Stroke is the leading cause of death worldwide (1), accounting for 11.8% of deaths worldwide (2), and is the leading cause of long-term physical, cognitive or psychological disability. Psychological complications of stroke include depression and anxiety in 29-33% of stroke survivors (3–5). Due to the sudden onset of stroke, it is difficult to predict and uncontrollable, which seriously affects the physical and mental health of patients and causes post-traumatic stress disorder (PTSD) (6). PTSD is a form of mental trauma that is delayed or persists for a long time after an individual experiences sudden, threatening, or even catastrophic events (7). The main manifestations are that the content or scenes related to trauma repeatedly surface in the mind uncontrollably. Individuals often resist participating in activities related to the traumatic event and try to avoid places and people related to the traumatic event (7). In addition, patients may also experience emotional reactions such as irritability and excessive alertness. Some people may even show somatization symptoms of anxiety (8). The prevalence rate of PTSD after stroke is up to 18% (9). PTSD not only affects patients’ interpersonal communication, work, and life but also comorbidities such as anxiety, depression, drug abuse, and fear, which seriously affect patients’ quality of life and mental health. Research shows that most people with PTSD are not detected and treated in time and that this traumatic event causes widespread suffering for almost everyone (10, 11). Foreign studies have shown that PTSD significantly affects patients’ cognitive problems and adaptation problems (12), and the more severe the PTSD symptoms, the worse the cognitive function (13).There are various clinical symptoms of PTSD, and the interaction between symptoms will affect the progression of the disease (14). Previous studies on PTSD in stroke patients mainly focus on the risk factors of PTSD and the possible harm caused by PTSD, using the overall score. To explain the severity of PTSD, it is assumed that each symptom or item is of equal importance, ignoring the correlation and function of the symptoms (15).

Borsboom proposed the network theory of mental disorder (NTMD) in 2017 (16). This theory holds that mental disorders are complex network systems formed by the interactions among symptoms, and the direct interactions among symptoms lead to the emergence of mental disorders (16). Specifically, a certain stimulus may activate a certain symptom, and the emergence of this symptom will further activate other related symptoms (17). Thus, a continuous activation cycle is formed. When the activated symptom cluster reaches a certain diagnostic criterion, mental disorders occur. Network analysis is a data analysis method based on network theory (17). It is a statistical approach capable of discovering and visualizing complex relationships among multiple variables and identifying potential influencing factors (18). An essential goal of network analysis methods is identifying central and bridging symptoms in a network and analyzing the mechanisms affecting its connectivity (19). A network diagram visually represents a system consisting of nodes and edges. Nodes represent variables, and edges represent connections between nodes. The centrality index is used to identify the most critical nodes in the network, including strength, tightness, and intermediateness (20). Strength centrality determines the strength of the relationship between a node and its neighbors. Proximity centrality represents the average distance between a node and other nodes. Intermediate centrality represents the frequency at which a node is connected between two nodes (21). Researchers can better understand the mechanisms underpinning component-to-symptom interaction and provide more accurate intervention targets at a finer level with the use of NA (22).

The central symptoms vary from person to person. Therefore, based on NA, this study attaches importance to the interaction of PTSD symptoms in stroke patients and constructs PTSD symptom networks through symptom network analysis. Driven by data, this study presents the connection between symptoms and symptom interactions through network maps, intuitively identifies network features and core symptoms, and proposes corresponding nursing countermeasures. It provides the basis for exploring the target of psychological rehabilitation intervention and accurate symptom management.

In our study, we found that the PTSD score of stroke patients was 32.05 (SD 15.472), which was at a moderate level. Stroke patients with sudden onset and severe disease, easy to cause the body’s nervous, endocrine and immune system dysfunction. The suddenness, unpredictability, uncontrollability and severity of stroke have caused severe blows to patients both physically and psychologically, which can easily lead to PTSD in patients. We suggest conducting PTSD assessment for stroke patients at an early stage, promptly formulating and implementing care plans. Additionally, through interdisciplinary collaboration, integrating professional knowledge from fields such as psychology, neuroscience, and rehabilitation medicine, we aim to further promote research and practice on PTSD in stroke patients, thereby facilitating their mental health and overall recovery.

Symptom network analysis results of this study showed that symptoms “I tried not to think about it (A11)” and symptoms “Other things kept making me think about it (I3)”, The strongest association was found between symptoms such as “I thought about it when I didn’t mean to (I6)” and “Pictures about it popped into my mind” (I9). Avoidance is a common behavior in mental illness (30). People who experience trauma often avoid thoughts, feelings, and places that remind them of the traumatic experience. In fact, individuals who have experienced trauma often distort attribution about themselves and the world, forming negative cognitive styles (31, 32). In order to avoid having this negative experience, they will shift their attention away from the thoughts and feelings associated with the traumatic event, i.e. show symptoms of thoughts avoidance. Recalling the thoughts and feelings of stroke may cause pain to patients. In order to reduce the pain, some patients will choose to avoid recalling the thoughts and feelings related to stroke experience (33), such as the feeling of numbness and dizziness during stroke attack, and the dialogue and scenes during stroke attack will also remind patients of stroke. Stroke is a sudden, significant physical and psychological traumatic event. When a patient experiences an episode of stroke, it is often accompanied by intense physical pain, fear, confusion, or a sense of death. Emotionally intense events tend to leave deep memory traces in the brain, especially those that are physically or psychologically extremely upsetting or frightening. These memories are reinforced and stored by the brain’s amygdala (emotional processing center), causing the patient’s mind to repeatedly reproduce images, situations or fragments associated with stroke. Active psychological care should be given to patients with cerebral stroke to guide them in understanding stroke and coping with trauma. Nurses should achieve precise positioning in clinical practice, help patients understand the nature of stroke and the rehabilitation process, and alleviate patients’ mental stress through measures such as cognitive therapy (34). On the basis of routine care, psychological care should be provided, and patients should be guided to correctly deal with trauma. In future research, the above symptoms should be closely monitored, and symptoms with strong preventive identification should be identified. Taking this as the entry point, a combination of early psychological intervention and drug treatment is adopted to weaken the interaction between symptoms (35), cut off the strong connection between symptoms, improve the efficiency and effect of intervention (35), and control the progression of PTSD.

Among the symptoms, “I was jumpy and easily startled”(H10) showed the highest EI value. This is an effective target for the prevention, treatment and intervention of PTSD in stroke patients. Individuals who experience trauma become more sensitive to similar stimuli or triggering events, and with a heightened panic response, the patient exhibits a heightened state of alertness (36). Studies have found that patients with PTSD have apparent abnormal changes in brain function in the amygdala, ventromedial prefrontal cortex, dorsal anterior cingulate cortex and hippocampus (37, 38). The amygdala and dorsal anterior cingulate gyrus are essential brain regions for cognitive function and emotional generation and regulation, and enhancing activation will cause hypervigilance in patients (39). Thus, intensive interventions by caregivers targeting the symptom “I was jumpy and easily startled”(H10) “may be more effective in reducing the overall level of PTSD than interventions targeting the remaining symptoms, which may have the greatest clinical significance at the moment.” Psychological interventions can be implemented to reduce the symptoms (40). At present, the common psychological interventions include cognitive behavioral therapy (41), cognitive processing therapy, exposure therapy (42), eye movement desensitization and reprocessing therapy (43). However, it is important to note that each patient’s situation is unique, and it is important to choose treatment options individually. This study provides several important implications for addressing mental disorders in stroke patients. First, the prevalence of PTSD in patients with brain stroke (3-37%) remains alarmingly high (5, 44–48), and our study also found moderate levels of PTSD in stroke patients. This demonstrates the urgent need for timely screening and targeted mental health interventions, the implementation of which is essential to maintain the well-being of stroke patients and maintain quality of life. Second, our study not only provides a detailed understanding of PTSD in stroke patients, but also lays the foundation for future psychological interventions aimed at reducing PTSD in stroke patients. Third, “I was jumpy and easily startled”(H10) is considered to be the core symptom of PTSD in patients with brain stroke. This suggests that in future research, more attention should be paid to whether patients will show negative emotional manifestations after stroke. During health education and nursing intervention, patients should be guided to have a correct understanding of the occurrence of stroke. At the same time, psychological counseling should be provided to patients in a timely manner, encouraging them to express and vent their emotions. Emphasis should be placed on improving patients’ understanding of the disease and eliminating their fears. Reduce the physiological responses caused by fright (49), provide precise rehabilitation guidance, improve the patient’s psychological cognition, avoid emotional imbalance, accelerate the progression of PTSD, and at the same time tell the patient to maintain healthy behaviors and lifestyles. Moreover, in future research, it is necessary to further understand the influencing factors of this symptom, so as to achieve more precise intervention effects, promote the psychological rehabilitation of patients, and more widely reduce the overall level of PTSD.

In summary, this study found the symptom network characteristics and key symptoms of PTSD in stroke patients through symptom network analysis. In future studies, preventive identification of strongly linked and key symptoms should be considered, and scientific psychological intervention measures should be developed to promote the improvement of the mental health status of stroke patients.