Aphagia is the inability or refusal to swallow. The word is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

prefix α, meaning "not" or "without," and the suffix φαγία, derived from the verb φαγεῖν, meaning "to eat." It is related to

dysphagia Dysphagia is difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, in some contexts it is classified as a disease#Terminology, condition in its own right. It may be a sensation that suggests difficulty in the passag ...

which is difficulty swallowing (Greek prefix δυσ, ''dys'', meaning difficult, or defective), and

odynophagia Odynophagia is pain when swallowing. The pain may be felt in the mouth or throat and can occur with or without difficulty swallowing. The pain may be described as an ache, burning sensation, or occasionally a stabbing pain that radiates to the b ...

, painful swallowing (from ὀδύνη, ''odyn(o)'', meaning "pain"). Aphagia may be temporary or long term, depending on the affected organ. It is an extreme, life-threatening case of dysphagia. Depending on the cause, untreated dysphagia may develop into aphagia.

Behavioural classification

The following behavioural classifications result from studies performed on rats, in which lesions were made on the lateral

hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...

region in the brain. #Passive aphagia: An animal with passive aphagia will not respond to food if it is presented. However, if food is inserted into the mouth, the animal will chew. #Active aphagia: Active aphagia is a complete rejection of food. The animal will physically push food away or move its head from it. One might first sample the food by smelling or tasting, then spit out anything in the mouth. Afterwards the animal will show a complete repulsion to the food. The animal reacts to food as if it is bitter or foul. #Mixed aphagia: When presented with food, the animal initially does not react positively or negatively. However, when food is placed in the mouth, the animal demonstrates active aphagia, spitting out the food and refusing to eat thereafter. These studies point to the function of the hypothalamus in regulating

food intake Eating (also known as consuming) is the ingestion of food, typically to provide a heterotrophic organism with energy and to allow for growth. Animals and other heterotrophs must eat in order to survive — carnivores eat other animals, herbi ...

. Animals in this study also demonstrated several other types of eating behaviour: "weak eating," in which the animal slowly approaches, chews, and swallows small observable amounts of food for a brief period; "good eating," in which the animal reaches normally for the food and eats reliably; and "vigorous eating," in which the animal gluttonously reaches for and devours the food. In these cases, there was either minor or no damage to the lateral hypothalamus. Aphagia not classified under behavioral aphagia typically has a structural cause, see

causes Causes, or causality, is the relationship between one event and another. It may also refer to: * Causes (band), an indie band based in the Netherlands * Causes (company) Causes.com is a civic-technology app and website that enables users to orga ...

Causes

Aphagia is usually the result of many different diseases as well as different medical treatments. The most common causes of aphagia are: * Aesophageal cancer – there are two types of aesophageal cancer. The squamous cell cancer from the

squamous Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...

cells of the

tongue The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ...

or the

adenocarcinoma Adenocarcinoma (; plural adenocarcinomas or adenocarcinomata ) (AC) is a type of cancerous tumor that can occur in several parts of the body. It is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or ...

from glandular cells present at the junction of the

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the ...

and

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

. This leads to a local tumour growth with spreading later. This spreading may lead to larger tumors that would result in the inability to swallow. * Aesophageal webs – thin membranes located in the

. Abnormalities can cause constrictions within the esophagus. *

Globus pharyngis Globus pharyngis or globus sensation is the persistent but painless sensation of having a pill, food bolus, or some other sort of obstruction in the throat when there is none. Swallowing is typically performed normally, so it is not a true case o ...

– commonly referred to as lumps in ones

throat In vertebrate anatomy, the throat is the front part of the neck, internally positioned in front of the vertebrae. It contains the pharynx and larynx. An important section of it is the epiglottis, separating the esophagus from the trachea (windpipe ...

Myasthenia gravis Myasthenia gravis (MG) is a long-term neuromuscular junction disease that leads to varying degrees of skeletal muscle weakness. The most commonly affected muscles are those of the eyes, face, and swallowing. It can result in double vision, dro ...

– the thymus gland is thought to be necessary for the deletion of auto-reactive

T cells A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell re ...

, and seems to have an important role in the

pathogenesis Pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes from Greek πάθος ''pat ...

myasthenia gravis Myasthenia gravis (MG) is a long-term neuromuscular junction disease that leads to varying degrees of skeletal muscle weakness. The most commonly affected muscles are those of the eyes, face, and swallowing. It can result in double vision, dro ...

. In patients the thymus is typically enlarged, and contains many germinal centres with T and

B cell B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or ...

areas very similar to those seen in lymph nodes. The tumour in

thymoma A thymoma is a tumor originating from the epithelial cells of the thymus that is considered a rare malignancy. Thymomas are frequently associated with neuromuscular disorders such as myasthenia gravis; thymoma is found in 20% of patients with mya ...

associated disease is typically

epithelial Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...

in nature. *

Facioscapulohumeral muscular dystrophy Facioscapulohumeral muscular dystrophy (FSHD) is a type of muscular dystrophy, a group of heritable diseases that cause degeneration of muscle and progressive weakness. Per the name, FSHD tends to sequentially weaken the muscles of the face, ...

– even though there is not a clear correlation between the facioscapulohumeral muscular dystrophy and the pharyngeal and upper aesophageal striated muscle. Minor, and nonspecific, primary aesophageal dysmotility was present as seen in the 2008 study by Joerg-patrick Stübgen. *

Multiple sclerosis Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...

– may lead to aesophageal dysmotility Takubo K. "Pathology of the aesophagus : an atlas and textbook. 2nd ed..: Springer Verlag; 2007. *

Chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...

– radiation from cancer therapy may cause a stricture of the throat leading to the inability to swallow. *

Stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

– swallowing problems can cause stroke victims to aspirate food or liquid into the lungs and cause

pneumonia Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...

mostly in elderly people. *

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...

– the mechanism of swallowing disorders in Parkinson's disease may be related to extrapyramidal and autonomic system disorders. The cardinal symptoms of Parkinson's disease: tremor,

bradykinesia Hypokinesia is one of the classifications of movement disorders, and refers to decreased bodily movement. Hypokinesia is characterized by a partial or complete loss of muscle movement due to a disruption in the basal ganglia. Hypokinesia is a sym ...

, and rigidity are initially responsible for swallowing, which is mainly observed in the advanced stages of the disease * Damage to the lateral

can also lead to aphagia, as seen in the 1978 study by Timothy Schallert and Ian Whishaw. * Other causes might be due to depression, cervical spine disease and

conversion disorder Conversion disorder (CD), or functional neurologic symptom disorder, is a diagnostic category used in some psychiatric classification systems. It is sometimes applied to patients who present with neurological symptoms, such as numbness, blindness ...

s. It is important to note that all these causes (except due to the damage of the lateral hypothalamus) are indirect.

Diagnosis

* Modified barium swallow – videofluoroscopic swallow (

fluoroscopy Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a physician to see the internal structure and functio ...

). A lateral video X-ray that provides objective information on bolus transport, safest consistency of bolus, and possible head positioning and maneuvers that may facilitate swallow function depending on each individual's anatomy and physiology. *

Esophagogastroduodenoscopy Esophagogastroduodenoscopy (EGD) or oesophagogastroduodenoscopy (OGD), also called by various other names, is a diagnostic endoscopic procedure that visualizes the upper part of the gastrointestinal tract down to the duodenum. It is considered ...

– a diagnostic endoscopic procedure that visualizes the upper part of the

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...

. *

Esophageal motility study An esophageal motility study (EMS) or esophageal manometry is a test to assess motor function of the upper esophageal sphincter (UES), esophageal body and lower esophageal sphincter (LES). Indications An EMS is typically done to evaluate suspecte ...

– a test to assess motor function of the upper and

lower esophageal sphincter The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the ...

as well as the esophageal body.

Treatment and compensatory techniques

During the treatment of aphagia (or dysphagia), it is important to provide adequate nutrition and hydration. If a person is not able to tolerate a regular diet, diet modifications and alternative means of nutrition may be considered. These include thickening liquids (typical thickening hierarchy is nectar/syrup thick, honey thick, and pudding thick) or by changing the texture of the solid foods to reduce the required amount of mastication (chewing) needed or to reduce other symptoms of oral dysphagia (such as buccal pocketing or anterior loss). Alternative means of nutrition may also be needed in more severe cases (such as when a person is deemed NPO and is not safe to eat anything orally). In these cases, nasogastric (NG) or percutaneous endoscopic gastronomy (PEG) tubes may be placed. Other compensatory measures may include reducing the bolus size (small bites/sips) or postural strategies (such as tucking the chin, turning the head to one side or the other). A speech-language pathologist is one professional who evaluates and treats aphagia and dysphagia and can recommend these strategies depending on the etiology of the deficit and the location of the breakdown within the swallowing mechanism. True treatment of aphagia/dysphagia comes from neuromuscular re-education and strengthening/coordination in most cases. This can be achieved by use of pharyngeal strengthening exercises, thermal stimulation of the swallowing trigger and oral motor exercises. In some cases, it is also appropriate to complete therapeutic exercises in conjunction with neuromuscular electrical stimulation (NMES) which utilizes low-level electrical currents to target muscle fibers from an external source (electrodes placed on the surface of the skin in strategic places to target muscles and nerves needed during the swallowing process).

References

Esophagus disorders Symptoms and signs: Digestive system and abdomen