RD neurology: formatted Flashcards
- Features of pilocytic astrocytoma (which is false?)
a. The most common posterior fossa tumour in children
b. Calcify more commonly than medulloblastoma
c. Usually a less aggressive lesion
d. Usually more cystic than solid
e. Show enhancement after contrast administration
b. Calcify more commonly than medulloblastoma F JPA < 10% calcify, while 10-20% of MB’s calcify (NeuroReq); Osborn says up to 20% of MB calcify, while says “uncommon” in JPA. Ependymoma calcifies in up to 80%.
1. Features of pilocytic astrocytoma (which is false?) (SK)ANSWER:
a. The most common posterior fossa tumour in children T (although some may MB is); peak age 8-13 years. In adults mets & haemangioblastoma.
* LW: Per gospel of Donnelly: Pilocytic astrocytoma are most common posterior fossa tumour in tumour.
b. Calcify more commonly than medulloblastoma F JPA < 10% calcify, while 10-20% of MB’s calcify (NeuroReq); Osborn says up to 20% of MB calcify, while says “uncommon” in JPA. Ependymoma calcifies in up to 80%.
* LW: agree this is incorrect. Donelly states unlike medulloblastoma and ependymomas, pilocytic astrocytoma usually do not demonstrate calcification or haemorrhage
c. Usually a less aggressive lesion: T WHO grade I tumour
d. Usually more cystic than solid T typically well-circumscribed cyst-like masses with a discrete mural nodule – one-third are microcystic or solid, esp. in older patients
e. Show enhancement after contrast administration T solid portion (cyst with enhancing mural nodule)
- An 11yo girl presents with headache and on MRI an intraventricular tumour of the 4th ventricle is shown. The MOST likely tumour is?
a. Choroid plexus papilloma
b. Oligodendroglioma
c. Ependymoma
d. Haemangioblastoma
e. Medulloblastoma
- An 11yo girl presents with headache and on MRI an intraventricular tumour of the 4th ventricle is shown. The MOST likely tumour is?
ANSWER:e. Medulloblastoma T arise from roof of 4th ventricle (cerebellar vermis projecting into 4th ventricle); older age than ependymoma but usually < 10 years (but range 5-15 years); 2nd most common PF tumour in kids (after JPA)
a. Choroid plexus papilloma F in kids more common in lateral ventricle
b. Oligodendroglioma F
c. Ependymoma F peak age 1-5 years, 3rd most common PF tumour in kids
d. Haemangioblastoma F rare in children without VHL
e. Medulloblastoma T arise from roof of 4th ventricle (cerebellar vermis projecting into 4th ventricle); older age than ependymoma but usually < 10 years (but range 5-15 years); 2nd most common PF tumour in kids (after JPA)
- Cortically based tumour:
a. Low grade glioma
b. DNET
c. Pilocytic astrocytoma
d. Cavernous haemangioma
e. Ependymoma
- Cortically based tumour:
ANSWER:b. DNET - T - benign, focal intracortical mass superimposed on background of cortical dysplasia. Arises from secondary germinal layer of CNS, in particular the subpial granular layer.
a. Low grade glioma – F typically involve WM. However the pleomorphic xanthoastrocytoma (PXA) is cortically-based.
b. DNET - T - benign, focal intracortical mass superimposed on background of cortical dysplasia. Arises from secondary germinal layer of CNS, in particular the subpial granular layer.
c. Pilocytic astrocytoma - F - arises from astrocytic precursor cell. Typically cerebellar mass (hemisphere) which compresses 4th ventricle
d. Cavernous haemangioma - F
e. Ependymoma - F - floor of 4th ventricle mass, slow-growing tumor of ependymal cells.
- Young man with cerebral hemorrhage. Which of the following is less likely:
a. Amyloidosis
b. Metastasis
c. Vasculitis
d. AVM
e. Cavernoma
a. Amyloidosis AA occurs in patients > 65 years
- Guy having L ICA stent. Develops sudden onset neurological deficits. MRI shows bilateral frontal lobe . Most likely anatomical explanation
a. azygous ACA
b. Persistent trigeminal
c. enlarged posterior communicating artery
Answer: Azygous ACA Azygous ACA- single ACA. No AcomA- a/w holoprosencephaly
Persistent trigeminal artery- trigeminal artery that links posterior circulation to ICA - BELOW PcomA level
- Patient presents with acute confusion. MRI shows T2 high signal in the mesiotemporal lobe with restricted diffusion. Most likely diagnosis of
a. HSV encephalitis
b. MCA stroke
a. HSV encephalitis
B. MCA stroke is wrong- PCA distribution for medial temporal lobe, except for anterior temporal which may be MCA distribution
Man with gait problems. Fluid density extra dural lesion seen with segmentation abnormalities. Most likely. a. epidermoid b. arachnoid c neurenteric cyst d. myelocele e. nerve sheath tumour
Answer
:Neurenteric cyst
Presumably refers to extradural lesion in spinal canal with vertebral segmentation anomalies.
A = epidermoid = F = intramedullary (40%) or extramedullary intradural (60%) (extradural epidermoid rare); follows CSF (except on FLAIR & DWI); assoc/ w/ vertebral abnormalities (hemivertebra, scoliosis); tend to present in early adulthood with slowly progressive symptoms (radiculopathy/myelopathy)
B = arachnoid = F = usually intradural (extradural rare); usually asymptomatic
C = neurenteric cyst = partly intradural & partly extradural; fluid density; assoc/ w/ segmentation anomalies; dumbell lesion; present in 2nd-4th decades with back/radicular pain & gait disturbance
D = myelocele = F
E = nerve sheath tumour = F (not fluid density)
MRI characteristic features of PML.
a. No destruction of diffusion.
b. focal white matter abnormalities with sparing of subcortical U fibre
c. typical involvement of middle cerebral peduncle
d. increased aspartate on MRS
Answer: Probably A = ? = new lesions have slightly restricted diffusion (rim of restricted diffusion at advancing edge), older lesions don’t restrict OrC = ? = PML can involve the middle cerebral peduncle, but not “characteristic”Typically, PML is a confluent, bilateral but asymmetric, supratentorial white matter disease, peripheral. However, it can be unilateral, and there may be a single lesion.Asymmetric multifocal bilateral confluent supratentorial lobar white matter involvement is the most common manifestation. White matter of the posterior fossa is the next most common area of involvement.49,88 Typically the disease involves the middle cerebellar peduncle and adjacent pons and cerebellum.Spinal cord involvement in PML is exceedingly rare.[AJNR 2010]
- Regarding myelination of the brain (which is true?):
a. As myelination progresses the white matter becomes T1 hypointense.
b. The posterior internal capsule is myelinated at birth.
c. The optic nerves are myelinated by 2 months of age.
d. The splenium of the corpus callosum myelinates fisrt, myelination then progresses anteriorly.
e. At 24-30/12 the white matter is isointense to grey matter on T2.
- AJL - Multiple are true. (Tell me if you think I’m wrong)
- Posterior limb of internal capsule is myelinated at birth
- Optic nerves are myelinated by 2 months of age
- The corpus callosum myelinates from posterior to anterior starting at splenium.
Previous Answer:d. The splenium of the corpus callosum myelinates first, myelination then progresses anteriorly. dorsal to ventral, caudad to cephalad, central to peripheral. Splenium bright on T1 at 4 mths, genu at 6 mths; then low on T2 by 6 mths and 8 mths respectively. [Kieran’s ‘rules’]
a. As myelination progresses the white matter becomes T1 hypointense. F with myelination, deceased amounts of water → T1 hyperintense & T2 hypointense
b. The posterior internal capsule is myelinated at birth. T? the posterior portion of the posterior limb of IC is myelinated at birth on T1 (2 mo on T2), anterior part of posterior limb by 1mo (4-7 mo on T2); anterior limb at 2-3mo (5-11 mo on T2)
c. The optic nerves are myelinated by 2 months of age. T optic nerves & tracts myelinated by 1 mo
d. The splenium of the corpus callosum myelinates first, myelination then progresses anteriorly. dorsal to ventral, caudad to cephalad, central to peripheral. Splenium bright on T1 at 4 mths, genu at 6 mths; then low on T2 by 6 mths and 8 mths respectively. [Kieran’s ‘rules’]
e. At 24-30/12 the white matter is isointense to grey matter on T2. F
- A 45 year old man presents with a haemorrhage in the right basal ganglia. It demonstrates positive mass effect and is iso- to low intensity to grey matter on both T1 and T2 weighted sequences. The haemorrhage is most likely:
f. <3hrs old
g. 8-72 hrs old
h. Between 1 week and 3 months old
i. Between 3months and 12 months old.
j. Over a year old.
g. 8-72 hrs old
- Which of the following features is NOT associated with Spontaneous intracranial hypotension?
a. Subdural hygromas
b. Diffuse leptomeningeal enhancement
c. Reduced mamillo-pontine distance
d. Enlarged pituitary gland
e. Tonsillar ectopia
*AJL b. Diffuse leptomeningeal enhancement F - Pachymeningeal enhancement
- Which of the following features is NOT associated with Spontaneous intracranial hypotension? (Osborn II-4-35)
ANSWER: B
a. Subdural hygromas T
b. Diffuse leptomeningeal enhancement F dural enhancement (pachymeninges); enhancement is smooth, not nodular. Meningeal enhancement in ICH is thick, linear, without nodularity, and involves the pachymeninges of both the infra- and supratentorial compartments without evidence of involvement of the leptomeninges (no abnormal enhancement around the brainstem, within the sylvian fissures, or in the depth of cerebral sulci).
c. Reduced mamillo-pontine distance T
d. Enlarged pituitary gland T pituitary gland enlarged above sella in 50%
e. Tonsillar ectopia T caudal displacement of tonsils 25-75%List- pituitary enlargement- mid brain slump- tonsil ectopia- enlarged dural venous sinus- pachymeningeal enhancement- subdural hygroma/haematoma
12. 11 yr old female with ataxia and headache has a posterior fossa mass which is hyperdense and enhancing, it is likely to be. .f. Medulloblastoma/PNET g. Meningioma h. Pilocytic astrocytoma i. Ependymoma
- 11 yr old female with ataxia and headache has a posterior fossa mass which is hyperdense and enhancing, it is likely to be.
ANSWER: A
a. Medulloblastoma/PNET T iso-hyperdense, enhance heterogeneously; seed CSF
b. Meningioma F can be hyperdense & do enhance, but wrong age
c. Pilocytic astrocytoma F partly cystic, only mural nodule enhances
d. Ependymoma F typically hypo-isodense, but commonly have calcification (> 40%); younger age typically
- Mass at the CP angle. Heterogeneously enhancing T1 low and T2 bright, bright on DWI. (Outside – Young Female. T1 iso, T2 hyper, peripheral enhancement. Cystic portions. Restricted diffusion.)
j. Acoustic schwannoma
k. Meningioma
l. Epidermoid
m. Arachnoid cyst
- Mass at the CP angle. Heterogeneously enhancing T1 low and T2 bright, bright on DWI. (Outside – Young Female. T1 iso, T2 hyper, peripheral enhancement. Cystic portions. Restricted diffusion.)
ANSWER: C
if adding information from bracket
a. Acoustic schwannoma F doesn’t restrict; enhance strongly
b. Meningioma ?F minimal restriction
c. Epidermoid ?T similar to CSF intensity (except on FLAIR), restricted diffusion (this makes the diagnosis); however usually don’t enhance, 25% have mild marginal enhancement
d. Arachnoid cyst F CSF density on all sequence, no restriction
- Which of the following is NOT a feature of Posterior Reversible Encephalopathy syndrome (PRES)?
a. Typically has increased T2 signal in the occipital lobes and cerebellum.
b. May show increased diffusion co-efficient.
c. Posterior circulation vessels are normal.
d. Can uncommonly cause cortical necrosis (ARA some small portions are irreversible)
.e. Pathophysiology is the same whether PRES is caused by hypertension or Cyclosporine.
c. Posterior circulation vessels are normal.
6. Which of the following is NOT a feature of Posterior Reversible Encephalopathy syndrome (PRES)? Osborn I-10-32Answer: C
a. Typically has increased T2 signal in the occipital lobes and cerebellum (bilateral). T predilection for posterior circulation & involves subcortical WM (but cerebellum not “typical”)
b. May show increased diffusion co-efficient. ?T most common is no restriction, less commonly can have restriction. If they mean ↑ ADC then T – “markedly elevated” ADC values. (T2 shinethrough?)
c. Posterior circulation vessels are normal. ?F At catheter angiography (CA), diffuse vasoconstriction, focal vasoconstriction, vasodilation, and even a string-of-beads appearance have been noted in PRES, consistent with what is typically described as vasospasm or arteritis (AJNR 2008). Osborn says “CTA usually normal. Rare vasospasm with multifocal areas of arterial narrowing”.
d. Can uncommonly cause cortical necrosis (ARA a small portion are irreversible). T rarely causes frank infarctione. Pathophysiology is the same whether PRES is caused by hypertension or Cyclosporin
e. T diverse causes & clinical entities with HTN as common component – acute HTN damages vascular endothelium
- Regarding sellar lesions, which is MOST correct?
a. Dural tail can be a feature of pituitary macroadenoma.
b. Calcification is common in pituitary macroadenoma.
c. Craniopharyngiomas commonly calcify though don’t enhance.
d. Rathke cleft cyst has nodular enhancement.
e. Pituitary macroadenoma demonstrates delayed intense enhancement.
ANSWER: Aa. Dural tail can be a feature of pituitary macroadenoma. T subtle/mild dural thickening (“tail”) present in some cases (Osborn II-2-25)
- Regarding sellar lesions, which is MOST correct? Osborn II-2-25
ANSWER: Aa. Dural tail can be a feature of pituitary macroadenoma. T subtle/mild dural thickening (“tail”) present in some cases (Osborn II-2-25) *LW - radprimer agrees.
b. Calcification is common in pituitary macroadenoma. F 1-2% calcify
c. Craniopharyngiomas commonly calcify though don’t enhance. F calcification common in kids (adamant- 90% calcify), but rare in adults; solid portions do enhance heterogeneously
d. Rathke cleft cyst has nodular enhancement. F usually no enhancement
e. Pituitary macroadenoma demonstrates delayed intense enhancement. F most enhance strongly & heterogenously SG thinks this most true *LW - not for MACROadenoma, however MICROadenoma delayed / dynamic enhancement is a feature (Radprimer)
- Drowsy kid with meningitic symptoms. Best diagnostic test.
a. CSF
B. CTB noncontrast
C. CTB post contrast
d. MRI brain
*AJL: Best answer is A - CSF (explanation below)
Starship guidelines on meningitis say: “CT scan should be done if there are any focal neurological signs. Herniation may occur even in the presence of a normal scan. A normal head CT scan does not exclude presence of raised intracranial pressure and should not influence your decision to perform a lumbar puncture; this is a clinical decision.”
With regards to low GCS they say: “Lumbar puncture Contra-indicated in presence of coma (GCS <9), raised intra-cranial pressure or unstable clinical state. If meningitis is suspected but LP is contra-indicated, start antibiotics”
Drowsy is not a focal neurological sign. Also, even if they were super drowsy (eg <9) there is no mention of doing head imaging.
Therefore they seem to recommend do LP and don’t worry about imaging. (I note SG, presumably Sam, agrees)
**LJS agree, especially since it says “best diagnostic test”. CTB is not diagnostic, just excludes SOL prior to LP. Would depend on wording - if it were “what is the next test” and kid had significantly lowered GCS I would chose CT
Previous answers….
ANS = B. Assuming reduced GCS, CTB probably indicated before LP (see below)
SG – if just drowsy (GCS 14 ish) - CSF
French guidelines: CNS imaging is indicated if:
• Focal neurology
• GCS ≤ 11
• Seizures if > 5, only if hemiseizure in kids < 5
RCH guidelines on LP & CT:
CT Scans if focal neurological signs
• CT Scans are not helpful in most children with meningitis.
• A normal CT scan does not tell you that the patient does not have raised ICP
.• Herniation may occur even in the presence of a normal scan.
• Don’t delay antibiotics whilst waiting for a CT
UK NICE guidelines:
Use clinical assessment and not cranial computed tomography (CT), to decide whether it is safe to perform a lumbar puncture.
CT is unreliable for identifying raised intracranial pressure.
In children and young people with a reduced or fluctuating level of consciousness (Glasgow Coma Scale score less than 9 or a drop of 3 or more) or with focal neurological signs, perform a CT scan to detect alternative intracranial pathology.
Post partum .Head ache.
Bilateral thalamic abnormality. Most likely.
venous thrombosis of internal cerebral vein of Galen
young patient post neck manipulation. Ataxia, ptosis, nystagmus and some other eye stuff. MRA. Most likely to see
a. dissection of carotids
b. dissection of V3 portion of vertebral artery
ANS = B ⇒ symptoms suggest posterior circulation
ICA dissection- C1 (more common then VA), 2cm above bifurcation- C2- C5
Vertebral- V2 or V3
In patient with dissection, least likely to see
a. intracranial haematoma
b. wall haematoma
c. narrowed true lumen
a. intracranial haematoma least likely. - infarct more likely+/- haemorrhage transformation
Wall haematoma best seen with FAT SAT
18 yo. Mass in 3rd ventricular region. Contains calc and enhancing avidly. Negative bHCG in CSF. Most likel
a. germinoma
B. met
A = germinoma (engulfs calcifications of pineal gland, enhance intensely)
Patient with mesotemporal sclerosis. Most likely finding.
a. contralateral maxillary enlargement
b. ipsilateral hippocampal atrophy
c. ipsilateral maxillary atrophy
b. ipsilateral hippocampal atrophy
Signs of mesial temporal sclerosis (Osborn I-10-62)
• Abnormal T2 hyperintensity
• Hippocampal volume loss/atrophy
• Obscuration of internal architecture, loss of grey-white differentiation
• Hippocampus > amygdala > fornix > mamillary bodies
AUGUST 201022) Previous extracranial ICA stent, subsequent parietal and superior cerebellar infarct: (Note previous exam question was Occipital)
i) Persistent trigeminal
ii) Fetal posterior circulation
iii) Persistent hypoglossal
iv) ICA aneurysm
v) Azygous artery
ANSWER:i) Persistent trigeminal T (see below, Saltzmann type 2) the most common ICA-BA anomalous connection
1) Previous extracranial ICA stent, subsequent parietal and superior cerebellar infarct: (Note previous exam question was Occipital)
i) Persistent trigeminal T (see below, Saltzmann type 2) the most common ICA-BA anomalous connection
ii) Fetal posterior circulation F above SCA; would be correct if occipital & parietal lobe affected
iii) Persistent hypoglossal T also possible, as joins basilar artery low down, but rare (parallels CN12 in hypoglossal canal)
iv) ICA aneurysm F
v) Azygous artery F (single/fused ACA from A2 distal)
Trigeminal bridges precavernous ICA to the basilar artery below the level of the PCOM. The basilar artery below the anastamosis can be hypoplastic and enlarged above. The PCOM can also be small.
Saltzman type 1: PTA supplies distal BA, pcomms absent, prox BA hypoplastic
Saltzman type 2: PTA feed superior cerebellar arteries, patent pcomms suppy the PCA’s. Hypoglossal artery arises from the extracranial ICA at C2-3 level, traverses the hypoglossal canal and anastamoses with the basilar artery low down.
23) Regarding holoprosencephaly, which is least correct:
i) Is associated with endocrine abnormalities
ii) Increase in incidence likely secondary to more awareness of mild form
iii) Caused by mutations in Sonic Hedgehog gene
iv) Lobar form associated with non fusion of central grey matter
ii) Increase in incidence likely secondary to more awareness of mild forms ??F
2) Regarding holoprosencephaly, which is least correct:
i) Is associated with endocrine abnormalities (T - J Pediatr Endocrinol Metab. 2005 Oct;18(10):935-41)
ii) Increase in incidence likely secondary to more awareness of mild forms ??F
iii) Caused by mutations in Sonic Hedgehog gene (T – Robbins/Osborn) Sonic hedgehog SHH (7q36), SIX3 (2p21), TGIF1 (18p11.3)
iv) Lobar form associated with non fusion of central grey matter (T - Unlike semilobar holoprosencephaly, the falx is present, the interhemispheric fissure is fully formed and the thalami are not fused)
24) 16yo male. Wedge shaped area of decreased CT attenuation involving both cortex and white matter of posterior temporal lobe. No contrast enhancement. Most likely:
1) DNET
ii) Embolism
iii) Ganglioglioma
ANSWER: i) DNET T can mimic stroke on CT. Cortically-based mass. Clasically wedge-shaped & “bubbly” at MRI.
3) 16yo male. Wedge shaped area of decreased CT attenuation involving both cortex and white matter of posterior temporal lobe. No contrast enhancement. Most likely:
ANSWER: i) DNET T can mimic stroke on CT. Cortically-based mass. Clasically wedge-shaped & “bubbly” at MRI.
ii) Embolism
iii) Ganglioglioma Most common cause of temporal lobe epilepsy (Osborn).
25) Dilated VR spaces. Which of the following is false
i) MPS
ii) Metachromatic leukodystrophy
iii) Cysticercosis
iv) Craniopharyngioma
v) Muscular dystrophies
ANSWER: probably V (muscular dystrophies - but seen in myotonic dystrophy)
**LJS - I think metachromatic leukodystrophy is false. The tigroid pattern is due to sparing of normal signal perivascular WM within high T2 demyelinated WM. I think this is what they are testing.
Paper on leukodystrophies: https://pubs.rsna.org/doi/full/10.1148/radiographics.22.3.g02ma01461
Paper on perivascular spaces: https://pubs.rsna.org/doi/full/10.1148/rg.274065722
4) Dilated VR spaces. Which of the following is false
i) MPS T (Osborn)
ii) Metachromatic leukodystrophy T (not in Osborn, but found elsewhere)
iii) Cysticercosis T
iv) Craniopharyngioma T Edema-like change along the optic tract commonly occurs in association with craniopharyngiomas… and in association with pituitary region tumors other than craniopharyngiomas. It is related to distension of normally present large Virchow-Robin spaces adjacent to the optic tract. Because Virchow-Robin spaces are speculated to be a drainage route of interstitial fluid, their distension may be related to the fluid retention in and along the Virchow-Robin spaces, the outlet of which into the subarachnoid space is blocked by pituitary region tumors. [AJNR 2003 24: 336-342
]v) Muscular dystrophies F/T seen in myotonic dystrophy
Dilated Virchow-Robin spaces / basal ganglia cystic lesions • Normal variant • Vascular o Lacunar infarcts o Amyloid angiopathy • Infectious o Cryptococcosis (AIDS; look for miliary enhancing nodules!) o Neurocysticercosis o Tuberculosis • Congenital/idiopathic o Mucopolysaccharidoses (Hunter, Hurler – esp. CC & peritrigonal WM) o Sarcoidosis o Sturge-Weber syndrome o Meningioangiomatosis o Meningiomelanomatosis o Metachromatic leukodystrophy Types- type I: along lenticulostriate arteria entering basal ganglia - type II: along the path of perforating medullary arteries as they enter the cortical GM over the high convexities - type III: in the midbrain. [RG 2007]
26) 30 year old woman with cerebellar mass and ataxia. On CT the mass is hypodense with an enhancing nodule. The most likely cause is
i) Pilocytic astrocytoma
ii) Medulloblastoma
iii) Dysembryoplastic neuroepithelial tumour
iv) Haemangioblastoma
v) Metastasis
iv) Haemangioblastoma
27) 24yo male. Previously well. Presents with dysarthria and CN VII, XI, XII palsies. MRI shows restricted diffusion in premotor cortex. Most likely cause:
i) Seizure
ii) Migraine related vasospasm
iii) Paradoxical emboli
iv) MCA thrombus
ANSWER:iii) Paradoxical emboli T isolated cortical infarction may result from distal embolic infarcts (ClinRad 2008)
6) 24yo male. Previously well. Presents with dysarthria and CN VII, XI, XII palsies. MRI shows restricted diffusion in premotor cortex. Most likely cause:
i) Seizure ?F changes usually more diffuse, typically cortex &/or subcortical WM (Osborn – Status epilepticus topic).
ii) Migraine related vasospasm
iii) Paradoxical emboli T isolated cortical infarction may result from distal embolic infarcts (ClinRad 2008)
iv) MCA thrombus- 7, 11 and 12 are all involved in the corticobulbar tract, this suggests a pseudobulbar palsy- The restricted diffusion in the premotor cortex is likely an infarct as we have no history of headaches or seizures in the question.- A first time seizure in this region is a possibility but likely would be secondary suggesting a paradoxical emboli as the most likely.- The MCA thrombus would involve a larger area??
28) Consultant asks you what is most likely intracranial cyst to calcify. You reply
:i) Colloid cyst
ii) Choroid plexus cyst
iii) Arachnoid cyst
ANSWER:ii) Choroid plexus cyst T irregular, peripheral calcification in majority
7) Consultant asks you what is most likely intracranial cyst to calcify. You reply:
1) Colloid cyst F rarely calcify
ii) Choroid plexus cyst T irregular, peripheral calcification in majority
iii) Arachnoid cyst F not mentioned in Osborn
29) Sellar region. Which is most correct:
i) 17mm is within normal height for a post partum females pituitary
ii) Papillary craniopharyngiomas are more commonly cystic then adenomatous (their spelling, not mine) cranios
iii) A suprasellar arachnoid cyst displaces the pit stalk anteriorly
iv) Absence of sellar bony enlargement suggests meningioma over adenoma
ANSWER:iv) Absence of sellar bony enlargement suggests meningioma over adenoma T large adenomas expand sellar & may erode its floor, while meningioma is usually separated from sella by diaphragma sellae (probably the most correct answer, although…)
8) Sellar region. Which is most correct:
i) 17mm is within normal height for a post partum females pituitary F ≤ 12mm
ii) Papillary craniopharyngiomas are more commonly cystic then adenomatous (their spelling, not mine) cranios F papillary form more commonly solid than adamantinomatous form
iii) A suprasellar arachnoid cyst displaces the pit stalk anteriorly T 15% of arachnoid cysts arise in the suprasellar region, and they can have local mass effect (Req p371)
iv) Absence of sellar bony enlargement suggests meningioma over adenoma T large adenomas expand sellar & may erode its floor, while meningioma is usually separated from sella by diaphragma sellae (probably the most correct answer, although…)
30) Old dude with known coronary artery disease. Ovoid mass with areas of calcification adjacent to left sphenoid sinus. Most likely:
i) Fusiform basilar artery aneurysm
ii) Fusiform ICA aneurysm
iii) CoW berry aneurysm
iv) Micotic MCA aneurysm
ii) Fusiform ICA aneurysm T
31) Cyst in area of 4th ventricle. Least likely:
i) Porencephalic cyst
ii) Arachnoid cyst
iii) Villous hypertrophy
iv) Subependymal cyst
ANSWER:iii) Villous hypertrophy F hypertrophy of villi of choroid plexus. Osborn Radiology 2006: “Villous hyperplasia is very rare and, when present, enhances strongly and relatively uniformly.” AJR 2009 (Naeini): “Diffuse villous hyperplasia is a rare condition that usually involves the lateral ventricles and is manifested by bilateral enlargement of the entire choroid plexus without discrete masses, resulting in overproduction of CSF and communicating hydrocephalus”.
10) Cyst in area of 4th ventricle. Least likely:
i) Porencephalic cyst F usually adjacent to lateral ventricle, typically supratentorial
* *“LJS - can get in cerebellum
ii) Arachnoid cyst F atypical location
iii) Villous hypertrophy F hypertrophy of villi of choroid plexus. Osborn Radiology 2006: “Villous hyperplasia is very rare and, when present, enhances strongly and relatively uniformly.” AJR 2009 (Naeini): “Diffuse villous hyperplasia is a rare condition that usually involves the lateral ventricles and is manifested by bilateral enlargement of the entire choroid plexus without discrete masses, resulting in overproduction of CSF and communicating hydrocephalus”.
iv) Subependymal cyst F rare in 4th ventricle
MARCH 201032) A 5 year old presents with unsteady gait and lethargy. The neurosurgeon wants to know if a posterior fossa lesion may be a pilocytic astrocytoma. This would be suggested by the imaging appearance of a :
a. Hypodense mass in the cerebellum.
b. Solid hyperdense mass in the midline cerebellum with enhancement.
c. Solid hypodense mass in the midline cerebellum with no enhancement
d. Hypodense mass in a cerebellar hemisphere with no enhancement.
e. Hypodense mass in a cerebellar hemisphere with a nodule that enhances
e. Hypodense mass in a cerebellar hemisphere with a nodule that enhances
33) A 5 year old presents with unsteady gait and lethargy. The neurosurgeon wants to know if this lesion may be a medulloblastoma. This would be suggested by the imaging appearance of a :
a. Hypodense mass in the cerebellum.
b. Solid hyperdense mass in the midline cerebellum with enhancement.
c. Solid hypodense mass in the midline cerebellum with no enhancement
d. Hypodense mass in a cerebellar hemisphere with no enhancement.
e. Hypodense mass in a cerebellar hemisphere with a nodule that enhances.
b. Solid hyperdense mass in the midline cerebellum with enhancement.
34) 43. 70yo with TIA, US shows extracranial ICA stenosis 70-99%. As of January 2010, the current recommended treatment is:
a. Randomised controlled trial has shown medical therapy better than endarterectomy.
b. RCT shown endarterectomy better than medical
c. RCT shown stenting better than endarterectomy
d. RCT shown endarterctomy better than stenting
e. No randomised controlled trials have been performed to say which treatment is better.
ANSWER: B; RCT shown endarterectomy better than medical T (i.e. NASCET, ECST)
- 70yo with TIA, US shows extracranial ICA stenosis 70-99%. As of January 2010, the current recommended treatment is:
a. Randomised controlled trial has shown medical therapy better than endarterectomy. F at this degree of stenosis there is RCT proof that surgery is better
b. RCT shown endarterectomy better than medical T (i.e. NASCET, ECST)
c. RCT shown stenting better than endarterectomy F The results of randomized trials have not shown consistent outcome differences between CAS and CEA. CAS may be superior to CEA in certain patient groups, such as those exposed to previous neck surgery or radiation injury.
d. RCT shown endarterectomy better than stenting T MJA 2010: Recent evidence from RCTs has cast doubt on the safety of widespread use of stenting for the treatment of patients with symptomatic or asymptomatic carotid stenosis. The overall results from these RCTs indicate that carotid endarterectomy (endarterectomy) is still the preferred treatment option for symptomatic carotid stenosis. PAH was in one of the trials for CAS, but it finished eary due to the above.
e. No randomised controlled trials have been performed to say which treatment is better.
35) 27. 30 female left neck pain, 10 hrs of diplopia and dysarthria. Normal non contast CT head and neck. The next investigation should be:
a. Lumbar puncture
b. Contrast enhanced CT head
c. DSA
d. Carotid US
e. MRI brain
ANSWER:e. MRI brain T if with T1 fat sat neck and MRA neck/brain, although according to RG 08 has quite poor sens/spec for vertebral artery dissection. MRI brain to exclude other causes other than dissection
- 30 female left neck pain, 10 hrs of diplopia and dysarthria. Normal non contast CT head and neck. The next investigation should be:
a. Lumbar puncture F
b. Contrast enhanced CT F, but would be T if CTA head/neck
c. DSA ?T invasive, but “gold standard”
d. Carotid US F
e. MRI brain T if with T1 fat sat neck and MRA neck/brain, although according to RG 08 has quite poor sens/spec for vertebral artery dissection. MRI brain to exclude other causes other than dissection
Obsorn – best imaging tool (vertebral dissection)
• CTA of neck with coronal + sagittal reconstructions usually diagnostic
• MR including axial T1WI with fat-sat + TOF MRA will make the diagnosis in most cases; Gd MRA better
• In equivocal cases or in cases where endovascular treatment is contemplated (SAH, hemodynamically significant stenosis) catheter angiography should be performed
36. Woman on OCP. Bilateral haemorrhagic thalamic and BG infarcts. A. Superior sagital sinus thrombosis B. Inferior sagital sinus C. Vein of Labbe D. Internal cerebral vein E. Cavernous sinus
ANSWER:D. Internal cerebral vein T (pink) – would have to involve both veins; a better answer would be vein of Galen (great cerebral vein) or straight sinus
- Woman on OCP. Bilateral haemorrhagic thalamic and BG infarcts.
A. Superior sagital sinus thrombosis F (green)
B. Inferior sagital sinus F
C. Vein of Labbe F temporal lobe (blue)
D. Internal cerebral vein T (pink) – would have to involve both veins; a better answer would be vein of Galen (great cerebral vein) or straight sinus
E. Cavernous sinus F
37. AVM (which is true?) A. CT with contrast pick up >90% B. V of Galen is AVM C. Venous angioma haemorrhage D. Cavernous haemangioma seen on angiogram E. Typically have mass effect
ANSWER:A. CT with contrast pick up >90% T (“strong enhancement of arterial feeders, nidus & draining veins”), can’t find figures
- AVM (Osborn I-5-4)
A. CT with contrast pick up >90% T (“strong enhancement of arterial feeders, nidus & draining veins”), can’t find figures
B. V of Galen is AVM F Osborn – AVF between deep choroidal arteries & large midline varix (embryonic median prosencephalic vein of Markowski)
C. Venous angioma haemorrhage F venous angioma = DVA = do not normally bleed (if bleed look for co-existent cavernoma). Capillary telangiectasias also do not bleed unless other associated malformation (e.g. cavernoma) present.
D. Cavernous haemangioma seen on angiogram F (cavernoma angiographically occult)
E. Typically have mass effect F RG 2010 “mass effect is a rare pathomechanism that may result from large venous ectasias or compression of critical structures by the nidus”. StatDx “minimal or no mass effect”
- 35 yr old with cerebellar hemisphere mass. Hyperdense on CT. Enhance.
f. Meningioma
g. Pilocytic astrocytoma
h. Medulloblastoma
i. Ganglioglioma
j. DNET
ANSWER: c. Medulloblastoma T? hemispheric MB’s can occur in adults, almost always < 40 years, but still most occur in children < 20 years
- 35 yr old with cerebellar hemisphere mass. Hyperdense on CT. Enhance.
a. Meningioma F? extra-axial (if didn’t specify in the cerebellar hemisphere this would probably be best answer, although usually in older age group)
b. Pilocytic astrocytoma F cyst + nodule, childhood
c. Medulloblastoma T? hemispheric MB’s can occur in adults, almost always < 40 years, but still most occur in children < 20 years
d. Ganglioglioma F like peripheral temporal lobes, rare in cerebellum
e. DNET F peripheral, supratentorial
- 30 year old woman presents with history of ataxia and headache. Contrast CT shows cystic lesion in cerebellar hemisphere with enhancing nodule. Which is likely?
k. Ganglioglioma
l. Pilocytic astrocytoma
m. Haemangioblastoma
c. Haemangioblastoma T in this age; cyst + nodule
- Patient having left extracranial ICA angiogram (stent). Sudden neurological symptoms. MRI shows left parietal and occipital infarct. Most likely…
a. Persistent trigeminal
b. Fetal posterior circulation
c. Persistent hypoglossal
d. ICA aneurysm
*AJL - I favour persistent trigeminal (if patient had fetal right circulation this would explain the unilateral changes).
Fetal left circulation with emboli could explain it as well but they seem to be angling towards posterior circulation changes which fits best with peristent trigeminal.
Previous answer:
a. is not true because PCA and ACA will be affected- parieto-occipital infarct- superior cerebellar ifnarct
b. fetal PCA is more correct because only PCA distribution affected
41. 70yr old. MRI for dementia. Cyst in the atria of left lateral ventricle. A. Choroid plexus cyst B. Ependymal cyst C. Mets D. Choroids plexus papilloma
ANSWER : AA. Choroid plexus cyst T most common choroid plexus mass in adults; common in elderly & fetuses, up to 40% in elderly, often bilateral. Common location is at the atria. (Osborn I-7-38)
- 70yr old. MRI for dementia. Cyst in the atria of left lateral ventricle.ANSWER : A
A. Choroid plexus cyst T most common choroid plexus mass in adults; common in elderly & fetuses, up to 40% in elderly, often bilateral. Common location is at the atria. (Osborn I-7-38)
B. Ependymal cyst F rare and usu younger (Osborn I-7-42)
C. Mets F can cause intraventricular mass, less common c.f. CPC
D. Choroids plexus papilloma F in kids in lateral ventricles; adults get in 4th ventricle
- Gelastic seizure and precocious puberty:
n. Tuber cinerum hamartoma
a. Tuber cinerum hamartoma T non-enhancing hypothalamic mass contiguous with tuber cinereum. Located between pons/mammillary bodies and hypothalamic infundibulumAnatomy of the hypothalamus
• Forms the floor (& part of the walls) of the 3rd ventricle & is located inferior to the thalamus
• Made up of (from anterior to posterior):
o Optic chiasm
o Tuber cinereum
– a convex sheet of grey matter extending posterosuperiorly from the infundibulum
– located b/w the optic chiasm & mamillary bodies
o Infundibular stalk
– leading down to posterior lobe of pituitary gland
o Mamillary bodies
– small round masses anterior to the posterior perforated substance in which the columns of the fornix (vide infra) end
- Adrenoleukodystrophy, which is least correct:
a More common in males
b. There is enhancement
c. Asymmetrical involvement
d. Involves periatrial and splenium of the corpus callosum
ANSWER: C. normally symmetrical
- Adrenoleukodystrophy, which is least correct: (SK) (Osborn I-9-40)’ANSWER:
a. More common in males T X-linked condition – severe progressive form usually affects pre-teen males
b. There is enhancement T leading edge enhancing; enhancement strongly linked to progression
c. Asymmetrical involvement F usually symmetric
d. Involves periatrial and splenium of the corpus callosum T
e. Affects the white matter, adrenals, and testicles T affects Leydig cells in testes
Note
- x linked disease
- metabolic disease
- mechanism: lack of myelination of veery long change fatty asid
- peritrogonal posterior pattern
- symmetrica
- enhance
- around atrium and selenium of corpus callosum
• Enhancing peritrigonal demyelination; leading edge enhances
• Location
o Peritrigonal white matter (WM)
o Pattern: Splenium → peritrigonal WM → corticospinal tracts/fornix/commisural fibers/visual and auditory pathways
o Typically spares subcortical U-fibers
• Morphology
o Usually symmetrical, confluent, posterior involvement; rare frontal pattern occurs
o Central (splenium) to peripheral gradient is usual
44. Dilated perivascular spaces. False A. Can have mass effect B. May confuse with lacunar infarct C. Often involves the cortex D. Suppress on FLAIR
ANSWER: C
C. Often involves the cortex F (BG, mid brain, deep white matter, extreme capsule)
*AJL - while I agree with the answer above, dilated perivascular space can involve the cortex though I’m guessing not ‘often’ (as per radiopaedia there are 3 types; basal ganglia, cortical grey matter, midbrain)
- Dilated perivascular spaces. False (SK) (Osborn I-7-30)
A. Can have mass effect T focal mass effect can occur (giant/tumefactive PVS)
B. May confuse with lacunar infarct T
C. Often involves the cortex F (BG, mid brain, deep white matter, extreme capsule)
D. Suppress on FLAIR T suppress completely, although 25% have minimal increased signal in brain surrounding enlarged PVS.
- A cerebral infarct can be differentiated from penumbra by:
a. Decreased cerebral flow (CBF)
b. Increased cerebral flow (CBF)
c. Decreased cerebral volume (CBV)
d. Increased cerebral volume (CBV)
e. Increased mean transit time (MTT)
f. Decreased MTT
c. Decreased cerebral volume (CBV)
46. Craniopharyngioma. True: A. Typical age 30 B. More likely to be intrasellar C. Can have nodular/curvilinear calcification D. MRI: most likely show solid mass
ANSWER: C
C. Can have nodular/curvilinear calcification T 90% of adamantinatous forms calcify, but rarely calcify in papillary type. Adamantinomatous mixed solid-cystic, while papillary type often solid.
- Craniopharyngioma. True (SK) (Osborn II-2-33)
A. Typical age 30 F 5-15 (kids, adamantinomatous) and >50 for papillary squamous
B. More likely to be intrasellar F supra 75%, both 20% and intra 4%
C. Can have nodular/curvilinear calcification T 90% of adamantinatous forms calcify, but rarely calcify in papillary type. Adamantinomatous mixed solid-cystic, while papillary type often solid.
D. MRI: most likely show solid mass F in kids (adamantinomatous) solid & cystic, while papillary type often solid.
- MBA, confused 9/12 later. Best sequence for DAI?
a. 3D spoiled gradient
b. DWI
c. FLAIR
d. T2* GRE
e. 3D GRE
f. FSE
ANSWER : 3D GRE = SWI
- MBA, confused 9/12 later. Best sequence for DAI?
a. 3D spoiled gradient F These sequences allow for fast 3D imaging during short apnea (10 to 20 seconds). They are used in angiography after gadolinium injection
b. DWI
c. FLAIR
d. T2* GRE good, but not as good as SWI
e. 3D GRE (i.e. SWI)
f. FSE
Susceptibility-weighted imaging (SWI) is a 3D, flow-compensated, radiofrequency spoiled gradient-recalled echo sequence that takes advantage of susceptibility variations between tissues. SWI combines magnitude and phase images to detect these differences. (AJR Oct 2010; JMIRO 2010).
- Cerebral vascular lesions, which is true?
- 90% are detected on CT
- Angiography detects cavernomata
- Vein of Galen aneurysm is an AVM
- Venous angiomas bleed more commonly in posterior fossa than anteriorly
- AVMs are most commonly dural-based
ANSWER: A
90% are detected on CT (?? T)
- Cerebral vascular lesions, which is true?
a. 90% are detected on CT (?? T)
b. Angiography detects cavernomata F cavernoma angiographically occult
c. Vein of Galen aneurysm is an AVM F? Osborn – AVF between deep choroidal arteries & large midline varix (embryonic median prosencephalic vein of Markowski)
d. Venous angiomas bleed more commonly in posterior fossa than anteriorly F venous angioma = DVA = do not normally bleed (if bleed look for co-existent cavernoma)
e. AVMs are most commonly dural-based F most common type is a parenchymal (pial) AVM
- Regarding MRI T1 weighted imaging of the brain, which is true?
a. Best sequence for imaging haemorrhage (subarachnoid blood)
b. Calcium is bright (hyperintense)
c. Grey matter is hyperintense compared to white matter
d. Posterior pituitary is of lower signal intensity than gray matter
e. Signal within the superior sagittal sinus is a reliable indicator of thrombosis
ANSWER: b. Calcium is bright (hyperintense) T/F certain crystalline forms of calcium are T1 hyper. Intracranial calcifications show variable MRI signal characteristics and have an unspecific appearance, making them difficult to characterize. MRI cannot reliably rule out or determine the presence of calcifications. (Radiologia 2006)
- Regarding MRI T1 weighted imaging of the brain, which is true?
a. Best sequence for imaging haemorrhage (subarachnoid blood) F for SAH use FLAIR, for other blood use T2* or SWI; T1 good for subacute blood
b. Calcium is bright (hyperintense) T/F certain crystalline forms of calcium are T1 hyper. Intracranial calcifications show variable MRI signal characteristics and have an unspecific appearance, making them difficult to characterize. MRI cannot reliably rule out or determine the presence of calcifications. (Radiologia 2006)
c. Grey matter is hyperintense compared to white matter F - at T1 GM is hypointense, WM is hyperintense
d. Posterior pituitary is of lower signal intensity than gray matter F bright spot
e. Signal within the superior sagittal sinus is a reliable indicator of thrombosis F signal intensity is variable, and acute venous thrombus can mimic a normal flow state (RG 2006)
AUGUST 200950. NOT associated with vHL?
a. Cerebellar hemangioblastoma
b. Renal cell carcinoma
c. Phaeochromocytoma
d. Endolymphatic sac tumors
e. Mucinous adenoma of the pancreas
ANSWER:e. Mucinous adenoma of the pancreas F
- NOT associated with vHL?
a. Cerebellar hemangioblastoma – 40-70%, most frequent cause of death
b. Renal cell carcinoma –50-66% of patients.
c. Phaeochromocytoma – 10-15%
d. Endolymphatic sac tumors <10-15% of VHL
e. Mucinous adenoma of the pancreas F
- Which of the following is NOT a characteristic CT feature of acute herpes simplex encephalitis
a. Sparing of the basal ganglia
b. Unilateral changes seen on MRI
c. Evidence of hemorrhage on MRI
d. Involvement of the limbic system
e. Mass effect
b. Unilateral changes seen on MRI F - bilateral but asymmetrical
HSV-1 causes 95% of all herpetic encephalitis. HSV-2 more common in neonates. Haemorrhagic, necrotizing encephalitis of gray and white matter (primarly limbic system). May se mild patchy enhancement. DWI - may see restricted diffusion. Spares the basal ganglia, bilateral but asymmetrical.
- 21yo woman with Hx of headaches and ‘pressure symptoms’ for years. Large cystic mass in right temporal lobe with calcified mural nodule and scalloping of inner table of skull. MOST LIKELY?
a. Pilocytic astrocytoma
b. Lhermette-Duclos disease
c. Ganglioglioma
d. Low grade glioma
e. Oligodendroglioma
ANSWER:c. Ganglioglioma T most likely; most commonly cyst + mural nodule, produce TLE (>75% in temporal lobe), often calcified
- 21yo woman with Hx of headaches and ‘pressure symptoms’ for years. Large cystic mass in right temporal lobe with calcified mural nodule and scalloping of inner table of skull. MOST LIKELY? Osborn I-6-82
a. Pilocytic astrocytoma F uncommon location (cerebellum>optic nerve/chiasm>adjacent to 3rd ventricle>brainstem)
b. Lhermette-Duclos disease F in cerebellum; striated cerebellar hamartoma; Cowden disease
c. Ganglioglioma T most likely; most commonly cyst + mural nodule, produce TLE (>75% in temporal lobe), often calcified
d. Low grade glioma F commonest tumour, but unlikely to have cyst+nodule
e. Oligodendroglioma – more solid, more calcium, slightly older
Cyst + nodule neoplasm DDx • Posterior fossa o Pilocytic astrocytoma o Haemangioblastoma • Supratentoria lo Craniopharyngioma o Ganglioglioma (& DIG in infants < 1 yr) o Pleomorphic xanthoastrocytoma (PXA) o S-PNET (uncommon variant) o Schwannoma (intraparenchymal, rare)
- 30yo female. Abnormal gait and headache of a few weeks duration. No previous history of note. NeuroSx want to exclude a post fossa tumor. Which (CT) would suggest medulloblastoma as MOST LIKELY diagnosis.
a. Hyperdense, contrast enhancing mass arising from cerebellar vermia
b. Hyperdense, contrast enhancing mass involving the left cerebellar hemisphere
c. Hyperdense, non contrast enhancing mass involving the cerebellar vermis
d. Hyper dense, unilateral enhancing mass involving the brain stem
e. Hyperdense mass with an enhancing nodule involving the left cerebellar hemisphere.
ANSWER:b. Hyperdense, contrast enhancing mass involving the left cerebellar hemisphere T 50-89% arise laterally (cerebellar hemisphere) in older children & adults (Osborn)
- 30yo female. Abnormal gait and headache of a few weeks duration. No previous history of note. NeuroSx want to exclude a post fossa tumor. Which (CT) would suggest medulloblastoma as MOST LIKELY diagnosis.
a. Hyperdense, contrast enhancing mass arising from cerebellar vermia (>90 % hyperdense and > 90% enhance on CT) in children arises from roof of 4th ventricle, i.e. midline lesion
b. Hyperdense, contrast enhancing mass involving the left cerebellar hemisphere T 50-89% arise laterally (cerebellar hemisphere) in older children & adults (Osborn)
c. Hyperdense, non contrast enhancing mass involving the cerebellar vermis
d. Hyper dense, unilateral enhancing mass involving the brain stem
e. Hyperdense mass with an enhancing nodule involving the left cerebellar hemisphere.
- Regarding cerebral venous thrombosis, which is FALSE? (they decided to repeat this question x2 in the exam)
a. Most common cause in adults in infection
b. Higher risk during puerperium than in pregnancy
c. In adults, a coagulopathy is the most important contributing factor
d. May be mimicked by subdural hematoma on unenhanced CT
e. May be accompanied by subarachnoid on CT
ANSWER: A
. Most common cause in adults in infection F – Infections contribute to < 10% of cerebral venous thrombosis (40% in children though). Resistance to activated protein C (typically due to factor V Leiden mutation) = most common cause of sporadic CVT. (StatDx)
- Regarding cerebral venous thrombosis, which is FALSE? (they decided to repeat this question x2 in the exam) (SK/RS)
a. Most common cause in adults in infection F – Infections contribute to < 10% of cerebral venous thrombosis (40% in children though). Resistance to activated protein C (typically due to factor V Leiden mutation) = most common cause of sporadic CVT. (StatDx)
b. Higher risk during puerperium than in pregnancy T Majority of studies have reported a higher proportion of CVT during puerperium compared to pregnancy
c. In adults, a coagulopathy is the most important contributing factor T
d. May be mimicked by subdural hematoma on unenhanced CT T layered blood on tentorium cerebelli may mimic transverse sinus thrombosis (Osborn)
e. May be accompanied by subarachnoid on CT T Am J Emerg Med Jan 2009.
- The following regarding DAI of brain is TRUE?
a. The dorsal brain stem is commonly affected
b. Most lesions are haemorrhagic
c. Genu is the portion of corpus callosum most often involved
d. Acute lesions are of low signal on T2W MRI
e. Lesions characteristically involve the cortex
ANSWER:a. The dorsal brain stem is commonly affected F? only in severe cases, poor prognosis. Neuro Req “lesions are also seen in the dorsolateral quadrant of the rostral (superior) part of the brainstem, adjacent to the superior cerebellar peduncle. Brainstem DAI associated with more profound injury.”
- The following regarding DAI of brain is TRUE? (SK)
a. The dorsal brain stem is commonly affected F? only in severe cases, poor prognosis. Neuro Req “lesions are also seen in the dorsolateral quadrant of the rostral (superior) part of the brainstem, adjacent to the superior cerebellar peduncle. Brainstem DAI associated with more profound injury.”
b. Most lesions are haemorrhagic F 80% of lesions are microscopic, non-haemorrhagic (Osborn I-2-36)
c. Genu is the portion of corpus callosum most often involved F splenium and under surface of posterior body
d. Acute lesions are of low signal on T2W MRI F Neuro Req “high intensity on T2/FLAIR +/- haemorrhage”; Osborn - depends if haemorrhagic or non-haemorrhagic
e. Lesions characteristically involve the cortex F grey-white junction
o Characteristic locations:
occur at interfaces b/w tissues
• Cerebral hemispheric grey-white matter junctions (67%)
– milder injuries confined to parasagittal frontal lobes & periventricular temporal lobes
• Corpus callosum (esp. posterior body & splenium)
– in 20%
• Dorsolateral brainstem & superior cerebellar peduncles
– in severe cases
• Basal ganglia & internal capsule
- Regarding imaging in the Immunocompromised patient, which is TRUE?
a. Low density lymphadenopathy on CT is characteristic of Kaposi’s sarcoma
b. MRI is sensitive to early changes in HIV encephalitis
c. Pneumocystic carinii pneumonia typically involves the lung bases following Rx with inhaled pentamidine
d. MAC infection, peripheral lymphadenopathy is usually more marked than abdominal lymphadenopathy
e. Toxoplasmosis lesions occur most commonly in the basal ganglia
ANSWER:e. Toxoplasmosis lesions occur most commonly in the basal ganglia T( BG are a favored site as well as corticomedullary junction, thalamus & cerebellum) – Osborn I-8-86. Also consider lymphoma, esp. if solitary.
- Regarding imaging in the Immunocompromised patient, which is TRUE?
a. Low density lymphadenopathy on CT is characteristic of Kaposi’s sarcoma F – hyperenhancing in 2/3.
b. MRI is sensitive to early changes in HIV F
c. Pneumocystic carinii pneumonia typically involves the lung bases following Rx with inhaled pentamidine F upper lobes
d. MAC infection, peripheral lymphadenopathy is usually more marked than abdominal lymphadenopathy F
e. Toxoplasmosis lesions occur most commonly in the basal ganglia T( BG are a favored site as well as corticomedullary junction, thalamus & cerebellum) – Osborn I-8-86. Also consider lymphoma, esp. if solitary.
- Not seen in NF1
a. Rib notching
b. Clinodactyly
c. Dural ectasia
d. Scoliosis
e. Lateral thoracic meningocele
b. Clinodactyly F T21 or familial clinodactyly
- Which of the following conditions is NOT associated with agenesis or hypogenesis of the corpus callosum
a. Interhemispheric lipoma
b. Chiari I malformation
c. Absence of the anterior commisure
d. Gray matter heteropia
e. Sphenoidal menigo-encephalocele
b. Chiari I malformation
- Regarding T1 imaging of brain, which is TRUE?
a. Posterior pituitary is of lower signal intensity than gray matter
b. Calcification is a recognised cause of hyperintense signal
c. Signal within the superior sagittal sinus is a reliable indicator of thrombosis
d. Gray matter is higher signal than white matter
e. Is optimal sequence for indentifying subarachnoid blood
ANSWER:b. Calcification is a recognised cause of hyperintense signal T certain forms of crystalline calcium are T1 hyperintense
- Regarding T1 imaging of brain, which is TRUE?
a. Posterior pituitary is of lower signal intensity than gray matter F T1 bright spot.
b. Calcification is a recognised cause of hyperintense signal T certain forms of crystalline calcium are T1 hyperintense
c. Signal within the superior sagittal sinus is a reliable indicator of thrombosis F artefactual ↑ signal common
d. Gray matter is higher signal than white matter F vice versa
e. Is optimal sequence for indentifying subarachnoid blood F FLAIR best
- Regarding hemangioblastomas of the CNS, which is FALSE?
a. Most common primary infra-tentorial intra-axial tumour in adults
b. Majority are confined to paravermian cerebellum
c. Associated with secondary polycythemia
d. Associated with syringomyelia
e. Calcification is common
ANSWER:e. Calcification is common F calcification very rare (not described in Osborn)
- Regarding hemangioblastomas of the CNS, which is FALSE? Osborn I-6-143
a. Most common primary infra-tentorial intra-axial tumour in adults T
b. Majority are confined to paravermian cerebellum T? 80% in cerebellar hemispheres
c. Associated with secondary polycythemia T secrete EPO
d. Associated with syringomyelia T? presumably
e. Calcification is common F calcification very rare (not described in Osborn)
- Which is NOT a feature of idiopathic intracranial hypertension
a. Cranial nerve palsy
b. Orthostatic headache, worse when upright
c. Transverse sinus stenosis
d. Cerebral venous thrombosis
e. Clinical improvement with placement of intrasinus stents
ANSWER:b. Orthostatic headache, worse when upright F feature of intracranial hypotension (Osborn II-4-34). BIH/IIH presents in obese woman with headache & papilloedema. Headache in BIH exacerbated by Valsalva.
- Which is NOT a feature of idiopathic intracranial hypertension (BIH) Osborn I-10-40
a. Cranial nerve palsy T CN 6 most commonly. Progressive visual loss, diplopia.
b. Orthostatic headache, worse when upright F feature of intracranial hypotension (Osborn II-4-34). BIH/IIH presents in obese woman with headache & papilloedema. Headache in BIH exacerbated by Valsalva.
c. Transverse sinus stenosis T cause or effect – debated
d. Cerebral venous thrombosis T? must exclude this diagnosis
e. Clinical improvement with placement of intrasinus stents T
- Which is FALSE regarding idiopathic intracranial hypertension?
a. Cranial neve palsies
b. Orthostatic postural headache
c. Caused by sinus stenosis
d. Caused by sinus thrombosis
e. Symptoms improve with sinus shunting
b. Orthostatic postural headache
MARCH 2009 EXAM RECALLS
- A bilateral infarct involving the basal ganglia and thalami could be best explained by thrombosis of:
- Superior sagittal sinus
- Inferior sagittal sinus
- Veins of Labbe
- Internal cerebral veins 5.Cavernous sinus
4.Internal cerebral veins - T - The deep system includes the vein of Galen, internal cerebral veins, and their tributaries; the Rosenthal vein (basal vein) and its tributaries; and the medullary and subependymal veins, which drain the hemispheric white matter. The deep system drains the inferior frontal lobe; most of the deep WM of the frontal, temporal, and parietal lobes; corpus callosum; upper brainstem; basal ganglia; and thalamus. The parenchymal alterations that occur with deep venous occlusion typically involve the thalami, probably because the primary venous pathways that drain the thalami extend directly into the internal cerebral veins (see diagram).
- Dilated VR spaces. Which of the following is false?
- MPS
- Metachromatic leukodystrophy
- Cysticercosis
- Craniopharyngioma
- Muscular dystrophy
ANSWER: 5
5.Muscular dystrophy - F - however, in myotonic dystrophy (amplification of an unstable CTG trinucleotide repeat sequence in a protein kinase gene on chromosome 19), the cerebral MRI features include diffuse atrophy (68%), subcortical WM lesions (65%), wide VR spaces (38%) and thickening of the skull (35%). [Neuroradiology 1996]
2.Dilated VR spaces. Which of the following is false? (GC)
- MPS - T - inherited disorder of metabolism characterised by enzyme deficiency and inability to break down glycosaminoglycan (GAG). VR spaces are dilated by accumulated GAG, esp. peritrigonal region.
- Metachromatic leukodystrophy - T - may have a ‘tigroid’ or ‘leopard’ apprearance due to perivascular sparing.
- Cysticercosis - T - fluid-filled ovoid cyst +/- scolex
- Craniopharyngioma - T - Because VR spaces are speculated to be a drainage route of interstitial fluid into the subarachnoid space, their distension may be related to the fluid retention in and along the VR spaces, the outlet of which into the subpial and/or subarachnoid space(s) is blocked by pituitary region tumors. [AJNR 2003]
- Muscular dystrophy - F - however, in myotonic dystrophy (amplification of an unstable CTG trinucleotide repeat sequence in a protein kinase gene on chromosome 19), the cerebral MRI features include diffuse atrophy (68%), subcortical WM lesions (65%), wide VR spaces (38%) and thickening of the skull (35%). [Neuroradiology 1996]
- Regarding myelination in children, which is of the following is the most correct?
- Myelination causes reduced / low signal on T1
- The anterior internal capsule is myelinated at birth.
- White matter and grey matter appear the same on T2 at 24-30 months
- Optic nerves myelinated by two months.
- From the splenium of the corpus callosum forwards
ANSWER:5.From the splenium of the corpus callosum forwards - T - dorsal to ventral, caudad to cephalad, central to peripheral. Splenium bright on T1 at 4 mths, genu at 6 mths; then low on T2 by 6 mths and 8 mths respectively. [Kieran’s ‘rules’]
3.Regarding myelination in children, which is of the following is the most correct? (GC)
- Myelination causes reduced / low signal on T1 - F - bright on T1 (fatty myelin).
- The anterior internal capsule is myelinated at birth - F - at birth, there is myelination of dorsal WM tracts of brainstem, cerebellar peduncles, dorsomedial tracts of diaencephalon, posterior limb of IC, and WM in the post-central gyrus. The anterior limb and genu of CC myelinate 4 mths later that the posterior limb & splenium. [Clinical MRI 2006]
- White matter and grey matter appear the same on T2 at 24-30 months - F - adult pattern attained by 18 mths.
- Optic nerves myelinated by two months – T? - assume this means 2 months after birth… The optic nerves and tracts are myelinated by one month, optic radiations at 3 months. [Osborn]
- From the splenium of the corpus callosum forwards - T - dorsal to ventral, caudad to cephalad, central to peripheral. Splenium bright on T1 at 4 mths, genu at 6 mths; then low on T2 by 6 mths and 8 mths respectively. [Kieran’s ‘rules’]
- 60 year old woman on a tread mill. Brain haemorrhage in posterior frontal lobe and corona radiata. MRI and angiogram normal other than the area of bleed. DSA normal. Becomes well again. MRI three months later shows old haematoma as the only abnormality. The cause of the haemorrhage is best explained by:
- Hypertensive bleed
- Amyloid angiopathy
- Malignancy
- Bleed into a metastasis
- AVM
ANSWER:1.Hypertensive bleed - T - atypical location (usually BG, thalamus, pons, cerebellum). However, more likely in a patient of this age, and that the repeat MRI shows old haematoma only. Also accounts for history/exercise, which means she’d be unlikely to be dementing from her amyloid angiopathy.
4.60 year old woman on a tread mill. Brain haemorrhage in posterior frontal lobe and corona radiata. MRI and angiogram normal other than the area of bleed. DSA normal. Becomes well again. MRI three months later shows old haematoma as the only abnormality. The cause of the haemorrhage is best explained by: (GC, TW, JS)
ANSWER:
1.Hypertensive bleed - T - as above
- Amyloid angiopathy - F – should see other foci of small haemorrhae on T2* GRE. According to the Boston criteria, this patient would fit into “possible” CAA category (clinical data suggesting CAA and the imaging finding of a single cortical-subcortical hematoma in a patient older than 55yrs, without other cause of hemorrhage). [RG 2006]
- Malignancy - F - should see on imaging.
- Bleed into a metastasis - F - should see on imaging. Correlate with history of malignancy.
- AVM - F - Parietal >frontal >temporal. MRI: flow voids, TOF. Angio: “bag of worms”.
- 10 year old child is drowsy with a headache. The most appropriate next investigation is:
- Observation
- CT brain
- CT brain with contrast
- LP
- MRI
3.CT brain non contrast
Indications for neuroimaging in children with headache: High priority:
acute headache, worst headache of life, thunderclap headache chronic-progressive pattern, focal neuro symptoms, abnormal neuro examination, papilloedema, abnormal eye movements, hemiparesis, ataxia, abnormal reflexes, VP shunt, neurocutaneous syndrome, age <3 years
Moderate priority: headaches or vomiting on awakening, unvarying location of headache, meningeal signs. [Guideline for diagnosis and management of migraine headaches in chlidren, Gunner et al 2008]
6.A young female has neck pain, dysarthria and diplopia. Non contrast CT brain and cervical spine both normal. The next most appropriate investigation is:
1.CT brain with contrast
2.MRI brain
3.Duplex ultrasound neck
4 DSA
5. LP
- MRI brain - T - MR is the modality of choice (but should specify MRI + MRA?). MRI detects both the intramural thrombus and intimal flap that are characteristic of VAD. Hyperintensity of the vessel wall seen on T1 fat sat axial images is considered pathognomonic of VAD. MRA can identify abnormalities that are characteristic of the disturbed arterial flow seen in VAD. These include the presence of a pseudolumen and aneurysmal dilation of the artery. MRI and MRA are less sensitive than cerebral angiography for the detection of VAD, although they probably have equivalent specificity.
- A young female has neck pain, dysarthria and diplopia. Non contrast CT brain and cervical spine both normal. The next most appropriate investigation is: (GC)
- CT brain with contrast - F - possibly CTA (accessibility after hours).
- MRI brain - T - MR is the modality of choice (but should specify MRI + MRA?). MRI detects both the intramural thrombus and intimal flap that are characteristic of VAD. Hyperintensity of the vessel wall seen on T1 fat sat axial images is considered pathognomonic of VAD. MRA can identify abnormalities that are characteristic of the disturbed arterial flow seen in VAD. These include the presence of a pseudolumen and aneurysmal dilation of the artery. MRI and MRA are less sensitive than cerebral angiography for the detection of VAD, although they probably have equivalent specificity.
- Duplex ultrasound neck - F - demonstrates abnormal flow in 95% of patients with VAD; US signs specific to VAD (eg, segmental dilation of the vessel, eccentric channel) are detectable in only 20% of patients.
- DSA - T - indicated when clinical suspicion is high but MRI/MRA has failed to isolate the lesion; characteristic angiographic finding in a dissected vertebral artery is the string or “string and pearl” appearance of the stenotic vessel lumen; also intimal flap / complete occlusion.
- LP - F - patients with suspected SAH and a normal CT scan may undergo LP if VAD is not pursued by other imaging modalities. The typical presentation of VAD is a young person with severe occipital headache and posterior nuchal pain following a recent, relatively minor, head or neck injury. The trauma is generally from a trivial mechanism but is associated with some degree of cervical distortion.
Focal neurologic signs attributable to ischaemia of the brainstem / cerebellum ultimately develop in 85% of pts; however, a latent period as long as 3 days between onset of pain and development of CNS sx is not uncommon.
Symptoms of vertebral a. dissection include: Ipsilateral facial dysaesthesia (pain and numbness) - most common symptom Dysarthria or hoarseness (CN IX and X) Contralateral loss of pain and temperature sensation in the trunk and limbs
Ipsilateral loss of taste (nucleus and tractus solitarius) Hiccups Vertigo Nausea and vomiting Diplopia or oscillopsia (image movement experienced with head motion) Dysphagia (CN IX and X) Disequilibrium Unilateral hearing loss [eMedicine; Craniocervical arterial dissection RG 2008]
- An elderly man has an MRI that shows a lesion which is isointense on T1, hyperintense on T2 and some enhancement post gadolinium. (Also recalled as isointense on T1 and hypointense on T2??) The most likely explanation is
- Haemorrhage into a cavernoma
- Haemorrhage into a metastasis
- Amyloid angiopathy
- Hypertensive haemorrhage
ANSWER:2.Haemorrhage into a metastasis - T - may see enhancement if hemorrhage is secondary to neoplasm (hyperacute blood Iso/Hyper, or Acute blood Iso/Hypo). Although peripheral “ring” enhancement of a hematoma (vascularized capsule) is possible after a few days this is in subacute phase.
- An elderly man has an MRI that shows a lesion which is isointense on T1, hyperintense on T2 and some enhancement post gadolinium. (Also recalled as isointense on T1 and hypointense on T2??) The most likely explanation is (TW)
- Haemorrhage into a cavernoma - F - cavernoma: minimal or no enhancement (unless mixed with other lesion eg DVA).
- Haemorrhage into a metastasis - T - may see enhancement if hemorrhage is secondary to neoplasm (hyperacute blood Iso/Hyper, or Acute blood Iso/Hypo). Although peripheral “ring” enhancement of a hematoma (vascularized capsule) is possible after a few days this is in subacute phase.
- Amyloid angiopathy - F
- Hypertensive haemorrhage - F - shouldn’t show enhancement acutely, see ans 1.
- 30 year old woman with cerebellar mass and ataxia. On CT the mass is hypodense with an enhancing nodule. The most likely cause is
- Pilocytic astrocytoma
- Medulloblastoma
- Dysembryoplastic neuroepithelial tumour
- Haemangioblastoma
- Metastasis
4.Haemangioblastoma - T - familial VHL associated HGBL occur at younger age, sporadiac HGBL peak is 40-60yo. Intraaxial posterior fossa mass with cyst, enhancing mural nodule, abutting pia.
