cerebral dysfunction Flashcards
levels of consciousness
full consciousness - awake and alert; oriented; behaviour appropriate for age
confusion - impaired decision making
disorientation - disoriented to time and place, decreased LOC
lethargy - limited spontaneous movement, sluggish speech, drowsy, falling asleep quickly
obtundation - a severe reduction in LOC, arouses with strong stimuli but is close to comatose
stupor - remaining in deep sleep, responsive only to vigorous and repeated stimulation or moaning response to stimuli
coma - no motor or verbal response or extension posturing to noxious stimuli
persistent vegetative state - permanently lost function of the cerebral cortex; eyes follow objects by reflex or when attracted to loud sound, four limbs spastic but can withdraw from painful stimuli, hands show reflexive grasping, face grimace, some food may be swallowed, groaning or crying
decorticate posture
flexion posture seen with severe dysfunction of the cerebral cortex or with lesions to corticospinal tracts above the brainstem.
decerebrate posture
extension posturing sign of dysfunction in the midbrain or lesions to the brainstem. unilateral extension cause by tentorial herniation
indication to insert an intercranial pressure monitor
GCS of less than 8
traumatic brain injury with abnormal CT scan
deterioration of condition
subjective judgement
four major types of ICP monitor
intraventricular catheter with fibroscopic sensors attached to a monitoring device - gold standard
subarachnoid bolt (richmond screw)
epidural sensor
anterior fontanel pressure monitor
head injury
3 major causes in childhood: fall, motor vehicle injury, bicycle injury
young children particularly vulnerable to acceleration-deceleration injury. coup - bruising on brain at point of contact
countercoup - bruising on brain at point far removed from point of impact
types of skull fractures
linear - single fracture line that does not cross suture lines
depressed - bone locally broken, usually in several irregular fragments that are pushed inward, causing pressure on the brain. ping pong ball fracture.
comminuted - multiple associated linear fracture, may suggest child abuse
basilar - involve basilar portion of frontal, ethmoid, sphenoid, temporal or occipital bone, proximity of fracture to brainstem means it is a serious head injury.
open - cause communication between skull and scalp or surface of the upper respiratory tract. increase risk of CNS infection
growing - skull fracture with underlying dural tear that fails to heal
epidural and subdural hemorrhage
epidural - bleeding between the dura and the skull to form a hematoma. causes dura to be stripped from the bone and forces underlying brain content downward and inward as the brain expands
subdural - bleeding between the dura and arachnoid membrane, result of rupture of cortical veins that bridge the subdural space. subdural hematomas spread wide and thin
categories of submersion injury
category A - awake, minimal injury, may have mild hypothermia, mild chest radiograph changes, mild arterial blood gas anomalies
category B - blunted sensorium, moderate injury, obtund, stupors, purposeful response to painful stimuli, mild to moderate hypothermia, frequent resp. distress, abnormal chest radiograph, abnormal arterial blood gas
category C - comatose, severe anoxia, abnormal response to pain
types of brain tumours
astrocytoma - common glial tumour from astrocytes (cell that for the supportive tissue for neurons)
ependymoma - arises within or adjacent to the ependymoma lining of the ventricular system
CNS tumour in children typically glial or neuronal, located in the infratentorium, and sensitive to radiation and adjunct chemotherapy
infratentorial brain tumours - area of brain below the tentorium cerebelli involving cerebellum or brainstem
supratentorial tumour - above the tentorium
germ cell tumour - suprasellar and pineal regions of the brain
neuroblastoma
originate from embryonic neural crest cells that normally give rise to the adrenal medulla and sympathetic ganglia. majority of tumours develop in abdomen along adrenal gland or the retroperitoneal sympathetic chain. one of few tumours that show spontaneous regression as a result of maturity of the embryonic cell or the development of an active immune system
3 types of meningitis
bacterial, or pyogenic, cause by pus forming bacteria - most serious form
viral, or aseptic, cause by viral agents
tuberculous, caused by tuberculin bacillus
note: most children with cute febrile intracranial infections have bacterial or viral meningitis
bacterial meningitis
acute inflammation of the meninges and CSF. spread through vascular dissemination from infections elsewhere.
pt presents nuchal rigidity, history of upper respiratory infection, and kernig and brudzinski signs
kernig sign: supine position with hip and knee flexed 90 degree cannot extend knee past 135 degree and pain felt in hamstring
brudzinski sign: supine position flexes lower extremities and passive flexion of neck occurs
management of bacterial meningitis
isolation precaution initiation of antimicrobial therapy restrict hydration maintenance of ventilation reduction of increased ICP management of systemic shock control of seizure control of temperature treatment of complication
nonbacterial (aseptic) meningitis
difference from bacterial meningitis determined from CSF culture
bacterial CSF findings: elevated WBC, elevated protein content, decreased glucose, positive bacteria culture, cloudy colour
viral CSF findings: WBC slightly elevated, protein normal or slightly elevated, glucose normal, negative for bacteria, clear colour
