Tuesday, June 29, 2010

Long-term prognosis from severe brain injuries

Hi. I'm back from my interstate-moving hiatus, and I thought I'd get right back into the loving of perplexing, data-challenged articles which must (must!) tell us something about what we do to/say to our patients.  They must, right, or why else would I be blogging about them?  This is the sort of radical new thinking that these northern latitudes are inspiring in me.

Neurology has two articles about the long-term prognosis, and the phenomenon of late-recovery, for patients with severe brain injuries (patients in the vegetative state - VS - and the minimally conscious state - MCS).

First is a case series of patients admitted to a specialized Italian brain injury program, looking particularly at the small percentage who showed some recovery.  It's important to understand who these patients were: they were 50 patients, all described as being in a vegetative state (the authors assiduously avoid the term 'persistent VS'), who were already at least 6 months out from their injury (most were ~10 months out) and were medically stable (no vents, etc.).  They were a pretty even mix of patients who had suffered anoxic brain injuries, hemorrhagic strokes, and traumatic brain injuries.  The program is initially an inpatient one then transitions patients to home/community settings, and the average follow up for this case series was 26 months (post-injury).  The authors note it can be very difficult at times to differentiate patients who are vegetative vs. those in MCS; they state they excluded any patient admitted to their program for whom there was any question about their diagnosis.  Reading between the lines, they imply that they are experts in assessing these disorders of consciousness, and do it fastidiously and carefully, and they're probably right.

At the end of follow-up, ~75% patients had either died (42%) or were still in a VS (34%).  10% 'recovered' to a MCS, and 14% had recovered further to what they describe as 'consciousness' (basically: better than a MCS).  The numbers a bit more complicated than this because a few patients who recovered to the MCS then died, etc., but that doesn't change these basic findings.

All the patients who recovered to consciousness were described as severely or very severely disabled.  It's not entirely clear what that means from the text:  they used the Disability Rating Scale, but it's not clear what the cognitive/communicative status of the patients were.  (A summary of the DRS is here: still tough to get a good sense of what exactly 14+ means other than, yes, severe.   Looking at it carefully you can see that someone could have a severe disability and have normal or at least pretty good cognition/communication skills.  I find summative disability scores frustrating for these reasons:  of course physical/functional disabilities are important, but I think for some families, particularly those of younger patients, the key to decision making really is cognitive/communication abilities, and not whether a patient is 100% dependent in ADLs....)

In addition, 10 of the patients who showed some recovery, did so quite late (14+ months post-injury).   As has been shown previously, patients with TBIs recovered more commonly, and later, than those with anoxic injuries.  Neuroimaging findings didn't seem to predict who would improve.  However, no one improved who had no pupillary light response at the time of study entry.

A few thoughts.  This study does not mean that 25% of patients in a VS will 'recover'!  This is a highly select group of patients (they had already survived 6 months and were medically stable), and despite all the effort ~85% of them died, stayed in a VS, or improved only to the MCS.  I'll stick my neck out and argue that that is not much of a recovery.  However, some, and not a tiny amount (~14%) recovered further, to 'consciousness' (that is the authors' term), albeit were severely disabled.

The other, related, study is a retrospective cohort study looking at long-term outcomes for patients who survive a year after an injury in the VS or MCS.  The 50 patients were identified from a single institution's (France) population of ICU patients with brain injuries, who survived a year but in VS or MCS.  They did yearly reviews on the patients' outcomes for up to 5 years; they note that the outcomes were classified by neurologists or the 'physical rehabilitation therapies' 'using information from the medical files.'  That is, unlike the prior study in which they seemed to go out of their way to let us know they were doing careful physical exams to try to determine the patients' state, this analysis is based on chart review.

They found that at 5 years all the patients in a VS either had died or were still in a VS.  Same with most of the MCS patients, however 1/3 improved - most did so within the first couple years, but a handful had quite late recoveries.  This study gives a more detailed presentation of the cognitive state of those who improved:  all were described as cognitively impaired, although 4 were described as having intact memory and executive functions (this is 10% of the MCS cohort).  All but one had profound physical disabilities as well (one patient, a young woman with a closed head injury, was described as having a pretty good cognitive recovery, and needing only 'partial' assistance with ADLs.).

As with the first study, it's important in interpreting these data, besides all the usual cautions (retrospective! chart review! single institution! France!) to recognize that these are a very special group of patients, who have already made it a year - these data do not give us any sort of actual figures as to the rates of 'pretty good' outcomes for all-comers with MCS who survive their initial injury.  What is clear is that a small number of MCS patients do 'pretty good' (can communicate, and have intact memory and executive functions - although still with some unspecified cognitive impairment).

What is not clear, between these two studies, is whether patients in long-term VS, recover significantly.  The first implies that a small percent make some sort of cognitive recovery, although remain severely disabled, whatever that means.  The second - nada, and the difference here is not because the inclusion criteria for one study was 6 mo and the other was 1 year as several of the VS patients in the first study initially improved after a year.  The numbers may make a difference - there were just that many more VS patients in the first than second.  The fact that the first group were themselves doing the patient assessments may have mean more were instances of 'recovery' to MCS were found.

What is clear, for the VS patients, is that none 'woke up' and started resembling anything like their premorbid selves.  Which brings us to the big question:  how do we counsel families about this?  We've said before on the blog that I think, despite popular opinion, palliative clinicians are probably more comfortable with the uncertainty of these situations, at times, that non-palliative colleagues, when it comes to counseling families about prognosis.  'Never' is a big word, and one that I hardly ever use at the bedside, particularly when it comes to brain injuries and chances of some sort of recovery.  As a medical student and resident I was taught the very comforting 'fact' that a patient who is in a VS for 6 months (after an anoxic injury; 12 months after a traumatic one) will never recover.  That's the sort of factoid one quickly learns to be skeptical of.  However these data aren't necessarily a complete repudiation of that:  while it's probable that a small minority of patients in VS, particularly those after TBIs, but even those after ABIs, will make some sort of improvement which can be late (year+ later), the chances of recovery beyond severe-profound impairments remains tiny/nil.  MCS is different, but it always was.

'Never be themselves again' seems like safe language to use - and I do use it at times - and it seems to help many families.  In fact 'never' can be remarkably helpful for families making a decision about treatment goals - I realize and appreciate that - but still hesitate to say it because it seems intellectually dishonest (some of the time, at least in the context of brain injuries), although I see my non-palliative colleagues say it, and witness how helpful it is to families, and wonder if I'm over-thinking this situation.

Please comment about your thoughts about, and use of, 'never' in these situations.

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