These were the posterior cingulate, medial prefrontal cortex, and the occipital cortex. Even though functional brain imaging can objectively measure changes in brain function during noxious stimulation, the role of different areas of the brain in pain processing is only partially understood. Furthermore, there is still the problem of the subjective experience. MCS patients by definition cannot consistently and reliably communicate their experiences. Even if they were able to answer the question "are you in pain? ", there would not be a reliable response. Further clinical trials are needed to access the appropriateness of the use of analgesia in patients with MCS. Residual language function
A functional magnetic resonance imaging (fMRI) study found that minimally conscious state patients showed activation in auditory networks when they heard narratives that had personally meaningful content that were read forwards by a familiar voice. These activations were not seen when the narratives were read backwards.Another study compared patients in vegetative state and minimally conscious state in their ability to recognize language. They found that some patients in minimally conscious state demonstrated some evidence of preserved speech processing. There was more activation in response to sentences compared to white noise. Diagnostic
Medical definition
Minimally conscious state (MCS) is defined as a condition of severely altered consciousness in which minimal but definite behavioral evidence of self or environmental awareness is demonstrated. Diagnosis
Although MCS patients are able to demonstrate cognitively mediated behaviors, they occur inconsistently. They are, however, reproducible or can be sustained long enough to be differentiated from reflexive behavior.
There are currently multiple clinical trials underway investigating potential treatments. In one case study, stimulation of thalamus using deep brain stimulation (DBS) led to some behavioral improvements. The patient was a 38-year-old male who had remained in minimally conscious state following a severe traumatic brain injury. He had been unresponsive to consistent command following or communication ability and had remained non-verbal over two years in inpatient rehabilitation. fMRI scans showed preservation of a large-scale, bi-hemispheric cerebral language network, which indicates that possibility for further recovery may exist. Positron emission tomography showed that the patients global cerebral metabolism levels were markedly reduced. He had DBS electrodes implanted bilaterally within his central thalamus. More specifically, the DBS electrodes targeted the anterior intralaminar nuclei of thalamus and adjacent paralaminar regions of thalamic association nuclei. Both electrodes were positioned within the central lateral nucleus, the paralaminar regions of the median dorsalis, and the posterior-medial aspect of the centromedian/parafasicularis nucleus complex. This allowed maximum coverage of the thalamic bodies. A DBS stimulation was conducted such that the patient was exposed to various patterns of stimulation to help identify optimal behavioral responses. Approximately 140 days after the stimulation began, qualitative changes in behavior emerged. There were longer periods of eye opening and increased responses to command stimuli as well as higher scores on the JFK coma recovery scale (CRS). Functional object use and intelligible verbalization was also observed.