Physiology-guided quantitative symptom analysis for gastroduodenal disorders

Abstract

Background Current approaches to symptom-based classifications in gastroduodenal disorders are binary and substantially overlapping. We aimed to develop a standardized and quantitative system for classifying patient-level symptom profiles guided on physiological principles. Methods A large database (n = 787) of 4.5 h (30 min baseline; 4-h postprandial) Gastric Alimetry® (Alimetry, NZ) recordings were used to identify, and quantify distinct symptom patterns based on established gastroduodenal physiology concepts. Tests comprised a standardized meal challenge and symptoms were simultaneously recorded at minimum 15 minute intervals using a 10-point likert scale with pictograms encoded in a validated digital App. Key Results Six symptom profiles were defined. The meal change metric was used to define 'meal-induced' and 'meal-relieved' symptom profiles, defined as an increase (+2) or decrease (-2) in the average symptom severity between the first post- and pre-prandial hours of recordings. The continuous profile was defined as a reduced range (<3; i.e., difference between the 95th and 5th percentile symptom severity), and thresholded to the 5th percentile of symptom severity being > 2. The symptom/amplitude correlation metric defined the 'sensorimotor' profile, thresholded when the correlation was >0.5. The symptom/amplitude time lag metric was used to define 'activity-relieved' and 'post-gastric' symptom profiles, defined as negative (< -0.25) or positive (>0.25) average difference between the cumulative distribution functions of the symptom and amplitude curves. Conclusions & Inferences Standardized quantification of symptom profiles in relation to a meal-stimulus and gastric amplitude offer a novel classification scheme based on gastroduodenal physiology.

Characterisation of post-fundoplication gastric dysfunction using Gastric Alimetry

“…We identified two patients (12.5%) with normal gastric myoelectrical activity but a strong correlation between meal ingestion, gastric amplitude, and symptom severity, classified as a 'sensorimotor' symptom profile according to Gastric Alimetry criteria. 25 This finding has previously been postulated to reflect a gastric accommodation disorder or visceral hypersensitivity. 23,25 Significantly impaired gastric accommodation impairment has also been previously demonstrated in those with post-fundoplication dyspepsia symptoms.…”

“…25 This finding has previously been postulated to reflect a gastric accommodation disorder or visceral hypersensitivity. 23,25 Significantly impaired gastric accommodation impairment has also been previously demonstrated in those with post-fundoplication dyspepsia symptoms. 5 The impairment of gastric accommodation is likely multifactorial, with contributions from anatomical distortion of the fundus, surgical manipulation of the gastro-oesophageal junction, and vagal dysfunction.…”

“…These findings are anticipated to improve the management of post-fundoplication patients through improved selection of patients for procedural therapies. Final Gastric Alimetry phenotypes 17,20,25 are as follows: (A-B) low rhythm stability, (C-E) high frequency, (F) high amplitude Figure S3: Averaged spectrograms and amplitude curves of abnormal spectrograms (A) Sensorimotor phenotype (amplitude-dependent) whereby there is a high correlation between gastric amplitude and symptom burden (r>0.5). (B).…”

“…23,24 Post-gastric: symptoms trending upward late in postprandial period; after the gastric meal response had peaked, indicating a likely more distal pathology (e.g., small bowel dysmotility or other disorders). 25 ii) Amplitude-independent symptoms: symptoms continuous/do not relate to gastric activity, suggesting possible gut-brain axis disorders. 23…”

Comparison of Gastric Alimetry® body surface gastric mapping versus electrogastrography spectral analysis

“…As such, nuanced relationships between the temporal evolution of symptom severities as they relate to meal consumption and dynamic gastric signals were not captured. Nevertheless, BSGM showed an 8× increase in the number of significant symptom correlations compared to EGG, and we expect that this relative improvement would persist, with improved symptom correlations, when applying the more in-depth quantitative analyses that are the subject of ongoing work 46 , 47 . The essential diagnostic advantage of BSGM, as distinct from EGG, is the capability to robustly identify individual patients with or without gastric neuromuscular abnormalities, as guided by reference intervals 22 , and as recently demonstrated in populations with NVS and T1D 17 , 23 .…”