出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/10/23 05:58:50」(JST)
paracusia | |
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Classification and external resources | |
ICD-10 | R44.0 |
ICD-9-CM | 780.1 |
Neuropsychology |
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A paracusia, or auditory hallucination,[1] is a form of hallucination that involves perceiving sounds without auditory stimulus. Auditory hallucinations need to be distinguished from endaural phenomena in which sounds are heard without any external acoustic stimulation but arise from disorders of the ear or auditory system.
A common form of auditory hallucination involves hearing one or more talking voices. This may be associated with psychotic disorders such as schizophrenia or mania, and holds special significance in diagnosing these conditions.[2] However, individuals may hear voices without suffering from diagnosable mental illness.[3]
There are three main categories into which the hearing of talking voices can often fall: a person hearing a voice speak one's thoughts, a person hearing one or more voices arguing, or a person hearing a voice narrating his/her own actions.[4] These three categories do not account for all types of auditory hallucinations.
Other types of auditory hallucination include exploding head syndrome and musical ear syndrome. In the latter, people will hear music playing in their mind, usually songs they are familiar with. Reports have also mentioned that it is also possible to get musical hallucinations from listening to music for long periods of time.[5] This can be caused by: lesions on the brain stem (often resulting from a stroke); also, sleep disorders such as narcolepsy, tumors, encephalitis, or abscesses.[6] Other reasons include hearing loss and epileptic activity.[7]
Robert Schumann, a famous music composer, spent the end of his life experiencing auditory hallucinations. Schumann’s diaries state that he suffered perpetually from imagining that he had the note A5 sounding in his ears. The musical hallucinations became increasingly complex. One night he claimed to have been visited by the ghost of Schubert and wrote down the music that he was hearing. Thereafter, he began making claims that he could hear an angelic choir singing to him. As his condition worsened, the angelic voices transmogrified into demonic voices.[8]
Joan of Arc claimed to hear the voices of Saints who were the force that guided her and was resolved to obey these messages as she believed they were sent directly from God. She first began hearing voices when she was thirteen and soon after had visions of St. Michael, St. Catherine and St. Margaret.[8]
Brian Wilson, songwriter and co-founder of the Beach Boys, is afflicted with schizoaffective disorder that presents itself in the form of disembodied voices.[9] They formed a major component of Bill Pohlad's Love & Mercy (2014), a biographical film which depicts Wilson's hallucinations as a source of musical inspiration,[10] constructing songs that were partly designed to converse with them.[11] Wilson has said of the voices: "Mostly [they're] derogatory. Some of it's cheerful. Most of it isn't."[12] To combat them, his psychiatrist advised that he "talk humorously to them", which he says has helped "a little bit".[9]
The onset of delusional thinking is most often described as being gradual and insidious. Patients described an interest in psychic phenomena progressing to increasingly unusual preoccupations and then to bizarre beliefs "in which I believed wholeheartedly". One author wrote of their hallucinations: "they deceive, derange and force me into a world of crippling paranoia". In many cases, the delusional beliefs could be seen as fairly rational explanations for abnormal experiences: "I increasingly heard voices (which I'd always call ‘loud thoughts’)... I concluded that other people were putting these loud thoughts into my head".[13] Some cases have been described as an "auditory ransom note".
A group of emergency responders experienced a group auditory hallucination. Officers named Bryan Dewitt, Jared Warner, and Tyler Beddoes report they heard a voice that said, 'Help me, help me'. On Saturday, March 7, 2015, three police officers and four firefighters entered the Spanish Fork River in Spanish Fork to push the wrecked car of Lynn Groesbeck on its side. [14][15][16][17]
The ancient world viewed hallucinations as it did most of the natural world, with awe and superstition. As such, it was viewed as either a gift or curse by God, or the gods (depending on the specific culture). During the reign of Tiberius (A.D. 14–37), a sailor named Thamus heard a voice that told him the God Pan was dead. The oracles of ancient Greece were known to experience auditory hallucinations while breathing in certain neurologically active vapors, while the more pervasive delusions and symptomology were often viewed as possession by demonic forces as punishment for misdeeds.[8]
Treatment in the ancient world is ill documented, but there are some cases of therapeutics being used to attempt treatment, while the common treatment was sacrifice and prayer in an attempt to placate the gods. The Dark Ages saw the most horrific accounts where the sufferers of auditory hallucinations were subjected to trepanning or trial as a witch.[8] In other cases of extreme symptomatology individuals were seen as being reduced to animals by a curse, these individuals were either left on the streets or imprisoned in insane asylums. It was the latter response that eventually led to modern psychiatric hospitals.[18]
Auditory hallucinations were rethought during the enlightenment. As a result, the predominant theory in the western world beginning in the late 18th century was that auditory hallucinations were the result of a disease in the brain (e.g. mania), and treated as such.[18]
There were no effective treatments for hallucinations at this time. Conventional thought was that clean food, water, and air would allow the body to heal itself (Sanatorium). Beginning in the 16th century Insane Asylums were first introduced in order to remove “the mad dogs” from the streets and left them chained to walls and living in their own filth.[18] These asylums acted as prisons until the late 18th century. This is when doctors began the attempt to treat patients. Often attending doctors would douse patients in cold water, starve them, or spin patients on a wheel. Soon, this gave way to brain specific treatments with the most famous examples including Lobotomies, shock therapy and branding the skull with hot iron.[18]
The premier cause of auditory hallucinations in the case of psychotic patients is schizophrenia. In those cases, patients show a consistent increase in activity of the thalamic and strietal subcortical nuclei, hypothalamus, and paralimbic regions; confirmed via PET scan and fMRI.[19][20] Other research shows an enlargement of temporal white matter, frontal gray matter, and temporal gray matter volumes (those areas crucial to both inner and outer speech) when compared to control patients.[21][22] This implies both functional and structural abnormalities in the brain can induce auditory hallucinations, both of which may have a genetic component.[23][24][25] Mood disorders have also been known to cause auditory hallucinations, but tend to be milder than their psychosis induced counterpart. Auditory hallucinations are a relatively common sequelae of Major Neurocognitive Disorders (formerly dementia) such as Alzheimer's disease.[26]
Auditory hallucinations have been known to manifest as a result of intense stress, sleep deprivation, drug use, and errors in development of proper psychological processes.[clarification needed][27] Genetic correlation has been identified with auditory hallucinations,[25] but most work with non-psychotic causes of auditory hallucinations is still ongoing.[27][28]
High caffeine consumption has been linked to an increase in the likelihood of experiencing auditory hallucinations. A study conducted by the La Trobe University School of Psychological Sciences revealed that as few as five cups of coffee a day could trigger the phenomenon.[29]
The primary means of treating auditory hallucinations is antipsychotic medications which affect dopamine metabolism. If the primary diagnosis is a mood disorder (with psychotic features), adjunctive medications are often used (e.g., antidepressants or mood stabilizers). These medical approaches may allow the person to function normally but are not a cure as they do not eradicate the underlying thought disorder.[30]
Cognitive-Behavioral Therapy has been shown to help decrease the frequency and distressfulness of auditory hallucinations, particularly when other psychotic symptoms were presenting.[31] Enhanced Supportive Therapy has been shown to reduce the frequency of auditory hallucinations, the violent resistance the patient displayed towards said hallucinations, and an overall decrease in the perceived malignancy of the hallucinations.[31] Other cognitive and behavioral therapies have been used with mixed success.[32][33]
Electroconvulsive therapy or ECT has been shown to reduce psychotic symptoms associated with schizophrenia[citation needed], mania, and depression, and is often used in psychiatric hospitals.
In recent years, repetitive transcranial magnetic stimulation (rTMS) has been studied as a biological method of treatment for auditory hallucinations. rTMS plays a role in altering neural activity over language cortical regions. Studies have shown that when rTMS is used as an adjunct to antipsychotic medication in treatment-resistant cases, the frequency and severity of auditory hallucinations can be reduced.[34]
Another source of non-conventional techniques to cope with the voices are provided by the research and findings of the Hearing Voices Movement[35]
There is on-going research that supports the prevalence of auditory hallucinations, with a lack of other conventional psychotic symptoms (such as delusions, or paranoia), particularly in pre-pubertal children.[36] These studies indicate a remarkably high percentage of children (up to 14% of the population sampled[37]) experienced sounds or voices without any external cause, though it should also be noted that "sounds" are not considered by psychiatrists to be examples of auditory hallucinations. Differentating actual auditory hallucinations from "sounds" or a normal internal dialogue is important since the latter phenomena are not indicative of mental illness.
The causes of auditory hallucinations are unclear.
Dr. Charles Fernyhough, of the University of Durham poses one theory among many but stands as a reasonable example of the literature. Given standing evidence towards involvement of the inner voice in auditory hallucinations,[38] he proposes two alternative hypotheses on the origins of auditory hallucinations in the non-psychotic. They both rely on an understanding of the internalization process of the inner voice.[27][37][39]
The internalization process of the inner voice is the process of creating an inner voice during early childhood, and can be separated into four distinct levels.[27][37][39]
Level one (external dialogue) involves the capacity to maintain an external dialogue with another person, i.e. a toddler talking with their parent(s).
Level two (private speech) involves the capacity to maintain a private external dialogue, as seen in children voicing the actions of play using dolls or other toys.
Level three (expanded inner speech) is the first internal level in speech. This involves the capacity to carry out internal monologues, as seen in reading to oneself, or going over a list silently.
Level four (condensed inner speech) is the final level in the internalization process. It involves the capacity to think in terms of pure meaning without the need to put thoughts into words in order to grasp the meaning of the thought.
A disruption could occur during the normal process of internalizing ones’ inner voice, where the individual would not interpret their own voice as belonging to them; a problem that would be interpreted as level one to level four error.[27][37][39]
Alternatively, the disruption could occur during the process of re-externalizing one's inner voice, resulting in an apparent second voice that seems alien to the individual; a problem that would be interpreted as a level four to level one error.[27][37][39]
Psychopharmacological treatments include anti-psychotic medications. Psychology research shows that first step in treatment is for the patient to realize that the voices they hear are creation of their own mind. This realization is argued to allow patients to reclaim a measure of control over their lives. Some additional psychological interventions might allow for the process of controlling these phenomena of auditory hallucinations but more research is needed.[27]
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リンク元 | 「統合失調症」「dissociative hallucination」「unformed visual hallucination」「gustatory hallucination」「幻聴」 |
関連記事 | 「auditory」 |
A. | 特徴的症状:以下のうち2つ以上が1ヶ月以上の存在 |
(1) 妄想 | |
(2) 幻覚 | |
(3) 解体した会話 | |
(4) ひどく解体したまたは緊張病性の行動 | |
(5) 陰性症状:感情平板化、思考貧困、意欲欠如 | |
B. | 社会的または職業的機能の低下 |
C. | 期間:少なくとも6ヶ月間存在 |
D. | 失調感覚障害(統合失調感情障害)と気分障害を除外 |
E. | 物質や一般身体疾患の除外 |
F. | 広汎性発達障害との関係:自閉性障害や 他の広汎性発達障害の既往歴がある場合、 顕著な幻覚や妄想が少なくとも1ヶ月存在すること |
(a) | 考想化声 thought echo、考想吹込 thought insertion、思考奪取 thought withdrawal、考想伝播 thought broadcasting | いずれか1つ |
(b) | させられ体験 delusion of control、身体的被影響体験 delusion of influence、妄想知覚 delusional perception | |
(c) | 注釈幻声、会話形式の幻聴 auditory hallucination | |
(d) | 宗教的・政治的な身分や超人的な力や能力といった、文化的に不適切で実現不可能なことがらについての持続的な妄想(たとえば天候をコントロールできるとか、別世界の宇宙人と交信しているといったもの)。 | |
(e) | 持続的な幻覚が、感傷的内容を持たない浮動性あるいは部分的な妄想や支配観念に伴って継続的に(数週から数ヶ月)現れる。 | いずれか2つ |
(f) | 思考の流れに途絶や挿入があり(思考途絶)、その結果まとまりのない話しかたをしたり(連合弛緩)、言語新作が見られたりする。 | |
(g) | 興奮、常同姿勢、蝋屈症、拒絶症、緘黙、昏迷などの緊張病性行動 catatonic behavior。 | |
(h) | 著しい無気力、会話の貧困、情動的反応の鈍麻や不適切さのような、社会的引きこもりや、社会的能力の低下をもたらす陰性症状。 | |
(i) | 関心喪失、目的欠如、無為、自分のことだけに没頭する態度、社会的引きこもりなど、個人的行動の質的変化。 |
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