Central Nervous System Tumors in Children

00:01 In this lecture, we're going to review central nervous system tumors in children.

00:07 So, in children, CNS tumors are the second most common pediatric malignancy.

00:14 About 20% of all cases of childhood cancer are CNS masses and younger children are more likely to have embrional tumors such as medulloblastoma compared to older patients.

00:28 This is generally a sporadic problem.

00:30 It's without real risk factors or causes.

00:33 It's just extraordinary bad luck, although certain genetic syndromes may predispose patients to development of CNS tumors.

00:42 So, to diagnose it as a CNS tumor, we have to take a good history, do a physical exam, and do some diagnostic imaging.

00:50 Let's start with the history.

00:52 So, the historical findings of CNS tumors in general depend on the location of the tumor in the brain.

01:00 Symptoms may result from an increased intracranial pressure.

01:06 I would say the exception being pituitary adenomas which generally don't do that.

01:11 However, most other tumors can cause an increase in ICP which will present with the classic finding of morning headache and morning emesis.

01:22 If you think about it, the child's been lying down all night and there's increased pressure because they've been in a resplendent pose and once they get up and move around, the pressure may reduce slightly.

01:32 These patients may also be lethargic or sleepy, or feel out of it.

01:37 We may see other signs indirectly such as poor school performance, fatigue, behavioral changes, weight gain or weight loss, increased clumsiness, or walking difficulty.

01:51 So all of these can be signs of a problem in the intracranial vault.

01:56 Also, patients with focal seizures or with prolonged postictal paralysis, that may be a sign of increased ICP.

02:05 So, then we have to do a good physical exam and in particular, the cranial nerves are very important to evaluate.

02:14 As cranial nerve palsies are fairly common with brainstem lesions.

02:19 You may also see papilledema, you may see ataxia, you may see a facial droop or weakness which is really a cranial nerve palsy, you may see hearing loss, and you may see diplopia, especially diplopia in patients with a pituitary lesion.

02:37 You can also find focal symptoms if it's a little bit higher up such as hemiparesis or a hemisensory loss.

02:45 You may notice hyperreflexia or visual defects or seizures, especially focal seizures are concerning, and any hypothalamic tumor can present with a diencephalic syndrome.

02:59 The diencephalic syndrome is euphoria, hyperphagia, and anorexia.

03:05 Okay. Let's talk about pineal lesions and optic chiasm lesions very briefly.

03:14 These can cause defects in pupillary constriction and patients may have an inability to look upward.

03:23 This is called the Parinaud syndrome.

03:25 Also, we will do some diagnostic testing to rule out CNS tumors.

03:33 So the MRI with gadolinium is the imaging of choice.

03:38 It does require sedation in younger children.

03:41 Generally, we will also get an MRI of the spine because generally there may be metastasis to the spine or this might not be a tumor, it could be something like acute disseminated encephalomyelitis for example which presents with diffuse disease.

03:56 You may early, if you're worried, get a CAT scan.

04:01 You might want to do a CAT scan, for example, before you do a lumbar puncture if you are thinking this patient might have meningitis because you don't want to cause an increased ICP to be depressurized after the foramen magnum and result in a herniation.

04:16 So, we usually will do a CSF though once we've made the diagnosis of brain tumor to try and get cytology or cells.

04:25 So, there are a multiple ways, you can sit patients for a lumbar puncture.

04:30 Generally, for older patients we prefer the sitting position.

04:34 For younger patients or babies, you might do a lying down position.

04:37 Doesn't really matter except remember, if you're looking for an increased ICP, you're gonna wanna use your manometer in the lying down position.

04:46 We will send this CSF for beta-hCG and AFP which may be positive in teratomas which can present in the brain.