Bacterial and aspiration pneumonia would both present with much more acute symptoms. Boys and men with Duchenne muscular dystrophy rarely get deep venous thromboses or pulmonary emboli. If left untreated, the patient will likely develop congestive heart failure from cardiomyopathy. The decreased cardiac output usually responds to treatment with digoxin and ACE-inhibitors. Question A normal 6-month-old infant may demonstrate which reflex? • (a) Rooting • (b) Automatic walking • (c) Plantar grasp • (d) Posterior protective extension Answer • • • • • • • • • • • (c) Rooting and automatic walking reflexes are present at birth, and are integrated by 4 months of age. Posterior protective extension does not appear until 7 to 8 months of age. Plantar grasp is present at birth and not integrated until after independent walking occurs at approximately 12 months of age. Reflex Age of Emergence Age of Suppression (or Integration) Moro Birth 4–6 months Rooting Birth 4 months Asymmetric tonic neck reflex (ATNR) 1–3 months 6–7 months Plantar grasp Birth 12–14 months–ie, when walking well Automatic walking Birth 3–4 months Posterior protective extension 7–8 months Question Which statement is TRUE about swallowing in infants? • (a) Sucking and swallowing are well-coordinated for oral intake by 34 weeks of gestation. • (b) The infant’s larynx is low, about the level of the sixth cervical vertebra. • (c) The infant’s tongue fills less of the oral cavity than the adult’s tongue. • (d) Oral breathing occurs at birth and may interfere with sucking. Answer • (a) Sucking and swallowing are wellcoordinated at 34 weeks’ gestation. Because the infant’s tongue is more anterior than the adult’s, the tongue fills more of the oral cavity than in the adult. The larynx in the infant is high, about at the C2–3 level. Newborn infants are obligate nose breathers and oral breathing is not observed until 3 to 4 months of age. Question You are performing a consult on an 8-year-old child who has sustained a traumatic brain injury. The child has hyperthermia, hypertension, tachycardia, and rigidity. The best management for this child would be • (a) Propranolol (Inderal). • (b) Baclofen (Lioresal). • (c) Nonsteroidal anti-inflammatory drugs (NSAIDs). • (d) Amantadine (Symmetrel). Answer • (a) Fever in a child with a severe traumatic brain injury should be investigated and infections treated with appropriate antibiotics. In the absence of infection, the fever in central autonomic dysfunction is poorly responsive to nonsteroidal anti-inflammatory drugs. Baclofen may help to control the spasticity, but propranolol is more effective in controlling the hypertension, tachycardia, and hyperthermia. Question The Education for All Handicapped Children Act (EHA, PL 94-142), passed in 1976, and the Individuals with Disabilities Education Act (IDEA, PL 105-17), passed in 1997, guarantee that children with disabilities have • • (a) education in special schools. • (b) medical care at school. • (c) education in the least restrictive environment. • (d) education in regular classrooms. • Answer • c) The Education for All Handicapped Children Act and the Individuals with Disabilities Education Act guarantee children with disabilities education in the least restrictive environment. They also guarantee necessary health care be provided in the school environment (eg, intermittent catheterization) but do not require medical care be provided. Question Randomized controlled trials examining intrathecal baclofen (ITB) use in children with cerebral palsy show that children who receive ITB have • (a) improved upper extremity function. • (b) reduced spasticity in lower extremities. • (c) improved walking and transfers. • (d) improved knee range of motion. Answer • (b) A comprehensive review of published English language studies on intrathecal baclofen (ITB) showed evidence of statistically significant improvement in upper and lower extremity tone with ITB use in children with cerebral palsy (CP). Other reported improvements with ITB in children with CP are either anecdotal or not substantiated by randomized controlled trials. • Question The most common congenital limb deficiency is a • (a) transverse tibial and fibular limb deficiency (below-knee limb deletion). • (b) transverse transmetacarpal limb deficiency (partial hand deletion). • (c) longitudinal fibular deficiency (fibular hemimelia). • (d) transverse radial limb deficiency (belowelbow limb deletion). Answer • (d) The left short transradial congenital limb deficiency (below-elbow limb deletion) is the most common congenital limb deficiency. It is thought to be caused by a clot which occludes the artery, resulting in resorption of the distal limb, often leaving nubbins of fingers at the end of the stump. Question 46. You are covering for your partner who is a pediatric physiatrist. Today, you are admitting a 2-year old girl who sustained a burn. You suspect that this girl is a victim of a nonaccidental injury (ie,child abuse) because you see • (a) non-symmetrical burns. • (b) splash marks in a scald-type injury. • (c) injuries in various stages of healing. • (d) non-uniform burn depth. Answer • (c) Non-accidental injuries account for approximately 10% to 28% of pediatric burns. Of all nonaccidental injuries experienced by children, 10% are due to burns. Among abused children 30% to 70% suffer a repeat injury. Signs of abuse include injury that does not correlate with the type and location of injury observed on examination; uniform burn depth; sharp lines of demarcation between burned and non-burned areas; symmetrical wounds (eg, in a stocking or glove pattern); an absence of splash marks in scald injuries; the presence of other injuries in various stages of healing. Question A 6-month-old infant presents to you with hypotonia. You perform an electrodiagnostic study which shows normal motor conduction velocity, normal sensory conduction velocity and amplitude, normal motor units, and occasional fibrillations and positive waves. The most likely cause of these findings is • (a) congenital myotonic dystrophy. • (b) spinal muscular atrophy. • (c) metachromatic leukodystrophy. • (d) infantile botulism. Answer • (a) Hypotonia in infants can be caused by many abnormalities, including cerebral lesions, spinal cord pathology, polyneuropathies, and myopathies. These electrodiagnostic findings are most consistent with congenital myotonic dystrophy.