Sensory Disorders

Hyperesthesia - hypersensitivity to real ordinary or even weak influences. In these cases, both external and inter- and proprioceptive stimuli cause an extremely intense reaction due to a sharp decrease in the lower absolute thresholds of sensations . ^[1] For example, the clatter of a typewriter stuns the patient , the burning candle blinds, and the shirt adjacent to the body irritates so much that it seems made of barbed wire , etc. It is observed in case of neurosis , intoxication with certain substances ( opiates , hashish , cycloid, etc.), the initial stages of stupefaction, acute psychoses .

Hypesthesia - decreased sensitivity to real stimuli , increased lower absolute thresholds of sensations . The patient almost does not respond to an injection, to a fly crawling over his face, etc. A reduced sensitivity to temperature stimuli can lead to accidents - burns and frostbite . In extreme cases of hypesthesia, the analyzer is completely unable to respond to irritation, and this phenomenon is called anesthesia . Anesthesia usually occurs with a complete anatomical break of one of the peripheral nerve trunks or the destruction of the central part of the analyzer. Loss of sensitivity usually extends to tactile, pain and temperature sensitivity (total anesthesia ) or only to its individual types (partial anesthesia ). ^[one]

In case of mental hypesthesia and anesthesia, the corresponding analyzer is formally anatomically physiologically preserved. In particular, hypesthesia and anesthesia can be instilled into a person in a hypnotic sleep . Mental amblyopia ( blindness ), mental anosmia (insensitivity to smells ), mental agesia (loss of taste ), mental deafness , mental tactile and pain anesthesia are often found in hysterical neurotic disorders. ^[2]

Paresthesia is associated with qualitative changes in the information coming from the receptor to the cortical part of the analyzer. Paresthesias are more often a sign of a neurological or vascular lesion. Probably, everyone knows about the sensations arising from prolonged squeezing of a nerve with an uncomfortable position - “lay out a hand”, “served a leg”. In case of nerve conduction disturbances, there are sensations of “crawling creeps ”, tightening of the skin, tingling sensation (these are peculiar fluctuations in the modality of sensation ). Paresthesias are more often a sign of a neurological or vascular lesion. ^[2]
They are close to paresthesia and senestopathy , but they occupy an intermediate position with visceral hallucinations , as they are even less associated with any real irritation of the peripheral part of the analyzer.

Senestopathy is an indefinite, often migrating, very unpleasant and painful sensation that projects into the body (into the bodily “I”): squeezing and stretching, rolling and trembling, “suction”, “sticking”, etc. They never have a clear localization , and patients are not even able to describe them correctly. Senestopathies are found in many mental illnesses . ^[3]

Kolesnik N. T., Orlova E. A. “Clinical Psychology: a textbook for academic undergraduate studies”, Moscow: Yurayt Publishing House, 2016, 359 pp.