Coma Flashcards
What is tested in a Coma Examination?
- Level of Consciousness
- Vital Signs
- Respiratory Patterns
- Pupils
- Ocular Movements
- Motor Responses
What are the possible findings of a Neurological Examination of Altered Consciousness?
Patient will be at a particular level of consciousness:
- Normal : No external stimulation necessary
- Somnolent: External stimulation > N1 wakefulness
- Obtunded: External stimulation > Abnormal waking
- Coma: No wakefulness
Name the 4 abnormal respiration patterns
- Cheyne- Stokes
- Central Neurogenic Hyperventilation
- Apneustic Respirations
- Ataxic Respirations
What pattern is seen in Cheyne-Stokes breathing? caused by a lesion in what area of brain?
waxing and waning caused by lesions of diancephalon and cortex
What pattern is seen in Central Nuerogenic Hyperventilation
Deep and Regular with no waxing and waning
What respiration pattern is seen by lesion at the midbrain (colliculi)?
Central Neurogenic Hyperventilation
What pattern is seen in Apneustic Respirations?
Inspiration is followed by prolonged inspiration pause and expiration is followed by prolonged expiration pause
What level cut leads to apneustic respirations?
pontine (Often upper pons) and tegmentum
Describe Ataxic Respirations
Incoordinated breathing with inspiratory spasm
What level lesion may cause ataxic breathing?
medulla oblongta
Big pupil with coma indicates? no coma?
Midbrain; 3rd nerve
What pupillary reaction is seen in a patient with a damaged diancephelon?
small reactive
What pupillary reaction is seen in a patient with a damaged tectum?
large fixed pupils; hippus
Describe decorticate Posturing
Abnormal flexor response of the arm (fully developed includes wrist and fingers with upper extremity adduction) with extension of the legs (internal rotation and plantar flexion of the lower extremity is seen when fully developed)
Disconnecting cortex from brainstem will yield what motor response?
Spastic Hemiparesis- similar to deorticate posturing
What level of midbrain is suspected in Spastic Hemiparesis?
Above the Red Nucleus
Describe decerebrate posturing
When more cerebrum is lost, there is an abnormal extensor response of arm and leg. When fully developed, opisthotonos, clenching of the jaws, stiff extension of the limbs, internal rotation of teh arms, and plantar flexion of the feet occurs.
Extension of trunk and neck is known as
opisthotonos
Decerebrate posturing indicates what level lesion?
caudal to red nucleus in maid brain. Also thought to indicates release of vestibulospinal outputs.
What respiratory pattern is seen in a lesion of thee bilateral midbrain?
Sustained regular hyperventilation
Rarely, chayne-Strokes
Doll’s Head Maneuver (Oculocephalic) findings in Bilateral midbrain stage:
impaired, may be dysconjugate
midbrain is damaged and thus cant drive 1 eye movements when head is turned to right or left
How does the ice water calorics maneuver test the eye?
It is an oculovestibular test. Adding ice water to ear drives the vestiubular nuclei by setting up a convection current in the lateral circular canal just like when you move your head
Oculocephalic findings in bilateral diancephalic stage
midprain , pons, MLF work fine. Absent nystagmus
Bilateral Diencephalic Stage; Motor response at rest? to stimulation?
no response aka motionless; decorticate posture
