Thread by @michael_train10

DISORDERS OF CONSCIOUSNESS (DoCs)

Join me for another #neuropalliative care Tweetorial about a very broad and complicated topic: @MedTweetorials #NeuroTwitter #NeuroPal #hapc #MedEd

My goal for this 🧵 is to define key features of coma, vegetative state (VS), and minimally conscious state (MCS). And why it matters for #PalliativeCare.
This is not a Tweetorial on brain death or prognostication right after brain injury. Stay tuned for those🤓 2/17

To understand differences between disorders of consciousness (DoC) is to separate the ideas of being awake and being aware:
3/17

Coma is a state of unarousable unconsciousness, lasting < 4 weeks. Patients either die during the acute period of their illness or progress to VS / MCS.
The concept of a “long-lasting coma” is case reportable. ncbi.nlm.nih.gov/pmc/articles/P…
4/17

It’s much more difficult to separate VS and MCS, as patients in either category can smile, grimace, vocalize, move, etc. The key is whether or not those behaviors are in response to appropriate stimuli (e.g vocalizing in response to questions and not statements)

5/17

I’ll also mention here that for many, "vegetative state” is falling out of favor. Most of Europe and many in the United States are now using unconscious wakefulness syndrome (UWS).

6/17

Why does exact diagnosis matter?
1️⃣The prognosis differs for each
2️⃣Symptom control: coma and VS are not “aware” and therefore do not experience pain or discomfort
3️⃣Ethical and legal considerations of consciousness re: withdrawal of life-prolonging treatments

7/17

How good are we at these distinctions?

It’s time for me to commit #NeurologistHeresy - the bedside examination is historically unreliable. A prospective study of 103 patients with DOCs found that 40% of patients felt to be in VS by bedside examination were actually in MCS.
8/17

The Coma Response Scale - Revised (CRS-R) is a standardized 23 item measure designed for diagnosis of DoCs.

It is recommended that this be administered multiple times in a 2 week interval.

What happens when you have families help administer the CRS-R?

Families help! There has been growing interest in ancillary testing (fMRI, EEG, evoked potentials) in ddx of DoCs.

While this is an exciting field of research, it’s not quite ready for routine clinical practice due to access, interpretation, and replicability.
10/17

The use of fMRI and EEG in research studies has shown that about 15% of patients in VS actually modify brain activity in response to commands. This has been termed “covert consciousness” 🕵️ and “complete cognitive-motor dissociation.”
pubmed.ncbi.nlm.nih.gov/26139551/

11/17

If you’re like me, it’s hard just to think about the level of detail and intricacy that goes into these diagnoses let alone how to communicate the diagnoses to families.

I’ll leave you with a few additional things to think about as you care for these patients:

12/17

As above, symptom management for VS should focus on prevention of complications (i.e, managing spasticity). Remember, there is no awareness to experience pain.

With MCS, it is difficult to balance empiric(?) pain control and preservation of mental status.

13/17

Our ability to prognosticate is limited, but rules of thumb (via Dr. Sunil Kothari):
✨Traumatic DoCs have better prognoses than non-traumatic
✨At any point in time MCS has a better outcome than VS
✨The rate of initial recovery is positively correlated with outcome

14/17

Communication between families and caregivers is rife with bias. Many palliative care specialists are familiar with the concept of the “disability paradox” - where people who do not live with a disability underestimate the quality of life of living with that disability.

15/17

For example, I would not have expected 70% of patients with chronic locked-in syndrome to be happy:
bmjopen.bmj.com/content/1/1/e0…

16/17

Conclusion: This is a very complicated medical topic that brings in legal, ethical, and metaphysical arguments.

Next, I'll cover hospice eligibility for neurologic disorders. #HAPC Twitter, what else do you want to see covered?

17/17

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