Painful Diabetic Neuropathy (PDN) is a complex and multi-dimensional condition that affects up to 20% of people with diabetes. PDN is associated with considerable morbidity, mortality and diminished quality of life (QOL). Unfortunately, pain treatment with medication in PDN is frequently unsuccessful or only partially successful [1]. Patients with PDN often suffer from enhanced levels of anxiety, fears, and other negative feelings, such as depression, as well as unsteadiness and loss of mobility, resulting in further social isolation [2]. To gain more insight into the perceptions, fears and consequences of PDN for these patients, several studies have been conducted by our research group at the Department of rehabilitation, Maastricht University, the Netherlands, supervised by Professor Verbunt and Professor Smeets.
The first study on the subject of PDN was a qualitative study that aimed to understand the experiences of living with symptoms of diabetes and pain, and the beliefs, fears and concerns of patients with PDN in relation to pain and activities of daily living (n=12) [8]. Patients reported suffering from substantial pain, disability and diminished QOL. The consequences of the PDN were physical (weakness, pain, physical restrictions), psychological (feelings of loss, feelings of depression, anger, sadness), and social (social withdrawal, isolation, work limitations, lower career opportunities). Furthermore, patients reported several fears related to diabetes and pain that might be important predictors of physical and social activities, such as fear of: hypoglycaemia, (increased) pain, total exhaustion, physical injury, falling, loss of identity and negative evaluation. Another important finding in the majority of PDN patients was that fear seemed to be associated with different types of avoidance behaviour. Patients with PDN avoided various activities, and were less physically active.
Based on these results, a cross-sectional study was initiated using validated questionnaires that matched the above-mentioned fears. Preliminary results of multivariate analyses show that, in 154 patients with PDN, pain intensity, fear of falling and fear of hypoglycaemia seem to be important contributors to disability and diminished QOL. Unravelling these specific fears enables us to identify targets for behavioral interventions that aim to improve psychosocial well-being in patients with PDN.
For the cross-sectional study, each validated questionnaire measured one specific element of various kinds of diabetes-related fears or pain-related fears. Unfortunately, in daily clinical practice it would not be feasible to use all of these questionnaires. Furthermore, it is unknown whether there could be an overlap between the questions that presumably assess the different constructs. To overcome this problem, we have used Rasch analyses to develop the Painful Diabetic Neuropathy (PDN) overall Anxiety Questionnaire (PART-Q30©) [3]. Interestingly, the final items retained in the PART-Q30© cover almost all fears that were identified in our qualitative study [4]. The PART-Q30© consists of three items regarding fear of hypoglycaemia, 13 items regarding fear of pain, five items regarding kinesiophobia, six items regarding fear of falling, one item regarding fear of fatigue, and two items regarding fear of negative evaluation. The PART-Q30© explained approximately 1/3 of disability and almost half of the loss of QOL experienced by the patients with PDN. Reducing the original 88 items to 30, with a uniform response option, will simplify anxiety assessment in PDN and reduce the burden on patients.
Since patients with PDN frequently share the comorbidities of depression and fear (and, as a consequence, disability) with other chronic pain populations, it may be possible to integrate the knowledge obtained in these latter populations to the field of PDN. A well-known and frequently used model to explain chronic pain from a bio-psycho-social perspective is the Fear-Avoidance Model [5]. This model states that fearful patients expect that certain movements/ activities/ situations may be harmful to their body by causing (re)injury. Negative irrational (catastrophizing) thoughts about the pain arise. As a result, fear stimulates avoidance behaviour, which can have enormous health consequences, such as disability, depression and disuse-related physical deconditioning [6, 7], further fueling the vicious circle of chronic disabling pain. Interestingly, this mechanism was also found in our cross-sectional study: PDN was associated with catastrophic thinking, and we believe catastrophic thinking led to a perceived decline in physical activity, increased disability and lower QOL [8]. Interestingly, pain catastrophizing was associated with the subjective feeling of loss of physical activities due to the pain, but it was not associated with the estimated actual level of activity [8].
The results of our research suggest that the overall QOL of PDN patients may be optimally improved when comorbid anxiety and negative emotions are optimally screened, diagnosed and treated. Therefore, a multidisciplinary therapeutic approach focusing on these psychological factors, instead of only focusing on a reduction of physical pain alone, is recommended for the treatment of PDN. Graded Exposure in Vivo treatment (GEXP) is a cognitive behavioural therapy that has appeared to be successful in breaking the aforementioned vicious circle in nonspecific pain syndromes, resulting in less fear, more physical activity, and better QOL, and also, in the long term, less disability. In this treatment, catastrophic interpretations regarding these stimuli are challenged and corrected, resulting in a lowered threat-value of these stimuli, thereby improving functional ability and quality of life of these patients. In our centre, plans are currently underway to initiate a study that investigates whether GEXP is an effective treatment to improve the level of activity and QOL in patients with PDN.
About Charlotte Geelen
Charlotte Geelen, MD, is a medical trainee and PhD student in the field of Physical Medicine and Rehabilitation, supervised by Prof. J.A. Verbunt and Prof. R.J.E.M. Smeets at the department of Rehabilitation Medicine at Adelante Zorggroep, Maastricht University Medical Center, Maastricht, The Netherlands.
In her PhD project, Charlotte Geelen focusses on patients with painful diabetic neuropathy (PDN) and the way in which PDN interacts with fears, physical activity and quality of life. The aim of this PhD research is to identify fears that lead to a greater burden in the daily life of patients with PDN and to develop a valid instrument to identify these fears. Furthermore, she aims to create a multidisciplinary rehabilitation treatment program that specifically targets these fears, increasing physical activity and quality of life.
After finishing her PhD and traineeship in Rehabilitation Medicine, Charlotte Geelen wants to pursue a medical career that combines research with clinical work. Her final goal is to improve patient care by gaining more insights and understanding in the mechanisms that cause disability in patients with chronic neuropathic pain and by developing treatment programs that can improve the lives of these patients.
References
- Geerts, M., et al., Effective pharmacological treatment of painful diabetic neuropathy by nurse practitioners: results of an algorithm-based experience. Pain Med, 2012. 13(10): p. 1324-33.
- Gore, M., et al., Pain Severity in Diabetic Peripheral Neuropathy is Associated with Patient Functioning, Symptom Levels of Anxiety and Depression, and Sleep. Journal of Pain and Symptom Management, 2005. 30(4): p. 374-85.
- Geelen, C.C., et al., Painful diabetic neuropathy Anxiety Rasch-Transformed Questionnaire (PART-Q30 ). J Peripher Nerv Syst, 2016.
- Kanera, I.M., et al., A qualitative investigation into living with diabetic peripheral neuropathic pain: patient’s experiences, beliefs, and fears. Submitted.
- Vlaeyen, J.W., et al., Fear of movement/(re)injury in chronic low back pain and its relation to behavioral performance. Pain, 1995. 62(3): p. 363-72.
- Leeuw, M., et al., The fear-avoidance model of musculoskeletal pain: current state of scientific evidence. J Behav Med., 2007. 30(1): p. 77-94.
- Verbunt, J.A., et al., Disuse and deconditioning in chronic low back pain: concepts and hypotheses on contributing mechanisms. Eur J Pain, 2003. 7(1): p. 9-21.
- Geelen, C.C., et al., Perceived Physical Activity Decline as a Mediator in the Relationship Between Pain Catastrophizing, Disability, and Quality of Life in Patients with Painful Diabetic Neuropathy. Pain Pract, 2016.
Commissioning Editor: Claudia Campbell; Associate Editor: Tory Madden