PEDIATRIC NEUROLOGY LECTURES: INCREASED - PowerPoint Presentation

Slide1

PEDIATRIC NEUROLOGY LECTURES: INCREASED INTRACRANIAL PRESSURE; CEREBRAL EDEMA, BRAIN TUMORS

Assoc. Prof. Ingrid

Miron

Slide2

INCREASED INTRACRANIAL PRESSURESYMPTOMS

Headaches

of recent

onset

and

increasing

severity

associated

with

nausea,

vomiting

, or transient

visual

obscuration

in

the

older

child

,

complaints

related

by

the

parents

of

poor

feeding

,

vomiting

,

excessive

irritability

, or

lethargy

in an

infant

t

he

child

with

an acute

onset

of

increased

ICP

presents

with

stupor

or coma

.

Etiologies

:

trauma,

hemorrhage

,

hypoxic

ischemic

encephalopathy

, diabetic

ketoacidosis

, CNS

infections

,

and

parainfectious

encephalopathies

Slide3

INCREASED INTRACRANIAL PRESSURESYMPTOMS

Increased

ICP

on neurologic examination of children less than

3

years

of age: an

excessive rate of head growth, separated sutures (by palpation or on skull x-ray), and a full or bulging anterior fontanel (in infants).

Enlargement

of the third ventricle in infants results in spontaneous downward deviation of the eyes (

sunsetting

sign), while enlargement of the lateral ventricles causes pathologically brisk reflexes in the lower extremities.

In the older child (over 3 years) the cranium becomes

nonresilient

, and increased

ICP

is reflected by pressure on the optic nerve sheaths, resulting in papilledema, and pressure on the sixth cranial nerve, causing paresis of the lateral rectus muscle

.

Ventricular enlargement in the older child causes an impairment of upward gaze, pathologically brisk reflexes, and less commonly, an unsteady gaze.

Slide4

INCREASED INTRACRANIAL PRESSURE

computed

tomographic (CT) scan or magnetic resonance imaging (MRI) scan are essential to look for surgically correctible lesions. MRI scanning may show more anatomic detail and better visualization of cerebral edema, but CT scanning is entirely adequate in most cases.

Brain

tumors, subdural empyema or brain abscess, epidural, subdural or

intraparenchymal

hematomas may cause increased

ICP

from mass effect or obstruction of cerebrospinal fluid (CSF) flow. Most brain tumors in childhood are in the posterior

fosa

or midline and produce increased

ICP

by causing obstruction of CSF flow. Hydrocephalus, not associated with an obstructing mass, is also a common cause of increased

ICP

.

Slide5

INCREASED INTRACRANIAL PRESSURE

If

the CT or MRI scan shows small ventricles and basal cisterns, the probable diagnosis is cerebral edema. Additional signs include the loss of distinction between gray and white matter and a homogenous appearance of the parenchyma.

Neurologic deterioration after trauma, hypoxic ischemic encephalopathy, or diabetic ketoacidosis is often associated with increased

ICP

.

the child

has to be admitted to

the intensive care unit and

monitors have to be placed

for continuous measurement of

ICP

and arterial blood pressure.

The

epidural

ICP

monitors

are

preffered

as

there are fewer problems with

infections. The

ventricular catheter for

ICP

monitoring has the advantage to allow withdrawal

of CSF.

Particular attention has to be

payed

to cerebral perfusion pressure (

CPP

), which is defined as mean arterial pressure minus intracranial pressure and attempt to maintain a

CPP

greater than or equal to 50 mmHg

.

In

general, for brief episodes of increased

ICP

, we start with

mannitol

and use intermittent hyperventilation. Morphine is given prior to painful procedures. If this is not successful, pentobarbital coma is considered. Hypothermia is used in some centers. We avoid it because of potential circulatory compromise and increased

susceptibility

to sepsis.

Slide6

INCREASED INTRACRANIAL PRESSURE

Lumbar

puncture should be

performed - if

the etiology for increased intracranial pressure is

unknown,

particularly when meningitis or encephalitis are

considered. If

the CT scan has not shown a mass lesion, this procedure is reasonably safe.

If

there is concern about significant increased

ICP

, the child is sedated prior to the procedure and given

mannitol

20 minutes prior to the lumbar puncture. The opening pressure is measured and the CSF is sent for routine analysis. A normal opening pressure suggests either a mistaken diagnosis, such as the confusion of papilledema with

papillitis

or

pseudopapilledema

, or possibly resolved increased

ICP

. If the opening pressure is elevated, the CSF analysis normal, and the child is not

encephalopathic

, the most likely diagnosis is begin intracranial hypertension (

pseudotumor

cerebri

). If the child is

encephalopathic

, the most likely diagnosis is a

parainfectious

noninflammatory

encephalopathy such as Reye syndrome. An abnormal CSF formula suggests infectious or neoplastic meningitis or encephalitis.

Slide7

Slide8

Slide9

IDIOPATHIC INTRACRANIAL HYPERTENSION (

PSEUDOTUMOR

CEREBRI

)

Pseudotumor

cerebri

is defined as a diffuse increase in intracranial pressure in the presence of normal cerebrospinal fluid and normal brain imaging.

Symptoms:

- headache increases with

Valsalva

maneuver

- vomiting

- diplopia

- visual obscuration

- in young children are also seen somnolence and irritability and bulging

fontanelle

.

Signs:

- papilledema

- sixth nerve palsy:

nonlateralizing

Slide10

IDIOPATHIC INTRACRANIAL HYPERTENSION (

PSEUDOTUMOR

CEREBRI

)

Risk factors:

- drugs: tetracycline, birth control pills, vitamin A (increased or decreased), steroid withdrawal

-

endocrinopathy

: treatment with growth hormone, with thyroid hormone, hyperthyroidism, adrenal insufficiency or

hyperadrenalism

,

hypoparathyroidism

-

refeeding

in malnourished children and those with cystic fibrosis

- iron deficiency anemia.

Differential diagnosis:

- mass lesion

- hydrocephalus

- lateral sinus thrombosis (

mastoiditis

, otitis media)

-

sagital

sinus

trombosis

(systemic lupus

erythematosus

, polycythemia, dehydration,

hypercoagulable

states)

- malignancy (

carcinomatosis

,

gliomatosis

cerebri

,

leukemia)

Slide11

IDIOPATHIC INTRACRANIAL HYPERTENSION (

PSEUDOTUMOR

CEREBRI

)

Evaluation:

- magnetic resonance imaging of the brain

- normal

- small

ventricles may or may not be present

- effacement

of cortical sulci may or may not be present

- visual acuity and visual fields – repeat frequently

- lumbar puncture:

- increased

opening pressure (greater than 200 mmH2O)

- normal

protein and glucose levels, normal cell count.

Slide12

IDIOPATHIC INTRACRANIAL HYPERTENSION

(

PSEUDOTUMOR

CEREBRI

)

Treatment:

- relieve pressure to preserve vision

- lumbar puncture

- reduce pressure to half the opening pressure

- remove 10-20 ml cerebrospinal fluid, but not below 200 mmH2O

- acetazolamide

- dose of 10-20 mg/kg/day

- can range from 250 mg twice daily to 500 mg twice daily

- failure of lumbar puncture and acetazolamide – try the following:

- prednisone 2 mg/kg (maximum of 60 mg) for 2 weeks

- failure of the above – try the following:

- optic nerve fenestration

-

lumboperitoneal

shunt (may cause acquired

Chiari

malformatio

or tethered cord)

If this condition is left untreated the increased intracranial pressure may cause optic atrophy and permanent visual loss.

Slide13

Cerebral edemaCerebral edema is frequent complication of neurological disease processes. While the initial brain swelling seen immediately following head injury is due to cerebral vascular congestion, cerebral edema follows, with a peak of swelling usually evident in 48-96 hours. Cerebral edema can be either localized or generalized, but both contribute to intracranial hypertension if there is not a compensatory drop in CSF and/or intracranial blood volume. Two

pathophysiologically

distinct types of cerebral edema have been described:

vasogenic

edema and

citotoxic

or metabolic edema. A third type, interstitial edema, has also been described.

Slide14

Cerebral edema - vasogenic

Vasogenic

cerebral edema starts locally, around the area of brain injury, but may spread to become generalized. Vascular damage interrupts the permeability pattern of the blood vessels in the injured area of the brain. There is disruption of the normal blood/brain barrier, with leakage of plasma proteins out of the blood vessels into the extracellular space. This is followed by an osmatic influx of water into the area. Most

vasogenic

edema fluid accumulates in the white matter of the brain, because of the white matter’s less closely interwoven cellular structures.

Vasogenic

edema can cause focal neurological deficits as well as disturbances of consciousness. Like a leaking water pipe, the higher the patient’s blood pressure, the greater the potential for

vasogenic

edema. Nursing actions may need to be directed toward preventing and treating hypertensive episodes.

Slide15

Cerebral edema - cytotoxic

Cytotoxic cerebral edema refers to the actual swelling of brain cells. It is more generalized and is thought

to be

due to some toxic factor that causes destructive alteration of brain cellular elements. While neuronal, glial, and endothelial cells are affected, it occurs most often in the gray matter. It may be due to failure of the sodium pump, a situation that results in abnormal distribution or electrolytes and water across the cell membranes.

Slide16

Cerebral edema - cytotoxic

occurs as a result of hypoxia and

hypercapnia

, as seen following cardiac arrest.

occurs in conditions associated with low serum levels of sodium. These include the syndrome of inappropriate antidiuretic hormone secretion (

SIADH

), severe sodium depletion, and water intoxication.

Brain

ischemia can results in both

vasogenic

and cytotoxic edema. Progressive ischemia causes cytotoxic edema, which leads to brain cell death. This contributes to the disruption of the blood-brain barrier and the formation of

vasogenic

edema.

Interstitial or extracellular cerebral edema forms as a result of hydrocephalus with leakage of CSF from the ventricles into the surrounding tissues. This edema may develop as a result of impaired CSF

reabsoption

in the arachnoid villi.

Slide17

Cerebral edema: clinical features

signs

and symptoms do not always occur in any particular

order

Prompt

action is necessary at the first sign of neurological deterioration if brain herniation is to be prevented. Nausea and vomiting and/or increased restlessness and confusion may be the earliest signs.

Decreased level of consciousness

is usually the first sign of neurological deterioration. This occurs because of compression of the reticular activating system (RAS) located in the diencephalon and brainstem.

Alteration in respiratory pattern

. Abnormal respiratory patterns develop depending on the area of the brain or brainstem being compressed

.

Slide18

Cerebral edema: clinical features

Papillary changes also depend on the area of brain compression.

Midbrain

compression affects the third cranial nerve, which may initially cause the appearance of oval pupil. This can progress to a dilating, nonreactive pupil, usually on the same side as the expanding lesion.

Pontine compression causes small, fixed pupils

.

There

may be paralysis of eye movements and loss of upward gaze.

Bilateral

dilated and fixed pupils

imply bilateral brainstem compression and usually indicate a fatal outcome for the patient.

Slide19

Cerebral edema: clinical features

Motor

deficits

Hemiparesis

or hemiplegia occurs as the descending motor fibers passing through the brainstem are

compressed.

Paralysis

often begins in a lower extremity, progressing upward to include the arm and face. Most often the motor deficit is noted on the side opposite the brain pathology as the

corticospinal

motor fibers have not yet crossed to the opposite side in the medullary region.

Ipsilateral

motor deficits may occur from displacement of the brain medially, compressing the

controlateral

motor fibers

.

Abnormal posturing

may be

seen:

-

flexor

or decorticate posturing is due to hemispheric compression of

corticospinal

tracts

.

-extensor

or

decerebrate

posturing is due to

diencephalic

or upper brainstem compression.

-

m

edullary

compression causes flaccidity in all extremities.

Slide20

Cerebral edema: clinical features

Alterations in blood pressure and

pulse

Changes

in blood pressure and pulse rate and rhythm are often seen in progressive compression of the brainstem. As intracranial pressure rises, the brain and brainstem become increasingly more ischemic. Sympathetic stimulation induces a systemic vasoconstriction and an increase in cardiac output, which increases the blood pressure in an effort to perfuse the tight brain.

Bradycardia

ensues because of

pressoreceptor

responses and stimulation of the vagal nuclei in the brainstem. Respiratory variations are often seen in combination with the elevating blood pressure and slowing pulse rate. This triad of clinical signs is known as the Cushing response. It is felt to be due to ischemia of the medulla.

Slide21

BRAIN TUMORS

Brain tumors are the most common solid tumor and the second most common malignancy in children. Signs and symptoms vary depending on the

location

.

Incidence: 3 per 100000 children with a peak from the age of 5 to 9 years.

Nonlocalizing

signs and symptoms that reflect increasing intracranial pressure:

Symptoms

- irritability

- personality change

- headache

- vomiting especially in the early morning or during sleep

- diplopia (may or may not be localizing) usually sixth nerve palsy

Signs:

- an increase in head circumference

- papilledema (may have a larger blind spot)

- head tilt (incipient

tonsillar

herniation, fourth nerve palsy)

- sixth nerve paresis (inability to abduct the eye fully on lateral gaze)

Slide22

BRAIN TUMORSPOSTERIOR

FOSSA (

INFRATENTORIAL

) TUMOR

Most posterior fossa tumor in children present with signs and symptoms of increased

ICP

.

These

may be accompanied by either head tilt or

truncal

ataxia.

The

three most common tumors that present with increased

ICP

are cerebellar astrocytoma,

medulloblastoma

, and

ependymoma

.

These

are difficult to distinguish on the basis of history, but

:

the

cerebellar astrocytoma is likely to present insidiously over 4 to 8 months in

an older

child (5 to 8 years),

the

medulloblastoma

commonly

produces

symptoms dating back less than 2 months and tends to occur in the younger child (3 to 5 years).

t

he

ependymoma

is intermediate in regard to age of onset and duration of symptoms and may present with vomiting as the most prominent feature

.

Brainstem

gliomas

in contrast to the other three types of tumors, present with symptoms of brainstem dysfunction in the absence of increased

ICP

.

Slide23

POSTERIOR FOSSA (INFRATENTORIAL) TUMOR

The neurological

examination reveals increased

ICP

in patients with tumors that obstruct the spinal fluid (CSF) pathways.

Medulloblastomas

and

ependymomas

usually produce an unsteady gait without

intentional

tremor or

dysmetria

.

The

brain stem

glioma

:

usually presents with the triad of multiple cranial nerve deficits, cerebellar, and pyramidal track signs in the absence of signs of increased

ICP

.

Slide24

POSTERIOR FOSSA (INFRATENTORIAL) TUMOR

A CT or MRI scan helps distinguish the specific types of tumor.

- the cerebellar astrocytoma,

medulloblastoma

, and

ependymoma

produce enlarged ventricles secondary to obstruction of the CSF pathways.

the cerebellar astrocytoma is often, but not always, cystic in appearance with a small mural nodule, which may be enhanced by contrast medium. It is most often laterally placed in the cerebellar hemisphere but may be in the midline.

The

meduloblastoma

, a midline tumor, is uniformly

hyperdense

, may be enhanced by contrast medium, and tends to compress the fourth ventricle from behind.

the

ependymoma

usually grows within the fourth ventricle and may show flecks of calcification or faint enhancement.

The CT scan may be normal with brainstem

gliomas

, but usually shows a low density mass enlarging the brainstem. MRI is probably more sensitive for identifying lesions within the brainstem and for showing brainstem invasion by tumors in or around the fourth ventricle.

Slide25

POSTERIOR FOSSA (INFRATENTORIAL) TUMOR

Increased

ICP

, when present, is managed with ventricular drainage or by placement of a

ventriculoperitoneal

shunt before direct surgical resection is attempted. This decision requires neurosurgical consultation.

Complete

surgical resection

is possible with laterally placed cerebellar

astrocytomas

. This is rarely accomplished with

medulloblastomas

or

ependymomas

and is not attempted with brainstem

gliomas

.

The

diagnosis

of

braistem

glioma

is usually made on a clinical basis by the characteristic presentation of multiple brainstem signs in the absence of increased

ICP

and is confirmed by demonstrating an intrinsic brainstem mass by CT or MRI scanning. In some institutions the diagnosis is confirmed by a small tissue biopsy; often, however, treatment is begun without histologic confirmation.

Slide26

POSTERIOR FOSSA (INFRATENTORIAL) TUMOR - treatment

Cystic

cerebellar

astrocytomas

may be completely removed surgically. If residual tumor is thought to be present, local radiation therapy is used.

M

edulloblastoma

and

ependymoma

:

subtotal resection is followed by radiation therapy of the entire

neuraxis

because of the tendency of both these tumors to seed the subarachnoid space. Chemotherapy has begun to show promise in the treatment of

medulloblastoma

.

Brainstem

gliomas

are treated with radiation therapy.

Slide27

POSTERIOR FOSSA (INFRATENTORIAL) TUMOR

The prognosis in cerebellar astrocytoma is often good, with complete cures possible

.

Medulloblastomas

and

ependymomas

tend to

relapse

in 1 to 2 years, in spite of treatment, although more instances of long term survival of children with

medulloblastoma

are now being seen following a combination of radiation therapy and

chemotherapy.

The

prognosis in children with brainstem

gliomas

still remains poor. Occasional children respond dramatically to the newer radiation therapy protocols. Most, brainstem

gliomas

, however, have a recurrence within 6 to 12 months.

Slide28

MIDLINE CEREBRAL TUMORS

t

hey grow

in or around the third ventricle.

may

present with obstruction of the CSF flow causing signs of increased

ICP

, indistinguishable from tumors in the posterior

fossa.

some

characteristic signs or symptoms caused by involvement of the surrounding midbrain, thalamic, and hypothalamic structures may be present.

1.

The neurologic

examination

:

confirms only

the presence if increased

ICP

,

or

may

provide localizing

signs:

paralysis of upward gaze with posterior third ventricle tumors,

the

characteristic wasting of

diencephalic

syndrome in infants with hypothalamic tumors,

or

- contralateral hemiparesis

or tremor with thalamic tumors.

2.

The CT scan or MRI scan

shows enlargement of the ventricular system when CSF flow is obstructed in or around the third ventricle. Tumors within the third ventricle are usually easily recognized. Thalamic tumors cause displacement of the third ventricle to the

controlateral

side. Hypothalamic tumors and other low-grade

astrocytomas

in the structures around the third ventricle can be difficult to visualize on CT scan, but are usually seen on MRI scan.

Slide29

MIDLINE CEREBRAL TUMORS - imaging

The CT scan or MRI scan shows enlargement of the ventricular system when CSF flow is obstructed in or around the third ventricle. Tumors within the third ventricle are usually easily recognized.

Thalamic

tumors cause displacement of the third ventricle to the

controlateral

side.

Hypothalamic

tumors and other low-grade

astrocytomas

in the structures around the third ventricle can be difficult to visualize on CT scan, but are usually seen on MRI scan.

Slide30

MIDLINE CEREBRAL TUMORS

Colloid

cysts are benign tumors within the anterior third ventricle.

Presenting

symptoms may overlap with those of

suprasellar

and

chiasmatic

tumors, which distort the anterior third ventricle from below.

Colloid

cysts occur infrequently in childhood and present with intermittent or progressive signs of increased

ICP

. This can include sudden loss of consciousness or even death, from acute obstruction of the aqueduct.

Progressive

dementia and endocrine signs, including obesity, weight loss, polyuria, polyphagia or acromegaly, have been reported.

These

tumors are treated either with biventricular shunting, or by surgical removal. The

long-term

prognosis following removal of colloid cysts is excellent. Less common tumors within the third ventricle are the choroids plexus papilloma or

ependymoma

.

Slide31

MIDLINE CEREBRAL TUMORS

Tumors

of the posterior third ventricle (pineal region) are histologically

pinealomas

,

dysgerminomas

, or glial tumors of the surrounding structures. A characteristic presentation is paralysis of upward gaze (

Parinaud’s

syndrome). Additional findings may include bilateral ptosis or impaired accommodation. Less commonly, bilateral hearing loss may be present owing to involvement of the inferior

colliculi

. Subtotal resection of these tumors is possible and is followed by radiation therapy. Survival is variable, averaging 2 to 5 years, occasionally considerably longer. Treatment depends on tumor histology.

Slide32

MIDLINE CEREBRAL TUMORS

Hypothalamic

tumor

(usually in infants): characteristic

symptom complex designated the

diencephalic

syndrome. These children show marked wasting of subcutaneous fat, alert and often euphoric

facies

, and

hyperkinesis

.

Vomiting

is

frequent.

Neurologic signs are limited to bilateral optic atrophy and

nystagmus

caused by decreased visual acuity

.

Older children with hypothalamic tumors are more likely to show growth retardation or obesity. Radiation therapy usually provides palliation of symptoms, sometimes for several years.

Thalamic

tumors

signs of increased

ICP

owing to displacement of the third

ventricle

focal signs including contralateral tremor or hemiparesis

less commonly,

athetosis

, dystonic posturing, or rigidity

.

Impaired sensation is rare. These tumors may occasionally be partially resected, but are most often treated with radiation therapy. The prognosis is poor.

Slide33

SUPRASELLAR

AND

CHIASMATIC

TUMOR

 

Suprasellar

and optic chiasm tumors often have in common the following presenting symptoms: visual defects, signs or symptoms of endocrine or hypothalamic dysfunction, and symptoms of increased intracranial pressure (

ICP

).

Assessing

the degree of decreased visual acuity and

ploting

visual field defects are often difficult in young children.

Tumors

of the optic chiasm may extend to either or both optic nerves, causing virtually any combination of unilateral or bilateral decreased acuity or field defect.

Slide34

SUPRASELLAR AND CHIASMATIC TUMOR

Craniopharyngiomas

characteristically compress the optic chiasm, producing

bitemporal

hemianopia. Optic atrophy is found with both types of tumors. Endocrine dysfunction (specifically growth retardation and sexual infantilism) is commonly seen with

craniopharyngiomas

.

Chiasmal

gliomas

, by contrast, produce little or no endocrine change early in the course; if changes are present, they are usually those of precocious puberty.

Slide35

SUPRASELLAR AND CHIASMATIC TUMOR

Neurodiagnostic

studies help distinguish the types of tumors in this region.

Skull

x-ray studies with optic foramen views are particularly useful.

Chiasmal

gliomas

characteristically produce

deformities

of the anterior

clinoid

processes and frequently cause enlargement of one or both optic foramina.

Plain

skull films in addition may reveal

suprasellar

calcifications, frequently seen in

craniopharyngiomas

.

The

CT scan is limited in demonstrating

chiasmal

gliomas

owing to the proximity of the tumor to bone unless the study is

perfomed

with

metrizamide

to highlight the subarachnoid space around the

tumor.

Craniopharyngiomas

are easily visualized, may be partially cystic, and often show contrast enhancement or calcification.

Craniopharyngiomas

and large optic chiasm tumors show deformation and obstruction of the anterior third ventricle

.

Small

chiasmal

gliomas

may be identified only by

pneumoencephalography

.

MRI

scanning would be expected to demonstrate

craniopharyngiomas

easily and may be of value in diagnosing even small

chiasmatic

tumors. Experience with this modality is still limited

Slide36

SUPRASELLAR AND CHIASMATIC TUMOR

Optic

chiasm

gliomas

cannot be resected;

the

treatment consists of radiotherapy,

occasionally

with an adjunctive

ventriculoperitoneal

shunt to relieve obstruction of the third ventricle.

The

prognosis in children with

chiasmal

gliomas

varies considerably. In the majority of cases the tumor is slow growing, and long term survival is common. In a minority of patients, however, the tumor shows rapid growth with invasion of surrounding structures and death within 1 year.

Slide37

SUPRASELLAR AND CHIASMATIC TUMOR

The treatment of

craniopharyngioma

in most cases involves craniotomy with subtotal and rarely total resection of the

tumor

Preoperative

endocrine evaluation is mandatory, although findings in most studies are

normal

Cortisone

replacement is routinely given preoperatively regardless of the endocrine

status.

Total

excision is possible only when the tumor is not adherent to major cerebral vessels, the optic chiasm, or the hypothalamus

.

The tumor is relatively

radioresistant

.

The

immediate postoperative period is frequently stormy, with diabetes

insipidus

and potentially severe fluid and electrolyte

disturbances

Panhypopituitarism

is common postoperatively and requires appropriate replacement therapy.

The

prognosis following complete resection of this tumor is excellent, for endocrine abnormalities can be managed readily. Subtotal resection usually results in recurrence; however, this tumor may be slow growing and survival for many years is possible. Ultimately compromise in vision and tumor extension to the hypothalamus or laterally to the temporal lobes results in increasing morbidity.

Slide38

HEMISPHERIC CEREBRAL TUMORS

Most

children with tumors of the cerebral hemispheres present with a combination of symptoms,

including:

personality change

headaches,

less commonly:

unilateral motor weakness, aphasia, or a sensory or visual

deficit

s

eizures

are a common presenting symptom in children with these tumors. They may be

focal

or generalized in type, and can be present for many years before the diagnosis of tumor is made.

A

neurologic

examination:

evidence of increased

ICP

including papilledema or sixth nerve paresis.

The

most common focal findings

are:

controlateral

hyperreflexia

, extensor plantar response (Babinski), or spasticity, with or without associated motor weakness (hemiparesis).

Visual

field defects or sensory deficits may be demonstrated.

Slide39

HEMISPHERIC CEREBRAL TUMORS

Neurodiagnostic

studies are usually helpful in making the diagnosis of cerebral hemisphere tumors.

The

electroencephalogram often shows a focal slow wave abnormality in the region of the tumor. Focal paroxysmal activity (spike or sharp wave) is a less reliable indication of a mass lesion

.

A CT scan or a MRI scan usually reveals the location of the tumor if it is larger than 1 cm. Larger lesions produce distortion or displacement of the third or lateral ventricles. Many of these tumors show contrast enhancement.

Very

small tumors presenting with seizures may be missed on initial scanning. Refractory focal (partial) seizures or the onset of new focal neurological deficits in a patient with seizures should

impose promptly repeated

studies.

Slide40

HEMISPHERIC CEREBRAL TUMORS

The

treatment of cerebral hemisphere tumors usually begins with a craniotomy and subtotal resection of the tumor mass.

Because

these are mostly infiltrating glial tumors, total resection is rarely

possible.

Steroids

(to reduce inflammation) and anticonvulsant medication are commonly given before surgery.

Anticonvulsant

medication is usually required for a long period.

Decisions about additional therapy are made in conjunction with the neurosurgeon, oncologist, and radiation oncologist. The most common hemispheric tumor of childhood is the

glioma

, the majority being low grade. Cystic tumors may be completely resected with a resultant cure. Solid

gliomas

can be only partially resected. For the low grade

glioma

, radiation therapy has not been proven effective, though most authorities recommend local radiation. For higher grade tumors, a combination of whole brain radiation and chemotherapy is recommended. Patients with low grade solid

gliomas

have a 30 to 50% five-year survival rate, and those with

glioblastoma

multiforme

have a less than 5% five-year survival rate. The other tumors are much less common. Both the choroids plexus papilloma and the

oligodendroglioma

can often be completely resected. No additional therapy is necessary. Approximately one-third of

ependymomas

grow in the lateral ventricle. Spinal metastasis may occur with high grade

ependymomas

, thus

craniospinal

radiation should be given. Low grade tumors are less likely to metastasize, and radiation is given only to the tumor bed. The five-year cure rate is approximately 30%.

Meningiomas

in children are often

sarcomatous

. Complete resection is possible only occasionally. When partial resection is carried out, radiation therapy is necessary.

Slide41

HEMISPHERIC CEREBRAL TUMORS

Decisions about additional therapy are made in conjunction with the neurosurgeon, oncologist, and radiation oncologist.

The

most common hemispheric tumor of childhood is the

glioma

, the majority being low grade.

Cystic

tumors may be completely resected with a resultant cure

.

Solid

gliomas

can be only partially resected

.

For the low grade

glioma

, radiation therapy has not been proven effective, though most authorities recommend local radiation

.

For higher grade tumors, a combination of whole brain radiation and chemotherapy is recommended. Patients with low grade solid

gliomas

have a 30 to 50% five-year survival rate, and those with

glioblastoma

multiforme

have a less than 5% five-year survival rate.

The

other tumors are much less common. Both the choroids plexus papilloma and the

oligodendroglioma

can often be completely resected. No additional therapy is necessary.

Approximately

one-third of

ependymomas

grow in the lateral ventricle. Spinal metastasis may occur with high grade

ependymomas

, thus

craniospinal

radiation should be given. Low grade tumors are less likely to metastasize, and radiation is given only to the tumor bed. The five-year cure rate is approximately 30%.

Meningiomas

in children are often

sarcomatous

. Complete resection is possible only occasionally. When partial resection is carried out, radiation therapy is necessary.