Intestinal pseudo-obstruction in mitochondrial diseases

we retrospectively analyzed the clinical and radiological features of the symptomatic individuals harboring the m.3243A>G mutation investigated in our neuromuscular center between 1 January 2011 and 30 May 2016. All patients were classified according to the clinical phenotypes in mitochondrial encephalomyopathy, lactic acidosis, and stroke like episode syndrome (MELAS; n 5 10), maternally inherited diabetes and deafness (n 5 10), chronic progressive external ophthalmoplegia (n 5 6), and in subjects with atypical clinical presentations (n 5 4). Six patients of our cohort (20%) had a history of intestinal pseudo-obstruction (6 pedigrees, 3 men; mean age, 37 years; range, 16–65; mean body mass index [BMI], 16; range, 13–18). Differently from what was reported by Ng et al, all patients manifested MELAS syndrome and only 1 patient developed intestinal pseudo-obstruction concomitantly with an acute stroke-like episode (SLE). Moreover, we, too, observed 1 patient who developed a severe gastrointestinal dysmotility episode 14 years before his first SLE. Radiological investigations on 5 patients showed a concomitant dilation of small and large bowels in 3 patients and an isolated distension of large bowel in 2 patients. One patient had clinical evidence of urinary retention during an acute presentation of intestinal pseudoobstruction. Three patients died concomitantly with the severe gastrointestinal event: 2 of aspiration pneumonia and sepsis and 1 of aspiration pneumonia and cardiorespiratory failure. All patients with a history of intestinal pseudo-obstruction had at least an SLE. These data confirm that SLE and BMI are strong predictors of the development of intestinal pseudo-obstruction. Interestingly, the 3 patients of our cohort who died concurrently with this severe gastrointestinal episode presented a severe cortical atrophy and dementia, and we speculate that these clinical and radiological conditions increase risk of death during an intestinal pseudo-obstruction episode probably attributed to the inability to protect their own airways. We suggest to extend the gastrointestinal screening to all patients with mitochondrial diseases. In fact, also in our experience, severe gastrointestinal events are associated in other primary mitochondrial DNA and nuclear mutations (eg, a TWINKLE-related mitochondrial disease and a patient with mutation in the COX3 gene). Finally, we fully agree with Ng et al to avoid surgical intervention for this clinical condition and to begin an adequate medical treatment as early as possible