Visual hallucinations are visual perception disorders characterized by the formation of visions in the absence of a real object. Elementary visual images are represented by sparks, flashes, spots. Simple hallucinations are static objects that do not change shape, unambiguously interpreted by the patient. Complex hallucinatory visions are plot pictures, one or more characters that can move, increase or decrease, inspire ideas. Examination of patients is carried out by observation and conversation, with the help of provocative samples. Symptomatic therapy involves taking neuroleptics.
General characteristics
Visual hallucinations are the second most common after auditory hallucinations. They are perceived as real objects, so the behavior of patients is determined by the content of false perceptions. Hallucinating patients can stare at empty walls for a long time, dismiss the vision, avoid it, bypass it, changing the original route. Unlike memories, fantasies, ideas, hallucinations occur spontaneously, without a reason, regardless of the will of the patient. They cannot change or be driven out by willpower (like unpleasant thoughts).
Another feature of visual hallucinations is the projection of images outside. True hallucinations are assimilated with real objects, for example, insects are perceived crawling on a wall. Another kind of symptom is pseudohallucinations. They are perceived as something abnormal, subjective, do not have the properties of objective reality, arise for no reason, are violent or intrusive, intertwined with delusional ideas of influence. Pseudo-hallucinatory images are projected in subjective space – in front of the eyes, to the side of the gaze. They can decrease when approaching, increase when moving away.
According to the content, visual hallucinations are elementary – smoke, fog, flashes, lightning, sparks; simple – static simple objects; complex – dynamic phenomena united by an idea. Simple and complex hallucinations are divided into zoopetic (images of animals), polyopic (many identical visions), demonomanic (images of mythological characters), panoramic, scene-like, endoscopic (seeing objects inside the body), autovisceroscopic (seeing one’s own internal organs).
Causes of visual hallucinations
Visual hallucinations are more characteristic of organic brain lesions, namely, the occipital and temporal lobes of the cortex, the rostral parts of the trunk, and the thalamus. They are also a frequent companion of clouded confused consciousness, hypnotic or half-asleep state. The content of the images is diverse, but neurological causes often provoke hallucinations of the true type, and psychotic and hypnotic states – pseudo-hallucinations. Causes include extreme exposure, organic brain damage, mental illness, acute intoxication.
Intense stress factors
The causes of passing single hallucinatory surges are states of acute physical or mental stress. Extreme situations that threaten a person’s life lead to changes in the functioning of the brain. Factors affecting the mental state can provoke visions with increased suggestibility and impressionability – psychological readiness to see something related to experiences, but not existing in a real situation. How stressful causes are considered:
- The effects of critical temperatures. A decrease or increase in body temperature is accompanied by a change in the blood supply to the brain – the body strives to maintain the constancy of the internal environment, regulates heat transfer by narrowing or expanding blood vessels. Visual hallucinations appear with hypothermia, when the body temperature drops to 35 ° C, with hyperthermia with a body temperature of 39 ° C and above. The state of hallucination does not last long, is accompanied by disorientation, confusion, disruption of vital organs.
- Deprivation of physiological needs. The causes of hallucinatory visions can be critical conditions in which a person is deprived of the ability to satisfy basic physiological needs – food, water, sleep, rest. Blurred images begin to appear on the 8-9 day of fasting, on the 2-3 day without water (up to about 10% of the body fluid is lost). The critical phase of sleep deprivation is 4 days, when irreversible life-threatening processes occur, apathy increases, abulia occurs, hallucinatory symptoms unfold.
- Lack of sensory stimulation. The human nervous system is able to function normally when a variety of information is received from the outside – when the sensory organs are stimulated. Sensory deprivation is partial or complete isolation from external influences. Its causes are the loss of the analyzer, staying indoors without light, sounds, vibrations. Sometimes such a condition is created artificially with the use of derivation chambers, baths. In the absence of external visual stimuli, the brain begins to compensate for the lack of information by creating visual hallucinations.
- Social isolation. Visual hallucinatory images are formed as a result of prolonged forced or specially organized loneliness (hermitage). This phenomenon has been studied in the most detail on the examples of prisoners in solitary prison cells. They have elementary auditory, visual hallucinations (flashes of light, screams, noises) provoked by sensory deprivation, as well as complex dynamic images – “friends”, “mentors”, “saviors”. They contact the prisoner with looks, silent decrees, words.
- Psychological trauma. Possible causes of visual hallucinatory symptoms are psychotraumatic situations. The first pathogenetic mechanism is associated with situations of loss of loved ones, places or events to which a person was attached. Hallucinatory images “return” what was lost. Another mechanism is based on post-traumatic experience: emotions of fear, anger, horror were not experienced in a critical situation, so a person involuntarily returns to it through thoughts, dreams, visual hallucinations. Example: a former military man suffering from PTSD “sees” explosions, shooting opponents.
Neurological diseases
Visions in neurological patients occur with local and diffuse brain lesions. Visual images can be provoked by pathological irritation of the areas responsible for receiving and processing visual information. This type of disorder is characterized by elementary images – photopsias. In addition, visual hallucinations are sometimes included in the structure of the hallucinatory-delusional symptom complex, the syndrome of clouded consciousness. The most common causes of visions:
- Dementia with Levi’s corpuscles. The disease is diagnosed in patients 65-70 years old, characterized by a change in the structure of neurons in the cerebral cortex. Typically, it begins with a triad of symptoms, including extrapyramidal disorders, dementia, visual hallucinations. Most often, hallucinatory images develop, which have a clear color, shape, size, volume. A typical sign of this type of dementia is the rapid disappearance of visions when the patient tries to interact with them.
- Alzheimer’s disease. The basis of pathology is the process of neuronal death, loss of synaptic connections in cortical zones and subcortical areas of the brain. Visual hallucinations are likely at the second stage of the disease, when there is a noticeable deterioration in everyday, professional activity, the process of constructing a speech utterance is disrupted, it becomes impossible to perform arbitrary actions. Hallucinatory symptoms manifest themselves in the context of delusional syndrome, often accompanied by anxiety, fear, panic.
- Parkinson’s disease. The disease proceeds with the progressive death of neurons producing the neurotransmitter dopamine. With a mild (outpatient) form of the disease, psychosis develops in about 20% of patients, with severe – in 65%. The psychotic state is manifested by unmotivated fear, absent-mindedness, insomnia, hallucinatory-paranoid symptoms, disorientation. As the causes of psychosis in Parkinson’s disease, the rapid progress of pathology and the use of medications aimed at alleviating motor function disorders are considered.
- Traumatic brain injuries. TBI includes bruises and concussions, barotrauma, skull injuries. With focal lesions of the occipital regions, visual hallucinations are represented by elementary forms: zigzags, flashes in one half of the visual field. Hallucinatory-delusional psychoses are more likely to develop in men after moderate and severe injuries. They manifest themselves many years later, in a distant period. Visual hallucinations are formed before psychosis against the background of twilight, delirious or oneiroid changes in consciousness. In a psychotic state, auditory pseudohallucinations occur more often.
- Cerebral vascular pathologies. Vascular diseases of the brain (atherosclerosis, arteritis, hypertension) lead to deterioration of blood supply to its individual areas, diffuse organic lesions. Neurological symptoms are represented by headache, dizziness, vomiting, perception disorders, speech disorders. Patients see flashes, sparks, flickering. Visual phenomena unfold with the exacerbation of the disease, accompanied by disorientation in space, general weakness.
- Brain tumors. Clinically, brain neoplasms are manifested by focal and cerebral symptoms. The causes of visions are neoplasia localized at the junction of the frontal and temporal lobes. Visions arise within the framework of paroxysmal disorders – short-term hallucinatory surges without delirium. The patient’s critical abilities remain relatively intact, after a certain duration of the disease, he begins to understand that visible images are a symptom of the spread of the tumor.
Mental disorders
Visual hallucinations develop in psychotic states of various origins. Exogenous psychoses are characterized by true hallucinatory images, endogenous ones – pseudo-hallucinations. In both cases, there is an emotional and behavioral inadequacy of the patient, a decrease or complete absence of a critical attitude to his condition. Common psychotic causes of hallucinations:
- Symptomatic psychoses. This group includes infectious psychoses, psychotic states provoked by endocrinopathies, vascular pathologies, acute intoxication of surfactants, alcohol. The confusion of consciousness proceeds in the form of an oneiroid – a dream-like disorientation with detailed pictures of fantastic pseudo-hallucinatory experiences intertwined with reality. The content is usually adventurous, fabulous, less commonplace. Visual hallucinations are colorful, mobile, massive. Patients either actively participate in visions or remain observers.
- Schizophrenic disorder. Common causes of the disease are head injuries, neuroinfections, epilepsy. In organic delusional disorder, visual hallucinations predominate, and not auditory hallucinations as in schizophrenia. Their content is often related to the subject of delirium, reflects scenes of a mystical or religious nature. Hallucinatory delusional syndrome is manifested by inadequate behavior, impulsivity, emotional excitability.
- Schizophrenia. Auditory hallucinatory phenomena are characteristic of this disease. Visual hallucinatory disorders unfold less often, they are dimly expressed, unstable, flash fragments, resemble visions. Often their purpose, content, and causes are completed by patients on the basis of delusional ideas, information from hallucinatory voices. If schizophrenia has developed as a result of taking psychoactive substances, “flashbacks” appear – pictures from the past.
Acute period of intoxication
The state of acute intoxication develops after the administration of a large dose of a psychoactive substance. It leads to a violation of consciousness, deterioration of cognitive activity, distortion of perception. People’s behavior and emotions become inadequate, uncontrollable. There is no critical attitude to one’s own condition. Visual hallucinations are most likely in cases of poisoning with the following substances:
- Drugs. Common causes of visions are the use of hallucinogens, volatile solvents, cannabis preparations. When intoxicated with hallucinogens, the world begins to seem brighter, objects are painted in unusual colors. Visual hallucinations are elementary and scene-like, more often true. Substance abuse with the use of volatile solvents is manifested by a violation of consciousness with acute hallucinosis, delirium or oneiroid. Hallucinatory pictures are vivid, storylines. Taking cannabinoids provokes visions that are brighter than the real world, present with open and closed eyes.
- Medicinal products. Visual hallucinations as part of delirious confusion are manifested by poisoning with diphenhydramine, atropine, antidepressants. When taking large doses of psychostimulants, an intoxicating paranoid develops, which includes delusional ideas, visual and other types of hallucinations. There is a risk of the formation of manic-like states with euphoria, motor disinhibition, accelerated thinking.
- Alcohol. Delirium tremens occurs when drunkenness ceases in patients with stage II-III alcoholism. Alcoholic delirium is manifested by delusions associated with hallucinatory images of various modalities. Visions are usually threatening, appear in the images of unpleasant and dangerous creatures – demons, devils, creeping reptiles. The state of psychosis, psychomotor agitation during intoxication is a common cause of self-harm.
Diagnostics
The diagnosis is handled by a psychiatrist. Family members of the patient are the first to notice the presence of deviations in his behavior. The patient himself is often uncritical of visions, perceives them as part of reality. States with emotionally colored images – frightening, surprising, irritating – are most quickly identified. If the hallucination is constant and does not bother the patient, then the symptom sometimes remains undiagnosed for several years. The examination is performed by the following methods:
- Discussion. The doctor does not ask direct questions about the presence of hallucinations, but identifies them in the process of communicating with the patient. Since the visions are bright, unusual, cause fear and other experiences, they often become the subject of discussion. Sometimes the psychopathological nature of the described phenomena is obvious, in other cases the doctor needs clarifying information from relatives.
- Observation. Patients with visual hallucinations can peer into the empty space in front of them, look at an empty wall. Sometimes, for no apparent reason, they turn to the side or look back if the image appears on the periphery of the visual field. Viewing the vision that has arisen is accompanied by instability of the emotional state: the appearance of anger, fright, surprise.
- Pathopsychological tests. Special provocative tests are used to identify perception disorders. Visual hallucinations can be detected during the execution of the Reichardt test: the patient is asked to tell what is depicted on a piece of paper that is actually clean. Another variant of provocation is the Lipman test: pressing on the eyelids can cause visions.
Treatment
With intoxication and stressful effects, hallucinations have a passing character, so it is enough to eliminate their causes: stop taking narcotic or medicinal products, prevent the effects of extreme factors. Hallucinatory manifestations in neurological diseases and psychoses are stopped with the help of antipsychotic drugs. They reduce psychomotor agitation, suppress delusions and hallucinations.
