Arthrogryposis Multiplex Congenita (AMC)

1. Advocate Christ Medical Center Inspiring medicine, Changing lives AMC may be caused by neurological and non-neurological causes. An example of a neurological type of AMC include: Amyoplasia Congenita. • Characteristics Amyoplasia Congenita: • Fatty- and fibrous- tissue replacement of limb muscles2. • Muscle mass of the limbs have atrophied appearance4. • Usually symmetric, involving all 4 extremities 84% of the time. • Some patients only have isolated upper 11%, or lower 5%, extremity involvement 5. • Upper limbs tend to have internally rotated shoulders, extended elbows, and flexed wrists, creating the so called "policeman tip"4. • Knees fixed and often dislocated. • Feet are often in an equinovarus position. • 11.6% of children have anomalies such as gastroschisis, bowel atresia & abdominal wall defects. • Facial features: a midface capillary hemangioma, a round face, short upturned nostrils, and micrognathia. • No inheritance pattern. Thought to be sporadic2. Amyloplasia Congenita: A Rare Case with an Optimistic Outlook Nancy H. Youssef M.D., Jared Terronez M.D., Rujuta R. Gandhi M.D. Advocate Christ Family Medicine Residency Program INTRODUCTION CASE cont. OUTCOME DISCUSSION cont. • Arthrogryposis Multiplex Congenita (AMC) • Syndrome diagnosed when 2 or more joints in more than one limb are fixed from birth • Occurrence rate of 1 in 3,000 births. • Pathogenesis is unknown • May be caused by neurological and non-neurological causes. Amyoplasia Congenita: • Most common type of AMC • Occurrence rate of 1 in 10,000 live births • Poor prognosis unless identified correctly & early therapy initiated. • Therapy: • Infant undergoes continuous stretching and fitted bracing of upper extremities to improve position of wrists and hands. • Contracture release maneuvers taught to mom. • The child's prognosis is very good. • At 4 month well child visit, infant exhibited spontaneous movement of her arms from the shoulder joints bilaterally. • Work up for Amyoplasia Congenita: • Important to rule out other AMC associated disorders. • Chromosomal blood work. • Full body X-ray to R/O spinal dysraphism & congenital hip dislocation. • Head & abdominal ultrasounds to R/O anomalies. • MRI of the brain & spinal cord3. • EEG, muscle biopsy, EMG & nerve conduction studies3 can help assess severity of the Amyoplasia Congenita. Treatment of Amyoplasia Congenita: • Increase movements to decrease stiffness. • Aggressive physical and occupational therapy beginning shortly after birth are key to good outcomes4. DISCUSSION CASE • Prenatal Care: • 23 year old femaleG1P0 with no previous OB history and no PMH. • Denied all genetic disorders in herself, her family, and in the father of the baby. • Ultrasound: appeared to be farther along in her pregnancy than expected. • Prenatal labs & Quad screen were normal, but not accurately interpreted due to incorrect gestational age. • Noted that the child kicked mainly in the right upper quadrant during her pregnancy • Had a vertical/oblique lie. • Quickening not accurately recorded due to the late start of prenatal care. Delivery: • NSVD at 37 3/7 WGA. • Birth weight: 5lbs and 4 oz • APGAR scores of 91 and 95. • On exam immediately following delivery, infant was found to have bilateral elbow extension contractures, bilateral wrist flexion contractures and atrophy of the shoulder girdle. X-ray and Physical Features of Amyoplasia Congenita: The child's appearance and her x-ray on 2nd day of life show clearly that there is no muscle development or contour of the muscles in the upper extremities. The bones appear normal. The shoulders appear medially rotated, the forearm is pronated, wrists are flexed with ulnar deviation and fingers flexed. CONCLUSION • Important that if AMC is suspected a full work up is done to rule out serious types. • The baby's future is bright! She may find compensatory ways to use her upper extremities. MANAGEMENT ACKNOWLEDGMENTS • Work Up: • 2-D echo was normal for age. • Ultrasound of the head was unremarkable. • Bone x-ray: - the spine and pelvis were unremarkable. - both hands flexed at the wrist - delineation of the feet is limited. Diagnosis of Amyoplasia Congenita: • Made by physical exam findings • Confirmed by the genetics team. Physical therapy and occupational therapy consulted to begin management and therapy of contractures. We would like to thank the parents of our patient for permission to photograph their child and share this case. REFERENCES 1. Alfonso I, Papazian O, Paez JC, Grossman J. Review Article: Arthrogryposis Multiplex Congenita. International Pediatrics. 2000; 15: 197-204 2. Sells JM, Jaffe KM, Hall JG. Amyoplasia, the most common type of arthrogryposis: the potential for good outcome. Pediatric. 1996; 97: 225-231 3. O'Flahery P. Arthrogryposis Multiplex Congenita. Neonatal Network. 2001; 20:13-20 4. Kulayat N, Narchi H, Tunnessen W. Picture of the Month. Arch Pediatr Adolesc Med 2001; 155: 407-08 5. Hall JG, Reed SD, Driscoll EP. Amyoplasia: a common sporadic condition with Congenital contractures. Am J Med Genet.1983: 15: 571-590 6. Lee HS. Amyoplasia Congenita of the Lower Extermity: Report in a premature baby. Yonesi Medical Journal 2005; 46:567-570