Delta: Neuro-oncology Flashcards
the cerebrum is derived from what?
telencephalon
what are the 6 lobes of the cerebral hemispheres?
frontal parietal temporal occipital insular limbic
where is the frontal lobe and what important structures are contained within it?
between central sulcus and frontal pole, above sylvian fissure
- precentral gyrus (motor)
- superior frontal gyrus
- middle frontal gyrus (frontal eye movement)
- inferior frontal gyrus (brocas area)
damage to brocas area causes what?
expressive dysphasia
- can comprehend language but has difficulty with own language/speech
where is the parietal lobe and what important structures are contained within it?
between central sulcus and occipital lobe, superior to temporal lobes
- postcentral gyrus (sensation)
- superior parietal lobule
- inferior parietal lobule
what does damage to inferior parietal lobule cause?
nominal aphasia
- problems recalling words, names and numbers
where is the temporal lobe and what important structures are contained within it?
inferior to sylvian fissure, between temporal pole and occipital lobe
- superior temporal gyrus (auditory cortex and wernickes speech area in dominant hemisphere)
- middle temporal gyrus
- inferior temporal gyrus
where is the occipital lobe and what is contained within it?
caudal to parieto-occipital sulcus
contains visual cortex
where is the insular lobe?
deep within lateral sulcus
what is the limbic system?
group of structures located on medial hemisphere surface that encircle corpus callosum
serves for higher emotional functions and memory
- includes hippocampus
where is the cerebellum derived from?
metencephalon
what connects the right and left hemispheres of the cerebellum?
vermis
what are the 3 functional components of the cerebellum?
vestibulocerebellum (balance and vestibulo-ocular reflexes)
spinocerebellum (muscle tone, posture and gait)
cerebrocerebellum (voluntary motor movement, corrects any error in movement to ensure smooth movements)
pneumonic for symptoms of cerebellar dysfunction?
DANISH
- Dysdiadochokinesia
- Ataxia (broad based gait)
- Nystagmus
- Intention tremor
- Scanning dysarthria
- Hypotonia
what 4 structures are derived from the diencephalon?
thalamus
hypothalamus
subthalamus
epthalamus
what is the largest part of the diencephalon and what does it do?
thalamus
- major relay centre for the brain (motor function, sensory, visual and auditory impulses, ARAS system)
what would a thalamic infarction cause?
hemiparesis
spontaneous pain
hemichorea
can cause severe impairment of consciousness
what is the function of the hypothalamus?
influences 3 systems
- autonomic nervous system
- endocrine system
- limbic system
list 5 roles of the hypothalamus
body thermal regulation
regulates release of hormones from adenohypophysis (anterior pituitary)
synthesises ADH and oxytocin which project to neurohypophysis (posterior pituitary)
regulates feeding and starvation
mammillary nucleus receives input from hippocampal formation (wernickes encephalopathy in thiamine deficiency)
lesions of mammillary nucleus produce what symptoms?
confusion
ataxia
nystagmus
can progress to koraskoff’s syndrome (amnesia and confabulation)
lesions of subthalamus cause what symptoms?
contralateral hemiballism
what are the 5 basal ganglia?
caudate nucleus putamen globus pallidus substantia nigra subthalamic nucleus
what is the general role of the basal ganglia?
role in initiation and facilitation of movement and in the control of muscle tone
what causes parkinsons disease?
neuronal loss and presence of alpha-synuclein protein inclusions (Lewy Bodies) in areas of the brain, mainly the substantia nigra where dopaminergic neurons are found
what are the 3 main features of parkinsons disease?
akinesia (slowness, difficulty initiating movement)
rigidity
resting tremor (“pill rolling tremor”)
tumours of the CNS essentially present with what 5 symptoms?
progressive, focal neurological deficits
headaches (ICP features)
seizures
gradual cognitive decline and personality changes
endocrine disturbances (in hypothalamus/pituitary tumours)
when might a tumour cause acute symptoms?
if it bleeds
6 features of a frontal lobe tumour/lesion?
- contralateral weakness (motor cortex deficit)
- personality changes
- urinary incontinence (disruption of micturition inhibitory centre)
- gaze abnormalities
- expressive dysphasia/aphasia (if left sided and brocas affected)
- seizures
4 features of a temporal lobe tumour/lesion?
memory deficits
receptive aphasia/dysphasia (wernickes affected)
contralateral superior quadrantanopia
seizures
4 features of a parietal lobe tumour/lesion?
contralateral weakness and sensory loss (somatosensory cortex damage)
contralateral inferior quadrantanopia
gerstmann syndrome
neglect, apraxia
what is gerstmann syndrome?
dyscalculia-maths, dysgraphia-writing, finger agnosia- distinguish fingers, right/left disorientation
occurs due to parietal lobe damage
2 features of occipital lobe tumour/lesion?
contralateral homonymous hemianopia (with macular sparing?)
visual hallucinations
5 features of cerebellar tumour/lesion?
ipsilateral ataxia nausea and vomiting dizziness and vertigo slurred speech intention tremor
how are the 4 grades of CNS tumours defined?
1 = no morphological features 2 = atypia alone 3 = atypia and mitosis 4 = atypia, mitosis with vascular proliferation or necrosis
what are the most common primary brain tumours?
high-grade gliomas
- anaplastic astrocytoma (grade 3)
- glioblastoma multiforme (grade 4, most common)
describe an anaplastic astrocytoma
WHO grade 3
may have progressed from low-grade astrocytoma or can be seen without any underlying lesion
often progress to a glioblastoma multiforme
who and where in the brain is a glioblastoma multiforme most common?
older people (60-70) usually in cerebral hemispheres (temporal, parietal and frontal lobes)
how does a GBM appear on imaging?
MRI is best
heterogeneously enhancing space occupying lesions with areas of necrosis
can have a butterfly appearance
how is a GBM diagnosed?
MRI
if MRI suggestive of high grade glioma then a histology sample is required
how is a GBM managed?
surgery + radiotherapy +/- chemotherapy
- improves median survival to 14 months
what are the most common low grade gliomas and when do they most commonly occur?
pilocytic astrocytoma (grade 1) diffuse astrocytoma (grade 2) oligodendroglioma (grade 2) peak incidence = 20s and 30s
who and where is pilocytic astrocytoma most common in?
children and young adults
most common sites = cerebellum and midline structrures (thalamus, chiasm etc)
clinical features of pilocytic astrocytoma?
depends on site of tumour
optic pathway gliomas are common in which condition?
NF1
how are grade 2 tumour different to grade 1?
grade 2 has potential to transform to high grade
less histologically stable
describe how diffuse astrocytomas develop
usually in cerebral hemispheres (frontal and temporal lobes)
slow growing
tendency to progress to higher grade
how does diffuse astrocytoma commonly present?
often in young adults
often presents with seizures
how is a diffuse astrocytoma managed?
maximal resective surgery + chemo/radiotherapy
high cure rate is seen in pilocytic astrocytoma with what treatment?
maximal resective surgery with or without adjuvant treatment
which tumours have the best prognosis?
oligodendrogliomas
where do oligodendrogliomas usually affect in the brain?
frontal lobe and can affect the white matter and the cortex
invade the subarachnoid space leading to a white toothpaste appearance
how do oligodendrogliomas typically present?
25-45 yrs old
seizures and headaches
what is a meningioma?
common, benign, slow growing extra-axial tumours originating from arachnoidal cap cells in arachnoid mater
who are meningiomas most common in?
elderly 6th and 7th decade
slightly more common in females
multiple meningiomas are common in which condition?
NF2
radiation in childhood
how does a meningioma present?
usually asymptomatic and found incidentally on imaging
can have headaches and symptoms of increased ICP
can have foster kennedy syndrome if olfactory groove affected
what is foster kennedy syndrome?
optic atrophy in ipsilateral eye and papilloedema in contralateral eye
imaging features of meningioma?
well demarcated
do not infiltrate the brain
most pituitary adenomas are functional or non-functional?
non-functional
what is the most common functional pituitary adenoma?
prolactinoma
features of prolactinoma?
amenorrhoea infertility galactorrhoea loss of libido ED
how is a prolactinoma managed?
dopamine agonists
- cabergoline
features of GH secreting adenoma?
gigantism/acromegaly
features of ACTH secreting adenoma?
cushings features
features of thyrotropin secreting adenoma?
palpitations weight loss insomnia nervousness/anxiety goiter
most common surgical intervention for pituitary tumours?
transphenoidal hypophysectomy
how is GH secreting adenoma managed?
pegvisomant and somatostatin analogues (octreotide)
surgery
what is an acoustic neuroma and where are they found?
benign tumours derived from schwann cells
commonly arise in cerebellopontine angle affecting the vestibular portion of CN8
AKA vestibular schwannoma
bilateral acoustic neuroma suggests what?
NF2
what can be seen on pathology in acoustic neuroma?
verocay bodies
- palisading nuclei against a fibrillary background
how does an acoustic neuroma present?
30-50 year olds
unilateral sensorineural hearing loss
tinnitus
vertigo
can have a headache depending on size of tumour
can have facial pain if trigeminal nerve affected
how is an acoustic neuroma managed?
serial observation
stereotactic radiosurgery
microsurgical excision
what is a haemangioblastoma?
beningn, cystic, highly vascular tumour
where do haemangiobatomas develop and what do they cause?
posterior fossa
lead to cerebellar dysfunction symptoms and raised ICP
haemangioblastomas are associated with what condition?
von-hippel lindau syndrome
