Pain–depression relationship, quality of life and acceptance of illness among patients with Chiari malformation type I: A cross-sectional study

Abstract

Chiari malformation type I (CM-I) is a congenital anomaly of the hindbrain. The most common symptoms include suboccipital tussive headache, dizziness and neck pain. Recently there has been growing interest in the psychological and psychiatric aspects of functioning in patients with CM-I, which have a significant effect on treatment outcomes and quality of life (QoL). The aim of the study was to assess the severity of depressive symptoms and the QoL in patients with CM-I and to identify the main factors responsible for these phenomena. A total of 178 people participated in the study and were divided into 3 groups: patients with CM-I who had undergone surgery (n = 59); patients with CM-I who had not undergone surgery (n = 63); and healthy volunteers (n = 56). Psychological evaluation included a set of questionnaires: the Beck Depression Inventory II, the World Health Organization shortened version of the WHOQOL-100 quality of life questionnaire, the Acceptance of Illness Scale and the Beliefs about Pain Control Questionnaire. Results showed that the control group participants obtained significantly better results than both groups of CM-I patients in terms of all indicators of QoL, symptoms of depression, acceptance of illness, pain level (average and present) and perceived influence of doctors regarding coping with pain. Patients with CM-I (operated and non-operated) obtained similar results in most of the questionnaires and the QoL indices correlated significantly with the majority of the analyzed variables. Moreover, CM-I patients with higher depression scores described their pain as more severe and had a stronger belief that pain levels were not influenced by them but only by doctors, or that it could be controlled randomly; they were also less willing to accept their illness. CM-I symptoms affect the mood and QoL of patients. Psychological and psychiatric care should be the golden standard in managing this clinical group.

1. Introduction

Chiari malformation (CM), described for the first time by pathologist Hans Chiari in 1891, is a congenital anomaly of the hindbrain.^[1] Today, many types of CM are recognized, with type I as the most common. Chiari malformation type I (CM-I) is mainly diagnosed among the adult population in the second or third decade, with female predominance.^[2] The diagnostic method of choice is magnetic resonance imaging and CM-I is defined as downward displacement of the cerebellum tonsils ≥ 5 mm below the level of the foramen magnum. The most common symptoms include suboccipital tussive headache, dizziness and neck pain.^[3] However, in cases of secondary development of syringomyelia, symptoms of spinal cord damage and related pain are observed.^[4] Surgery, which includes posterior fossa decompression, is a widely recommended treatment for patients with CM-I.^[4,5]

Physical manifestations and surgical techniques and outcomes have been extensively investigated and described in the literature.^[6] However, recently there has been growing interest in neuropsychological and psychiatric aspects of patients suffering from CM-I, which have a significant effect on the treatment outcomes and continued quality of life (QoL).^[7–9] As well as cognitive deficits, it was observed that CM-I is very often accompanied by the development of depression.^[8,10]

The aim of our study was to assess the severity of depressive symptoms as well as the QoL in patients with CM-I (operated and non-operated). Moreover, we tried to identify the main factors responsible for these phenomena and compare the results obtained with data derived from healthy controls.

2. Materials and methods

2.1. Participants

The data was collected from October 2019 to August 2021. A total of 178 adults were divided into 3 subgroups: patients with CM-I who had undergone surgery (operated group, n = 59); patients with CM-I who had not undergone surgery (non-operated group, n = 63); and healthy volunteers (n = 56) (Table 1). The number of cases in the area during the study period determined the sample size. The patient groups were obtained from a Polish online forum for those with CM-I: the operated group comprised patients who were treated in different medical centers and the non-operated group consisted of patients with CM-I symptoms who were scheduled for surgery (some had a date and were awaiting surgery; some were hesitant and some refused treatment). The control group consisted of healthy volunteers, recruited via online advertisement, without any health issues and taking no medications on a permanent basis. Control group members were demographically matched to the clinical groups of patients.

Table 1 - Demographic and clinical date characteristics of the studied groups.

	Non-operated patients (N-OP)	Operated patients (OP)	Control group (CG)	P value
Number of patients (%)	63 (35.4%)	59 (33.1%)	56 (31.5%)
Men/women (number)	14/49	6/53	8/48	>.05
Mean age (SD)	41.6 (12.4)	44.1 (10.9)	40.9 (7.8)	>.05
Syringomyelia	28 (44%)	42 (71%)	N/A
Mean duration of signs/symptoms in months (SD)	39.61 (52.13)	110.81 (102.17)	N/A	.000

2.2. Instruments

The demographic and clinical data were collected via an anonymous questionnaire that included standard questions on gender, age, and educational status. Clinical questions included: having/not having CM-I syndrome, duration of the disease, having/not having syringomyelia and having/not having surgery. The participants were also asked to mark the current and average (last month) pain levels on the visual analogue scale.

2.2.1. Beck depression inventory II (BDI-II)

The BDI-II is a 21-item multiple-choice self-report measure used to assess the occurrence and severity of symptoms of depression. Each item is rated from 0 to 3. The total possible score ranges from 0 to 63, with scores of 0 to 13, 14 to 19, 20 to 28, and 29 to 63 indicating minimal, mild, moderate, and severe depression, respectively.^[11]

2.2.2. WHOQOL-BREF

The WHOQOL-BREF is a shortened version of the WHOQOL-100, which is an assessment tool introduced by the World Health Organization to evaluate QoL. It is composed of 4 domains: somatic health, psychological health, social relationships and environmental health. The score in each domain ranges from 4 to 20, with a higher score reflecting higher QoL within each domain. The Polish adaptation of the original WHO-BREF questionnaire was used in this study.^[12]

2.2.3. Acceptance of illness scale (AIS)

The AIS is a questionnaire that measures the level of disease acceptance in an adult population. The scale is composed of 8 statements concerning the negative impact of disease that result in adjustment to the limitations caused by the disease, lack of self-esteem, sense of dependence, burden, and embarrassing others. The score ranges from 8 to 40. A lower score indicates a worse level of disease acceptance and higher emotional discomfort. The results are divided into 3 levels of disease acceptance: poor (< 20), medium (20–30) and high (> 30).^[13,14]

2.2.4. Beliefs about pain control questionnaire

The Beliefs about Pain Control Questionnaire comprises 13 statements that are subdivided into 3 categories: internal pain control (beliefs about personal control of pain), influence of doctors (beliefs that physicians can control pain) and random control (beliefs that pain is dependent on chance). The higher the score achieved in a particular category, the stronger the belief that the given factor can control the pain.^[14,15]

2.3. Procedure

The subjects were recruited through an online forum for patients with CM-I. After being given details of the study and providing informed consent to participate, each participant completed an anonymous questionnaire (to collect demographic and clinical data) and several psychometric tools. The task took approximately 45 minutes. All procedures were carried out in accordance with the Declaration of Helsinki and were approved by the ethics committee of the Faculty of Psychology at the University of Warsaw.^[16] All participants gave written informed consent to participate in the study and each person was surveyed only once.

2.4. Statistical analyses

Statistical analyses were performed using SPSS Statistics v.26 for Windows (IBM Corp., Armonk, NY). One-way analysis of variance was used to investigate test score differences between groups. Sheffe test was used for post hoc comparisons to maximize the reliability of the results. Spearman rho was used for correlational analyses between variables due to the non-normal distribution of some variables measured with the Kolmogorov-Smirfnoff test. Intergroup discrepancies in the distribution of individual variables were assessed using the Kruskal–Wallis test. Significance was set at P < .05 (2-tailed testing).

3. Results

The studied groups did not differ in terms of the demographic variables (Table 1). In the first stage of the analysis, the results obtained from the subjects in the 3 groups were evaluated (Table 2). Post hoc analyses showed the presence of significant differences in most of the analyzed variables. The control group participants obtained significantly better results than both groups of CM-I patients in terms of all indicators of QoL, symptoms of depression, health condition acceptance, pain level (average and present) and influence of doctors regarding coping with pain. Patients with CM-I (operated and non-operated) obtained similar results in most of the questionnaires. Participants who underwent surgery obtained significantly higher results than those without surgery only in terms of the environmental aspect of the QoL, the perceived influence of doctors on the level of pain and, interestingly, the severity of depressive symptoms. Co-occurring syringomyelia did not significantly affect the level of reported pain in the operated and non-operated groups of patients with CM-I (both P > .05).

Table 2 - Between-group comparisons using analysis of variance and Sheffe post hoc test.

	Non-operated patients (N-OP)	Operated patients (OP)	Control group (CG)	F	P value	Tukey post hoc
WHO (somatic)	18.91	17.65	26.37	8.050	.000	CG > N-OP CG > OP
WHO (psychological)	10.57	8.65	15.50	3.110	.023	CG > N-OP CG > OP
WHO (social)	25.71	22.82	29.54	4.566	.019	CG > N-OP CG > OP
WHO (enviromental)	19.40	27.06	32.92	5.738	.021	CG > N-OP CG > OP OP > N-OP
BDI-II	33.51	43.12	13.16	6.533	.000	CG < OP CG < N-OP OP > N-OP
AIS	20.66	23.06	35.27	8.953	.012	CG < N-OP CG < OP
BPCQ (internal pain control)	15.89	15.24	14.61	0.469	.603	N/S
BPCQ (influence of doctors)	15.63	24.12	9.33	4.165	.006	CG < OP CG < N-OP N-OP < OP
BPCQ (random control)	14.40	15.18	14.15	0.105	.127	N/S
Average pain level	6.31	4.59	3.51	3.203	.006	CG < N-OP CG < OP
Present pain level	5.86	3.76	2.57	8.578	.016	CG < N-OP CG < OP

AIS = Acceptance of Illness Scale, BDI-II = Beck Depression Inventory II, BPCQ = Beliefs about Pain Control Questionnaire, N/S = Not significant, WHO = World Health Organization, WHOQOL-BREF = World Health Organization shortened version of the WHOQOL-100 quality of life questionnaire that includes four domains (somatic health, psychological health, social relationships and environmental health).

In patients with CM-I who were not operated on, the QoL indices correlated significantly with the majority of the analyzed variables (Table 3). The index of the somatic aspect of the QoL (apart from the correlation with other subscales of the WHOQOL questionnaire) correlated positively with the level of acceptance of the disease (P = .009) and negatively with the severity of depressive symptoms (P = .004), pain intensity (average: P = .007; present: P = .005), duration of symptoms (P = .04) and the belief that doctors have an influence on pain control (P = .009). The psychological aspect of the QoL correlated positively with the level of acceptance of the disease (P = .002) and self-perception of its own impact on pain control (P = .000), and negatively with the severity of depressive symptoms (P = .003), pain intensity (average: P = .000; present: P = .03), duration of symptoms (P = .007), the belief that doctors influence pain control (P = .005) and the feeling of lack of possibility (randomness) of pain control (P = .006). The QoL in the social aspect was positively related to the level of acceptance of the disease (P = .000) and negatively related to the severity of depressive symptoms (P = .008), the pain intensity (average: P = .009; present: P = .009) and the duration of symptoms (P = .03). Finally, environmental QoL was positively related to the level of disease acceptance (P = .000) and self-control of pain (P = .000), and negatively to the severity of pain symptoms (average: P = .003; present: P = .002) and the belief that pain was randomly controlled (P = .000).

Table 3 - Correlations between variables in the non-operated group of patients with Chiari malformation.

	WHO (somatic)	WHO (psychological)	WHO (social)	WHO (environmental)	BDI II	AIS	BPCQ - internal pain control	BPCQ–influence of doctors	BPCQ - random control	Average pain level	Present pain level	Symptoms duration
WHO (somatic)	1	.629†	.631†	.723†	−.575†	.634†	.131	−.235†	−.167	−.379†	−.355†	−.150*
WHO (psychological)	.629†	1	.674†	.659†	−.451†	.438†	.750*	−.301†	−.507†	−.814*	−.193*	−.307†
WHO (social)	.631†	.674†	1	.702†	−.611†	.589*	.154	−.334	−.242	−.358†	−.379†	−.226*
WHO (environmental)	.723†	.659†	.702†	1	−.784	.700*	.409*	.365	−.555*	−.452†	−.405†	.237*
BDI-II	−.575†	−.451†	−.611†	−.784	1	−.694†	−.885*	.404†	.415*	.717*	.699*	.085
AIS	.634†	.438†	.589*	.700*	−.694†	1	.861*	−.425†	−.324†	−.658*	−.617†	.121
BPCQ– Internal pain control	.131	.750*	.154	.409*	−.885*	.861*	1	−.670*	−.790*	−.400*	−.198*	−.775†
BPCQ–influence of doctors	−.235†	−.301†	.334	.365	.404†	−.425†	−.670*	1	.411	.314†	.431†	.102
BPCQ– random control	−.167	−.507†	−.242	−.555*	.415*	−.324†	−.790*	.411	1	.315*	.539*	.596†
Average pain level	−.379†	−.814*	−.358†	−.452†	.717*	−.658*	−.400*	.314†	.315*	1	.662†	.617†
Present pain level	−.355†	−.193*	−.379†	−.405†	.699*	−.617†	−.198*	.431†	.539*	.662†	1	.112
Symptoms duration	−.150*	−.307†	−.226*	−.237*	.085	.121	−.775†	.102	.596†	.617†	.112	1

AIS = acceptance of illness scale, BDI-II = beck depression inventory II, BPCQ = beliefs about pain control questionnaire, WHO = World Health Organization, WHOQOL-BREF = World Health Organization shortened version of the WHOQOL-100 quality of life questionnaire that includes four domains (somatic health, psychological health, social relationships and environmental health).

^*P < .001 (two-tailed).

^†P < .01 (two-tailed).

A strong positive correlation was found between depression and the severity of pain symptoms (average: P = .000; present: P = .000). Moreover, people with higher depression scores had a stronger belief that pain levels were not influenced by them but only by doctors (P = .006), or that it could be controlled randomly (P = .000); they were also less willing to accept their illness (P = .002). People with longer duration of symptoms of CM-I rated their average pain levels as higher (P = .004) and had a stronger sense of randomness in pain control (P = .000) and a lesser sense of their own impact on pain (P = .002).

In patients who underwent surgical treatment of CM-I (Table 4), all aspects of the QoL correlated positively with the level of disease acceptance (somatic: P = .004; psychological: P = .005; social: P = .005; environmental: P = .008) and negatively with the severity of depressive symptoms (somatic: P = .000; psychological: P = .002; social: P = .008; environmental: P = .005) and pain intensity – both averaged (somatic: P = .000; psychological: P = .002; social: P = .007; environmental: P = .007) over the last period and at the time of the study (somatic: P = .03; psychological: P = .002; social: P = .006; environmental: P = .008).

Table 4 - Correlations between variables in the operated group of patients with Chiari malformation.

	WHO (somatic)	WHO (psychological)	WHO (social)	WHO (environmental)	BDI II	AIS	BPCQ - internal pain control	BPCQ–influence of doctors	BPCQ - random control	Average pain level	Present pain level	Symptoms duration
WHO (somatic)	1	.693†	.657†	.769†	−.543*	.664†	.607*	.250‡	−.201*	−.354*	−.259‡	−.347†
WHO (psychological)	.693†	1	.732†	.721†	−.411†	.577†	.790*	−.287‡	−.690†	−.374†	−.340†	−.479*
WHO (social)	.657†	.732†	1	.761†	−.607†	.680†	.113	.410†	−.178	−.421†	−.422†	−.148
WHO (environmental)	.769†	.721†	.761†	1	−.734†	.743†	.150	.393†	−.294‡	−.478†	−.373†	−.200
BDI-II	−.543*	−.411†	−.607†	−.734†	1	−.664*	−.886*	.448†	.368*	.329*	.295‡	.087‡
AIS	.664†	.577†	.680†	.743†	−.664*	1	.543†	−.388†	−.188*	−.651†	−.627†	−.052‡
BPCQ–internal pain control	.607*	.790†	.113	.150	−.886*	.543†	1	−.071	−.431†	−.321*	−.420†	−.061
BPCQ–influence of doctors	.250‡	−.287‡	.410†	.393†	.448†	−.388†	−.071	1	−.423†	−.359*	−.286‡	−.046
BPCQ–random control	−.201*	−.690†	−.178	−.294‡	.368*	−.188*	−.431†	−.423†	1	.316†	.047	.226†
Average pain level	−.354*	−.374†	−.421†	−.478†	.329*	−.651†	−.321*	−.359*	.316†	1	.801†	.168
Present pain level	−.259‡	−.340†	−.422†	−.373†	.295‡	−.627†	−.420†	−.286‡	.047	.801†	1	.160
Symptoms duration	−.347†	−.479*	−.148	−.200	.087‡	−.052‡	−.061	−.046	.226†	.168	.160	1

AIS = acceptance of illness scale, BDI-II = beck depression inventory II, BPCQ = beliefs about pain control questionnaire, WHO = World Health Organization, WHOQOL-BREF = World Health Organization shortened version of the WHOQOL-100 quality of life questionnaire that includes four domains (somatic health, psychological health, social relationships and environmental health).

^*P < .001 (two-tailed).

^†P < .01 (two-tailed).

^‡P < .05 (two-tailed).

The sense of self-control over pain was strongly positively correlated with the somatic (P = .000) and psychological (P = .000) aspects of the QoL and with the acceptance of the disease (P = .004). On the other hand, the belief that pain is random in appearance correlated negatively with the somatic (P = .000), psychological (P = .002) and environmental (P = .03) aspects of the QoL as well as with the acceptance of the disease (P = .000). People who believed that doctors influenced their pain had a higher QoL in the somatic (P = .04), social (P = .004) and environmental (P = .007) aspects and a lower QoL in the psychological aspect (P = .02) and lower level of disease acceptance (P = .006).

The severity of depressive symptoms was strongly negatively correlated with the level of acceptance of the disease (P = .000) and the conviction of one’s own influence on pain control (P = .000) and positively associated with the conviction of the influence of doctors (P = .002) or randomness in the appearance of pain (P = .000), pain intensity (average: P = .000; present: P = .03) and duration of symptoms (P = .02). The duration of symptoms in people treated surgically due to CM-I correlated negatively with the somatic (P = .007) and psychological (P = .000) aspects of the QoL, as well as with the acceptance of the disease (P = .01), and was positively associated with the belief that the appearance of pain was random (P = .002).

4. Discussion

The present study investigated the relationships between chronic pain, beliefs about pain control, depression, and QoL in operated and non-operated groups of patients with CM-I.

We did not follow-up and compare the results in the same group of patients before and after surgery to get the clinical results of operation and its impact on patient’s functioning and well-being. Our objective was to demonstrate certain differences in functioning between the non-operated and operated cases. We carried out a comparative analysis of both clinical groups (operated and non-operated) with each other and with a control group. But, most importantly, we focused on assessing the relationship between individual clinical variables and assessing their impact on the QoL of CM-I patients.

4.1. Pain

CM-I is characterized by chronicity, with pain as a predominant symptom and headache as the main complaint.^[17] The main source of headache is stretching of innervated, intracranial dura due to increases of cerebrospinal fluid pressure, secondary to disturbance of cerebrospinal fluid flow.^[4] The nature of headache varies from sudden onset or even “explosive,” usually triggered by the Valsalva maneuver (e.g., cough), to continuous or diffuse, radiating to the neck and upper limbs. In cases of coexisting syringomyelia, neuropathic pain or painful dysesthesias may also occur, described by patients as “burning,” “tingling” or “stinging.”^[3,4,18,19]

Surgery is the treatment of choice, aimed at reducing or eliminating symptoms and signs of CM-I, especially pain.^[20] The available literature shows a reduction in the severity of symptoms and an improvement of QoL after decompression surgery in the vast majority of patients, confirming the effectiveness of this treatment despite differences in technique.^[5,21–23] In our study we noted a greater percentage of patients with co-occurring syringomyelia in the operated group (Table 1). This result is most likely due to the fact that diagnosed syringomyelia is a strict indication for surgery because of the potential risk of subsequent damage to the spinal cord.^[24] Therefore, despite the claimed statistically nonsignificant between-group differences of level of pain (P > .05), patients with syringomyelia were more likely to give their consent to the operation to stop the progression of the disease in the future. Moreover, the preoperative clinical status could not be established objectively, therefore additional factors leading to surgery could also be aggravating symptoms.

In general, our research showed a significantly higher level of pain (present and average) in both groups of patients compared to healthy controls. In the operated group we also noted a lower level of pain intensity, although it was not statistically significant.

4.2. Depression

Female gender, lengthiness of symptoms and chronic pain are known risk factors of depression.^[25–27] In addition, a compressed and deformed cerebellum is involved in emotional control and plays a role in depression.^[28,29] The above-mentioned factors result in a particularly high prevalence of depression, affecting up to 44% of patients with CM-I.^[30]

4.3. Pain–depression relationship

Pain and depression are conditions that frequently occur together, suggesting a close relationship.^[31] However, this complex phenomenon is still unclear and controversial.^[27,32] Nevertheless, a positive feedback mechanism is commonly observed, where increasing pain is related to a higher level of depression, and depression leads to a lower threshold of pain.^[32,33] Long duration of pain also co-occurred with a higher risk of depression^[34]; however in our study, the duration of symptoms did not significantly correlate with the severity of depression, indicating that other factors were probably more important.

In view of the above, it appears that this relationship creates a vicious circle, which is also present in CM-I. Despite the complexity, variety and severity of symptoms of CM-I, it seems that the pain–depression interaction is one of the most important factors impacting a patient’s QoL. The results of this study support this phenomenon, where depression positively and highly correlated with the pain level (Table 3). Surgical treatment should interrupt this pathological interdependence, resulting in a lessening of pain and thereby causing improvement of mood and QoL.^[5,21] This relief of pain after the operation should also induce the alleviation of depressive symptoms. Garcia et al^[30] reported quite a comparable prevalence of depression in patients with CM regardless of surgical treatment, with an indication of slightly higher symptoms of depression among patients who had no surgery. In this study, we surprisingly noted a considerably higher presence of depression and a lower level of QoL in the operated group of patients, despite an observed decrease of their present and average pain (Table 2).

Further analyses indicate a significant relationship between depression, pain and the level of acceptance of the disease (measured with the AIS). We found a strong negative correlation between the AIS and depression, as well as between the AIS and pain levels in each group (Tables 3 and 4). This finding suggests that, along with the acceptance of illness, higher awareness and coming to terms with the disease mood state tended to improve. The relationship between these 3 variables may partially explain the greater severity of depressive symptoms in the operated group of patients, despite the lower intensity of pain in this group. The level of declared pain was highly correlated with the level of disease acceptance and the level of depression in both the operated and non-operated groups. Probably patients undergoing surgery hope for the symptoms to subside completely, so we can assume that when this does not happen, frustration appears, leading to a negative attitude towards the disease and exacerbation of depressive disorders. On the other hand, people who have not yet had surgery still have this “last resort” up their sleeve, which is probably also a protective factor against the deterioration of depressive symptoms. Following the surgery, patients have had their main treatment, which has not caused complete cure and the remaining symptoms can exacerbate their depression.

Another finding was related to the relationship between depression and patients’ beliefs about pain control. The study showed that people who believed that they had an influence on pain control had a lower severity of depressive symptoms than people who believed that their pain was controlled by a doctor or by chance. This is a very interesting discovery pointing to the potentially significant importance of psychotherapy aimed at increasing the sense of agency, as some research shows that an external locus of control is a significant risk factor for depression.^[35] Research shows that chronic disease significantly increases the risk of depression.^[36,37] In most chronic diseases, the risk will decrease over time, but not always. As reported in the literature, cardiology patients maintained a high level of risk of developing depression up to 8 years after diagnosis, whereas in people with arthritis the risk increased over time.^[38] In our study, the longer duration of symptoms was also associated with higher rates of depressive symptoms, but the results were significant only in patients who underwent surgery.

4.4. CM-I and QoL

As demonstrated by numerous studies, the severity of depressive symptoms also negatively correlates with the QoL.^[39,40] Therefore, it was not surprising that in our study significant correlations between these variables were found, which were observed in both the operated and non-operated groups of patients with CM-I (Tables 3 and 4). We also found that the psychological aspect of QoL was positively associated with believing in internal pain control, whereas believing in the influence of doctors or random control was associated negatively in both the non-operated and operated groups. Moreover, people experiencing CM-I symptoms for a longer time tended to have a lower QoL, which is in line with other studies evaluating people with chronic diseases.^[41] In our research, the difference in duration of symptoms was significantly longer in the operated group, which could also affect the QoL in this group (Table 1).

However, patients in the operated group obtained significantly higher results than the non-operated group for the environmental aspect of the QoL, wherein home environment, financial resources and access to services are evaluated (Table 2). This may suggest improved functionality (health status) and better adaptability to live with CM-I in this group of patients. Present and average pain levels were also significantly correlated with all subscales of the QoL test, which is congruent with other findings.^[42]

In view of the above, the reason for the high incidence of depression and low QoL in the operated group due to CM-I is presumably complex. However, the relief in pain (symptoms) but often not complete remission, the high recurrent rate of symptoms and the debilitating impact of CM-I on daily activities may cause a high level of dissatisfaction or even disappointment after operation treatment.^[43,44] These factors have a high predisposition to depression among patients and may play a dominant role. Feghali et al^[10] highlighted an analogy with outcome dissatisfaction after microvascular decompression in trigeminal neuralgia in a study presented by Chang et al^[45]

CM-I is a great challenge not only for neurosurgeons, neurologists or pain management doctors but apparently also for psychologists and psychiatrists familiar with this disease. Hence, in high-quality CM-I patient care, not only the physical symptoms but also the complex psychological status should be taken into consideration. Patients after or qualifying for surgery should be under the care of a neuropsychologist and referred to a psychiatrist in cases of suspected depression. After surgery, patients should continue to be provided with psychological support.

This psychological aspect may require modification with regard to treatment approach, wherein the preparation of patients before surgery and also the postsurgical care provided by mental health professionals will be crucial. Chang et al^[45] in their study suggested some psychological interventions (relaxation training, music treatment and increased sleep quality) as a tool for improving mental status in patients with trigeminal neuralgia. Majeed et al^[46] showed that cognitive-behavioral therapy, acceptance and commitment therapy and mindfulness-based programs can be helpful in the treatment of chronic pain, thereby improving the QoL and emotional functioning. In a study by Zanini et al^[47], it was shown that in patients with chronic non-oncological pain, 10 months of psychotherapy resulted in a significant reduction of anxiety, depression and well-being that was strongly correlated with a reduction of subjective pain intensity.

In the process of preparing patients for surgery, besides the aspects mentioned above, patients should learn in detail about the benefits of surgical treatment as well as the limitations of this method of therapy. Because of the specificity of CM-I, the main aim of the surgery is to stop further deterioration and also, to a small extent, reduce the present symptoms, and this fact can be frustrating for some patients. This disappointment in the treatment outcome presumably acts as an additional triggering factor for depressive symptoms in already-burdened CM-I patients, which in the long term will negatively impact the QoL. Thus, although the surgical treatment is medically justified and necessary because it stops the disease progression, it does not significantly affect the psychological well-being of the patients. The need to cope with and come to terms with the presence of symptoms may require long term psychological and psychiatric care, regardless of the surgical treatment.

4.5. Limitations

Our study has several limitations and the results obtained should thus be interpreted with caution.

Firstly, this study should not be considered as an evaluation of surgical treatment because the results did not allow for simple comparison of patients before and after surgery, for several reasons: The non-operated and operated groups did not include the same patients (cross-sectional design of study; no follow-up of the same participants); The non-operated group comprised patients who qualified for an operation (some decided to undergo the procedure; some were hesitant or refused surgical treatment) but were not at the same stage of management and might have had a different severity of symptoms at baseline; and All data were obtained from self-assessment questionnaires and the patients were not evaluated by clinicians, therefore the description of CM-I symptoms (in the operated and non-operated groups) is subjective. Secondly, the relatively small sample size of the CM-I patients limited the possibility of conducting more advanced statistical analyses. Finally, assessment of depressive symptoms was based only on the BDI-II, with no further psychiatric evaluation; however, the BDI was advocated as a sensitive and specific tool for detecting depression among chronic pain patients.^[48]

5. Conclusion

Detailed information from a neurosurgeon, psychological care throughout the period of diagnosis and treatment and, if necessary, the introduction of pharmacotherapy by a psychiatrist seem necessary and should be treated as the gold standard of care for this group of patients, reducing the risk of developing depressive disorders, increasing their quality of life and thus improving surgical treatment outcome.^[10] A longitudinal study on a larger sample with psychiatric evaluation would be useful to verify the results obtained.

Author contributions

Conceptualization: Artur Balasa, Aleksandra Bala, Przemysław Kunert.

Data curation: Artur Balasa, Aleksandra Bala, Agnieszka Olejnik.

Formal analysis: Aleksandra Bala.

Investigation: Artur Balasa, Aleksandra Bala, Agnieszka Olejnik.

Methodology: Artur Balasa, Aleksandra Bala.

Project administration: Artur Balasa.

Supervision: Andrzej Marchel, Przemysław Kunert.

Validation: Aleksandra Bala.

Writing – original draft: Artur Balasa, Aleksandra Bala.

Writing – review & editing: Artur Balasa, Aleksandra Bala, Agnieszka Olejnik, Przemysław Kunert.