Neurology Flashcards
what is part of the GCS scoring system?
E - eye opening - 4 = open spontaneously - 3 = opens to voice (command) M - motor response - 6 = obeys commands - 5 = localizes painful stimulus - 4 = withdraws from pain V - verbal response - 5 = appropriate and oriented - 4 = confused
what indicates coma by GCS score?
<8
what does unilateral, dilated, nonreactive pupil suggest?
focal mass lesion with ipsilateral herniation and compression of CN III
what do bilateral fixed and dilated pupils suggest?
diffusely increased ICP
what are the four signs of basilar skull fracture?
raccoons eyes - periorbital ecchymoses
battle’s sign - post auricular ecchymoses
hemotympanum
CSF - rhinorrhea/otorrhea
what is the initial radiographic neuroimaging in trauma?
head CT scan
C-spine CT scan
T/L spine AP and lateral
should the trauma head CT scan be with or without IV contrast?
without
what is Cushing’s reflex?
physiologic response to increased ICP:
- hypertension
- bradycardia
- decreased RR
what is the acronym for the treatment of elevated ICP?
ICP HEAD
- intubate
- calm (sedate)
- place drain (ventriculostomy)/paralysis
- hyperventilate to pCO2 =35
- elevate head
- adequate blood pressure
- diuretic
how does hyperventilation decrease ICP?
by decreasing pCO2, resulting in cerebral vasoconstriction (and thus less intracranial volume)
how does cranial nerve examination localize the injury in a comatose patient?
CNs proceed caudally in the brainstem as numbered:
- presence of corneal reflex (CN V+VII) indicates intact pons
- intact gag reflex (CN IX + X) indicates functioning upper medulla
- CN VI palsy is often false localizing sign
what is acute treatment of seizures after head trauma?
benzodiazepines
what is seizure prophylaxis after severe head injury?
phenytoin for 7d
what is the significance of hyponatremia after head injury?
SIADH must be ruled out
what is an epidural hematoma?
collection of blood between the skull and dura
what causes an epidural hematoma?
usually occurs in association with a skull fracture as bone fragments lacerate meningeal arteries
which artery is associated with epidural hematoma?
middle meningeal artery
what is the most common sign of an epidural hematoma?
ipsilateral blown pupil
what is the classic history with an epidural hematoma?
LOC followed by a ‘lucid interval’ followed by neurologic deterioration
what are the classic CT findings with an epidural hematoma?
lenticular (lens) shaped hematoma
what is the surgical treatment for an epidural hematoma?
surgical evacuation
what is a subdural hematoma?
blood collection under the dura
what are the three types of subdural hematomas?
acute - symptoms within 48hrs of injury
subacute - symptoms within 3-14d of injury
chronic - symptoms after 2wks or longer
what is the treatment of epidural and subdural hematoma?
mass effect (pressure) must be reduced - craniotomy with clot evacuation is usually required
what classic findings appear on head CT for a subdural hematoma?
curved, crescent-shaped hematoma
what is a traumatic subarachnoid hemorrhage?
head trauma resulting in blood below the arachnoid membrane and above the pia
what is the treatment for a traumatic subarachnoid hemorrhage?
anticonvulsants and observation
what is a cerebral contusion?
hemorrhagic contusion of brain parenchyma
what are the coup and countercoupe injuries?
coup - injury at the site of impact
contrecoup - injury at the site opposite the point of impact
what is DAI?
diffuse axonal injury
- shear injury to brain parenchyma from rapid deceleration injury
what is the best diagnostic test for DAI
MRI
what can present after blunt trauma with neurologic deficits and a normal brain CT scan?
DAI, carotid artery injury
what is a depressed skull fracture?
fracture in which one or more fragments of the skull are forced below the inner table of the skull
what are the indications for surgery?
contaminated wound requiring cleaning and debridement severe deformity impingement on cortex open fracture CSF leak
