Research progress of male sexual dysfunction following stroke

Quan Wen,Gai Hang,Hua-Kang Wang,Ling-Xue Bao,Bo Chen＊

1Inner Mongolia Medical University,Hohhot,China.2Tongliao Hospital,Inner Mongolia,Tongliao,China.

Abstract

Keywords:Stroke,Quality of life,Sexual dysfunction

Background

Stroke is one of the common diseases in neurology.The incidence, recurrence rate, mortality and disability rate of this disease are relatively high, which is the second cause of death in the world population, second only to cardiovascular diseases.Along with changes in lifestyle habits, the incidence of stroke increased doubled during the past 30 years, while the etiology varies with age [1-3]. According to statistics, 95% of strokes occur after the age of 45 years, and two-thirds of stroke patients are more than 65 years old.The most painful thing for patients after stroke is the loss of all or part of their living ability, which seriously affects the self-care ability and quality of life of patients.Sexual function is a necessary and important component of quality of life. For stroke patients with neurological deficits, especially young stroke patients,their sexual dysfunction should be concerned and necessary treatment should be given [4-5]. In fact,although stroke has a great impact on patients' sexual function, patients basically do not seek medical attention for sexual dysfunction, and physicians do not ask about this content. Therefore, sexual dysfunction of patients after stroke should be paid more attention by both doctors and patients. The normal function of sexual function depends on a complex neural network,including the cerebral hemispheres and central pathways,involving the participation of autonomic and somatic nerves, and the integration of numerous spinal cords and supraspinal sites in the central nervous system, of which the hypothalamus and limbic system play an important role [6]. The effect of neurological disorders on sexual dysfunction is characterized by diminished response to sexual stimulation,increased or decreased libido, and reduced congestion of reproductive organs [7].Many studies have shown that sexual satisfaction decreases significantly after cerebrovascular events. Decreased libido, erectile and ejaculatory disorders are common in male stroke patients. The manifestations of sexual dysfunction in young and middle-aged male patients are mainly ED(erectile dysfunction). During sexual activity, men are often active acquisitors, and ED occurrence is multifactorial. Studies have shown that the factors affecting male erection are mainly related to the patient's smoking history, combined hypertension,worry about stroke recurrence and taking antihypertensive drugs β-receptor inhibitors. There are many and complex factors affecting sexual function in stroke patients. The location and area of stroke and the occurrence and development process of the disease may affect the sexual function of patients. However,there was no difference in sexual life among patients with different degrees of stroke. In the literature, the incidence of decreased libido after stroke ranges from 17% to 42% [8]. Moreover, stroke patients with mild or no disability also have a significant decrease in sexual frequency, sexual satisfaction, libido, sexual excitement, and high sexual tide [9]. However, the study by Korpelainen et al. [10] showed that only a small number of patients would stop having sex as a result.

1.Etiology of post-stroke sexual dysfunction

1.1 Limb paralysis

Limb dysfunction is an important cause of long-term dysfunction. Limb motor dysfunction caused by stroke affects the patient's ability to maintain certain positions,which in turn affects the ability to hug and caress sexual partners during sex. At the same time, facial paralysis,language and memory problems,hemiplegia,eating difficulties and fecal and urinary incontinence will make the charm of life decreased, affect libido,resulting in reduced sexual life.

1.2 Sensory disturbance

Sexual dysfunction is closely related to hemisensory disturbance. Sj-gren et al. [11] found that changes in the frequency of sexual intercourse were associated with the degree of skin sensory impairment and the level of self-care ability in daily life, but not with the degree of motor function impairment. In fact, tactile stimulation is very important during sexual excitement and foreplay as well as during orgasm. Generally, a stroke in the right middle cerebral artery territory may cause numbness and loss of sensation in the hemibody,which may affect how you feel during sex.

1.3 Aphasia

Aphasia can lead to difficulties in communicating for stroke patients. The research on aphasia and sexual dysfunction has been very scarce during the past 20 years. A prospective study by Lemieux et al. [12]showed that patients with aphasia had decreased frequency of sexual life and increased other forms of sexual activity. Patients believe that it is difficult to initiate sex linguistically; at the same time, their partners also experience some pain, such as aphasia patients are unable to express their feelings and communicate about sex. Therefore, it is believed that sexual function is impaired in stroke aphasia patients unlike in other types of stroke patients, and couples need to discuss this issue with their physicians together.However, the majority of medical staff do not care about this, which makes it more difficult for stroke aphasia patients to maintain social relations and sexual relations.

Previous reviews analyzed that sexual dysfunction in post-stroke patients was not caused by stroke itself,but by multiple effects of clinical and psychological factors. The study conducted by Mak et al. [13] in Belgium showed hypertension, diabetes, peripheral vascular disease and cardiac disease as important influencing factors of ED. Risk factors for stroke include diabetes, hypertension, dyslipidemia,hyperhomocysteinemia, heart disease, and peripheral vascular disease in addition to age. Atherosclerosis can cause heart disease, hypertension, and stroke; it may also affect the blood circulation of the genitalia,leading to erectile dysfunction.In addition,drugs taken to treat hypertension, diabetes, and hyperlipidemia may also lead to sexual dysfunction. Hypertension and other cardiovascular risk factors have a similar pathophysiological basis to erectile dysfunction,suggesting that appropriate treatment of hypertension and other risk factors may slow the progression and reduce the severity of erectile dysfunction. However,special adverse effects of many antihypertensive drugs,may seriously affect sexual function. When selecting appropriate antihypertensive strategies for patients, it should be considered that thiazide diuretics have a higher incidence of ED than β-blockers; angiotensin II inhibitors have lower sex-related adverse effects than angiotensin II inhibitors. Calcium channel antagonists do not cause ED, although there are some clinical reports that this drugs will increase prolactin levels and affect sexual function [14]. Hypoglycemic drugs do not cause sexual dysfunction. Statins and fibrate lipid-lowering drugs can lead to sexual dysfunction[15]. In addition, stroke patients mostly take psychotropic drugs due to depression and/or related behavioral abnormalities, which can cause iatrogenic sexual dysfunction [16]. For example, serotonin reuptake inhibitors and neurorelaxants can lead to serotonin/dopamine imbalance or increased prolactin in the central nervous system, which leads to sexual dysfunction[17].

2. Diagnosis of sexual dysfunction after stroke

2.1 Diagnostic principles of male sexual dysfunction following stroke

For male stroke patients, the diagnosis of sexual dysfunction usually requires the full cooperation of multidisciplinary physicians such as neurologists,psychiatrists and urologists. A full understanding of the patient's personal history, sexual history, social relationship history, and medication can help physicians better understand the patient's condition.Commonly used sedatives, antidepressants,antiepileptics, diuretics, β-blockers and other drugs in clinical practice may lead to sexual dysfunction in patients, to understand whether patients have depression or anxiety, so as to rule out psychological or mental factors[18].

2.2 Diagnostic methods for ED

The following methods are often used in the diagnosis of ED [19]. International Index of Erectile Function(IIEF-5)scores is often used to assess erectile function,12 to 21 scores as mild ED, 8 to 11 as moderate ED, 5 to 7 as severe ED. ② ED outpatient medical history form is used to understand the time and degree of ED,possible inducement, past medical history, factors, and feelings and attitudes of sexual partners. ③Comprehensive physical examination, especially neurological, cardiovascular system, secondary sexual characteristics and genital examination, as well as routine laboratory tests such as blood lipid, blood glucose, liver and kidney function. ④ Determination of sex hormones: follicle-stimulating hormone (FSH),luteinizing hormone (LH), estradiol (E2), testosterone(T) and pituitary prolactin (PRL). ⑤Nocturnal electrobioimpedance volumetric assessment (NEVA)is commonly used for detection of ED.It can be judged as normal if the blood volume exceeds 200% for two consecutive nights. ⑥ Penile artery blood pressure index is commonly used to detect the penile arterial blood pressure and calculate the ratio to brachial artery blood pressure. ⑦Stiffness tester (RigiScan Plus)manufactured in the United States is used to detect penile stiffness after being induced by PGE1 corpus cavernosum injection. ⑧Color Doppler examination:the maximum blood flow (PSV) in systole, the minimum velocity (EDV) in diastole, and the penile vascular resistance index(RI)of the penile artery were measured by penile color Doppler detection system after penile erection was induced by PGE1 penile injection. ⑨Determination of bulbocavernosal reflex latency time: Electrodes were inserted into the penis and both cavernosal muscles to observe their response and time[20].

3. Treatment of sexual dysfunction after stroke

3.1 Treatment of post-stroke sexual dysfunction in men

The treatment of male post-stroke sexual dysfunction is first to reduce iatrogenic sexual dysfunction. If sexual dysfunction is consistent with the use of a drug in time, then the replacement of drugs should be considered. For example, receptor blockers should be replaced by drugs to reduce their adverse effects on sexual function. When the patient has a coexisting disease of psychiatric disorders, the drugs that have as little effect on sexual function and reproductive function as possible first considered to use,such as rice breath flat and butylene-phenylacetone. At present,most scholars believe that 5-phosphodiesterase inhibitors can be used to treat ED in stroke patients,but there are not many treatment methods that can be used in patients with ejaculatory dysfunction. Oral administration of some anxiolytic and depressive drugs such as chlorpromazine, paroxetine, fluoxetine,citalopram and sertraline has certain clinical efficacy in the treatment of premature ejaculation. In addition,

dapoxetine is the only drug approved for the treatment of ejaculatory disorders, and it is a novel fast-acting serotonin reuptake inhibitor [21]. It is also very important to convey the correct and positive information to patients with post-stroke disability and their partners, and patient and correct education and guidance help them make the necessary adjustments and resume sex. Since hypertension and other cardiovascular risk factors have a similar pathophysiological basis to ED, simultaneous appropriate treatment of hypertension and other risk factors has the potential to slow the progression and reduce the severity of ED [22]. Other further treatments such as intracavernosal injection of Yinlian or intraurethral use of prostaglandins, vacuum suction devices, or Yinlian prosthesis placement surgery [23]are mainly done or guided by urologists and are indicated for patients who fail to respond to or have limited response to oral drug therapy. In addition to pharmacotherapy, scientific and appropriate guidance can convey correct and positive information to patients with post-stroke disability and their partners,help them make necessary adjustments,and resume sex[24].

4. Summary

Sexual life is one of the important and indispensable components in assessing individual quality of life. The patients with stroke account for a large proportion of the population,and the incidence of sexual dysfunction following stroke is high, which leads to complex causes, including both organic and functional causes.Sexual life changes after stroke are often ignored by medical staff. In addition to helping patients to improve their sexual life disorders through drugs,active sexual life rehabilitation guidance is also of great and irreplaceable significance.