Predisposition is easily aggravated by any of the following: poor motility of the digestive tract, retroperitional tumors, loss of appetite, malabsorption, cachexia, exaggerated lumbar lordosis, visceroptosis, abdominal wall laxity, peritoneal adhesions, abdominal trauma, rapid linear adolescent growth spurt, weight loss, starvation, catabolic states (as with cancer and burns), and history of neurological injury.The acute form of SMA syndrome develops rapidly after traumatic incidents that forcibly hyper-extend the SMA across the duodenum, inducing the obstruction, or sudden weight loss for any reason. Causes include prolonged supine bed rest, scoliosis surgery, left nephrectomy, ileo-anal pouch surgery.SMA syndrome is usually difficult to differentiate with anorexia nervosa. Patients with SMA syndrome can be hindered restoring weight in those with anorexia nervosa. Diagnosis
Diagnosis is very difficult, and usually one of exclusion. SMA syndrome is thus considered only after patients have undergone an extensive evaluation of their gastrointestinal tract including upper endoscopy, and evaluation for various malabsorptive, ulcerative and inflammatory intestinal conditions with a higher diagnostic frequency. Diagnosis may follow X-ray examination revealing duodenal dilation followed by abrupt constriction proximal to the overlying SMA, as well as a delay in transit of four to six hours through the gastroduodenal region. Standard diagnostic exams include abdominal and pelvic computed tomography (CT) scan with oral and IV contrast, upper gastrointestinal series (UGI), and, for equivocal cases, hypotonic duodenography.
According to the doctors in one of these studies, the expected outcome for SMA syndrome treatment is generally considered to be excellent. Epidemiology
According to a 1956 study, only 0.3% of patients referred for an upper-gastrointestinal-tract barium studies fit this diagnosis, and is thus a rare disease. Recognition of SMA syndrome as a distinct clinical entity is controversial, due in part to its possible confusion with a number of other conditions, though it is now widely acknowledged. However, unfamiliarity with this condition in the medical community coupled with its intermittent and nonspecific symptomatology probably results in its underdiagnosis.As the syndrome involves a lack of essential fat, more than half of those diagnosed are underweight, sometimes to the point of sickliness and emaciation. Females are impacted more often than males, and while the syndrome can occur at any age, it is most frequently diagnosed in early adulthood. The most common co-morbid conditions include mental and behavioral disorders including eating disorders and depression, infectious diseases including tuberculosis and acute gastroenteritis, and nervous system diseases including muscular dystrophy, Parkinsons disease, and cerebral palsy. History
SMA syndrome was first described in 1861 by Carl Freiherr von Rokitansky in victims at autopsy, but remained pathologically undefined until 1927 when Wilkie published the first comprehensive series of 75 patients. Society and culture
American actor, director, producer, and writer Christopher Reeve had the acute form of SMA syndrome as a result of spinal cord injury. Non-profit
In 2017 the only US non-profit began distributing grants to those with SMAS.