10.4 Pediatric Neurology, Nephrology & Musculoskeletal Disorders

Pediatric Neurology, Nephrology & Musculoskeletal Disorders

The SMLE Pediatrics domain includes dedicated subsections on the central nervous system, nephrology, and the musculoskeletal system. High-yield content covers seizure disorders, neuromuscular weakness, glomerular and nephrotic disease, and inflammatory joint and bone conditions. Saudi-relevant considerations (consanguinity and autosomal recessive neurometabolic disease, post-streptococcal glomerulonephritis, and Kawasaki disease) appear frequently.

Pediatric Neurology

Seizure Disorders

• Febrile seizures occur in children 6 months–5 years with fever and no CNS infection. Simple febrile seizures are generalized, last <15 minutes, and do not recur within 24 hours; management is supportive with antipyretics — antiepileptics are not routinely indicated. Complex febrile seizures (>15 min, focal, or recurrent within 24 h) carry a higher risk of later epilepsy.
• Epilepsy is recurrent unprovoked seizures. First-line for focal seizures is carbamazepine or levetiracetam; for absence seizures, ethosuximide or valproate.
• Status epilepticus: a seizure lasting ≥5 minutes or recurrent seizures without recovery between them. First-line is IV lorazepam (or rectal diazepam), repeated once if needed, followed by a loading dose of fosphenytoin; simultaneously identify and treat the precipitant (fever, non-adherence, metabolic derangement, CNS infection).

Cerebral Palsy

• A non-progressive motor disorder from a static brain lesion acquired before age 2; spastic diplegia is associated with premature birth (periventricular leukomalacia). The SMLE trap: a child with early hypotonia that later progresses to hypertonia/spasticity — distinguish this static picture from a progressive neurodegenerative disorder.

Guillain-Barré Syndrome (GBS)

• Acute ascending symmetric flaccid paralysis with areflexia, often following a Campylobacter jejuni diarrheal illness. Diagnosis is clinical, supported by albuminocytologic dissociation on CSF (elevated protein, normal cell count). Treatment is IV immunoglobulin (IVIG) or plasmapheresis; monitor respiratory function with serial forced vital capacity.

Myasthenia Gravis

• Fatigable weakness with ocular onset (ptosis, diplopia); acetylcholine-receptor antibodies. The ice pack test is a bedside aid. Treat with pyridostigmine ± thymectomy.

Pediatric Nephrology

Nephrotic vs Nephritic Syndromes

• Minimal change disease: the most common nephrotic syndrome in children (peak 2–6 years); normal light microscopy with foot-process effacement on electron microscopy; responds to corticosteroids.
• Post-streptococcal glomerulonephritis (PSGN): 1–2 weeks after group A strep pharyngitis (or 3–6 weeks after strep pyoderma). Presents with hematuria (cola-colored urine), edema, hypertension, and low C3. Management is supportive; confirm with elevated antistreptolysin O (ASO) and anti-DNase B. Immunocompromise is not usually required.

Enuresis & Vesicoureteral Reflux

• Enuresis: repeated involuntary voiding in a child ≥5 years. For monosymptomatic nocturnal enuresis, first-line is behavioral — the bedwetting alarm; desmopressin is the pharmacologic option for short-term use (e.g., sleepovers), with attention to fluid restriction to avoid hyponatremia.
• Vesicoureteral reflux (VUR): the most common cause of recurrent childhood UTI and a recognized risk for renal scarring and hypertension. Low-grade reflux is managed with continuous prophylactic antibiotics and surveillance ultrasound; high-grade reflux or recurrent pyelonephritis warrants surgical reimplantation.

Pediatric Musculoskeletal

Kawasaki Disease

• A medium-vessel vasculitis in children <5 years. Diagnostic criteria: fever ≥5 days plus ≥4 of 5: bilateral non-exudative conjunctivitis, polymorphous rash, strawberry tongue/cracked lips, erythema and swelling of extremities (later desquamation), and cervical lymphadenopathy ≥1.5 cm.
• Coronary artery aneurysms are the major complication; echocardiography is mandatory.
• Treatment: IVIG + high-dose aspirin; low-dose aspirin continues until coronary arteries normalize.

Juvenile Idiopathic Arthritis (JIA)

• Arthritis persisting ≥6 weeks in a child <16 years with other causes excluded. Systemic JIA presents with quotidian fever, salmon-pink rash, and arthritis. Oligoarticular JIA is the most common subtype and carries the highest antinuclear antibody (ANA) and uveitis risk — mandatory slit-lamp screening.

Osteomyelitis & Septic Arthritis

• A child with acute refusal to bear weight or move a limb raises concern for septic arthritis of the hip. The Kocher criteria (fever, ESR >40, WBC >12,000, inability to bear weight) stratify risk; high-probability hips require urgent ultrasound and surgical washout. Staphylococcus aureus is the most common organism across all ages.

Orthopedic Conditions of Childhood

• Developmental dysplasia of the hip (DDH): risk factors are female sex, breech presentation, firstborn, and oligohydramnios. Neonates are screened with the Barlow (dislocatable) and Ortolani (reducible) maneuvers; confirmed DDH is treated with a Pavlik harness in early infancy.
• Legg-Calvé-Perthes disease: idiopathic avascular necrosis of the femoral head in children 4–8 years, presenting with a painless limp and limited hip abduction.
• Slipped capital femoral epiphysis (SCFE): displacement through the proximal femoral physis in overweight early adolescents (10–16 years); presents with hip or referred knee pain and external rotation — managed with urgent in situ pinning to prevent avascular necrosis.
• Osgood-Schlatter disease: traction apophysitis of the tibial tuberosity in active adolescents; managed with activity modification, ice, and short courses of NSAIDs.