ERGO2_Pediatrische_Pathologie_2526_alle_slides.pdf

# Introduction to pediatrics and child development This section defines pediatrics, highlights why children are distinct from adults, and outlines key developmental stages from pregnancy to adolescence. ### 1.1 What is pediatrics? Pediatrics, also known as child health, is a medical specialty focused on the curative, preventive, and often ethical care of both sick and healthy children from birth up to a certain age. It integrates the physical, psychological, and developmental aspects of a child. Pediatricians address pathologies exclusive to this life stage, including conditions arising from fetal developmental disorders (congenital disorders), growth disorders, childhood cancers, infections, and metabolic diseases [14](#page=14) [15](#page=15). #### 1.1.1 Age categories in pediatrics Pediatrics categorizes patients into specific age groups: * **Neonate or newborn:** Day 1 – day 28 postnatally [16](#page=16). * **Infant:** Day 1 – day 364 postnatally [16](#page=16). * **Baby:** 0–18 months [16](#page=16). * **Toddler:** 18 months – 3 years [16](#page=16). * **Preschooler:** 3 years – 6 years [16](#page=16). * **Child:** 6–12 years [16](#page=16). * **Adolescent/Youngster:** 12–18 years [16](#page=16). ### 1.2 The pediatric specialty: A child is not a small adult The field of pediatrics is distinct because the individual is constantly developing. Diseases can significantly impact a child's growth and development, with potential consequences for their entire future. Therefore, timely identification of developmental or growth disorders is crucial [17](#page=17). #### 1.2.1 Goals of studying child development in pediatrics The objective of this area of study is to gain insight into the normal growth and development of a child from birth. This knowledge is essential for the early recognition of developmental or growth disorders. It also aims to provide an understanding of pediatric pathology, with a focus on musculoskeletal disorders and their pathophysiology [18](#page=18). > **Tip:** Early detection of conditions like phenylketonuria can significantly mitigate their long-term impact on an individual's life [19](#page=19). ### 1.3 Key developmental stages (from pregnancy) While specific details on pregnancy and fetal development are referenced in the table of contents the document emphasizes understanding the child's development from birth onwards. The curriculum aims to cover the course of pregnancy though detailed content is not provided within the specified pages [11](#page=11) [18](#page=18) [9](#page=9). ### 1.4 Infant responses The study of pediatrics includes an understanding of infant responses. Specific details regarding these responses are not elaborated upon in the provided pages [9-19 [11](#page=11). ### 1.5 Relevance of pediatric knowledge Understanding pediatric conditions and development is important, even for adult care, as many issues have their origins in childhood [11](#page=11). --- # Normal fetal development and infant reflexes This section details the stages of pregnancy from conception to birth and explores the innate reflexes and responses observed in infants during their first year of life [20](#page=20). ### 2.1 Fetal development The duration of a normal pregnancy is approximately 280 days or 40 weeks, calculated from the first day of the last menstrual period (LMP). Fertilization, if the cycle is regular, occurs around day 14 of the menstrual cycle [22](#page=22). #### 2.1.1 Pregnancy trimesters Pregnancy is typically divided into three trimesters: * **First trimester:** Extends to the end of week 14. This period carries the highest risk of miscarriage. The Non-Invasive Prenatal Test (NIPT) is often performed between weeks 11 and 14 [23](#page=23). * **Second trimester:** Starts from week 15 to the end of week 28. During the fourth month, the fetus's sex becomes visible via ultrasound, and the mother may feel fetal movements due to a developing functional nervous system and motor skills [23](#page=23) [33](#page=33). * **Third trimester:** Begins at week 29 until birth. By the seventh month, the fetus opens its eyes. In the eighth month, subcutaneous fat reserves accumulate. By the ninth month, the fetus is typically ready for birth, with an average length of 53 cm and a weight of approximately 3500 grams for boys and 3350 grams for girls [23](#page=23) [35](#page=35). > **Tip:** More than 90% of babies can survive outside the uterus from the third trimester onwards [23](#page=23). #### 2.1.2 Key developmental milestones * **Conception:** Involves the fusion of the oocyte and spermatozoon, forming a zygote [27](#page=27). * **Blastocyst formation:** The zygote develops into a blastocyst approximately 4 days after fertilization [27](#page=27). * **Implantation:** The blastocyst embeds into the endometrium (uterine lining) about 7 days after fertilization [27](#page=27). * **Embryonic development (first 10 weeks):** This phase includes organogenesis. Key events include the formation of the neural plate and neural groove around week 5. The neural tube, a crucial embryonic structure, begins to form through the invagination and closure of the neural plate. This closure starts on day 22 after fertilization (week 5) and proceeds from cranial to caudal. The neural tube closes cranially around day 24 and caudally around day 26. A functioning liver and kidneys develop during this period [30](#page=30) [31](#page=31) [32](#page=32). * **Fetal development (from week 11):** External genitalia, teeth, and the bony skeleton begin to form [32](#page=32). #### 2.1.3 Gestational age classifications * **Premature:** Born less than 37 weeks gestation [25](#page=25). * **À terme/Voldragen:** Born between 37 and 42 weeks gestation [25](#page=25). * **Postmature/Serotien:** Born longer than 42 weeks gestation [25](#page=25). #### 2.1.4 Viability of premature infants The World Health Organization (WHO) categorizes premature infants into three groups: * **Extremely premature:** Less than 28 weeks gestation (less than 20 weeks is considered a miscarriage) [41](#page=41). * **Very premature:** 28 to 32 weeks gestation [41](#page=41). * **Mild to late premature:** 32 to 37 weeks gestation [41](#page=41). In Flanders, infants born before 30 weeks gestation and/or with a birth weight below 1250 grams receive specialized follow-up [41](#page=41). * **Before 24 weeks:** Not considered viable, and intensive care is generally not provided [42](#page=42). * **24 to 27 weeks (660-700g):** This is a "gray zone" between miscarriage and prematurity. An "unless" policy is applied, where active care is initiated unless there are specific adverse circumstances. Survival rates are around 60%, with a significant proportion developing moderate to severe disabilities [42](#page=42). * **After 28 weeks (over 1 kg):** With appropriate medical care, there is a good chance of survival and normal development [42](#page=42). > **Tip:** Birth weight is a significant indicator of viability in premature infants [42](#page=42). #### 2.1.5 Teratogens and fetal sensitivity The embryo/fetus is most sensitive to toxic substances (e.g., radiation, alcohol, medications) during the first trimester. The chart indicates high sensitivity to teratogenic substances is concentrated in the first trimester, with decreasing sensitivity in the second and third trimesters. Even low exposure to alcohol during pregnancy can lead to brain dysfunction [38](#page=38) [39](#page=39) [40](#page=40). ### 2.2 Infant reflexes and responses Infant reflexes and responses are innate, automatic reactions to stimuli that are crucial for survival and development. These responses are typically tested in a quiet environment when the baby is awake [51](#page=51) [60](#page=60) [67](#page=67). #### 2.2.1 Reflexes vs. infant responses * **Reflex:** An immediate, involuntary reaction of the body to the stimulation of a receptor, usually resulting in muscle contraction or gland secretion. A simple reflex follows a five-step reflex arc [53](#page=53) [54](#page=54). * **Infant response (or baby reaction):** A process or series of processes initiated by a stimulus (chemical, physical, psychological), which can be physiological or pathological. These responses typically disappear with the maturation of the nervous system, particularly the cerebral cortex [55](#page=55). > **Tip:** While often called "primitive reflexes," these are technically infant responses and can be confused with true reflexes [58](#page=58). #### 2.2.2 Distinguishing characteristics of infant responses Infant responses differ from simple reflexes in several ways: * Greater variability in response [58](#page=58). * The strength of the response is not always proportional to the stimulus strength [58](#page=58). * Can be influenced by environmental stimulation [58](#page=58). * Not always elicitable [58](#page=58). * Age-dependent and typically disappear by a certain age [58](#page=58). * Involve more complex neurological mechanisms than the basic reflex arc [58](#page=58). * Later inhibited by higher brain centers, such as through myelination of the pyramidal tracts [58](#page=58). > **Tip:** The inability to elicit an infant response or its persistence beyond the expected age can indicate a neurological disorder. Conversely, some responses can reappear after a brain injury [61](#page=61). #### 2.2.3 Key infant responses and their characteristics The following are important infant responses tested during the first year of life: * **Moro reflex (or startle reflex):** * **Stimulus:** Sudden, uncontrolled head movement, vestibular and neck proprioception stimulation, or abrupt acoustic and tactile stimuli [63](#page=63). * **Response:** Arms and legs first extend and abduct, followed by flexion and adduction [63](#page=63). * **Disappearance:** Becomes difficult to elicit around the third month of life [63](#page=63). * **Persistent Moro reflex:** Can be associated with neurological or sensory sensitivity, overstimulation, birth trauma, illness, developmental delay, or disturbed primary reflex integration [65](#page=65). * **Head raising response:** * **Stimulus:** Pulling the baby by the arms to bring them into a sitting position [68](#page=68). * **Response:** The head lifts for at least 2 seconds [68](#page=68). * **Onset:** Appears from about 5 days old [68](#page=68). * **Rooting, sucking, and swallowing responses:** * **Rooting:** * **Stimulus:** Stimulation at the side of the mouth (e.g., by a finger or nipple) [70](#page=70). * **Response:** The baby turns their head towards the stimulation [70](#page=70). * **Sucking:** * **Stimulus:** An object placed in or against the baby's mouth [72](#page=72). * **Response:** The baby sucks on the object [72](#page=72). * **Swallowing:** * **Stimulus:** Milk or another palatable substance in the baby's mouth [75](#page=75). * **Response:** The baby swallows [75](#page=75). * **Disappearance:** These responses typically disappear after the third month [75](#page=75). * **Palmar grasp response:** * **Stimulus:** Pressure applied to the palm of the open hand [76](#page=76). * **Response:** The hand closes around the object [76](#page=76). * **Disappearance:** Disappears between 2 to 3 months and is completely gone between 4 and 6 months [76](#page=76). * **Plantar grasp response:** * **Stimulus:** Pressure applied to the sole of the foot (ball of the foot) with a thumb or pencil [78](#page=78). * **Response:** A grasping movement of the foot (flexion of the toes) [78](#page=78). * **Disappearance:** Disappears between 10 to 18 months [78](#page=78). * **Galant or spinal incurvation reflex:** * **Stimulus:** Stroking the skin paravertebrally in a longitudinal direction while the infant is in a prone position [80](#page=80). * **Response:** Lateral flexion of the trunk towards the stimulated side [80](#page=80). * **Application:** Used to detect hemisyndromes and spinal lesions [80](#page=80). * **Development:** Increases from birth to one month, then gradually declines, disappearing by 3-4 months [80](#page=80). * **Babinski response:** * **Stimulus:** Stroking the sole of the foot from the heel towards the toes along the outer edge [82](#page=82). * **Response:** Dorsiflexion of the foot and fanning of the toes [82](#page=82). * **Disappearance:** Disappears during the second year of life. The response becomes more variable (dorsiflexion, indifferent, or plantar flexion) as it fades [82](#page=82). * **Diagnostic Significance:** A diagnostic tool when pyramidal tract lesions (e.g., CVA) are suspected [82](#page=82). * **Asymmetrical tonic neck reflex (ATNR):** * **Stimulus:** Turning the head to one side while the infant is in a supine position [84](#page=84). * **Response:** Extension of the limbs on the face side and flexion of the limbs on the occiput side [84](#page=84). * **Onset/Duration:** Present from birth to 5-6 months [84](#page=84). * **Note:** Sometimes called the "fencing reflex". Can remain present in cases of cerebral palsy and may reappear after brain injury [84](#page=84) [85](#page=85). * **Symmetrical tonic neck reflex (STNR):** * **Stimulus 1 (Neck extension):** Extension of the head along the midline [86](#page=86). * **Response 1:** Abduction and extension of the arms, and flexion of the legs [86](#page=86). * **Stimulus 2 (Neck flexion):** Flexion of the head along the midline [87](#page=87). * **Response 2:** Flexion of the arms and extension of the legs [87](#page=87). * **Prevalence:** Primarily observed between 4 to 6 months of age. It is noted that the STNR may only be observable in about 30% of babies and is relatively more common in premature infants [86](#page=86) [87](#page=87). * **Note:** Also referred to as a response rather than a reflex [86](#page=86). * **Landau response:** * **Stimulus 1:** Passively flexing the head while holding the baby prone [88](#page=88). * **Response 1:** Legs flex [88](#page=88). * **Stimulus 2:** Passively extending the head while holding the baby prone [88](#page=88). * **Response 2:** Legs extend [88](#page=88). * **Onset/Duration:** Best seen between 3 to 9 months and disappears well after the first birthday [88](#page=88). * **Walking response:** * **Stimulus:** Holding the baby vertically under the armpits, with feet touching a surface [90](#page=90). * **Response:** Rhythmic stepping movements [90](#page=90). * **Disappearance:** This response typically disappears before the 5th month unless practiced [90](#page=90). * **Labyrinthine response:** * **Stimulus:** Disrupting the baby's equilibrium [93](#page=93). * **Response:** The head remains upright, independent of the body's position [93](#page=93). * **Disappearance:** Disappears after 18 months [93](#page=93). * **Parachute response:** * **Stimulus:** Rapidly lowering the infant (held horizontally by the pelvis, head down) towards a surface [94](#page=94). * **Response:** Extension of the lower limbs and abduction of the arms and fingers [94](#page=94). * **Onset/Duration:** Appears from the 5th month and persists [94](#page=94). --- # Abnormal motor development in children Abnormal motor development in children encompasses a range of conditions that affect a child's ability to control their movements, often stemming from neurological or non-neurological causes. ### 3.1 Cerebral palsy Cerebral palsy (CP) is a collective term for motor impairments resulting from a developmental disorder or early damage to the brain, occurring prenatally, perinatally, or during the first year of life. It is a non-progressive neurological condition, though motor symptoms may progress. CP is often accompanied by sensory, perceptual, cognitive, communication, and behavioral impairments. Common comorbidities include epilepsy (4 in 10) and autism spectrum disorder (1 in 10). The spectrum of neurological dysfunction in CP is broad, ranging from severe immobility to mild clumsiness. Approximately 40-50% of children with CP cannot walk independently. The prevalence of CP is about 2 per 1,000 live births . #### 3.1.1 Etiology of cerebral palsy The etiology of CP involves anatomical damage to the developing brain during the prenatal, perinatal, or early postnatal periods. It is considered a static defect with a dynamic clinical presentation across different life stages. A diagnosis of CP should be made before the second year of life; otherwise, it is classified as acquired brain injury (NAH) . ##### 3.1.1.1 Prenatal causes Prenatal causes of CP include premature birth, conception via assisted reproductive technologies, intrauterine infections (e.g., HIV, TORCH), maternal intoxications (alcohol, drugs), and fetal brain circulatory problems. Prematurity is a significant risk factor, with approximately 40% of patients with CP being born prematurely . ##### 3.1.1.2 Perinatal causes Perinatal causes involve brain circulatory disorders, severe infections (sepsis, meningitis), intracranial hemorrhages, metabolic derangements, and epilepsy . ##### 3.1.1.3 Postnatal causes Postnatal causes include central nervous system infections, trauma or abuse, brain circulatory problems, metabolic derangements, and epilepsy . #### 3.1.2 Types of cerebral palsy CP can be classified based on the type of motor disorder, the location of the impairments, and the severity . ##### 3.1.2.1 Classification by type of motor disorder * **Spasticity:** This is the most common type, affecting 70-80% of CP patients. Spasticity is characterized by a velocity-dependent increase in muscle tone with exaggerated tendon reflexes, resulting from damage to the upper motor neuron of the pyramidal tracts. Clinical signs include exaggerated stretch reflexes, increased tone, spastic co-contractions (dysfunctional activation of antagonist muscles), motor weakness, positive Babinski sign, and clonus. Spasticity can lead to reduced muscle growth, contractures, restricted range of motion, joint instability, dislocation, and arthritis. It varies in severity from mild to severe, impacting functional mobility to varying degrees. The diagnosis is based on the quality of movement, not just tone. Factors like room temperature, time of day, and fatigue can influence spasticity . * **Mild spasticity:** Normal resting tone, with increased tone only during difficult, selective, fast, or new activities, which dissipates upon cessation of the activity . * **Moderate spasticity:** Increased resting tone, with significant increases during exertion, excitement, or stimulation, potentially halting movement. Associated reactions and risk of contractures are present . * **Severe spasticity:** Greater proximal than distal spasticity, patients remain in mid-range, abnormal total movement patterns with limited range, difficulty initiating movements, and fear of movement due to lack of adaptation . * **Dyskinesia:** This type involves involuntary, uncontrolled, and repetitive movements, often present even at rest but absent during sleep. It is associated with lesions in the basal ganglia, leading to difficulties in initiating and stopping movements. Dyskinesia occurs in 10-15% of CP patients and can be subdivided into hyperkinesia and dystonia, with forms potentially transitioning over development . * **Hyperkinesia:** Characterized by seemingly aimless and uncontrollable movements, especially during intentional movements or posture maintenance, but also possible at rest . * **Athetosis:** Slow, involuntary movements with fixation in the end range, primarily affecting distal muscles of the extremities and the face. It involves excessive movements, overstretching, and spreading of fingers, along with slow, ineffective rotational movements of the limbs, trunk, and mouth. Athetosis is rarely isolated and often co-occurs with spasticity (in 20% of CP patients) . * **Chorea:** Involves abnormal involuntary movements that are distal, short, unrhythmic, abrupt, and irregular, appearing to shift from one body part to another. These movements are unpredictable in direction, timing, and location, making it impossible to sustain specific muscle contractions . * **Dystonia:** Slower than hyperkinetic disorders, characterized by repetitive or patterned movements, particularly massive, asymmetrical axial movements with significant tone fluctuations, especially in the trunk and proximal limb muscles. Dystonic movements manifest with changes in body position, often in response to external stimuli or emotions, and may subside during sleep or mental relaxation. It can be associated with pain, sensory disturbances, and depression . * **Ataxia:** Affecting approximately 10% of children with CP, ataxia results from cerebellar dysfunction. Key features include balance disorders, hypotonia, jerky movements when attempting to sit, poor synergy between the trunk and lower limbs, abnormal gait patterns, tremor during manipulation and grasping, and abnormal posture . #### 3.1.3 Classification by topography CP can also be classified by the affected body parts: * **Hemiparesis/hemiplegia:** Affects the arm and leg on the same side of the body . * **Diplegia:** Primarily affects the legs . * **Triplegia:** Affects three limbs . * **Quadriplegia/tetraplegia:** Affects the entire body . #### 3.1.4 Classification by severity Severity is often assessed using systems like the Gross Motor Function Classification System (GMFCS) and the Manual Ability Classification System (MACS) . #### 3.1.5 Diagnosis and prognosis of cerebral palsy Diagnosis of CP relies on clinical presentation and can be supported by cerebral ultrasound, CT scans, MRI, and EEG. When diagnosing CP, it is crucial to specify the age, type of movement disorder, unilateral/bilateral involvement, and GMFCS level. The prognosis is influenced by the severity of the lesion; more severe injuries often lead to children reaching their maximum motor capacity earlier in life. CP cannot be cured, but interventions can improve functional abilities, participation, and quality of life. Management should consider the needs of the entire family . ### 3.2 Acquired brain injury in children (NAH) Acquired brain injury (NAH) refers to brain damage from any cause other than birth-related issues, leading to an irreversible disruption in life and requiring care. It is characterized by an abrupt change in development. Rehabilitation for children with NAH is complex and ideally occurs in specialized centers, with each life stage requiring a tailored approach. NAH affects children differently than adults, with acute causes leading to chronic consequences and reduced independence . #### 3.2.1 Etiology and epidemiology of NAH The causes of NAH are broadly categorized into traumatic and non-traumatic. Traumatic injuries are the most common . ##### 3.2.1.1 Traumatic causes Traumatic causes include traffic accidents, falls, severe object impacts to the head, shaken baby syndrome, and intoxication. Shaken baby syndrome (also known as abusive head trauma) is a leading cause of fatal head injuries in children under two years old, resulting from blunt trauma, vigorous shaking, or a combination thereof, often due to caregiver frustration with crying. Approximately 30% of head traumas in children under one year are due to abuse, with accidental falls rarely causing severe injuries like bleeding or skull fractures. For children aged 2-4, falls are a common cause of TBI, while motor accidents are a significant cause in older children . ##### 3.2.1.2 Non-traumatic causes Non-traumatic causes include hypoxia/anoxia (due to cardiac arrest, near-drowning, strangulation, smoke inhalation), infections (encephalitis), cerebrovascular accidents (CVA), tumors, epilepsy, hydrocephalus, and metabolic disorders . The incidence of NAH is approximately 180 per 100,000 annually. A significant percentage are mild (76-89%), with moderate (7-10%) and severe (5-13%) injuries occurring less frequently. Twenty-five percent of those affected are younger than 15 years . #### 3.2.2 Diagnosis of NAH Indicators that help estimate prognosis include serum biomarkers (e.g., neuron-specific enolase, S100b), EEG (alpha coma and burst suppression patterns indicate severe damage), SSEP (absence indicates severe damage), and the Pediatric Glasgow Coma Scale (GCS). The GCS is a universal standard for assessing the severity of head trauma, with scores ranging from 3 (minimum) to 15 (maximum); a score of 8 or less indicates coma . #### 3.2.3 Consequences of NAH in children NAH can lead to a wide range of consequences affecting various domains: * **Consciousness:** Coma is a common consequence, with a better prognosis if it lasts 4-6 weeks and a poorer prognosis if it exceeds 6 weeks. Death can occur, and a vegetative state may persist . * **Medical consequences:** Neurological damage, including epilepsy (which may appear later in recovery and can be detected with PET scans), can occur . * **Motor functions:** High muscle tension can lead to complications such as flexion or extension spasms, joint fusion (periarticular ossification), contractures, and pathological reflexes like the ATNR . * **Sensory and perceptual functions:** Audiological disorders (30% permanent), visual impairments (visual neglect), olfactory disorders, and increased pain sensitivity are possible . * **Cognitive functions:** Post-traumatic amnesia (PTA), short-term memory issues, attention deficits (which can mask other cognitive problems), and long-term difficulties with divided attention and memory are observed . * **Psychological and psychiatric consequences:** Behavioral problems are a significant risk, occurring shortly after injury or years later, and can be persistent or progressive. These include secondary ADHD, aggression, anxiety, depression, impulsivity, personality changes (labile, disinhibited, aggressive), and frontal syndromes (apathy, suspicion, irritability, egocentrism, regression, lack of self-criticism). These can stem from brain structure damage, environmental demands, or intrapsychic processes . #### 3.2.4 Prognosis after NAH in children The prognosis after NAH in children is complex and influenced by numerous factors. While good motor recovery is possible, it can sometimes lead to an underestimation of psychological and psychiatric morbidities. Studies show a significant percentage of adult prisoners had TBI as children. Research on pediatric patients with severe TBI indicates varying outcomes, including mortality and functional recovery measured by the Glasgow Outcome Scale (GOS). The resilience of the very young brain is debated; while some plasticity exists, it is not universal, and assumptions about better recovery in younger brains are considered naive. Family empowerment and effective rehabilitation are crucial . ### 3.3 Obstetric brachial plexus injury (OPBL) Obstetric brachial plexus injury (OPBL) is a traumatic condition of the brachial plexus that occurs due to traction on the plexus during birth, leading to elongation or rupture of the plexus. The incidence ranges from 100 to 500 per 100,000 live births . #### 3.3.1 Anatomy of the brachial plexus The brachial plexus is formed by nerve roots C5 to T1, each contributing to specific functions: * C5: Shoulder function and diaphragm . * C6: Elbow flexion . * C7: Elbow extension . * C8: Wrist extension . * T1: Hand function . #### 3.3.2 Risk factors for OPBL Risk factors include birth weight greater than 4 kg or less than 3 kg, abnormal fetal positioning, instrumental vaginal delivery, and shoulder dystocia . #### 3.3.3 Classification of OPBL The severity of nerve damage can be classified using Sunderland's classification, which describes five grades at the microscopic level : * **Grade 1:** Conduction block without axonal morphological changes; recovery within days to weeks . * **Grade 2:** Axonal damage with intact endoneurium, leading to Wallerian degeneration; slow but complete recovery . * **Grade 3:** Interruption of both axon and endoneurium, with intact perineurium and epineurium; regeneration with incomplete recovery . * **Grade 4:** Only epineurium remains intact; inadequate reinnervation . * **Grade 5:** Complete interruption of the nerve or root; no spontaneous reinnervation, often requiring surgery . Common clinical presentations include: * **Erb's palsy:** Occurs in 85% of cases, involving C5 and C6 roots (sometimes C7). It results in atrophy of the upper arm and shoulder girdle muscles, with the affected arm exhibiting shoulder adduction and internal rotation, elbow extension and pronation, and wrist palmar flexion, creating a characteristic "waiter's tip" posture. The Moro reflex may be intact or not intact . * **Klumpke's palsy:** Rare as an isolated condition, affecting C7, C8, and T1 roots. It involves intrinsic hand muscles and the wrist, leading to loss of finger abduction/adduction, finger flexion/extension, and wrist dorsiflexion. The grasp reflex may be intact or not intact . * **Total brachial plexus injury:** Very rare, causing flaccid paralysis of the arm with absent reflexes. If C4 is also involved, diaphragmatic paresis can occur. Involvement of cervical sympathetic fibers can lead to Horner's syndrome . **Horner's syndrome** is characterized by dysfunction of sympathetic nerves to the pupil, upper eyelid, and sweat glands/blood vessels on one side of the face. Symptoms include enophthalmos (recession of the eyeball), blepharoptosis (drooping of the upper eyelid), miosis (pupil constriction leading to anisocoria), and anhidrosis (inability to sweat) . #### 3.3.4 Diagnosis of OPBL Diagnosis involves observing spontaneous motor activity, checking reflexes (e.g., Moro reflex, grasp reflex), and may include further investigations like EMG, SSEP, CT, and MRI to gain a more detailed understanding of the lesion's severity and localization, especially when considering surgical intervention . #### 3.3.5 Prognosis and consequences of OPBL The prognosis depends on the speed of recovery. Most cases show improvement within 3-6 months. Persistent paresis after 3 months suggests a Sunderland grade of 2 or higher. Long-term, about 70% achieve full recovery, while 30% have permanent nerve deficits. OPBL can impact the child's further development, affecting motor skills and potentially requiring interventions . --- # Diseases in children This section details two significant pediatric diseases: spina bifida and Duchenne muscular dystrophy, outlining their definitions, etiologies, clinical presentations, co-morbidities, diagnostic approaches, and management strategies. ## 4. Diseases in children ### 4.1 Spina bifida Spina bifida (SB) is a dysraphic disorder characterized by an incomplete closure of the neural tube, resulting in one or more open vertebral arches along the spine, primarily in the lumbar region. This defect occurs before the third week of conception . #### 4.1.1 Definition and normal development The term "spina bifida" originates from Greek, meaning "split spine". The normal development of the embryo involves the closure of the neural tube, which later forms the central nervous system and the vertebral column . #### 4.1.2 Epidemiology The prevalence of spina bifida is approximately 60 per 100,000 births. There has been a notable decrease in its incidence since the 1970s. The recurrence risk is 1-3% if one child has SB and 10-12% if two children have SB . #### 4.1.3 Etiology Spina bifida has a multifactorial etiology, resulting from the interplay of genetic and environmental factors. Known risk factors include the use of anti-epileptic drugs, such as valproate, during the first trimester of pregnancy, which can increase the risk 10-20 fold. Conversely, folic acid intake around the time of conception can reduce the chance of SB by 50%. The recommendation is 0.4 mg of folic acid per day starting from when contraception is stopped . #### 4.1.4 Clinical forms Spina bifida is broadly categorized into two main clinical forms: spina bifida occulta and spina bifida aperta . ##### 4.1.4.1 Spina bifida occulta * **Definition:** Also known as "hidden spina bifida," this form involves a closure defect with an intact skin covering . * **Clinical Presentation:** One or more vertebral arches are dorsally not closed, with minimal to no nerve damage. There is no visible sac (cele) at birth, and it is often discovered incidentally . * **Consequences:** This is the least severe form. It can sometimes lead to back pain later in life or tethered cord syndrome . ##### 4.1.4.2 Spina bifida aperta * **Definition:** This form involves a closure defect that results in an open skin and vertebral arches. At birth, a visible "cele" (sac) is present on the back . * **Subtypes:** * **Meningocele:** The dura mater is intact. The sac contains cerebrospinal fluid (liquor) and meninges, but the spinal cord (RM) does not protrude . * **Myelomeningocele:** The dura mater is defective. This is the most common form of SB. The spinal cord or nerves of the cauda equina protrude to the surface and are often severely damaged . * **Consequences:** * **Meningocele:** Generally has less severe consequences, though bladder problems (incontinence) and walking difficulties (clubfoot) can occur . * **Myelomeningocele:** Neurological deficits depend on the level and severity of the defect, including partial or complete motor and sensory loss, and vegetative denervation. Frequent co-morbidities include hydrocephalus (70%), orthopedic, urological, and gastrointestinal problems, and strabismus . #### 4.1.5 Co-morbidities Two significant co-morbidities associated with spina bifida are tethered cord syndrome and Chiari malformation. ##### 4.1.5.1 Tethered cord * **Definition:** This condition, also known as "tethered spinal cord," occurs when the spinal cord is abnormally attached to the inside of the vertebral column, either to scar tissue in spina bifida aperta or to fat and connective tissue in spina bifida occulta. This creates traction on the spinal cord, limiting its mobility and potentially causing blood flow disturbances that lead to further damage . * **Symptoms:** Symptoms can include back pain, spinal abnormalities (scoliosis), stiffness in the back and legs, leg weakness, sensory disturbances, walking difficulties, skin abnormalities, incontinence, and progressive neurological decline . ##### 4.1.5.2 Chiari malformation * **Definition:** This involves the caudal displacement of the cerebellar tonsils through the foramen magnum, compressing the fourth ventricle and brainstem. This compression can obstruct the outflow of cerebrospinal fluid . * **Prevalence:** Approximately 85-95% of children with SB have a Chiari malformation, often associated with hydrocephalus at birth . * **Consequences:** While often asymptomatic apart from hydrocephalus, compression of the brainstem can lead to life-threatening apnea (especially when upright), ataxia, coordination disorders, swallowing difficulties, opisthotonus, and neck pain . #### 4.1.6 Diagnosis Prenatal screening for spina bifida includes measuring alpha-fetoprotein (AFP) in maternal serum, ultrasound, and amniocentesis . #### 4.1.7 Treatment Treatment for spina bifida is multi-faceted and aims to address the primary defect and its associated complications. * **Neurosurgery:** The primary goal is to close the defect surgically within days of birth. Hydrocephalus is also managed surgically . * **Hydrocephalus Management:** Hydrocephalus is treated with shunts that drain cerebrospinal fluid from the ventricles to either the right atrium (ventriculo-cardial drainage) or the peritoneal cavity (ventriculo-peritoneal drainage). It is important to note that hydrocephalus does not always impact intellectual performance . * **Bladder Dysfunction:** About 90% of SB children are born with intact bladder and urethral innervation, but incontinence can develop in up to 35% within the first year of life. Treatment involves medication, and patients and their parents are taught intermittent catheterization (sondering). Surgical intervention for incontinence may be considered. Catheters can be transurethral or suprapubic (#page=273, 274) . * **Bowel Dysfunction:** Constipation and incontinence are common. Treatment includes regular bowel irrigation (every 1-2 days) and laxatives for incontinence . * **Spinal Orthopedic Issues:** Congenital scoliosis and kyphosis due to vertebral anomalies are treated. Scoliosis with a Cobb angle greater than 20° may be managed with a Boston brace. Surgical correction is indicated for severe progressive scoliosis or kyphosis, which can also positively impact lung function. The Cobb angle is measured on X-rays of the entire spine. Bracing, such as the Boston brace, is utilized. Surgical correction is also an option . * **Hip Orthopedic Issues:** Contractures and (sub)luxations of the hip are frequent. Unilateral (sub)luxation can lead to scoliosis and poor sitting balance. Surgery is considered only if there is a positive prognosis for walking . * **Ankle and Foot Orthopedic Issues:** Clubfoot is treated with plaster cast reduction. If no improvement is seen after 12 weeks, surgical lengthening of the Achilles tendon may be performed, followed by further casting or bracing . ### 4.2 Duchenne muscular dystrophy (DMD) Duchenne muscular dystrophy (DMD) is a progressive degenerative disorder of skeletal muscle tissue. It is the most common subtype of muscular dystrophy . #### 4.2.1 Definition Duchenne muscular dystrophy is also known as pseudohypertrophic muscular dystrophy. It is an X-linked recessive inherited disorder, meaning it primarily affects males. Spontaneous mutations account for approximately 30% of cases. The incidence is about 1 in 5000 live male births. Symptoms typically begin between 2 and 3 years of age . #### 4.2.2 Cause DMD is caused by a mutation in the dystrophin gene. This gene is responsible for producing dystrophin, a membrane protein found in striated and cardiac muscle fibers. The mutation leads to the absence of dystrophin in the muscles. Approximately 70% of mutations are inherited from a carrier mother, while 30% are de novo mutations . #### 4.2.3 Pathophysiology The deficiency of dystrophin leads to the degeneration and necrosis of muscle cells. Skeletal muscle fibers are gradually replaced by fat cells and fibrous connective tissue, resulting in a hypertrophied appearance of the skeletal muscle and a progressive loss of muscle function. Cardiomyopathy is also a common associated condition . > **Tip:** The characteristic "pseudohypertrophy" refers to the enlarged appearance of calf muscles, which is due to the replacement of muscle tissue with fat and connective tissue, not actual muscle growth . #### 4.2.4 Symptoms Symptoms include proximal muscle weakness, which later becomes distal. This results in : * Weakening of motor functions, particularly around the pelvic girdle, leading to an unsteady gait, difficulty climbing stairs, and problems maintaining an upright posture . * Gower's maneuver is a classic sign demonstrating this weakness (#page=293, 294) . * Weakness also affects the shoulder girdle . * Diminished tendon reflexes . * Spinal malformations like scoliosis and multiple fractures . * Respiratory insufficiency and lung infections . * Cardiac problems (affecting 80% of patients) . * Mental retardation (affecting 50% of patients) . #### 4.2.5 Course and Prognosis There may be a slight improvement in muscle weakness between ages 3 and 6. By around age 10, individuals typically become wheelchair-bound. Around age 20, nocturnal ventilation may be required, progressing to 24-hour ventilation, potentially necessitating a tracheostomy. The life expectancy is such that 50% of individuals reach 30 years of age. The primary causes of death are respiratory or heart failure. Survival rates have improved with mechanical ventilation. Tracheostomies can impact speech, often requiring speaking valves, and may present initial swallowing difficulties that can be managed with speech therapy . #### 4.2.6 Diagnosis Diagnostic tests for DMD include: * **Prenatal:** Chorionic villus sampling at week 12 or amniocentesis at week 16, followed by a DNA test to detect genetic abnormalities. NIPT is not used for this diagnosis . * **Postnatal:** Clinical presentation, elevated creatine kinase (CK) levels, electromyography (EMG), and muscle biopsy . #### 4.2.7 Treatment There is no specific curative treatment for Duchenne muscular dystrophy. The goals of management are to maintain motor functions, prevent secondary complications, and provide respiratory rehabilitation. Occupational therapists play a significant role in care . --- ## Common mistakes to avoid - Review all topics thoroughly before exams - Pay attention to formulas and key definitions - Practice with examples provided in each section - Don't memorize without understanding the underlying concepts

| Term | Definition | |------|------------| | Pediatrics | The medical specialty dedicated to the care of children, encompassing curative, preventive, and ethical aspects from birth to young adulthood. | | Neonate | A newborn infant from day 1 to day 28 postnatally. | | Infant | A child from day 1 up to 364 days postnatally. | | Toddler | A child between 18 months and 3 years of age. | | Preschooler | A child between 3 years and 6 years of age. | | Child | A person between 6 and 12 years of age. | | Adolescent | A young person between 12 and 18 years of age. | | Congenital disorders | Conditions that are present from birth, either due to genetic factors or developmental issues during gestation. | | Gestation | The period of development of a child in the womb from conception to birth. | | Fertilization | The fusion of a sperm and an egg cell (oocyte) to form a zygote, marking the beginning of a new individual. | | Zygote | The initial cell formed when two gamete cells (sperm and egg) are fertilized. | | Blastocyst | A structure formed in the early development of mammals prior to implantation, consisting of a hollow ball of cells. | | Implantation | The process by which the blastocyst attaches to the wall of the uterus (endometrium) and begins to develop. | | Embryonic development | The phase of development from fertilization until the end of the eighth week, characterized by rapid cell differentiation and organ formation. | | Organogenesis | The process of organ formation during embryonic development. | | Fetal development | The phase of development from the ninth week until birth, characterized by the growth and maturation of organs and systems. | | NIPT (Non-invasive prenatal test) | A screening test performed on the mother's blood during pregnancy to detect chromosomal abnormalities in the fetus, such as Down syndrome. | | Premature | A baby born before 37 weeks of gestation. | | À terme neonate | A baby born between 37 and 42 weeks of gestation. | | Postmature neonate | A baby born after 42 weeks of gestation. | | Neural plate | A thickened region of the ectoderm that forms in the early embryo and gives rise to the neural tube and the central nervous system. | | Neural groove | A depression that forms in the neural plate during embryonic development, which will eventually close to form the neural tube. | | Neural tube | An embryonic structure that develops into the brain and spinal cord. | | Cranial | Relating to the head or skull. | | Caudal | Relating to the tail or posterior part of the body. | | Reflex | An immediate, involuntary reaction of the body to a stimulus, typically mediated by a reflex arc. | | Baby reaction | An innate, age-dependent behavior in infants that typically diminishes with neurological maturation. | | Stimulus | An agent, action, or condition that causes a response in an organism. | | Response | The reaction of an organism to a stimulus. | | Vestibule | The part of the inner ear responsible for balance and spatial orientation. | | Proprioception | The sense of the relative position of one's own parts of the body and strength of effort, which is being used in movement. | | Extensor | A muscle that straightens a limb or other part. | | Abductor | A muscle that moves a limb or part away from the midline of the body. | | Flexor | A muscle that bends a limb or other part. | | Adductor | A muscle that moves a limb or part toward the midline of the body. | | Moro reaction | A primitive reflex in infants characterized by sudden extension and abduction of the arms and legs in response to a startle stimulus, followed by flexion and adduction. | | Persistent Moro reflex | A Moro reflex that continues beyond the typical age of disappearance, potentially indicating neurological or sensory processing issues. | | Upper motor neuron (UMN) | Neurons that originate in the cerebral cortex and brainstem and carry motor commands to the spinal cord. | | Piramidal pathways | Motor pathways that originate in the cerebral cortex and descend through the brainstem and spinal cord, controlling voluntary movements. | | Spasticity | A motor disorder characterized by increased muscle tone and exaggerated reflexes, caused by damage to the upper motor neurons. | | Hypertonia | Increased muscle tone. | | Pathological reflexes | Reflexes that are abnormal or exaggerated, often indicating neurological damage. | | Babinski sign | A reflex in which the great toe extends upward and the other toes fan out when the sole of the foot is stroked firmly. | | Clonus | A series of involuntary, rhythmic muscle contractions that occur in response to a sustained stretch. | | Contracture | A condition of fixed, abnormal position of a joint. | | Range of motion | The full movement potential of a joint. | | Subluxation | A partial dislocation of a joint. | | Dislocation | Displacement of a bone from its normal position in a joint. | | Arthrosis | Joint inflammation or degeneration. | | Diplegia | Paralysis affecting symmetrical parts of the body, typically the legs more than the arms. | | Hemiplegia | Paralysis of one side of the body. | | Quadriplegia | Paralysis of all four limbs. | | Dyskinesia | Involuntary, abnormal movements that affect a person's ability to control their muscles. | | Basal ganglia | A group of subcortical nuclei in the forebrain that play a role in motor control, learning, and emotion. | | Hyperkinesia | Excessive, involuntary movements, often characterized by rapid, jerky motions. | | Athetosis | A movement disorder characterized by slow, writhing, involuntary movements, typically affecting the limbs and face. | | Chorea | A movement disorder characterized by involuntary, rapid, jerky movements that can appear dance-like. | | Dystonia | A movement disorder characterized by sustained muscle contractions that cause abnormal postures and repetitive movements. | | Ataxia | A neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and problems with eye movements. | | Cerebellum | A part of the brain located at the back of the skull, beneath the cerebrum, that coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity. | | Gross Motor Function Classification System (GMFCS) | A system used to classify the severity of motor dysfunction in children with cerebral palsy. | | Manual Ability Classification System (MACS) | A system used to classify the functional abilities of the hands in children with cerebral palsy. | | Prognosis | The likely course or outcome of a disease or condition. | | Acquired Brain Injury (ABI) | Brain damage that occurs after birth, caused by external forces or illness. | | Traumatic Brain Injury (TBI) | Brain damage caused by a direct blow to the head or violent shaking of the body. | | Hypoxia/Anoxia | A condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level. | | Encephalitis | Inflammation of the brain. | | Cerebrovascular Accident (CVA) | A stroke, caused by interruption of blood flow to the brain. | | Intracranial hemorrhage | Bleeding within the skull. | | Shaken Baby Syndrome (SBS) | A form of abusive head trauma in infants caused by violent shaking. | | Pediatric Glasgow Coma Scale (PGCS) | A standardized tool used to assess the level of consciousness in children after a brain injury. | | Vegetative state | A condition in which a person is awake but shows no signs of awareness. | | Post-traumatic epilepsy | Epilepsy that develops after a traumatic brain injury. | | Audiological disorders | Problems with hearing. | | Visual neglect | A neurological disorder in which a person is unable to process or attend to stimuli on one side of their visual field. | | Reukstoornis | A disorder of the sense of smell. | | Cognitive functions | Mental processes such as thinking, remembering, learning, and problem-solving. | | PTA (Post-traumatic amnesia) | A period of memory loss and confusion following a traumatic brain injury. | | ADHD (Attention-Deficit/Hyperactivity Disorder) | A neurodevelopmental disorder characterized by persistent patterns of inattention and/or hyperactivity-impulsivity that interfere with functioning or development. | | Frontal syndrome | A pattern of cognitive and behavioral deficits resulting from damage to the frontal lobes of the brain. | | Obstetric Brachial Plexus Lesion (OBPL) | Nerve damage to the brachial plexus that occurs during childbirth, usually due to excessive stretching of the baby's head and neck during delivery. | | Brachial plexus | A network of nerves in the shoulder that carries messages from the spinal cord to the shoulder and arm. | | Erb's palsy | A type of OBPL affecting the upper shoulder and arm, caused by damage to nerves C5 and C6 of the brachial plexus. | | Klumpke's palsy | A type of OBPL affecting the lower arm and hand, caused by damage to nerves C7, C8, and T1 of the brachial plexus. | | Horner's syndrome | A condition characterized by ptosis (drooping eyelid), miosis (constricted pupil), and anhidrosis (decreased sweating) on one side of the face, caused by damage to the sympathetic nerves. | | Ptosis | Drooping of the upper eyelid. | | Miosis | Constriction of the pupil. | | Anhidrosis | The inability to sweat normally. | | Electromyography (EMG) | A diagnostic test that measures the electrical activity of muscles. | | Somatosensory evoked potentials (SSEP) | A diagnostic test that measures the brain's response to sensory stimulation. | | Spina Bifida (SB) | A birth defect in which the spinal cord does not close properly. | | Neural tube defects | Birth defects that affect the brain and spinal cord, such as spina bifida and anencephaly. | | Spina bifida occulta | A mild form of spina bifida in which there is a small gap in the spine but no opening or sac on the outside. | | Spina bifida aperta | A more severe form of spina bifida in which there is an opening in the spine and the spinal cord may protrude through the opening. | | Meningocele | A type of spina bifida aperta in which the meninges (membranes surrounding the brain and spinal cord) protrude through the opening in the spine, but the spinal cord itself does not. | | Myelomeningocele | The most severe form of spina bifida aperta, in which both the meninges and the spinal cord protrude through the opening in the spine. | | Tethered cord syndrome | A neurological disorder caused by tissue attachments that limit the movement of the spinal cord in the spinal canal. | | Chiari malformation | A condition in which brain tissue extends into the spinal canal, often due to a defect in the skull. | | Hydrocephalus | A condition characterized by an abnormal accumulation of cerebrospinal fluid in the ventricles of the brain. | | Shunt | A medical device used to drain excess fluid from the body, such as cerebrospinal fluid from the brain. | | Ventriculo-peritoneal (VP) shunt | A shunt that drains cerebrospinal fluid from the ventricles of the brain to the peritoneal cavity. | | Ventriculo-atrial (VA) shunt | A shunt that drains cerebrospinal fluid from the ventricles of the brain to the right atrium of the heart. | | Sonde | A thin tube used to drain fluid from the body, such as urine from the bladder. | | Muscular dystrophy | A group of genetic diseases that cause progressive weakness and loss of muscle mass. | | Duchenne muscular dystrophy (DMD) | A severe form of muscular dystrophy that primarily affects boys, characterized by progressive muscle degeneration and weakness. | | Dystrophin | A protein that is essential for maintaining the structure and function of muscle fibers. | | Creatine kinase (CK) | An enzyme found in muscle tissue that is released into the bloodstream when muscle is damaged. | | Muscle biopsy | A surgical procedure to obtain a sample of muscle tissue for examination. | | Tracheostomy | A surgical opening made in the neck into the windpipe (trachea) to allow breathing. | | Speech valve | A device that attaches to a tracheostomy tube to allow for speech. |