Craniocerebral Trauma Flashcards
Among Immediately fatal head injuries, autopsy reveals an intact skull in what percent of cases?
20-30%
Mechanical factors of importance in brain injury
Differential mobility of head on neck
Mobility of brain within the cranium
Tethering of upper brainstem
Striking of parts of brain on dural septa and bony prominences
Battle sign
Tissue behind the ear and over the mastoid becomes boggy and discolored, from damage to sigmoid sinus
In basal skull fractures, cranial nerves most liable to injury
Olfactory
Facial
Auditory
Fracture of this bone may lacerate the optic nerve, resulting in blindness from the onset, unreactive pupil to direct light but with consensual light reflex
Sphenoid bone
Trochlear nerve injury
Diplopia worse on looking down and compensatory tilting of head
Match CN7 involvement with type of petrous bone fracture
1. Immediate facial palsy, requiring surgical intervention to regain function
2. Facial palsy delayed for several days, usually transitory
A. Transverse fracture
B. Longitudinal fracture
1A
2B
In concussion, what could explain immediate loss of consciousness?
Torque at level of of upper reticular formation
From point of tethering in the high midbrain
Reversible traumatic paralysis of nervous function; may last for a variable time
Concussion
Blows to 1. Back of head 2. Front of head 3. Side of head Mainly cause A. Coup B. Contrecoup C. Either or Both
1A
2B
3C
Usual location of lesions seen in concussion
Reticular Activating System
Corpus callosum
Superior cerebellar peduncles
Dorsolateral tegmentum of the midbrain
Pathology of diffuse axonal injury (DAI)
Uneven but diffuse degeneration of the white matter
In cases of shorter survival, ballooning and interruption of axis cylinders
All brainstem hemorrhages when there is mass effect that distorts the brainstem
Duret hemorrhage
In a small group of patients with these characteristics, there is a significant risk of ICH or other delayed complications of trauma
Slow in regaining consciousness
Severe headache
Vomiting
Skull fracture
Presence of skull fracture in children is a relatively poor indicator of intracranial injury EXCEPT when the fracture is in the following
Fracture through the squamous bone
Fracture through the groove of the Middle Meningeal Artery
= Risk for arterial and epidural hemorrhage
New Orleans Criteria for Head CT
Use in pts with head trauma and LOC seen gcs15 and neurologically normal
Any 1 of the ff warrants Head CT
Headache
Vomiting
Age >60y
Drug or alcohol intoxication
Persistent anterograde amnesia (deficits in short term memory)
Evidence of soft tissue or bone injury above clavicles
Seizure
Canadian CT Head Rule
Use for pts GCS13-15 with at least one of the ff
LOC, amnesia for the event, witnessed disorientation
Exclusion: age<16y, pt on blood thinners, sz after injury
Presence of any 1 requires CT
High risk for neurosurgical intervention
1. GCS <15 within 2H after injury
2. Suspected open or depressed skull fracture
3. Any sign of basal skull fracture (racoon eyes, hemotympanum, battle sign, CSF oto/rhinorrhea)
4. 2 or more episodes of vomiting
5. Age >54y
Moderate risk of brain injury detected by CT
- Retrograde amnesia for >/= 30mins
- Dangerous mechanism (pedestrian vs vehicle, occupant ejected from vehicle, fall for >3ft or >5stairs)
Most important factor in the expansion of subdural fluid
Pathologic permeability of developing capillaries in the outer pseudomembrane of the hematoma
Drug that has through a randomized trial shown effect of slight acceleration of emergence from vegetative or minimally conscious state.
Dosing and duration?
Amantadine
100mg twice a day increasing to 200mg twice a day
Given for 4weeks bet the 4th and 12th weeks after injury.
Volume of traumatic ICH found to be fatal in 9 out of 10 patients
> 25mL
Indicators of poor outcome in Shaken Baby Syndrome
Low initial GCS
Severe retinal hemorrhages
Skull fractures
3 Surgical problems outlined by Meirowsky in missile injuries
- prevention of infection
- Control of increased intracranial pressure
- Prevention of life-threatening systemic complications
Seizures are the most common delayed sequelae of craniocerebral trauma. Its overall incidence in pts with closed head injuries is? In those with compound skull fracture and direct wounds of the brain?
Severe head injury (LOC or amnesia >24h, sdh, brain contusion)?
Moderate (LOC or amnesia 30min-24h, skull fx)?
Mild
5% 50% 7% in 1 yr, 11.5% in 5y 0.7%, 1.6% Not significantly greater than general population
Early Epilepsy
Seizures within 1st week of injury
Associated with more frequent late seizures than immediate epilepsy
Posttraumatic epilepsy
Late epilepsy
Develop several weeks or months after closed head injury (1-3mos in most cases)
Persistent hypotension in a patient with cerebral trauma should raise suspicion of the ff:
Thoracic or abdominal bleeding
Extensive fractures
Trauma to cervical cord
Diabetes insipidus
Plaques jaunes
Old cortical contusions
This is considered to have an adverse effect on seizure and even in patients in whom seizures have ceased, this could precipitate recurrence
Alcoholism
Syndrome of episodic vigorous extensor posturing, profuse diaphoresis, hypertension, and tachycardia lasting mins to an hour esp in pts in the vegetative state and those comatose from severe head injury
Autonomic Dysfunction (“Storm”) Syndrome
Drug found most effective in the treatment of autonomic Dysfunction sydrome
Bromocriptine
Factors that make permanent cognitive and personality changes more likely among pts with craniocerebral trauma
Lower GCS immediately after injury
Longer posttraumatic gap
Neuropathologic pattern of chronic traumatic encephalopathy
Perivascular hyperphosphorylated tau protein embedded in astrocytic or neurofibrillary tangles with a predilection for depths of sulci of the frontal and temporal lobes (also in cortex, thalamus, brainstem) and eventually most extensive in the medial temporal lobes
Strongest predictor of occurrence of postconcussion syndrome
Previous anxiety disorder
Characteristic cranial pain of Postconcussion Syndrome
Generalized or localized pain, variable character, intensified by mental and physical effort, straining, stooping, and emotional excitement. And, relieved by rest and quiet.
ICP monitoring is deemed appropriate if
GCS 3-8 with
- Abnormality on CT scan
OR - No abnormality on CT BUT with any 2: age>40y, posturing, SBP<90mmHg
Duration for which ventricular catheter for ICP monitoring may be left in place
3-5days
May remove in fewer days if clinical state and ICP stable x 24-48hrs
Mechanism of Action of the ff Hyperosmolar agents: Mannitol Glycerol Urea Hyperosmolar saline
Mannitol, Glycerol, Urea
- produce serum hyperosmolarity > diuresis which maintains this state > 2rily causes hypernatremia and hypovolemia
Hyperosmolar saline
- raises serum sodium directly expanding intravascular volume
Recommended boluses of Hypertonic Saline
Accdg to concentration
3%, 7.5%, 23%
3% - 150mL
7.5% - 75mL
23% - 30mL
Main problem in using hypothermia
Rewarming induces substantial brain swelling and return of ICP to prior levels or higher
Results of the CRASH trial
Effect of infusion of methylprednisolone 2g ff by 0.4g/h for 48h favored Survival in the UNTREATED patients
Antihypertensives of choice for BP lowering in cases of craniocerebral trauma
Diuretics, B-Blockers, ACEi
