Summary: A new study has mapped the prevalence of an infrequent but impactful condition arising from acquired brain injuries: the minimally conscious state. This state manifests when victims of brain injuries exhibit faint indications of awareness despite a major loss of consciousness.
Through extensive surveys across Dutch healthcare centers, the research identified 32 individuals living in this semi-conscious condition. The findings promise to enhance both our grasp of this medical phenomenon and its associated care needs.
- The study is the first to provide a nationwide count of patients in a minimally conscious state.
- Out of the 32 identified patients, 65% had brain injuries caused by trauma, such as falls or accidents.
- The research was facilitated by the EEnnacoma network, an expertise network for severe acquired brain injury, established in 2016.
Source: Radboud University
Every year, approximately 130,000 Dutch people suffer some form of acquired brain injury. The causes can be traumatic such as a fall or road-traffic accident, but also a brain hemorrhages or lack of oxygen in the brain (for example after a resuscitation).
Sometimes severe brain injuries can lead to a prolonged disorder of consciousness (pDoC). This situation arises after coma when patients open their eyes and breathe on their own, but their consciousness does not return within four weeks after brain injury.
It was unknown how many patients were admitted to Dutch healthcare institutions with a specific form of pDoC: the minimally conscious state. In this situation, consciousness is severely diminished, but people do show one or more signs of consciousness. For example, they can follow a simple command, follow an object with their eyes or show emotions.
Researcher and elderly care physician Berno Overbeek approached all Dutch hospitals, the five specialized pDoC rehabilitation facilities and all nursing homes with the question whether they were treating one or more patients with pDoC.
If so, after permission from the legal representative, the level of consciousness was determined with the Coma Recovery Scale-Revised, the most widely used scale in these patients worldwide.
Through questionnaires completed by the attending physician, the researchers collected medical characteristics. The number of institutionalized patients in minimally conscious state in the Netherlands is 32.
These 32 patients were on average 45 years old, two-thirds were male, and more than half (53%) stayed in a facility where specialized, intensive neurorehabilitation for pDoC patients was offered. In two-thirds (65%) of patients, the brain injury was caused by a trauma, such as an accident or a fall. In the remaining patients, there was a non-traumatic brain injury, such as lack of oxygen in the brain after resuscitation, or a large brain hemorrhage.
This is the first study nationwide on the number of people in a minimally conscious state in an entire country. Researchers Jan Lavrijsen and Willemijn van Erp have already done similar research. They investigated another entity of pDoC, the unresponsive wakefulness syndrome (previously called vegetative state).
In this type of pDoC, no signs of consciousness are observed; observed behavior is based on reflexes. Elderly care physician and PhD candidate Berno Overbeek: ‘The group of patients in unresponsive wakefulness syndrome is also small, especially compared to other countries.
Expertise network for severe acquired brain injury
This study was possible because of the existence of EEnnacoma, an expertise network for severe acquired brain injury, founded in 2016. The EENnacoma network provides more information about coma and different levels of consciousness, such as unresponsive wakefulness syndrome and minimally conscious state.
In the EENnacoma network, institutions that provide specialized treatment and care to people with severe acquired brain injury and a research group are connected to each other. In recent years, with the support of, among others, the Dutch Brain Foundation, work has been done on the realization of appropriate treatment in a chain of care embedded in a nationwide network of academic expertise for patients with pDoC after the comatose phase in the hospital.
The group of patients with pDoC is one of the so-called low prevalence and high complexity target groups. The Ministry of Health initiated the development of knowledge and expertise centers for patient groups with a low prevalence and high complexity.
In May 2023, the network for people with pDoC, with a knowledge center at the Radboudumc and several nursing homes as centers of expertise, received a positive expert opinion from the Commission Expertise Centers in Long-Term Care, established by the Dutch Ministry of Health, Welfare and Sport. By doing so, the ministry is also enabling funding for the specialized care and knowledge infrastructure.
About this consciousness research news
Original Research: Closed access.
“Prevalence of the minimally conscious state among institutionalized patients in the Netherlands: a nationwide study” by Berno Overbeek et al. Neurology
Prevalence of the minimally conscious state among institutionalized patients in the Netherlands: a nationwide study
Background and objectives
The minimally conscious state (MCS) is a prolonged disorder of consciousness (pDoC) and one of the most severe outcomes of acquired brain injury. Prevalence data are scarce. The aim of this study was to establish the nationwide point prevalence of institutionalized patients in MCS in the Netherlands.
This was a descriptive cross-sectional study in which all 86 Dutch hospitals, all five specialized pDoC rehabilitation facilities, and all 274 nursing homes were asked whether they were treating patients with a pDoC on the point prevalence date of September 15, 2021. Each patient’s legal representative provided informed consent for their inclusion. Patient level of consciousness was verified using the Coma Recovery Scale-Revised (CRS-R) in a single assessment session performed in the facility of residence by an experienced physician. Data on patient demographics, etiology, level of consciousness, facility of residence, and clinical status were collected from a questionnaire by the treating physician. A prevalence figure of institutionalized of in MCS of per 100,000 members of the Dutch population was calculated, based on actual census data.
Seventy patients were reported to have a pDoC, of whom six were excluded. The level of consciousness was verified for 49 patients, while for 15 it could not be verified. Of the patients verified, 38 had a pDoC, of whom 32 were in MCS (mean age 44.8 years, 68.8% male). The prevalence of institutionalized patients in MCS is 0.2–0.3/100,000 Dutch inhabitants. Traumatic brain injury was present in 21/32 (65.6%) of these patients. Specialized pDoC rehabilitation was received by 17/32 (53%) of patients, with the rest admitted to nursing homes. The most frequent signs of consciousness on the CRS-R were visual pursuit, reproducible movement to command, and an automatic motor response.
This nationwide study revealed a low prevalence of institutionalized patients in MCS in the Netherlands. These findings are now being used to organize pDoC care in this country.