Complex-Traumatic brain injury and ICP

What is a traumatic brain injury?

​
“An insult to the brain... by​ an external physical force​ that may produce a​ diminished or altered​ state of consciousness,​ which results in​ impairments of cognitive​ abilities or physical​ functioning.”

What is the epidemiology of Traumatic brain injuries?

• 5.3 million Americans are living with TBI-related disability​

• 564,000 ED visits by children​

• 230,000 hospitalizations; 37,000 among children​

• 50,000 deaths; 2,685 among children​

• Falls are the leading cause of TBI; vehicular crashes (MVA) are the leading cause of TBI resulting in hospitalization​

• 74% of TBIs were in males ​

• Firearm-related suicide is linked to many of the TBI-related deaths in the US​

• Costs $48.3 billion annually

What are some potential negative outcomes from a head injury?

• Traumatic Brain Injury (TBI)​

• Brain function altered by an external force​

• Increased Intracranial Pressure (ICP)​

• The pressure within the cranial vault​

• Coma​

• Prolonged state of unconsciousness​

• Herniation​

• Compression of brain tissue or brain stem​

• Brain Death ​

• Absence of brain reflexes, apnea​

What are the types of Traumatic Brain Injuries (TBI)?

1. Concussion​

2. Contusion​

3. Coup Contrecoup​

4. Diffuse Axonal Injury​

5. Chronic Traumatic Encephalopathy (CTE)​

6. Traumatic Hemorrhage

What is a concussion?

A mild form of TBI caused by direct impact to the head or a whiplash

What is a contusion?

A form of TBI that causes bruising of the brain tissue

What is a Coup Contrecoup?

A contusion present at both initial place of impact and the exact opposite side of injury

What happens during a traumatic brain injury?

• Brain shifts and rotates inside the skull. ​

• Causes a shearing (tearing) of nerve fibers (axons). ​

• Usually causes coma and injury to many different parts of the brain.​

• A frequent cause of persistent vegetative states/morbidity in trauma patients​

• Clinical s/s are often worse than CT findings​

• Can be isolated with little or no SAH, SDH, or head fractures​

What is Chronic Traumatic Encephalopathy (CTE)/Repetitive Brain Injury?

• Term used to describe brain degeneration likely caused by repeated head traumas. ​

• The full diagnosis of CTE is made by autopsy and studying sections of the brain​

• Associated with changes in behavior, headaches, suicide, homicide. ​

• Believed to have connections to early onset of dementia, Parkinson’s, and possibly ALS!​

What are Hematomas?

Bleeding outside of the brain from trauma (not a CVA)

What is an Epidural hematoma?

• Arterial bleed​

• High pressure bleed​

• Most dangerous ​

• Bleeding above the dura​

• Leads to ↑ ICP​

• Untreated=death (fast)

What is a Subdural hematoma?

• More commonly under venous pressure​

• Low pressure bleed​

• In subdural space​

• Leads to ↑ ICP

What are the s/s of TBI?

• changes in LOC

• Loss of consciousness

• headache (sign of damage)

• Vomiting, dizziness

• motor function changes (weakness/coordination off)

• Spinal injury (must rule out SCI)

What Glasgow Coma Scale signifies a mild TBI?

GCS 13-15.

These patients are awake, can present with confusion but are able to follow directions and communicate.

What Glasgow Coma Scale signifies a Moderate TBI?

GCS 9-12.

These patients are typically drowsy or obtunded, they can open eyes and localise painful stimuli upon assessment.

What Glasgow Coma Scale signifies a Severe TBI?

GCS 3-8.

These patients present as obtunded to comatose, they are unable to follow directions. They may exhibit decorticate or decerebrate posturing.

What initial assessment is needed for TBI?

• Medical History and Symptoms: Healthcare providers will ask about the nature of the injury, symptoms experienced, and any loss of consciousness. ​

• Neurological Examination: This involves assessing thinking, motor function (movement), sensory function, coordination, eye movement, and reflexes. ​

• Glasgow Coma Scale (GCS): 

What imaging tests are needed for TBIs?

• CT Scan-immediate ​

• MRI 

What neurophysiological testing is needed for TBIs?

These tests assess cognitive functions like memory, thinking, and problem-solving, as well as emotional and behavioral functions. 

What other tests are needed to diagnose TBI?

• Blood Tests: Coags, Electrolytes, ABGs ​

• Electroencephalogram (EEG): This test measures brain activity and can help detect seizures or other abnormalities. ​

• Intracranial Pressure Monitoring

What immediate treatments are needed for TBIs?

• ABCs​

  • Secure/stabilize airway​

  • Supplemental Oxygen administration​

  • Establish venous access​

  • Intravenous fluids: To maintain hydration and blood pressure. ​

• Immobilization: ​

  • To prevent further damage to the spine and neck. 

Why might a pt w/ a TBI need surgery?

• Remove blood clots (hematomas)​

• Repair skull fractures​

• Reduce pressure on the brain 

What medications might be needed for an active TBI?

• Mannitol: To reduce brain swelling​

• Anticonvulsants: To prevent seizures​

• Antidepressants: To manage mood disorders

What is Intracranial Pressure (ICP)?

A type of compartment syndrome​

• Massive brain swelling causes brain tissue to become compressed​

• Blood flow to brain cut off​

• Common in coma patients​

• Can be lethal

• the pressures inside the skull. Includes the brain, CSF, and blood. ​

• Should always be balanced!!

What is the Monroe-Kellie Doctrine?

• The cranium is a rigid, enclosed structure.​

• The sum of these volumes (brain, CSF, and intracranial blood) should be constant.​

• An increase in one should cause a decrease in one or both of remaining two.​

V intracranial volume  = V brain matter + V CSF + V Blood

What is the cause of Acquired brain injuries (non-traumatic brain injuries)?

• CVAs (ICH or SAH-stroke)​

• Space occupying lesions-Brain Tumors-takes up space​

• Poisoning-causes cytotoxic events ​

• Encephalitis-“swelling of the brain”​

• End Stage Liver Failure-leads to cytotoxic edema and ammonia build up​

• Diffuse cerebral hypoxia like Cardio/Pulmonary arrest​

• Seizures (for reasons not totally understood)​

• Severe alcoholism

What are the causes of TBIs?

• External trauma to the head/skull​

• Subdural Hematoma​

• Epidural Hematoma​

• SAH from trauma

What is the pathology & etiology of TBIs?

• Mass Effect (space occupying lesions) ​

  • Hematoma/hemorrhage-trauma or non-trauma bleeding that takes up space​

  • Tumors (takes up space) benign or malignant ​

  • Abscesses (infection/puss-takes up space)​

• Focal or Diffuse Cerebral Edema​

  • Trauma ​

  • Infarcts (leads to cytotoxicity causing cellular edema)​

  • Anoxia (like infarcts) ​

• Overproduction of CSF or ↓ Reabsorption of CSF​

  • Obstructive hydrocephalus (build up of CSF in the ventricles)​

  • Meningitis-infection CX inflammation of the meninges (lining of the brain/spinal cord)=↑ production of CSF ​

• Increase in Blood Volume​

  • Acidosis can cause ↑CO2 in the blood and leads to ↑cerebral blood flow​

  • Aneurysms​

  • Venous stasis from thromboses​

• Skull deformities ​

  • i.e., birth defects​

What LOC s/s would you see in early increased ICP?

• Most sensitive indicator; early changes are subtle​

• Irritable, restless, mild confusion, inability to concentrate

What Pupillary changes would you see in early increased ICP?

Blurred vision, sluggish response

What speech s/s would you see in early increased ICP?

Slurring, trouble finding words or completing sentences

What motor s/s would you see in early increased ICP?

Decreased motor function like in a stroke

What GI s/s would you see in early increased ICP?

Vomiting &/or nausea due to pressure on medulla oblongata

What LOC s/s would you see in late increased ICP?

Increasing confusion, decreasing LOC, eventual coma

What Pupillary changes would you see in late increased ICP?

• Dilate, eventually fixed; may be unilateral, no reaction…​

• Papilledema-swelling of the optic nerve

What vital sign changes (Cushing’s Triad?) would you see in late increased ICP?

• Pressure on brainstem; EKG changes, labile BP and HR; changes in resp. pattern​

• Hypothalamus dysfunction w/ altered body temp. and DI or SIADH​

• HTN + Bradycardia + irregular shallow breathing

What Abnormal reflexes would you see in late increased ICP?

Babinski

What pathological posturing would you see in late increased ICP?

Decorticate and decerebrate posturing; seizures, flaccid

What loss of brainstem reflexes would you see in late increased ICP?

Sluggish then loss of corneal, cough, gag

What is Cushing’s Triad?

Sign of a cerebral hemorrhage resulting from trauma or a space occupying lesion (brain tumors) that is growing, posing an impending fatal herniation of the brain

• 1. A change in respirations-irregular and deep ​

  • Like Cheyne-Stokes breathing​

• 2. A widening pulse pressure​

  • Higher than 60 is a bad sign ​

• 3. Bradycardia​

  • The pressure innervates carotid artery Baroreceptors to slow down the HR (bad)​

VERY late and ominous sign!! Usually Coma!!

What is Confusion?

disoriented to surroundings, impaired judgement, needs cues for commands

What is Lethargy?

defect in attention with only minimally reduced wakefulness

What is Somnolence?

sleepy, drowsy, slow, disorganized response to stimuli

What does it mean when someone is Obtunded?

blunted awareness and lessened response to the environment

What does it mean when someone is in a Stupor?

deeper unresponsive state from which the patient can be only transiently aroused with vigorous stimulation

What does it mean when someone is in a Coma?

unresponsive to all external stimuli

What are Cheyne-Stokes respirations?

An abnormal breathing pattern characterized by periods of rapid, shallow breathing alternating w/ periods of apnea

What does Cheyne-Stokes respirations typically indicate in an unconscious pt?

Suggests lesions deep in both hemispheres; area of basal ganglia and upper brain stem

What does Ataxic respirations w/ irregularity in depth/rate indicate in an unconscious pt?

Suggests onset of metabolic problem or brain stem damage

Ominous sign of damage to medullary center

What does it indicate when an unconscious pt has equal, normally reactive pupils?

Suggests coma is toxic or metabolic in origin

What does it indicate when an unconscious pt’s eyes have Equal or unequal diameter?

Helps determine location of lesion

What does it indicate when an unconscious pt has progressive eye dilation?

Indicates increasing intracranial pressure

What does it indicate when an unconscious pt has fixed dilated pupils?

Indicates injury at level of midbrain

How is Functional and structural integrity of the brain stem assessed?

inspection of extraocular movements; usually absent in deep coma

What nerves does the corneal reflex test?

• Cranial nerves V & VII

• helps determine location of lesion if unilateral

• absent in deep coma

What does it mean if the pt is drooling vs spontaneously swallowing when assessing the swallow reflex?

• Absent in coma

• Paralysis of cranial nerves X & XII

What can it mean when a pt has a Stiff Neck during a neurological assessment?

Subarachnoid hemorrhage, meningitis

What does it mean when there is absence of spontaneous neck movement?

Fracture or dislocation of cervical spine

What abnormal finding can be seen when assessing the response of extremity to noxious stimuli (firm pressure on joint of upper and lower extremities)?

Assymetric response in paralysis

Absent in deep coma

What Pathologic response might you see when assessing deep tendon reflexes?

(illicited by tapping the patellar and bicep tendons)

• Brisk response may have localizing value

• Asymmetric response in paralysis

• Absent in deep coma

What does it mean when you see flaccidity w/ absence of motor response?

Seen w/ Cerebral hemisphere pathology and metabolic depression of brain function

What does it mean when you see Decorticate posturing?

(hug the core)

Implies brain pathology

less deep and severe than decerebrate posturing

What does it mean when there is decerebrate posturing?

indicates deeper and more severe dysfunction than decorticate

Implies brain pathology; poor prognostic sign

What are some gerontologic considerations for a pt w/ TBI?

• Important to distinguish normal aging changes from abnormal changes​

• Structural and physiologic changes​

• Motor and sensory alterations​

• Temperature regulation and pain perception​

• Determine previous mental status for comparison. Assess mental status carefully to distinguish delirium vs dementia

What are the 6 things you need to check during a neurologic exam?

• Mental Status: Consciousness and cognition, intellectual function, thought content, emotional status, language ability​

• Cranial nerves ​

• Cerebellar Function (balance & coordination)​

• Motor system: muscle size, muscle tone and strength, coordination and balance, Romberg test​ (feet together, with eyes open and then closed) (tests balance)

• Sensory system: tactile sensation, superficial pain, temperature, vibration, and position sense (proprioception)​

• Reflexes: DTRs, biceps, triceps, brachioradialis, patellar, Achilles, superficial, plantar (Babinski), pathological posturing (decerebrate, decorticate)

What is CN 1 called and what does it control?

Olfactory - Smell

What is CN II called and what does it control?

Optic - Visual acuity

What is CN III called and what does it control?

Oculomotor - eye movement and pupil dilation

What is CN IV called and what does it control?

Trochlear - vertical eye movement

What is CN V called and what does it control?

Trigeminal - S: facial stimulation; M: facial expression

What is CN VI called and what does it control?

Abducens - lateral movements of eyeballs

What is CN VII called and what does it control?

Facial - S: taste; M: facial expression

What is CN VIII called and what does it control?

Auditory - hearing & balance

What is CN IX called and what does it control?

Glossopharyngeal - S: taste; M: swallow

What is CN X called and what does it control?

Vagus - S: sensation in throat; M: vocal cords, peristalsis

What is CN XI called and what does it control?

Accessary - head & shoulder movement

What is CN XII called and what does it control?

hypoglossal - tongue movement (left and right)

What is the Glasgow Coma Scale?

• International scale used to assess LOC​

• Grades 3 different categories and assigns best score: Eye opening, verbal response, motor response​

• Lowest score = 3; ​

• Highest score = 15​

• Score < 8 = coma​

• Does not show deficits only on one side ​

• Hard to assess sedated pt’s

What CN is affected when there is a loss of a gag reflex?

• CN 9 ​

• Motor = CN10

What does it mean when there is abnormal Posturing in a coma pt?

• Decorticate-damage to cerebral cortex (outer portion of the brain) or damage to corticospinal tracts​

• Decerebrate-damage to the upper brain stem

What are some causes of pathological Posturing?

• Usually caused by ↑ ICP​

• Traumatic brain injury​

• Massive Strokes (esp. hemorrhagic) ​

• Space Occupying Lesions (brain tumors)​

• Intracranial hemorrhage​

• Encephalopathies (viruses/bacteria)​

• Diffuse Cerebral Hypoxia (Cardio-Pulmonary arrest)​

• Brain abscesses​

• Meningitis (brain/cord swelling)

What does it mean when there is Unilateral dilation of the eyes?

III nerve compression

(90% are ipsilateral)

What does it mean when the eyes are bilaterally dilated?

Midbrain injury

What does it mean when there are irregular pupils?

Orbital Trauma

What does it mean when there is a Conjugated gaze deviation? (gaze sustained)

Frontal lobe lesion

What does it mean when the pupils are small/pinpoint?

Pontinue injury or due to opiates

What does it mean when there is an Oculocephalic response (Doll’s eyes)?

• Eyes move like a doll-in the opposite direction of head movement=intact brainstem function. ​

• Eyes do not follow opposite direction=damage to brainstem

What does it mean when there is an Oculovestibular response (Cold/warm water calorics)?

• Intact Reflex-eyes “look’ towards the irrigated ear=brainstem intact​

• Does not “look” towards the irrigated ear=damage to the brainstem

What are Cheyne-Stokes respiration patterns?

(varying periods of breathing)

Causes: Brain tumors and injuries

What are Biot respiratory patterns?

Deep breath w/ periods of apnea

Causes: Spinal meningitis, head injury

What are Kussmaul respirations?

Fast and deep breathing

Causes: Renal failure, diabetic ketoacidosis

Which cranial nerve tests the Pupillary response?

III

Tested w/ light

Which cranial nerve tests the Corneal reflex?

V, VII

Test w/ a cotton swab

Which CN controls the Oculocephalic reflex?

III, IV, VI, VIII

Doll eye test

Which CN controls the Oculovestibular reflex?

III, VIII

cold water irrigation test

Which CN controls the cough reflex?

X

Suction tip

Which CN controls the Gag Reflex?

IX, X

Suction tip

What are some other potential causes of abnormal neurological findings?

• Central nervous system depressant drugs​

• Neuromuscular blocking agents​

• Abnormal core body temperature ​

• Abnormal systolic blood pressure ​

• Severe electrolyte, acid-base, or endocrine disturbances

What are some diagnostic tests for increased Intracranial Pressure?

• Computed tomography (CT)​

• Magnetic resonance imaging (MRI)​

• Cerebral angiography (with/without contrast)​

• Positron emission tomography (PET)​

• Single-photon emission computed tomography (SPECT)​

• Myelography​

• Noninvasive carotid flow studies​

• Transcranial Doppler​

• Electroencephalography (EEG)​

• Electromyography (EMG)​

• Nerve conduction studies, evoked potential studies​

• Lumbar puncture and analysis of cerebrospinal fluid​

• Labs: BG, electrolytes, ammonia, LFT, BUN, ​

serum osmolality, coagulation studies, ABG, drugs, etc.

How do you calculate Cerebral perfusion pressure?

• Tells us about blood flow to the brain.​

• Calculated:​

• The difference between the MAP and ICP = CPP mmHg​

  • CPP = MAP − ICP​

    • MAP=80​

    • ICP=10​

    • CPP would be 80-10=70 mmHg ​

• CPP normal=60-80 mm Hg​

  • CPP < 60 mmHg-ischemia ​

  • CPP < 40 mmHg-infarction​

  • CPP = 0 means brain death