The Visual hallucinations Consist of the perception of an element that is not really present, and appear in both children and the elderly.
Its causes are very diverse, and are commonly associated with schizophrenia Or use of certain drugs, although they may also appear due to stress.
Even the"healthy"population may experience hallucinations throughout their lives, such as those that occur when they fall asleep (hypnagogic) or upon awakening (hypnopompic).
On the other hand, in this article you will see that there are many types of visual hallucinations. Thus, they can be seen from simple optical experiences like flashes or colors, to complex constructions like objects, people, animals or insects.
The treatment for visual hallucinations is to control the underlying causes (stress, fever, lack of sleep, addiction to drugs or alcohol...), medication (for psychiatric illness), and Cognitive-behavioral therapy So that the patient learns to distinguish and control his own hallucinations.
Definition of visual hallucinations
Visual hallucinations are characterized by:
- Alterations in the perception that occur without the hallucinated object being present in the visual field of the person.
- The person who experiences it is convinced that the element is real, coming to adapt their behavior to them. That is why it is difficult for these people to recognize or identify their hallucinations.
- They usually have organic causes, involving visual pathways and areas of association of the brain.
It is important not to confuse visual hallucinations with pseudoalucinations. The latter are characterized by the existence of some preservation of the judgment of reality. That is, the person who lives them may suspect or know that what they are experiencing is not real.
In addition, pseudoalucination is more inaccurate, diffuse and imprecise; And their details can be modified to some extent of their own volition.
On the other hand, the hallucinations themselves are clear, detailed and persistent, and can not be changed by our will, nor can they be influenced by suggestion.
Hallucinations become pathological when:
- They are frequent
- Are part of diseases, disorders or syndromes
- They cause discomfort, preventing the person from leading a satisfactory life.
- They affect negatively the people around them and, therefore, to interpersonal relationships.
Causes of visual hallucinations and associated conditions
The causes are very varied, ranging from stress or exhaustion to psychiatric disorders or certain syndromes.
- Ophthalmological disorders or ocular lesions: they are usually simple hallucinations like lights and moving geometric forms. They appear as a consequence to conditions such as cataracts, glaucomas, retinal detachment, vitreous traction... among others.
- Injuries to the anatomical brain substrate of vision: that is, those areas of the nervous system that process visual information, such as the optic nerves, The optic chiasm , Areas of the brain stem (such as Cerebral peduncle ), he occipital lobe of the brain , etc.
On the other hand, an involvement in the primary visual cortex would cause simple hallucinations, whereas a lesion in the cortex of visual association would cause complex visual hallucinations.
- Prolonged visual deprivation: if we stay for several days blindfolded or in a dark environment, we may experience hallucinations when we return to the normal environment. This may be due to a hypersensitivity to visual stimulation because of lack of it.
This was demonstrated in a study of 13 healthy subjects who were blindfolded for 5 days. 10 of them experienced visual hallucinations after the band withdrawal (Merabet et al., 2004).
- Schizophrenia
Under these conditions, hallucinations are a symptom. Usually the most frequent are the auditory type (such as hearing voices), but can also be visual (16% - 72%). This percentage variability is due to the severity of the schizophrenia presented by the subjects. That is, the more severe the schizophrenia of the participants evaluated in the study, the more likely they are to have visual hallucinations.
It seems that the appearance of hallucinations is associated in these cases with a lack of regulation of Dopamine In the mesolimbic way of the brain. Specifically, an excess of dopamine or dopaminergic receptors in this region.
- Dementia : Encompass a group of diseases that have in common progressive cerebral degeneration.
Visual hallucinations may occur when diseases such as Alzheimer's or the Parkinson's Are in more advanced phases and begin to affect areas in charge of visual processing.
- Charles Bonnet Syndrome : Is a non-psychiatric cause of visual hallucinations in which patients have visual problems such as glaucomas, cataracts or macular degeneration.
Hallucinations are always visual and tend to be complex, the mental health of these patients being intact.
At first they are not aware that they have hallucinations, but little by little they realize that they have them.
- Anton o Syndrome Cortical blindness
- Epilepsy : In some cases, visual hallucinations may occur during epileptic seizures. Commonly they are simple and brief, and they consist of bright colors or lights that change of form.
This is because parts of the brain that control vision are overactive.
- Brain tumors or strokes affecting the visual areas. In fact, beginning to suffer from sudden visual hallucinations, along with other symptoms, may be a sign of the presence of a brain tumor.
- Substance abuse, drug intoxication, or abstinence syndrome : There are certain drugs like LSD , PCP or hallucinogenic fungi that can cause hallucinations of different levels. However, they are usually pseudoalucinations since normally those who consume know how to distinguish between hallucinations and reality.
Drinking too much alcohol, your abstinence, or drugs like cocaine and ether can also produce hallucinations.
- Lack of sleep: A person who spends several days without sleep (about three days), or does not sleep enough for long periods of time, is prone to hallucinations.
It seems that when we are awake our brain secretes Adenosine . It has inhibitory and sedative effects, and if it accumulates in large quantities in our brain, it can cause hallucinations.
- Side effects of medications: Certain medications taken for mental and physical conditions can also cause hallucinations. Some of them are aspirin, apomorphine, Ropinirole (for Parkinson's), Propranolol (for hypertension), atenolol, enflurane... among others.
- Heavy metal poisoning
- Diseases such as renal or hepatic failure, encephalitis, HIV, and uremia
- High fever, especially in children and the elderly
- Migraines: between 15% and 29% of the general population suffers migraines. Within this group, up to 31% have an"aura". Auras usually occur before or while the headache is present, and involves visual hallucinations (by 90%). Specifically, the experiencer sees blinking flashes making zig-zag movements.
- He stress Severe or prolonged insulation can cause visual hallucinations. The latter usually happens in older people living alone.
On the other hand, stress can cause brief pictures of visual hallucinations. In fact, studies with prisoners have suffered up to 25% of the subjects (Ronald, 1984).
- Altered states of consciousness.
Types of visual hallucinations
Hallucinations have been classified in many different ways, each author being based on different criteria.
Visual hallucinations are usually differentiated by:
Degree of complexity
- Simple or elemental : They are the simplest and are treated of simple geometric forms, lights, flashes, colors... They are called photopsies or photomas.
- Complexes : They are very real and elaborate. Subjects with this type of hallucinations can vividly observe animals, objects, people, scenes, etc. With all details, as if it were a real event.
Size
- Liliputienses: Seeing small beings, usually people or animals; Although objects of small size can also be seen. It implies a world in miniature, which is contemplated with a pleasant mood. It is often caused by excessive consumption of any drug.
- Gulliverianas: The opposite of the above, consists in seeing people, animals or gigantic objects.
As perceived or not
- Positive: Perceive a visual element that does not exist in the environment.
- Negative: They can not perceive an element that does exist.
According to the content
- Objects Which may be familiar, strange and even non-existent.
- Animals , Monsters and insects. When they are unpleasant or they produce terror, they are called zoopsias. For example, the patient may see lions' heads trying to devour him. Zoopsias are common in alcoholics.
- People
- Stains (Like blood or mud)
- According to the fears, desires, expectations, memories...
- Of a religious or cultural nature
- Related to the presence of certain Delusions (Like seeing cameras installed in your house if you have delirium of persecution).
According to the state of mind
- Congruent with the mood: If the person is depressed, for example, the hallucinations will be annoying according to their concerns.
- Not congruent with the mood: No relationship is found between the mood of the person and the subject of their hallucinations.
During the dream
When we fall asleep, our brain activity goes through different phases that change during sleep. Such transitions in brain activity, naturally, may manifest in hallucinations.
- Hypnopompic : Visual hallucinations that occur upon awakening.
- Hypnagogic : Those that arise when we are falling asleep.
Autoscopic
Regarding ourselves, it can be:
- Autoscopy : To see ourselves within our visual field, as if it were a clone.
- Negative Autoscopy : We do not see our image reflected in the mirror.
Treatment
Treatment for hallucinations depends on the causes that caused them. First you have to detect what is causing the hallucinations and thus get the treatment right, so it is important to make the correct diagnosis.
In addition, a treatment that may be beneficial for visual hallucinations arising from a certain cause may be negative if the cause is otherwise.
For example, for hallucinations delirium tremens Can serve the Benzodiazepines . However, if hallucinations are due to another cause, benzodiazepines may exacerbate such hallucinations (Teeple, Caplan & Stern, 2009).
If hallucinations are the result of psychotic diseases, neuroleptic drugs that are antagonists of Dopamine Such as haloperidol. In addition, these medications also treat delusions (very firm beliefs that do not fit with the logic, or with the culture of the individual, frequent in psychosis).
For dementias like Alzheimer disease , In mild and moderate phases cholineterase inhibitors such as galantamine, donepezil and rivastigmine are recommended.
For migraines, triptans (sumatriptan, zolmitriptan) or beta-blockers appear effective. Epilepsy should be treated with anticonvulsants, and tumors with radiation and surgery.
However, there are some cases where visual hallucinations do not have direct treatment. In these cases neuroleptics are used to minimize them and other types of therapy, such as psychological therapy.
Thanks to the Cognitive behavioral therapy , These patients can learn about hallucinations, what causes them, come to recognize that they suffer hallucinations, and train themselves in the hard task of identifying when they appear. At this point, patients are taught to ignore the visual elements of the hallucination.
Of course, to enhance the effects of any intervention it is essential that people maintain good habits such as sleeping the necessary hours each night, treating insomnia or stress if they exist, and abandoning the use of drugs and other addictive substances.
If side effects of a drug are treated, it may be useful to replace it with another that has the same mechanism of action, but does not produce visual hallucinations.
References
- Teeple, R.C., Caplan, J.P., & Stern, T.A. (2009). Visual Hallucinations: Differential Diagnosis and Treatment. Primary Care Companion to The Journal of Clinical Psychiatry, 11 (1), 26-32.
- Romero- Vargas, S.; Ruiz-Sandoval, J. L.; García-Navarro, V. (2004) Visual hallucinations. Semiology and pathophysiology. Rev Mex Neuroci; 5 (5): 488-494.
- Merabet L.B., Maguire D., Warde A., et al. (2004). Visual hallucinations during prolonged blindfolding in sighted subjects. J Neuroophthalmol; 24 (2): 109-113.
- Luque, R. (2007). Hallucinations: Historical and clinical review. Psychiatric Information, 189.
- Ronald, K.S. (1984). Hostage hallucinations. Visual Imagery Induced by isolation and life-threatening stress. J. Nervous and Mental Dis; 172: 264-72.
- CHAPTER 6: PSYCHOPATHOLOGY OF PERCEPTION AND IMAGINATION. (S.f.). Retrieved on October 3, 2016, from PsychologyUNED.com.
- Reyes Pérez, J. (s.f.). The clinical study of hallucinations . Retrieved on October 3, 2016, from Monographs.
- Rico, E.M. (s.f.). Schizophrenia: The Great Unknown . Retrieved on October 3, 2016, from Encounters in Biology.
- Sahún, J.L. (s.f.). Semiology and psychopathology of hallucinations . Retrieved on October 3, 2016, from descriptive psychopathology and phenomenology.
- What Are Hallucinations? (S.f.). Retrieved on October 3, 2016, from WebMD.
- What causes hallucinations? 19 possible conditions . (S.f.). Retrieved on October 3, 2016, from HealthLine.