Neuroscience Clinical Correlation: Coma Michael L. Vertino

Question 1

What are the levels of consciousness in the neurological exam?

Answer 1

1. normal
2. somnolent - External stimulation > NI wakefulness
3. obtunded - External stimulation > abnormal waking
4. coma -no wakefulness

Question 2

What are two common respiratory patterns in coma?

Answer 2

Cheyne - Stokes

Central Neurogenic Hyperventilation

Question 3

What is metabolic pupillary light reaction?

Answer 3

Small pupils, still reactive to light, equal

from drinking or heroin

Question 4

What is diencephalic pupillary light reaction?

Answer 4

Small pupils, equal, still reactive to light

problem in thalamus

Question 5

What is III nerve (uncal) pupillary light reaction?

Answer 5

The 3rd nerve nucleus was hit on one side, so one pupil is normal and one pupil is blown
problem at level of midbrain

Question 6

What is tectal pupillary light reaction?

Answer 6

Pupils are large and fixed, no reaction to light

Question 7

What is pons pupillary light reaction?

Answer 7

Pinpoint pupils

Question 8

What is midbrain pupillary light reaction?

Answer 8

Pupils are midposition and fixed

Question 9

What is internuclear opthalmoplegia?

Answer 9

Problem in medial longitudinal fasciculus, between pons and midbrain

Question 10

When the left eye moves laterally and the right eye moves medially (both toward left), what is this called?

Answer 10

Occulocephalic, occulovestibular reflex

Question 11

What is dicorticate posturing?

Answer 11

Abnormal flexor response of the arm and extension of the legs
Problem in midbrain at level of red nucleus

Question 12

Dicorticate posturing looks the same as:

Answer 12

Spastic hemiparesis (however this would be above the level of the midbrain)

Question 13

What is decerebate posturing?

Answer 13

Abnormal extensor response of the arm and leg (how horses sleep)
Most commonly seen with lesions caudal to the red nucleus

Question 14

What are secondary symptoms observed in full blown decerebate posturing?

Answer 14

Opisthotonos (extension of trunk and neck)
clenching of jaw
stiff extension of the limbs
internal rotation of the arms
plantar flexion of the feet

Question 15

Name 5 symptoms of bilateral midbrain coma:

Answer 15

1. Breathing is constant hyperventilation (rarely, Cheyne Stokes)
2. Pupils are irregular in shape, fixed and midline
3. Doll’s head maneuver
4. Ice water test, eyes move towards ear with ice water (means CN 6 is ok)
5. Decerebate posturing

Question 16

Name 5 symptoms of bilateral diencephalic coma:

Answer 16

1. Cheyne Stokes breathing
2. Small pupils, small reaction
3. Doll’s head maneuver
4. Ice water test, eyes move towards ear with ice water (means CN 6 is ok)
5. Decorticate posturing

Question 17

Name 5 symptoms of a bilateral pontine coma:

Answer 17

1. Breathing is shallow and rapid, or ataxic
2. Pupils are midposition and fixed
3. Doll’s head manuever - no response
4. Ice water test - no response
5. Body may be flaccid or Babinskis + bilaterally, some lower extremities may be flexed

Question 18

Name 5 symptoms of a unilateral diencephalic stage coma:

Answer 18

1. Breathing is Cheyne-Stokes or eupneic (deep sighs and yawns)
2. Small pupils with some reaction
3. Doll’s head maneuver turns eyes in opposite direction
4. Ice water test positive
5. Motor response to moxious pressure at orbital root, bilateral Babinski

Question 19

Name 4 symptoms of late third nerve stage coma:

Answer 19

1. Regular, sustained hyperventilation or Cheyne-Stokes
2. Pupils are uneven (one blown) and only the good pupil reacts to light
3. Ice water test - bad eye moves away, good eye moves toward water
4. Decorticate or decerebate posturing possible

Question 20

Where is the reticular activating system?

Answer 20

Midbrain

Question 21

What is uncal herniation?

Answer 21

Uncus of temporal lobe moves down brainstem

Question 22

A respiratory pattern of central hyperventilation suggests a problem of the:

Answer 22

midbrain