出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/05/04 22:53:14」(JST)
Overactive bladder | |
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Classification and external resources | |
ICD-10 | N32.8 |
ICD-9 | 596.51 |
MeSH | D053201 |
Overactive bladder (also known as OAB, or Overactive Bladder Syndrome) is a urological condition related to problems with urination. It is an often debilitating and stigmatised syndrome that is not life-threatening and does not always require treatment.[1][2]
The hallmark symptom of overactive bladder is urgency, but the diagnosis also includes frequent urination, frequent interruptions of sleep because of the need to urinate (nocturia), and urinating unintentionally followed by an urge to continue (urge incontinence). Overactive bladder has many causes which can include diseases such as diabetes,[citation needed] medications such as diuretics, or lifestyle choices such as excessive consumption of caffeine or alcohol.[3] Bothersome urinary symptoms that are related to neurological conditions such as multiple sclerosis are generally treated differently from overactive bladder in people who do not have neurological problems.
People with the condition often have the symptoms for a long time before seeking medical care, and the condition is sometimes identified by caregivers rather than the person with the symptoms. The condition is similar to polyuria and polydipsia and is distinguished from other conditions because the amount of urine passed when there is an urgent need to urinate is relatively small with overactive bladder. Pain while urinating suggests that there is a problem other than overactive bladder.[2]
Management of overactive bladder is addressed in terms of quality of life since it is not a life-threatening problem, and treatment is not always necessary if the treatment would cause more discomfort than the symptoms. The person often keeps a diary tracking urination to help determine whether treatments are working. If the person's quality of life is impaired and behavioral therapies do not work, medications such as anti-muscarinic drugs are used to control the symptoms. Invasive treatment such as surgery to modify spinal nerves is possible but is avoided because of the potential for permanent damage and the nonthreatening nature of the disorder. Overactive bladder is not rare, estimates in population studies vary widely and suggest that from 7-27% of men and 9-43% of women experience these symptoms.[citation needed] Other studies suggest that the condition is more common in men.[citation needed] Many people who have problems have them for less than a year.[2]
There is some controversy about the classification and diagnosis of OAB.[2][4] Some sources classify overactive bladder into "wet" and "dry" variants depending on whether it is an urgent need to urinate or if it includes incontinence. Wet variants are more common than dry variants.[5] The distinction is not absolute, one study suggested that many classified as "dry" were actually "wet" and that patients with no history of any leakage may have had other syndromes.[6]
Overactive bladder is characterized by a group of four symptoms: urgency, urinary frequency, nocturia, and urge incontinence. Urge incontinence is not present in the "dry" classification.
Urgency is considered the hallmark symptom of OAB, but there are no clear criteria for what constitutes urgency and studies often use other criteria.[2] Urgency is currently defined by the International Continence Society (ICS), as of 2002, as "Sudden, compelling desire to pass urine that is difficult to defer." The previous definition was "Strong desire to void accompanied by fear of leakage or pain."[7] The definition does not address the immediacy of the urge to void and has been criticized as subjective.[7]
Urinary frequency is considered abnormal if the person urinates more than eight times in a day. This frequency is usually monitored by having the patient keep a voiding diary where they record urination episodes.[2] The number of episodes varies depending on sleep, fluid intake, medications, and up to seven is considered normal if consistent with the other factors.
Nocturia is a symptom where the person complains of interrupted sleep because of an urge to void and, like the urinary frequency component, is affected by similar lifestyle and medical factors. Individual waking events are not considered abnormal, one study in Finland established two or more voids per night as affecting quality of life.[8]
Urge incontinence is a form of urinary incontinence characterized by the involuntary loss of urine occurring for no apparent reason while feeling urinary urgency as discussed above. Like frequency, the person can track incontinence in a diary to assist with diagnosis and management of symptoms. Urge incontinence can also be measured with pad tests, and these are often used for research purposes. Some people with urge incontinence also have stress incontinence and this can complicate clinical studies.[2]
It is important that the clinician and the patient both reach a consensus on the term, 'urgency.' Some common phrases used to describe OAB include, 'When I've got to go, I've got to go,' or 'When I have to go, I have to rush, because I think I will wet myself.' Hence the term, 'fear of leakage,' is an important concept to patients. [9]
The etiology of OAB is unclear, and indeed there may be multiple causes.[10] It is often associated with overactivity of the Detrusor urinae muscle, a pattern of bladder muscle contraction observed during urodynamics.[11] It is also possible that the increased contractile nature originates from within the urothelium and lamina propria, and abnormal contractions in this tissue could stimulate dysfunction in the detrusor or whole bladder.[12] Treatments for OAB are usually synonymous with treatments for detrusor overactivity. OAB is distinct from stress urinary incontinence, but when they occur together, the condition is usually known as mixed incontinence.
Diagnosis of OAB is made primarily by ruling out other causes of overactivity of the bladder such as an infection or bladder tumor.[11] The diagnosis is confirmed by cystometry. Additionally, urine culture may be done to rule out infection. The frequency/volume chart may be maintained and cystourethroscopy may be done to exclude tumor and kidney stones. If there is an underlying metabolic or pathologic condition that explains the symptoms, the symptoms may be considered part of that disease and not OAB.
OAB causes similar symptoms to some other conditions such as urinary tract infection (UTI), bladder cancer, and benign prostatic hyperplasia (BPH). Urinary tract infections often involve pain and hematuria (blood in the urine) which are typically absent in OAB. Bladder cancer usually includes hematuria and can include pain, both not associated with OAB, and the common symptoms of OAB (urgency, frequency, and nocturia) may be absent. BPH frequently includes symptoms at the time of voiding as well as sometimes including pain or hematuria, and all of these are not usually present in OAB.[7]
Treatment for OAB includes nonpharmacologic methods such as lifestyle modification (fluid restriction, avoidance of caffeine), bladder retraining or may involve the use of pharmaceutical agents such as antimuscarinic drugs (e.g., darifenacin, hyoscyamine, oxybutynin, tolterodine, solifenacin, trospium, fesoterodine).[11] β3 adrenergic receptor agonists (e.g., mirabegron),[13] and various devices (Urgent PC Neuromodulation System, InterStim) may also be used. Botulinum toxin A (Botox) is approved by the Food and Drug Administration in adults with neurological conditions, including multiple sclerosis and spinal cord injury.[14] Botulinum Toxin A injections into the bladder wall can suppress involuntary bladder contractions by blocking nerve signals and may be effective for up to 9 months.[15][16] The growing knowledge of pathophysiology of overactive bladder fuelled a huge amount of basic and clinical research in this field of pharmacotherapy.[17][18][19] A surgical intervention involves the enlargement of the bladder using bowel tissues, although generally used as a last resort. This procedure can greatly enlarge urine volume in the bladder.
Studies have shown that few people get complete relief from overactive bladder drugs and that all available drugs are no more than moderately effective.[20] A typical person with overactive bladder may urinate 12 times per day.[20] Medication may reduce this number by 2-3 and reduce urinary incontinence events by 1-2 per day.[20]
Earlier reports estimated that about one in six adults in the United States and Europe had OAB.[21][22] The prevalence of OAB increases with age,[21][22] thus it is expected that OAB will become more common in the future as the average age of people living in the developed world is increasing. However, a recent Finnish population-based survey[23] suggested that the prevalence had been largely overestimated due to methodological shortcomings regarding age distribution and low participation (in earlier reports). It is suspected, then, that OAB affects approximately half the number of individuals as earlier reported.[23]
The American Urological Association reports[citation needed] studies showing rates as low as 7% to as high as 27% in men and rates as low as 9% to 43% in women. Urge incontinence was reported as higher in women. Older people are more likely to be affected, and prevalence of symptoms increases with age. Many people with OAB symptoms had those symptoms subside within a year, with estimates as high as 39%, but most have symptoms for several years.[2]
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リンク元 | 「過活動膀胱」「神経因性膀胱」「ダリフェナシン」「過活動性膀胱」 |
拡張検索 | 「non-neurogecic overactive bladder」「neurogecic overactive bladder」 |
関連記事 | 「overactive」「bladder」 |
神経系に生じた障害により生じる蓄尿・排尿障害
橋排尿中枢より上位の障害 | 脳血管障害(脳出血、脳梗塞)、パーキンソン病、認知症、脳外傷、脳腫瘍 | [橋排尿中枢への抑制が失わる]蓄尿による求心性知覚線維(Aδ)の興奮→(中枢より抑制を受けず)PMCによる排尿指令→仙髄副交感神経中枢による排尿指令→排尿筋収縮 | 蓄尿障害(排尿筋不随意収縮、切迫尿失禁、頻尿) |
核上脊髄障害 | 脊髄損傷、多発性硬化症、損傷部位に依存して後縦靭帯骨化症、二分脊椎、HAMでも起こる | [異常な排尿回路の形成]蓄尿による求心性知覚線維(C)の興奮→(C線維による2つの異常な回路が形成され、求心性知覚情報はここに入力)(1)仙髄副交感神経中枢による排尿指令、(2)オヌフ核による外尿道筋収縮→排尿筋収縮+外尿道筋収縮 | 蓄尿障害(反射性尿失禁)、排尿障害(排尿筋括約筋協調不全) |
仙髄より下位の神経障害 | 下位脊髄損傷、仙髄以下馬尾神経の障害をきたす二分脊椎、脊髄稽留症候群、腰部脊柱管狭窄症、下位の損傷を起こすような後縦人口骨化症、シャイ・ドレガー症候群、脊髄小脳変性症、多発性硬化症、脊髄癆、HAM | 排尿障害、残尿、尿閉 |
[★] 膀胱 urinary bladder 胆嚢 gallbladder
.