Neurology/ neurosurgery Flashcards
List 4 life-threatening causes of ataxia
- Brain tumors (post. fossa) —> raised ICP
- Intracranial hemorrhage
- Stroke
- Infection (encephalitis, ADEM, abscess)
What are four/five non-cancer causes of ataxia?
- Acute cerebellar ataxia post varicella infection
- Intracranial hemorrhage
- Stroke (vertebral or basilar artery)
- Cerebellar abscess
- ADEM
- Guillain Barre syndrome – Miller Fisher variant: triad ataxia, areflexia, ophthalmoplegia
- Labyrinthitis
- Migraines
- Toxin exposure – antiepileptics, lead, CO, alcohol
- Post-traumatic
Most common cause of postinfectious cerebellitis, and general illness course
post-varicella
age 1-3, 8d-3 weeks post infection, VZV usually case, other include EBV and mycoplasma; mild increase WBC/protein in CSF; recovery several weeks (residual deficits in 10-30%); imaging studies normal; may see dysarthria/nystagmus, n/v
Which toxins can cause ataxia? (list 4)
alcohol, phenytoin, carbamazepine, benzo, TCA, antihistamines, lead, ethylene glycol, risperidone, gabapentin
What is the Miller Fischer variant of GBS?
Ataxia, ophthalmoplegia, areflexia
Etiology of coma? (and an acronym to remember it)
TIPS
T: Trauma
I: Insulin/Hypoglycemia, Intussusception, Inborn errors of metabolism
P: Psychiatric
S: Seizures, Stroke, Shock, Shunt malfunction
AEIOU A: Alcohol abuse E: Electrolyte abnormalities, Encephalopathy, Endocrinopathy I: Infection O: Overdose/Ingestion U: Uremia
What is considered clinically important TBI (ciTBI)?
depressed skull fracture requiring surgery, neurosurgical intervention (ICP monitor, ventriculostomy, hematoma evacuation, craniectomy), hospital admission for > 48 hours, death
Most common causes of head trauma in peds?
falls (most common), MVC/ pedestrian (highest fatality), bicycle injuries, non-accidental injury
Causes of secondary brain injury?
further neuronal damage (due to hypoxia, hypoperfusion, cerebral edema)
How is CPP calculated?
How does cerebral blood flow autoregulation work?
CPP (cerebral perfusion pressure) = MAP – ICP
Cerebral blood flow is autoregulated to remain constant across wide range of CPP (autoregulation lost with severe injury – so cerebral blood flow becomes directly related to MAP – therefore very important to maintain normal MAP)
o Autoregulation lost when MAP < 60 or ICP > 40
Signs and symptoms of increased ICP?
- Symptoms of increased ICP: headache, vomiting, irritability, lethargy
- Signs of increased ICP: depressed LOC, Cushing triad (bradycardia, hypertension, irregular respirations), CN palsy
4 types of cerebral herniation syndromes and how they present?
- Subfalcine (unilateral motor deficits or lower limbs, bladder incontinence)
- Central (forced downward gaze, dil. unreactive pupils, quickly lethal)
- Uncal = transtentorial (CN 3 palsy - pupil dilated, down and out on side of herniation, contralateral - rarely unilateral hemiparesis)
- Tonsillar (dec LOC, resp failure, flaccif paralysis)
Characteristics of epidural hematoma?
Lens-shaped on CT
overlying fracture in 60-80% of cases, lucid interval btw initial LOC and subsequent deterioration very rare in children – fixed and dilated pupil on the side of the lesion and contralateral hemiparesis (compression of CN III & corticospinal tract)
CATCH study - name 4 findings that predict neurosurgical intervention and 3 that predict CT findings
WIGS SDH
High risk: Worsening headache Irritability GCS < 15 at 2 hours Suspected open or depressed skull #
Medium risk:
Signs of basal skull
Dangerous mechanism
Boggy hematoma
+ >/= vomiting 4 x (CATCH 2)
What is considered a dangerous mechanism for the CATCH study? for PECARN?
for CATCH:
MVC, fall from elevation ≥ 3 ft or 5 stairs, fall from bicycle with no helmet
for PECARN:
• MVC with rollover, patient ejection, or death of another passenger
• pedestrian or bicycle w/o helmet struck by motorized vehicle
• fall > 3 feet if age > 2 years, fall > 5 feet if age > 2 years
• head struck by high impact object
What are some signs and symptoms of basal skull fracture?
hemotympanum, “raccoon” eyes, otorrhea or rhinorrhea of the cerebrospinal fluid, Battle’s sign
What are 3 indications for skull x-ray
- skeletal survey
- evaluate for location of a radiopaque foreign body
- in rare instances to screen for # in selected asymptomatic children 3-12 months of age with concerning scalp hematoma or question of depression
What were the risk factors for identifying a skull # according to a 2015 CMAJ study?
CMAJ 2015 study: risk factors for findings skull fracture are age < 2 months, or parietal/ occipital hematoma (in 3-12 months)
For skull xrays: list 4 x-ray findings suggestive of more serious underlying injury
depressed, basilar, linear with >3 mm separation, growing skull #
List 4 differences in CSF between subarachnoid hemorrhage and traumatic tap.
- Elevated opening pressures
- Presence of blood in CSF that does not clear between tubes
- Xanthochromia (noted at least 2 hours post headache onset, ideally >6 hours)
- Elevated ratio of RBC to WBC, absence of WBCs
What are the different types of skull fractures?
linear (75-90%) diastatic (separation at suture sites or fracture that is widely split) depressed compound (communicate with laceration) comminuted (several fragments)
Complications of basal skull #?
intracranial injury, CSF leak (with dural tear), meningitis, CN impairment, hearing loss
Characteristics of subdural hematomas?
bleeding between dura and arachnoid membranes. Tearing of cortical bridging veins, crescent-shape on CT scan (crosses suture lines)
List some common symptoms of concussion
headache, confusion, dizziness, light-headedness, nausea/vomiting, memory impairment
Definition of concussion?
functional (not structural) brain injury from a force/ blow to the head. May or may not have LOC
Grading severity of head trauma by GCS score?
Minor head trauma: GCS 14-15
Moderate: GCS 9-13
Severe: GCS ≤ 8
GCS score (E4,V5, M6)
Post-traumatic seizures - and risk of recurrence
• Timing : immediate, early or late
o Immediate – within seconds, traumatic depolarization of the cortex, generalized, rarely recur
o Early – within 1 week, most within 24 hours. Increased risk with skull fractures, intracranial hemorrhage, and focal signs
o Late: > 1 week. More likely to recur, due to scarring, intracranial hemorrhage
Discharge instructions / anticipatory guidance for head trauma (list 5)
- Persistent or increasing headache
- Repeated vomiting
- Drowsiness or change in behavior
- Weakness or clumsiness of an arm or leg
- Stiffness of neck or complaints of pain with neck movement
- Vision changes
- Poor balance when walking
- Seizures
- Leakage of clear fluid from nose or ears
Steps in management of ICP in context of trauma
o Head of bed to 30 degrees, head midline
o Analgesia, sedation +/- paralysis
o PaCO2 35-45 (if herniating: 30-35 – moderate hyperventilation)
o Hypertonic 3% saline (6-10 ml/kg) +/- continuous infusion – aim Na 145-155
o Consider prophylactic anti-epileptics
o Barbiturate coma
Which meds to use to intubate in head trauma?
use atropine if < 1 year old, lidocaine and RSI (etomidate and midazolam listed as good options)
Ketamine NOT associated with increased ICP (may actually lower ICP – safe to use in RSI)
Definition of migraine without aura
- At least 5 attacks
- Headaches last 4-72 hours
- At least 2 of: unilateral (more common bilateral in kids), pulsating, mod-severe, worse with activity
- At least 1 of: photo/phonophobia, N/V
Types of primary headache? (3)
migraine, cluster, tension
Common migraine triggers (4)
stress, lighting changes, minor head trauma, hormonal (OCP, menstruation), nitrates, tyramine (cheeses)
List 4 migraine variants
basilar (mimic posterior fossa mass), ophthalmoplegic (CN 3,4,6), hemiplegic, retinal, confusional, Alice in Wonderland syndrome
