General Information
0 Wakefulness is provided by the ascending reticular activating system -ARAS-.
0 This structure consists of diffuse connections extending to the brainstem, pons, mesencephalon, thalamus, and cortex.
0 Conditions such as hypoglycemia and intracranial bleeding that affect this structure cause coma.
0 Consciousness: It is the state of being awake, perceiving internal and external stimuli and showing the appropriate reaction.
0 Confusion: The patient is awake. Consciousness is blurred, perception, reaction, attention and concentration are reduced.
0 Lethargy (somnolence): The patient is asleep, but can be easily awakened by light stimuli. When the warning is removed, he falls asleep immediately. Orientation may be distorted.
0 Hypersomnia: The patient stays asleep for approximately 25% longer than normal sleep time. It is often associated with varying degrees of delirium.
0 Stupor: The patient is asleep and can only be awakened by painful stimuli. When the painful stimulus is removed, he falls asleep immediately.
0 Coma: The patient cannot be awakened in any way by external stimuli.
0 Vegetative state: The patient maintains the sleep-wake cycle; but cannot show cognitive reaction. Their reactions consist of primitive motor or emotional behavior.
Pupils
0 Pupillomotor parasympathetic fibers are located superficially superomedially to the third nerve.
0 Parasympathetic fibers are supplied by the pial blood vessels, while the main internal canal is supplied by the vasa nervorum of the nerve.
0 Aneurysms, trauma, and uncal herniations also affect the pupillomotor parasympathetic fibers by superficially compressing the pial blood vessels.
Pathologies such as hypertension and diabetes cause microangiopathy in the vasa nervorum and ischemia of the main trunk of the nerve, pupillomotor parasympathetic fibers are preserved in the early period.
Anisocoria
• Space-occupying lesion, herniation in midbrain lesions
• Oculomotor paralysis
• Horner's syndrome
pin point pupil
• Pons bleeding (light reflex preserved)
• Thalamus hemorrhage (no light reflex, eyes look down inward)
• Opiad, organophosphate intoxication
• Use of miotic eye drops (pilocarpine)
• Neurosyphilis
Bilateral fixed dilated pupil (> 5 mm)
• Diffuse cerebral anoxia
• Use of anticholinergic, sympathomimetics
• Hydrocephalus
Respiratory
|
Respiratory
Types in a Coma Patient |
||
|
Breathing
type |
Lesion
location |
Finding |
|
Cheyne-Stokes
respiration |
bilateral
hemisphere |
Initially
increasing in depth, then superficial and onset of apneas |
|
Central
neurogenic hyperventilation |
Mesencephalon-upper
pons |
Successive
deep inspirations and expirations |
|
apneustic
breathing |
Mid-lower
pons level |
Apnea
after each inspiration |
|
Ataxic
breathing (Biot breathing) |
Bulbus
(poor prognosis) |
irregular
breathing |
Other types of breathing:
Kusmall breathing: metabolic coma, diabetic ketoacidosis coma
Brain Death
Prerequisites for the Diagnosis of Brain Death
1- The patient must be in a deep coma and the cause of the coma must be distinguishable.
2- There should be no medical conditions that mimic the clinical picture, such as severe electrolyte, acid-base and endocrine disorders.
3- Since hypothermia suppresses the central nervous system function and causes an erroneous diagnosis of brain death, the central body temperature should be above 32°C.
4. Absence of spontaneous breathing
Tests Used in the Diagnosis of Brain Death
1. A Glasgow Coma Scale (GCS) score of 3.
2. There should be no motor response in the extremity or facial muscles to the painful stimulus.
3. The presence of fixed and dilated pupils without direct or indirect response to light should be demonstrated.
4. There should be no oculocephalic reflex.
5. There should be no oculovestibular reflex.
6. There should be no corneal reflex.
7. There should be no gag reflex.
8. There should be no cough reflex.
9. Apnea test result should be positive.
The most important diagnostic criterion is the absence of spontaneous breathing.
Tests that do not rule out brain death
1. Acquisition of deep tendon reflexes
2. getting surface reflexes
3. Obtaining the Babinski reflex
4. Respiration-like movements (shoulder elevation and adduction, intercostal expansion without significant tidal volume change)
5. Spontaneous extremity movements other than pathological flexion and extension response
Supportive tests
1. Electrophysiological Measurements
2. Cerebral Blood Flow Measurements: Angiography
3. Cerebral Metabolism Measurements
4. Pathomorphological Measurements: Computed tomography, magnetic resonance imaging, cerebrospinal fluid cytology.
5. Atropine Test Positive: No increase in heart rate after intravenous administration of 2 mg of atropine sulfate to indicate brainstem dysfunction and absence of vagal tone, indicating a positive test, that is, impaired brainstem functions.
• Brain death physician board (Ministry of Health)
• Permission of 2 specialists is required, one of which is an Anesthesiologist and the other is a Neurology or Neurosurgery specialist.
herbal life
• Deep coma from any cause
• It can improve in 2-4 weeks with adequate care.
• Respiration, brain stem functions, circulatory system are normal
• In selected cases, it can live for years with appropriate vacuum.
Reflex Eye Movements
- Oculocephalic reflex
The patient's eyelids are opened. The head is turned to one side.
If the brain stem is intact, the eyes should maintain their former position.
This test is called a doll scene.
If the eyes are fixed, there is a brain stem lesion.
Oculovestibular reflex (caloric tests)
Each ear is given cold and hot water.
In healthy person: (COWS)
• When cold water is given, the eyes shift to the watered ear first (deviated). Immediately after, nystagmus hitting the opposite ear starts (cold opposite) When hot water is given, nystagmus hitting the same ear becomes (warm same)
Coma patient, brain stem intact
• Nystagmus disappears (in hot and cold water)
• Eyes deviate to the ear given cold water.
In brain stem lesions
• Eye movements are affected and lost.
ciliospinal reflex
• If the brain stem is normal, it defines dilation of the pupil when stimulated by painful stimuli.
Body temperature
• Hypothermic coma → alcohol, sedative intoxication, hypoglycemia, hepatic myxedema coma
• Hyperthermic → heat stroke, status epilepticus, hypothalamic lesion, malignant hyperthermia, anticholinergic intoxication should be considered
Glasgow Coma Scoring
|
Glasgow
Coma Scoring |
|||||
|
Eyes 1-4 |
Verbal
Answer 1-5 |
Engine
answer 1-6 |
|||
|
It never opens |
1 |
Unanswered |
1 |
Unanswered |
1 |
|
Opens with painful stimulus |
2 |
incomprehensible voices |
2 |
Decerebration rigidity |
2 |
|
Opens with audible stimulus |
3 |
Inappropriate words |
3 |
Decortication rigidity |
3 |
|
spontaneous |
4 |
disorientated |
4 |
Flexor assembly |
4 |
|
|
5 |
Orientation is normal |
5 |
Localizing the pain |
5 |
|
|
|
|
|
normal motor response |
6 |
13-15 points: Minor head injury
9-12 points: Moderate head injury
8 points or less: Severe head injury and coma
3 points: Worst case
Decortication rigidity is seen as a result of the widespread loss of function of the centers from the cerebral cortex to the thalamus. There is an increase in tone bilaterally in the flexor muscles on the upper side and in the extensor muscles on the lower side.
Decerebration rigidity occurs as a result of anatomical or physiological interruption of the connections between the brain stem and the cerebellum. There is an increase in tone in the neck and masticatory muscles and in the extensor muscles of all extremities.
Flexor gathering: It is used to pull with pain, to avoid
Example: The patient presenting with a head injury does not open his eyes (1), gives meaningless answers to questions (3), and gives extensor responses (2) to painful stimuli.
Total: 6