Nelson Textbook of Pediatrics 22nd Edition — Essential tables for diagnosis: Major causes (Table 648.9), clinical history clues (Table 648.10), and laboratory evaluation (Table 648.11). Arthrogryposis = multiple congenital contractures due to fetal akinesia.
🌐 paeds.online — Pakistan's Pediatric PlatformArthrogryposis results from fetal akinesia/hypokinesia. Etiologies span the entire neuromuscular axis from brain to muscle, as well as connective tissue and mechanical restriction.
| SITE OF MAJOR PATHOLOGIC FINDINGS | DISORDERS |
|---|---|
| Cerebrum-brainstem | Microcephaly; migrational disorders (lissencephaly-pachygyria, Zellweger syndrome, schizencephaly, polymicrogyria, agenesis of corpus callosum); fetal alcohol syndrome; cytomegalovirus infection; pontocerebellar hypoplasia type I; dentato-olivary dysplasia; leptomeningeal angiomatosis; encephaloclastic processes; hydrocephalus |
| Anterior horn cell | Developmental agenesis-hypoplasia-dysgenesis (amyoplasia congenita); destructive disorders (apparent intrauterine ischemic events); degenerative disorders (severe Werdnig-Hoffmann disease [SMA type 0 or IA], lethal congenital contracture syndrome, spinal muscular atrophy with pontocerebellar hypoplasia, spinal muscular atrophy with respiratory distress, X-linked infantile spinal muscular atrophy, early-onset non-5q spinal muscular atrophy); Möbius syndrome; cervical spinal atrophy; lumbar spinal atrophy; lumbosacral meningomyelocele; sacral agenesis; other |
| Peripheral nerve or root | Hypomyelinating polyneuropathy; axonal polyneuropathy; neurofibromatosis |
| Neuromuscular junction | Infant of myasthenic mother; congenital myasthenic syndromes; multiple pterygium syndrome (Escobar type); infant of mother with multiple sclerosis (?) |
| Muscle | Congenital muscular dystrophy (merosin-positive and merosin-negative); congenital myotonic dystrophy; myotubular myopathy; central core disease; nemaline myopathy; congenital myopathy due to sodium channel gene variant; congenital polymyositis; congenital fiber-type disproportion; glycogen storage myopathy (muscle phosphorylase deficiency, phosphofructokinase deficiency); mitochondrial myopathy; Freeman-Sheldon syndrome |
| Primary disorder of joint or connective tissue | Marfan syndrome; contractual arachnodactyly; other disorders of connective tissue; intrauterine periarticular inflammation |
| Intrauterine mechanical obstruction | Uterine abnormality; amniotic bands; oligohydramnios; twin pregnancy; extrauterine pregnancy |
A thorough history can reveal the underlying etiology. Key areas: pregnancy, delivery, family history, and maternal health (myotonic dystrophy, myasthenia gravis).
| CATEGORY | SPECIFIC CLUES |
|---|---|
| Pregnancy | • Maternal illness, acute or chronic (diabetes, myasthenia gravis, myotonic dystrophy, etc.) • Infections (rubella, rubella, zika virus, coxsackievirus, enterovirus, Akabane virus, etc.) • Fever (>39°C, determine timing in gestation) • Nausea (viral encephalitis, position of baby, etc.) • Drugs (curare, Robaxin, alcohol, phenytoin, addictive drugs, misoprostol, etc.) • Fetal movement (polyhydramnios, fetal kicking in one place, rolling decreased) • Oligohydramnios, chronic leakage of amniotic fluid • Polyhydramnios, hydrops • Trauma during pregnancy (blow to the abdomen, attempted termination, car accident, etc.) • Other complications (bleeding, abnormal lie, threatened abortion) • Prenatal diagnosis (early amniocentesis, ultrasound studies, etc.) |
| Delivery history | • Presentation (breech, transverse, etc.) • Length of gestation • Traumatic delivery (limb, CNS, fracture, etc.) • Intrauterine mass (twin, fibroid, etc.) • Abnormal uterine structure or shape • Abnormal placenta, membranes, or cord length or position • Time of year, geographic location |
| Family history | • Marked variability within family • Change with time (degeneration vs improvement) • Increased incidence of congenital contractures in second- and third-degree relatives • Hyperextensibility or hypotonia present in family member • Rule out myotonic dystrophy, myasthenia gravis in parents (particularly mother) • Consanguinity • Advanced parental (mother or father) age • Increased stillbirths or miscarriages • If more than one consecutively affected child, consider maternal antibodies to fetal neurotransmitters |
No single test is diagnostic. Individualized approach based on clinical presentation. Includes imaging, electrophysiology, muscle biopsy, genetics, and metabolic screening.
| EVALUATION | DETAILS / INDICATIONS |
|---|---|
| Documentation | Range of motion and position with photographs |
| Radiographs | If bony anomalies (gracile, fusions, extra or missing carpals and tarsals, etc.), disproportionate, scoliosis, ankylosis, dislocation (hips, radial head, patella, etc.) |
| MRI | To evaluate CNS (brain and spinal cord) and muscle mass obscured by contractures |
| Ultrasonography | CNS (brain and spinal cord) or other anomalies, and to establish potential muscle tissue |
| Chromosome studies / CGH array | If multiple system involvement, CNS abnormality (eye, microcephaly, ID, lethargy, degenerative course), streaky or segmental involvement. Consider fibroblast studies if lymphocytes normal and patient has ID with no diagnosis. |
| DNA gene testing | If condition fits a known disorder for which gene testing is available. Consider next-generation sequencing (targeted gene panels, whole-exome sequencing, whole-genome sequencing) if family available. |
| Video of movement | Including facial, range of movement, strength — repeat at regular intervals |
| Viral culture / serology | As appropriate and specific antibodies or IgM levels in newborn |
| Muscle biopsy | In normal and affected areas at time of surgery to distinguish myopathic forms from neuropathic forms (special histopathology and electron microscopy). If elevated CK or unusual muscle response, consider earlier, examine mitochondria. |
| EMG | In normal and affected area |
| Nerve conduction studies | In normal and affected area |
| Creatine kinase (CK) | If generalized weakness, doughy or decreased muscle mass, progressive course |
| Eye examination | Opacities, retinal degeneration, etc. |
| Maternal antibodies | To neurotransmitters, if myasthenia gravis or recurrent affected pregnancies without diagnosis |
| SMA DNA testing | According to clinical features |
| Mitochondrial DNA analysis | If indicated |
| Metabolic screening | Urine organic acids, plasma amino acids, acylcarnitine profile |