Pain Perception in Disorder of Consciousness: A Scoping Review on Current Knowledge, Clinical Applications, and Future Perspective

Short-term outcomes of early intensive neurorehabilitation for prolonged disorders of consciousness: A prospective cohort study

BACKGROUND

Advances in medical care have increased survival in people with severe brain injuries and with that the number of survivors with prolonged disorders of consciousness (PDOC) has increased. In the literature, early intensive neurorehabilitation (EIN) for people with PDOC is recommended to achieve the best possible outcomes.

OBJECTIVES

To evaluate the frequency and extent of recovery of consciousness, mortality, complications, pain and discomfort, and medication during a nationwide EIN programme in people with PDOC after acquired brain injury. We hypothesized that level of consciousness would improve in half of people with PDOC.

METHODS

Prospective cohort study. People with PDOC aged 16 years and older admitted to the EIN department centralized in a single rehabilitation centre in the Netherlands (Libra Rehabilitation & Audiology) were included. The EIN delivers a subacute medical level of care and rehabilitation for a maximum duration of 14 weeks. The outcome measures were level of consciousness (CRS-R), mortality, number of complications, medication and pain/discomfort (NCS-R).

RESULTS

Of the 104 people included, 68 % emerged to a minimal conscious state with command-following or higher during EIN and 44 % regained consciousness. Mortality during EIN was 6 %, and 50 % of deaths followed a non-treatment decision or withdrawal of life-sustaining treatment. Almost all participants had at least 1 medical complication, leading to hospital readmission for 30 %. 73 % showed no pain or discomfort. During EIN, cardiovascular medication and analgesics were reduced by 15 %.

CONCLUSIONS

During the EIN programme, a large percentage of people with PDOC regained at least a minimal conscious state or even consciousness. These outcomes and the frequent medical complications in these people suggest that intensive specialized care should be offered to all people with PDOC. The outcomes of this study might help health professionals to better inform the families of people with PDOC about the short-term prognosis of PDOC.

PROTOCOL REGISTRATION NUMBER

The Dutch Trial Register, NL 8138.

International survey on the implementation of the European and American guidelines on disorders of consciousness

Diagnostic, prognostic, and therapeutic procedures for patients with prolonged disorders of consciousness (pDoCs) vary significantly across countries and clinical settings, likely due to organizational factors (e.g., research vs. non-academic hospitals), expertise and availability of resources (e.g., financial and human). Two international guidelines, one from the European Academy of Neurology (EAN) and one from the American Academy of Neurology (AAN) in collaboration with the American Congress of Rehabilitation Medicine (ACRM) and the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR), were developed to facilitate consistent practice among professionals working with this challenging patient population. While the recommendations of both guidelines agree in principle, it remains an open issue how to implement them into clinical practice in the care pathway for patients with pDoCs. We conducted an online survey to explore health professional clinical practices related to the management of patients with pDoCs, and compare said practices with selected recommendations from both the guidelines. The survey revealed that while some recommendations are being followed, others are not and/or may require more honing/specificity to enhance their clinical utility. Particular attention should be given to the implementation of a multimodal assessment of residual consciousness, to the detection and treatment of pain, and to the impact of restrictions imposed by COVID-19 pandemics on the involvement of patients' families/representatives.

Pain assessment during physiotherapy and noxious stimuli in patients with disorders of consciousness: A preliminary study

Objectives

The primary purpose of this study is to determine whether patients with disorders of consciousness (DOC) (unresponsive wakefulness syndrome, UWS; minimally conscious state, MCS) experience pain during physiotherapy and noxious stimuli in a larger patient population.

Materials and methods

The patients’ level of consciousness was measured with the Coma Recovery Scale-Revised (CRS-R). Additionally, the Nociception Coma Scale-revised (NCS-R) was used to assess their pain response. The NCS-R total scores between UWS and MCS at baseline, physiotherapy and noxious stimulus were compared using the Mann-Whitney U test (Wilcoxon rank-sum test) and the Kruskal-Wallis H test with Bonferroni correction.

Results

The study enrolled 93 participants. There was a statistically significant difference in NCS-R total scores between the three conditions (H = 215.25, p < 0.001). At baseline, there was no statistically significant difference between MCS and UWS (U = 378, z = –1.35, p = 0.178). While there was a statistically significant difference between MCS and UWS during physiotherapy (U = 1,362, z = –3.06, p < 0.01) and under noxious stimuli (U = 5142.5, z = –11.22, p < 0.001).

Conclusion

Physiotherapy improved the activity responsiveness of DOC patients, and patients experienced less potential pain. However, some DOC patients, especially MCS patients, perceived pain under the noxious stimuli.

Pain in Persons with Disorders of Consciousness

Pain and suffering in persons with disorders of consciousness (DoC) remain poorly understood, frequently unaddressed or inadequately addressed, and controversial on numerous levels. This narrative literature review will address a number of critical issues germane to pain and suffering in this challenging group of patients, providing an introductory overview of the topic, perspectives on current knowledge regarding pain pathoanatomy and pathophysiology, and a review of common pain generators and factors that can lead to the chronifcation of pain. Caveats on bedside pain assessment challenges, as well as electrophysiologic and neuroimaging findings in these patients, will also be explored. Pain management techniques, including non-pharmacological and pharmacological, will be reviewed. Ethical considerations in the context of pain and suffering in persons with disorders of consciousness will round out the review prior to our concluding comments.