Wednesday, October 31, 2012

DOUBLE hallucination and other phenomena



DOUBLE hallucination and other phenomena 

One of the best known types of hallucination is called "dual phenomenon" (also called autoscopy, heautoscopia, Doppelganger, etc..). The autoscopy (literally see himself) is defined as the visual experience in which the subject sees his picture in external space (as if reflected in a mirror) from their own cuerpo75. Vision may be brief or persistent, the whole person or parts of it, with a normal consistency or clear and accompanied by an emotional response. However, little is known about the natural history, clinical presentation, the meaning and etiology of this experience is not even clear that should always be considered a hallucination.

This phenomenon has been observed since antiquity. Aristotle, in his work Meteorological, and told of a man who every time he went for a walk persistently saw his own image walking towards él76. The consideration of the phenomenon as abnormal or pathological depends on cultural beliefs about the limits of self and the ability to view the image itself. So, this experience is in the mythology of the death and resurrection of some Asian tribes and among Aboriginal australianos77. In Western culture fads and secular beliefs have been important since in European folklore autoscópicas experiences were considered a harbinger of death inminente78. In the nineteenth century romantic literature there are descriptions of autoscopy and similar experiences in the works of Jean Paul Richter (Hesperus), Gabriele d'Annunzio (Notturno), Oscar Wilde (The Picture of Dorian Gray), Guy de Maupassant (The Horla ), Edgar Allan Poe (William Wilson) and Fyodor Dostoevsky (Twice). Other writers like Alfred de Musset, Robert Stevenson, Gerard de Nerval, James Hogg or own Maupassant and Poe's hallucinatory experiences doble76 suffered. In the nineteenth century the symptom was well known and was called variously 3, 75 Brierre of Boismont called deuteroscopie; Jean Paul Richter doppelganger used the term to refer to the 'bi'; autoscopy (Féré; Lemaitre; Sollier) was used in the early twentieth century, but failed to find the correct perception of the subject itself was replaced by heautoscopia (Menninger-Lerchenthal; L'Hermitte; Hecaen and Ajuriaguerra). The terms hallucination speculaire (Féré) and Spiegelphantom (Conrad) not jelled because the perception of the subject pointed itself. Dening and Berrios75 considered more appropriate to reserve the term autoscopy for alterations of visual perception in which subjects see their own image in the external space from his own physical body.

Autoscópicos phenomena have been described in neurological diseases such as epilepsy, migraine, tumors, strokes, head injuries and infecciones75, 79, 80, 81, 82, 83 and psychiatric disorders such as schizophrenia, depression, anxiety, depersonalization, and dissociative states identificación75 false syndromes, 78, 79, 84, 85, 86, 87.

It has been suggested that the autoscopy could arise from the convergence of several variables, such as gender, personality traits, psychiatric illness and / or neurological, and dissociative states whose depletion interaction could overcome the normal inhibition lobe activity temporal73.

Brugger82 group, 88, 89 has proposed a classification of autoscópicos phenomena including six types:

1. Sense of presence: in this phenomenon the "double somatestésico ghost" is "sense" but not seen (similar to phantom limb phenomenon) 90. It also goes by the names of Anwesenheit91, next falsa92 consciousness and somestésico93 doppelgänger.

2. Hallucination autoscopic: visual hallucination would double itself dicha94. That is, the double would be seen only from the body itself, lacking any component somatestésico. Originally called "hallucinations mirror" 95, 96.

3. Heautoscopia ghost or double vision and somatestésico: implies the existence of two selves (observer and observed), although recently described the experience heautoscopia poliópica where the existence of multiple dobles97. Also called self85 autoalucinación98 and hallucination. In this case the visual aspects are predominant and twice, seen also from the body is described as pale, hazy, transparent or ghostly. The most important is the psychological feeling of affinity towards the second self, "meaning" and physically recognized as "other me" even when the visual characteristics do not match their own (heautoscopia dissimilar) 94.

4. The out of body experience. This term, from the para-psychology, replaced previous expressions of the world of para-normal phenomena as "astral projection," "ectosomática experience" or "externalization of sensibility" and was related to statements such as "bi" ( the supposed ability of some people to be in two places at once), the "astral bodies" (hypothetically body consisting of a "light stuff") or experiences near the muerte99, 100. In medical and psychological literature have used other terms like "pseudo autoscopia", "ego trip", "floating syndrome experience," "hallucinations of physical duality" and "split visuo-vestibular somatosensory body image» 82. The phenomenon is the perception of oneself from the outside, ie from a visio-spatial parasomática unlike other autoscópicos phenomena are experienced within the corporate limits and the double is perceived from a visio-spatial física101. In OBE rarely used the term "double", and the main feature is the apparent remoteness of body awareness, which is seen or "seen" in another spatial point. Recently, it has been explained as poor integration of visual, tactile and proprioceptive body awareness with information relating to personal space and extrapersonal101, 102, 103, 104.

5. Heautoscopia negative: in this case the subject is not himself when his image reflected in a mirror. In most cases, is accompanied aschématie or loss of consciousness itself cuerpo105, 106. Some authors have proposed replacing the term by 'asomatoscopia »81, 107. Guy de Maupassant described this phenomenon in The Horla and E. T. A. Hoffman in his fairy tales.

6. In the internal heautoscopia internal organs are visually hallucinated extracorporeal space. This rare phenomenon, also called "organic self-representation," was described by several French writers of the early XX108, 109.

From neurology, autoscópicos phenomena have been related to the failure of the integration of proprioceptive, tactile and visual relative to body (multisensory disintegration in personal space) with vestibular dysfunction causing further disintegration among staff spaces (vestibular) and extrapersonal (visual). These disintegrations (personal personal-extrapersonal) are due to "paroxysmal brain dysfunction" in the temporo-parietal101 intersection, 102, 103. Moreover, it has been proposed that these experiences and the phantom limb phenomenon related to central representation of bodily self and suggest that the concept of 'neuromatrix "or" neuromatrix »* could help explicarlos82, 110. Specifically, there would be a "dissociation of neuromatrix" consisting temporal dissociation between the visual components and the neuromatrix somestésicos or between different subcomponents somatestésico field (for example, between the kinesthetic and tactile impressions).



* Melzack postulates that in the central nervous system there is a representation of body image or "neuromatrix 'which modulate cortical activities (affective and cognitive) with somatosensory afferents, visceral, nociceptive, autonomic, immune and endocrine generating pain perception. The neuromatrix is ​​a neural network that receives input and generates a "neurofirma" ("neurosignature") or print one for each person. Pathways involved there would be three: the first is sensitive and passes from the thalamus to the somatosensory cortex, the second is from the reticular formation to the limbic system and the third involves the parietal lobe where it generates the perception of the "self."



Lilliputian hallucinations

These complex visual hallucinations were described in 1834 by Leuret in the context of místicas111 experiences. In 1847, Sauvet used the term "midget" to refer to the vision of small beings that he himself experienced after poisoning by inhalation éter112 voluntary. They consist of the vision of "little people, men or women of diminutive height, which may be accompanied by small animals and objects provided in size" 113, 114. Hallucinations are usually multiple and people move and wear colored clothes. Occasionally represent a small puppet theater with miniature scenes and the patient hears these people speak in a "Lilliputian tone." Leroy said that unlike other visual hallucinations, the Lilliputians are accompanied by a pleasant mood and the patient attends funny representation of the world in miniature. Such hallucinations has little diagnostic value and have been described mainly in alcoholism and other poisoning as cocaine, cannabis, atropine, chloral and ether, and brain tumors, infections, vascular injury, dementia, epilepsy and hypnagogic states. In psychiatry have been described in schizophrenia and states disociativos115, 116.



Hypnologic hallucinations and hypnopompic
                                                                              
Hypnagogic hallucinations consist vivid perceptual experiences occurring at sleep onset, while hypnopompic happen to awaken it. For Hamilton, hypnopompic hallucinations, sensu stricto, is that, from sleep, remain when opening ojos117. The first systematic description of these phenomena was made in 1846 that Baillarger considered psychosensorial hallucinations. The term "hypnagogic"-of Hyno (sleep) and agogos (induced) - Maury introduced him in 1848 to designate the illusions that he experienced in sleepiness before sueño118, while the term "hypnopompic" first used it Myer time in 1918 to describe these phenomena during the transition between sleep and vigilia119. Hypnagogic and hypnopompic hallucinations are characteristic, and relatively frequent in narcolepsia120, but can also occur in normal subjects so sometimes hallucinations have been called physiological, and other psychological disorders such as depression, anxiety states , psychosis and intoxication. These are generally characterized by the perception of images (more rarely sounds) imposed in consciousness without the will of the subject although it recognizes the failure of the phenomenon, but at the same time experiencing them or, more often, when the state recovers normal waking. The duration varies from a few seconds to fifteen minutes, depending on the persistence of sleepiness. Fever or low vision can trigger hallucinations in subjects predispuestos121. The content of hallucinations is striking: usually bright spots of vivid colors or shapes that transform into shapes or complex images like human figures, faces, animals and landscapes of great beauty or adopt complex shapes from scratch. The images can be static or mobile and vividness and richness of experience outweigh any real phenomenon. Unlike what happens in deep sleep, the subject observes the action as a spectator without a plot that looks directly involved. The emotional response to the images can be neutral, pleasant, or terrorífica35 fascinating.



Musical hallucinations

Musical hallucinations are rare and are at the crossroads of otology practice, neurological and psiquiátrica122, 123, 124. Being so rare there is no commonly accepted theory on its diagnostic value, classification and path physiological mechanisms. Usually refers to hearing songs or melodies, although some authors consider this restrictive definition since music also includes harmonies, rhythm and timbres. This distinction is important because if the musical hallucinations causally related to specific brain locations is essential to know if the processing of information relating to the melody, harmony, rhythm or timbre locus occurs on a common brain. Also more likely to describe a musician as "music" more complex hallucinatory experiences that a person without musical training, so communication of musical hallucinations will be influenced by the musical knowledge of the patient. This would also influence the location of brain injury because the representation of musical information changes nondominant hemisphere dominant learning to musical125.

The history of musical hallucinations began in 1880s. Although authors such as Esquirol, Griesinger Baillarger or reports of patients had deaf hearing voices or music, psychiatrists are less interested in these phenomena that ENT. For example, stood Erhard126 various locations of these "subjective auditory sensations' sense of rhythm or pulsation in the internal carotid, the whispers in the hall, the songs or music in the cochlea, and tinnitus in the acoustic nerve. To Régis127, musical hallucinations are the result of positive and negative changes in sensory pathways: the first (eg, tinnitus) resulted in a sound that served as the point where crystallize musical hallucination, negative changes (eg deafness) helped create a state of deafferentation. Régis was forced to introduce other variables such as age or personality traits to explain why these hallucinations are so infrequent, although deafness and tinnitus are so common. During this same period, organic and psychological hypotheses proposed to explain the origin of such hallucinations. For example, unilateral musical hallucinations were considered organic aetiology (peripheral), although peripheral lesion could not alone explain the laterality of hallucination and suggest that there is also a cortical lesion. For insight Régis presence would serve to distinguish musical hallucinations of psychotic organic (functional). For example, Claude and Ey128 described the so-called "organic hallucinosis syndrome"-in which included musical hallucinations-and that is not related to psychotic hallucinations. At present there is still debate about the origin exclusively otologic or also could occur from neurológica124 pathology, 129, 130, 131.

In the history of music known several examples of composers who suffered hallucinations musicales132. The Czech Smetana, who probably suffered meningovascular neurosyphilis, persistently experienced hearing a high-pitched musical note he included in his String Quartet. The best known case is that of composer Robert Schumann, who for years suffered musical hallucinations from single notes to chords and melodies, which were reflected in works like the Kreisleriana, the Violin Concerto and the Symphony Spring.

Saba and Keshavan133 indicate that musical hallucinations are variable and complex phenomenon, and collected three causal mechanisms:

1. By "neuronal irritation" (excitatory phenomenon).

2. By "perceptual release" (release phenomenon).

3. By "musical memories parasites', ie, some memories (eg a song) are never 'unlearned', maintaining therefore fixed and independent presence in memory so that they become a regular experience.

Musical hallucinations have been described in different situations clínicas40, 122, 124, 134: hearing loss, brain damage from space-occupying processes to epilepsy and encephalitis vascular processes; psychoactive substance use and psychiatric disorders.

Depending on the etiology hallucinatory experience may vary in some respects as the form of onset (acute or insidious), the familiarity of what is heard, the type (instrumental, vocal or both) and genre, the origin of the perceived (in or outside the head), the location (right, left or bilateral), the sole presentation accompanied by other symptoms or impaired sensory perception or other psychiatric symptoms, the experience (pleasant, unpleasant or neutral) and the degree of insight.

To Berrios122, musical hallucinations are more common in women, in old age, with deafness and brain injuries most common causes. They tend to be persistent and continuous, but may be retained fragment and like a broken record. The most common form of hallucinations are either a cappella songs or instruments, the music is very common religious or patriotic hymns.

Regarding the specifics of hallucination in ear pathology hallucinations often accompany progressive onset and otherwise simple acoustic hallucination. Due to a brain process establishing abruptly, not accompanied by other hallucinations and insight remains on experience. Furthermore, it appears that no longer affect the hemisphere dominante135. The latter is very important because it suggests that the nondominant hemisphere plays an important role in the development of musical phenomena in patients with brain injury from tumors, strokes or epileptic foci. This finding is consistent with what is known of the relationship of music and the brain. It also suggests a dissociation between musical hallucinations and mechanisms related to verbal hallucinations in schizophrenia associated with the dominant hemisphere. Finally, the musical hallucinations in psychiatric disorders appear more frequently reported in depression, may be associated with other auditory hallucinations, visual and tactile, and there is usually no insight on them.
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