Although episodic hyperphagia, food foraging, and stealing of food may lead to gastric dilatation, the etiology of the gastric perforation and necrosis is still speculative. Acute gastric dilation and its complications, including stomach rupture, have been associated with anorexia nervosa, binge eating disorder, bulimia, acute pancreatitis, and gastric hemorrhage (8
). Wharton et al. reported six individuals with PWS who had gastric dilatation, two of whom died (6
). They suggested that the associated necrosis was due to acute gastric dilatation after polyphagia (6
). In addition, our series suggest that people with PWS are at significant risk of gastric perforation and necrosis. Particularly salient is the observation that gastric perforation/necrosis was the cause of mortality in 3% to 6% of subjects in the cohort of individuals who died who are known to the Prader-Willi Syndrome Association (USA). It is, however, possible that families of individuals with unusual causes of death could be more likely to contact the bereavement program introducing a potential bias.
Approximately a third of individuals with PWS have a weight greater than 200% of their ideal body weight (9
). The majority of individuals in this study were relatively non-obese compared to what is generally observed in PWS, or had a history of prior weight loss. Previously, Wharton et al. reported that three individuals with PWS with gastric dilatation and necrosis had gradually lost more than 45 kg at an average rate of 1 kg/week after strict dietary programs, and they suggested that alteration in stomach muscle integrity from weight loss may have been a predisposing factor (6
). Hence, individuals with PWS with recent weight loss or with a more ideal body weight may be at greater risk for gastric dilatation and perforation. With the advancement of nutritional strategies, group home programs, and growth hormone therapy, individuals with PWS may be more likely to maintain a more ideal body weight, although the underlying pathology leading to consumption of large quantities of food in a short period of time continues to persist. This may predispose subjects with PWS, particularly those with recent weight loss or absence of obesity, to gastric dilatation and perforation, necessitating wider awareness by medical care providers of this potential complication.
A high threshold for vomiting has been associated with PWS (4
), and data from the 54 familial-response questionnaires in our cohort subjectively reported decreased vomiting during viral illnesses in 78% of respondents. Attempts to induce vomiting in individuals with PWS were reported as unsuccessful in 64% in one study (11
). The finding of vomiting in the subjects with PWS who presented with gastric perforation and necrosis suggests that vomiting in PWS is a sign of serious underlying pathology.
Decreased sensitivity to pain has also been reported anecdotally in PWS and was a common parental response in our cohort (91%). The complaint of abdominal pain should be considered a further sign for potential gastric perforation. Several family members reported that they thought the occurrence of abdominal pain was extremely unusual, but felt that their concerns were ignored by their physicians as the complaints of abdominal pain were minimal in people with PWS compared to the general population. We think that the presence of abdominal pain and/or vomiting in individuals with PWS likely warrants an abdominal radiograph looking for evidence of perforation and monitoring in an inpatient facility or rapid treatment unit.
Avoiding episodes of binge eating is likely problematic in PWS due to their history of hyperphagia. Of major concern are changes in routine that may expose individuals with PWS to large quantities of food in new environments or in the presence of unusual food sources (e.g., holiday parties). For example, one individual in our study had a binging episode during a holiday event, suggesting that close supervision during special occasions (e.g., birthday parties) is important to avoid these episodes.
It is important for physicians working in emergency departments to be aware of this phenomenon in PWS in order to avoid the mistaken diagnosis of viral gastroenteritis, as they are likely to be the first physicians to encounter individuals with PWS with an impending gastric perforation. Reports of a binging episode in an individual with PWS with recent weight loss and a relatively normal body weight should alert the physician to an alternative diagnosis. In particular, vomiting and abdominal pain are signs that deserve rapid attention regardless of the intensity of complaint in this subject population in hopes of avoiding morbidity and mortality.