Richter, Castell:
The Esophagus, 5th Edition
In the first century AD, the Roman scientist Pliny the Elder described the first treatment for heartburn, coral powder, which contains calcium carbonate, a buffer still used in today’s antacids. In the second century, the Greek physician Galen defined the problem as kardialgia, or heart pain [1]. Although this problem was recognized over 2000 years ago, heartburn and other esophageal disorders remain a major source of distress for patients today. The esophagus is unique in gastrointestinal disease because it is the only structure of the gastrointestinal tract that resides normally within the thorax. As a result, the symptoms of an esophageal disease are distinct from the typical symptoms related to disorders affecting other gastrointestinal organs, but they often overlap with symptoms that result from organs outside of the gastrointestinal tract, as Galen recognized.
Sensory pathways and symptom production The development of symptoms related to the esophagus is a complex neurophysiologic phenomenon that is incompletely understood. A stimulus at the level of the esophagus acts upon one of several types of afferent neurons (nociceptors) that may be responsible for esophageal sensation. The nociceptors transmit the signal to the central nervous system, where it is processed at a subcortical level. If the signal is of sufficient strength to pass through subcortical suppressive pathways, it is transmitted to the cortical level, to allow the individual to respond to the signal. A patient can respond to the internal signal (sensation) in a variety of ways, depending on their circumstances and background
Several types of chemo -, thermo -, and/or mechanosensitive nociceptors have been identified within the esophagus. These nociceptors carry various sensors, such as the acid-sensitive transient receptor potential vanilloid receptor 1 (TRPV1), which stimulate an action potential within the nociceptor [2]. These receptors are ion channels that can be activated by various mediators of injury, such as hydrogen ions, histamine, bradykinin or serotonin. The impulses are transmitted by two types of nerve fibers, A δ-fibers, and C-fibers. A δ-fibers are myelinated fibers that carry pain impulses relatively rapidly, and typically generate a sensation of sharp, localized pain of sudden onset. C -fibers are unmyelinated fibers that transmit their signals more slowly and lead to a pain sensation that is dull, poorly localized, and of a more gradual onset
Symptoms commonly related to esophageal disorders.
Dysphagia: Difficulty swallowing
Esophageal (transport)
Oropharyngeal (transfer)
Heartburn
Regurgitation
Odynophagia (pain on swallowing)
Chest pain
Globus ( a feeling of something stuck on throat)
Supraesophageal symptoms:
Chronic Cough
Hoarseness
Asthma/wheezing
Hiccups
The incidence is almost equal between males and females except during years of childbearing GERD is more in females
"Central processing of the peripheral signals has two dimensions, sensation and affect [5]. The sensation dimension of the stimulus is responsible for determining the location and intensity of the symptom. The affective dimension relies on a very complex interplay of emotions, words, and personal experiences to modulate the sensation into a particular expression. Four predominant cortical regions have been hypothesized to be involved in central processing: the primary somatosensory cortex, secondary somatosensory cortex, insula, and cingulate cortex. The primary and secondary somatosensory cortices receive nociceptive projections from the ventroposterior lateral nuclei of the thalamus. The primary somatosensory cortex appears to be important in determining the concrete dimensions of the symptom (duration, location, intensity), whereas the secondary somatosensory cortex appears to play a principal role in recognizing the nature of the symptom (mechanical, thermal, chemical) [5]. The insula is thought to be responsible for integrating input from both the secondary somatosensory cortex and the thalamic nuclei, and for transmitting this information to limbic structures for affective processing. The anterior cingulate cortex (ACC) appears to be responsible for the affective-motivational aspects of symptom processing. This area appears to be especially active in symptom generation in functional bowel disorders"
" The localization of the bolus hold-up in the cervical region usually indicates a pharyngeal source of dysphagia, but patients with esophageal dysphagia can occasionally report sticking in the cervical region"
Patients with esophageal dysphagia usually complain that food sticks or “hangs up ” retrosternally during meals. Dysphagia is not often painful, although some individuals complain of a painful squeezing sensation or fullness in the chest.
obstruction to luminal flow (mechanical) or by altered esophageal motility
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