Brain Death, Decorticate Posturing, Persistent Vegetative State and Locked-In Syndrome

by Carlo Raj, MD

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    00:01 Brain death, irreversible cessation of brain and brainstem functioning, regardless of cause.

    00:08 Requirements varies from, well, state to state, hospital to hospital.

    00:13 Comatose, absence of brainstem reflexes that we talked about.

    00:17 No spontaneous respiration.

    00:21 Absence of complicating factors: Hypothermia, sedatives, metabolic abnormalities.

    00:30 Approach to brain death.

    00:32 Here, we have an algorithm or flow chart.

    00:35 And from the flow chart, on the top, we go from the coma.

    00:38 Is it present? And if it is, your next step of management is going to be neuroimaging and maybe CSF evaluation, as long as intracranial pressure is not elevated.

    00:50 If you find something to be interesting, yes, then you want to start thinking about how to rule things out.

    00:56 Was it hypothermia? Was it intoxication? Was it sedatives? Or was it neuromuscular blocking type of agents? Was it metabolic in terms of severe electrolyte disturbances? Was it acid-based disturbance? Or was it endocrine type of crises such as Addison’s disease? If there is something that you find to be yes with one of these differentials, then absence of brainstem reflexes and motor response.

    01:23 So here, what we mean by this is the brainstem reflex such as a pupillary or the cold caloric or the doll’s eye, whatnot.

    01:29 And we have apnea with the PCO2 being elevated.

    01:32 Remember the PCO2 should be normally around 40.

    01:36 And so therefore, if your brainstem isn’t functioning properly, there is every possibility that you might be then retaining carbon dioxide.

    01:43 Next, what would you do? Clinical diagnosis of brain death is what you’re thinking.

    01:49 At this point, maybe, maybe, there is eligible for organ type of harvesting, because now at this point, you’re thinking about asking the family members or a power-of-attorney as to whether or not the harvesting of organ from your patient is your next step of management.

    02:06 As objective and as cold-hearted as it may seem right now, please make sure that you’re very objective on your boards and your wards.

    02:18 So, your patient here, even though you wish to be optimistic at some point, you must know what your next approach would be.

    02:26 Now, if the patient, no for harvesting, at this point, you get into disconnection or the ventilator becomes the question or the point of concern.

    02:40 Disconnect your ventilator.

    02:42 If yes, then you proceed with the donor procurement.

    02:46 Here’s a brief little overview of what you can expect from going from coma to brain death to your ventilator.

    02:53 Here, we’ll talk about the different types of posturing.

    02:57 And by this, I mean either decorticate or decerebrate.

    03:01 We talked about that Glasgow coma scaling.

    03:05 We started from six in which your cognition was quite high.

    03:09 And then by the time your Glasgow scale move down to one, there was absolutely nothing in terms of cognition.

    03:15 And now at this point, you were thinking about level of consciousness and whether or not your patient was even awake.

    03:21 As you move from six to one, at that point, I had pointed out to you different types of posturing that may occur as you lose more and more of your awakening.

    03:32 Here, we have decorticate.

    03:35 Would you please take a look at your patient? This is important.

    03:38 What I want you to do immediately is I want you to focus upon the elbows, and I want you to focus upon the ankles.

    03:46 You’ll notice here, please, that the elbows are flexed and the wrists are flexed in very tight posture, almost as if like you’re jumping out of a plane into the sea where you are just being aerodynamically efficient.

    04:03 And take a look at the toes, we have plantar flexion,, and all of this is then representing the posture that you can expect with decorticate.

    04:10 I need you to spend a little bit of time to make sure that you have firmly implanted the image of decorticate and its posture in your head.

    04:20 So, bilateral flexion at the elbows and wrists.

    04:24 Extension of the lower extremities.

    04:26 We have poor localizing value.

    04:29 Indicates a lesion.

    04:30 Where? One of the most important points on this slide is this.

    04:35 With decorticate, indicates a lesion above the red nucleus, above the red nucleus, above the red nucleus.

    04:46 Less ominous that of, what we’ll get into next, known as your decerebrate posturing.

    04:53 So, if this is above the red nucleus with decorticate, then decerebrate must be below the red nucleus where we have possible injury.

    05:04 Please take a look at decerebrate posturing.

    05:08 With decerebrate posturing versus decorticate, here immediately, I want you to jump to the elbows and the wrists.

    05:17 At this time, we find that the elbows are extended.

    05:21 And we also have the wrists that are extended.

    05:24 Completely opposite that of decorticate.

    05:28 The extension of lower extremity would be similar in both.

    05:31 And most typically, indicates a lesion.

    05:33 Where? Below the red nucleus and maybe, perhaps, the mid brain.

    05:37 Once again, below the red nucleus with decerebrate.

    05:42 Rarely seen in severe cases of toxic or metabolic encephalopathy.

    05:48 Be familiar with the posturing.

    05:50 One is called decorticate, the other one is called decerebrate.

    05:54 So, what does a vegetative state mean to you? A vegetative state may develop after prolonged coma with continued life support.

    06:03 Patients maintain respiration and autonomic functioning.

    06:07 Eye opens and may blink to threat and exhibits sleep-wake cycles.

    06:13 No awareness or interaction with the environment though with the vegetative state.

    06:17 Prolonged coma.

    06:20 Something called locked-in syndrome.

    06:22 Where is this occurring? You should be thinking pons immediately, most often due to hemorrhage.

    06:28 Patients unable to move extremity.

    06:30 Literally, they are locked in, unable to move extremity or face, unable to vocalize, they’re trapped in their own body.

    06:38 Extremely frustrating if you can imagine.

    06:40 Completely awake and often cognitively intact with careful testing.

    06:46 Can communicate with vertical eye movement and blinks, and that’s important.

    06:51 So, then you get into habit of communicating with your patient virtually with the eyes.

    About the Lecture

    The lecture Brain Death, Decorticate Posturing, Persistent Vegetative State and Locked-In Syndrome by Carlo Raj, MD is from the course Altered Mental Status and Coma. It contains the following chapters:

    • Brain Death
    • Decorticate Posturing
    • Persistent Vegetative State & Locked-In Syndrome

    Included Quiz Questions

    1. Bradycardia.
    2. Absence of spontaneous breathing.
    3. Absence of brainstem reflexes.
    4. Coma.
    5. Oculocephalic reflex.
    1. Above the red nucleus.
    2. Below the red nucleus.
    3. Near the basal ganglia.
    4. In the brain stem.
    5. Hippocampus.
    1. Locked-In Syndrome, pons.
    2. Persistent vegetative state, pons.
    3. Coma, midbrain.
    4. Locked-In Syndrome, midbrain.
    5. Locked-In Syndrome, medulla oblongata.

    Author of lecture Brain Death, Decorticate Posturing, Persistent Vegetative State and Locked-In Syndrome

     Carlo Raj, MD

    Carlo Raj, MD

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