This case involved a patient who was suffering from vomiting and an abnormal left-leaning posture that started 4 years prior to presentation. He initially sought consultation from a pediatric neurologists. However, when no abnormalities were found on blood examination and head magnetic resonance imaging, he was placed under observation. Unfortunately, his symptoms did not improve, prompting referral to a pediatric psychiatrists 2 years prior to presentation. Electroencephalography and development examinations showed no abnormalities. As such, SS was suspected based on history, for which upper gastrointestinal examinations were performed. Upper gastrointestinal series (UGI) showed GER (Fig. 1a), whereas esophagogastroduodenoscopy (EGD) showed reflux esophagitis (Los Angeles classification: Grade D) and a hiatal hernia (Fig. 1b). Low esophageal pH (< 4) accounted for 19% of the 24-h recording cycle. These findings confirmed that SS was the correct diagnosis.

a Upper gastrointestinal series showing gastroesophageal reflux. b Esophagogastroduodenoscopy showing reflux esophagitis (Los Angeles classification: Grade D) and a hiatal hernia

Given the lack of improvement with proton pump inhibitor (PPI) treatment for 1 month, laparoscopic Toupet fundoplication was performed, which improved the patients symptoms 1 month after surgery. The left-leaning posture disappeared, and the patient did not develop any symptom recurrence for 2 years.

This case involved a patient who was suffering from abnormal posture with backward bending of the neck, violent speech, chronic cough, and vomiting 2 months prior to presentation (Fig. 2a), which prompted him to initially seek consultation from pediatricians. Computed tomography of the head performed in the emergency department of the previous hospital showed no abnormality. The patient was then transferred to our hospital. UGI showed GER (Fig. 2b), and EGD showed reflux esophagitis (Los Angeles classification: Grade D) and hiatal hernia (Fig. 2c). We could not perform low esophageal pH 24-h recording due to his symptom of abnormal posture.

a Abnormal posture with backward bending of the neck was observed. b Upper gastrointestinal series showing gastroesophageal reflux. c Esophagogastroduodenoscopy showing reflux esophagitis (Los Angeles classification: Grade D) and a hiatal hernia

Postural abnormalities temporarily disappeared after initiating PPI treatment 1 month prior to presentation. However, we opted to perform laparoscopic Toupet fundoplication given the recurrence of symptoms despite PPI treatment. At 2 weeks after the surgery, his symptoms improved as shown by the disappearance of postural abnormalities and cessation of voluble speech. No symptom recurrence had been noted for 9 months.

We subsequently reviewed articles published in MEDILINE/PubMed, Cochrane Library, and Web of Science using the following combinations of search terms: “Sandifer syndrome” and “gastroesophageal reflux.”

Original articles and case reports reporting details regarding patients with SS were included in the analysis. Two reviewers independently scanned the titles and abstracts of the identified articles. The exclusion criteria were as follows: (1) articles not written in English, (2) non-original articles or case reports (meeting abstracts, reviews), (3) studies that did not focus on patients with SS, and (4) studies with insufficient data on patients with SS. This systematic review was conducted based on the PRISMA principles.

Two reviewers separately collected the following data from the selected articles: the first author, year of publication, study design, sample size, patient characteristics, treatment course, and outcomes. Both reviewers reached a consensus at each stage of the data extraction process.

Continuous variables were presented as medians and interquartile ranges, whereas categorical variables were presented as frequencies and percentages. Fisher’s exact test was used to evaluate categorical variables. p values < 0.05 were considered statistically significant.