cerebral dysfunction

Question 1

levels of consciousness

Answer 1

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

Question 2

decorticate posture

Answer 2

flexion posture seen with severe dysfunction of the cerebral cortex or with lesions to corticospinal tracts above the brainstem.

Question 3

decerebrate posture

Answer 3

extension posturing sign of dysfunction in the midbrain or lesions to the brainstem. unilateral extension cause by tentorial herniation

Question 4

indication to insert an intercranial pressure monitor

Answer 4

GCS of less than 8
traumatic brain injury with abnormal CT scan
deterioration of condition
subjective judgement

Question 5

four major types of ICP monitor

Answer 5

intraventricular catheter with fibroscopic sensors attached to a monitoring device - gold standard
subarachnoid bolt (richmond screw)
epidural sensor
anterior fontanel pressure monitor

Question 6

head injury

Answer 6

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

Question 7

types of skull fractures

Answer 7

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

Question 8

epidural and subdural hemorrhage

Answer 8

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

Question 9

categories of submersion injury

Answer 9

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

Question 10

types of brain tumours

Answer 10

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

Question 11

neuroblastoma

Answer 11

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

Question 12

3 types of meningitis

Answer 12

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

Question 13

bacterial meningitis

Answer 13

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

Question 14

management of bacterial meningitis

Answer 14

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

Question 15

nonbacterial (aseptic) meningitis

Answer 15

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

Question 16

encephalitis

Answer 16

inflammatory process of the CNS that is caused by variety of organisms, including bacteria, fungi, viruses, etc. focus on viral encephalitis: can occur as result of direct invasion of the CNS by a virus or postinfection involvement of the CNS after viral disease

Question 17

reye syndrome

Answer 17

disorder defined as acute encephalopathy (disease or disorder of the brain) associated with other characteristic organ involvement. Fever, altered consciousness, and disordered hepatic function. Characterized by fatty changes of the liver and cerebral edema.

Question 18

seizures

Answer 18

caused by excessive and disorderly neuronal discharges in the brain. most common cause of seizure is febrile seizure in pediatric.
acute symptomatic seizure - associated with acute insult, such as head trauma or meningitis
remote symptomatic seizures - those without immediate cause but with an identifiable prior brain injury such as major head injury or meningitis

Question 19

epilepsy

Answer 19

condition characterized by two or more unprovoked seizures and can be caused by a variety of pathological processes in the brain

Question 20

idiopathic and cryptogenic seizure

Answer 20

idiopathic seizure - genetic in origin

cryptogenic seizure - occurring with no clear cause

Question 21

pathophysiology of seizures

Answer 21

regardless of etiology, the mechanism is the same in all seizures. abnormal electrical discharges may arise from central areas in the brain that affect consciousness, may be restricted to one area of the cerebral cortex - producing manifestations characteristic of that particular anatomical focus, or may begin in a localized area of the cortex and spread to other portions of the brain and, if sufficiently excited, produce generalized seizure activity.

Question 22

seizure classification

Answer 22

partial seizure, local onset and involve relatively small location in the brain
generalized seizure, involve both hemispheres of the brain and without local onset
unclassified epileptic seizures

Question 23

management of epilepsy

Answer 23

medication therapy -
ketogenic diet
vagus nerve stimulation
epilepsy surgery

Question 24

refractory seizure and status epilepticus

Answer 24

refractory seizure - persistence of seizure despite adequate trials of three antiepileptic medications, alone or in combination
status epilepticus - continuous seizure lasting 30 minutes or more or a series of seizures from which child does not regain premorbid LOC

Question 25

febrile seizure

Answer 25

simple febrile seizure - occur in children between 6 months and 5 yrs with no pre-existing neurological abnormality and consist of a general tonic-clonic seizure that occurs with a fever and resolved 15 min with return to alert mental status after seizure and no further seizure in the 24 hr period
complex febrile seizure - occur in any age, usually with previous neurological impairment, and consist of a prolonged seizure lasting more than 15 min and can recur within 24 hrs; can result in neurological deficit after seizure

Question 26

craniosynostosis

Answer 26

closure of a suture before expected time. forces skull to grow in direction parallel to fused sutures to accommodate for increase in brain volume. Head shape deformed due to brain growth, small head with normal shape and closed suture indicate deficient brain growth; closure of suture secondary to failed brain growth

Question 27

microcephaly

Answer 27

congenital condition that refers to a head circumference that measures more than 3 SD below mean for age and sex. brain growth restriction and cognitive impairment common.

Question 28

positional plagiocephaly

Answer 28

positional plagiocephaly is cranial asymmetry. Vast majority of cases resolve at 2 yrs.
prevention of plagiocephaly:
- positioning of the head to encourage lying on each side in the supine position
- prone position during awake time for 10-15 min at 3 x a day
- evaluation for craniosynostosis, congenital torticollis, etc should be part of examination of child with plagiocephaly
- repositioning therapy and physiotherapy as indicated
- moulding therapy for severe asymmetry

Question 29

hydrocephalus

Answer 29

condition caused by an imbalance in the production and absorption of CSF in the ventricular system. CSF accumulates within the ventricular system, usually under increased pressure, producing passive dilation of the ventricles. causes are varied.

Question 30

hydrocephalus pathophysiology

Answer 30

2 types of hydrocephalus causes: impaired absorption of CSF within the subarachnoid space, obliteration of the subarachnoid cisterns, or malfunction of the arachnoid villi (communicating hydrocephalus) OR obstruction to the flow of CSF through the ventricular system (noncommunicating hydrocephalus)

Question 31

noncommunicating hydrocephalus

Answer 31

most cases result of development malformations. an obstruction to the normal CSF flow can occur in any point in the CSF pathway to produce increased pressure and dilation of the pathways proximal to the obstruction.