Neurology Flashcards
What is the MRI characteristics of acute blood?
T1 isointense
T2 dark
30 yr old male with HIV with feature of meningitis. MRI –> low T1 signal and high T2 signal/FLAIR with basal ganglia. Leptomeningeal enhancement post contrast.
Diagnosis?
Cryptococcus
What are the most common cancers to metastasise to the brain?
Lung
Breast
Colon
Melanoma
Renal
What are the reversible causes of brain atrophy?
Dehydration & starvation
→ Addison’s disease
→ High dose steroid therapy
→ Abnormal fluid balance
What are the symptons of lateral medullary syndrome?
(Wallenberg syndrome)
- Vestibulocerebellar symptoms (vertigo, diplopia, nystagmus)
- Autonomic dysfunction (ipsilateral Horner’s syndrome, hiccups)
- Sensory symptoms (stabbing pain on ipsilateral face then loss of pain and temperature sensation contralateral side of the body)
- Ipsilateral bulbar muscle weakness (hoarseness, dysphonia, dysphagia, dysarthria)
Palsy of CN III would suggest an aneurysm where?
Posterior communicating artery (PCOM)
CN III palsy: down and out occular positioning (supplies SR, IR, MR, IO)
Ptosis
+/- enlarged pupil
Enlarged pupil suggest compression of CN III
Optical chiasmal syndrome (bitemporal field defect) would suggest an aneurysm where?
Anterior communicating artery (ACOM)
What are the imaging features of idiopathic intracranial hypertension?
Meckel’s cave enlargement
Optic disk protrusion
Venous sinus stenosis
Empty sella
Slit like ventricles
*Classic: overweight middle-aged female with headache
What is the diagnosis if there are T2 bright lesions involving the calloso-septal interface?
MS
Lesions in ADEM do NOT involve the callloso-septal interface
What are some of the secondary causes of Moyamoya disease appearance?
Neurofibromatosis type 1
Tuberous sclerosis
Sickle cell disease
Radiotherapy
Marfan
Fibromuscular dysplasia
Which condition, secondary to vitamin B12 deficiency causes degeneration of the dorsal cord, resulting in loss of position and vibration senses, sensory ataxia and hyperreflexia.
Subacute combined degeneration
What is the imaging features of subacute combined degeneration of the cord?
Longitudinal high T2 signal on sagittal sequence
Inverted V shape of high T2 signal on axial sequences
No enhancement
What is the differential for a CP angle mass?
Schwannoma (most common)
Meningioma
Epidermoid
Dermoid cyst
IAC lipoma Arachnoid cyst
Which CP angle masses can calcify?
Meningioma (frequently)
Epidermoid (occasionally)
Which is the diagnosis in a patient with bilateral vestibular schwannomas?
NF-2
Which CP angle mass widens the internal acoustic canal?
Schwannoma
What are the imaging features of a CP angle schwannoma?
Avid heterogeneous enhancement
May widen porus acusticus resulting in “trumpet shaped” IAC
What are the imaging features of a CP angle meningioma?
Strong homogenous enhancement (as extra-dural)
May have dural tail
Can calcify
What are the imaging features of a CP angle epidermoid?
Follow CSF density, bright on FLAIR
Will restrict diffusion
Off-midline
What are the imaging features of dermoid cyst?
Most common location is supracellar cistern.
Usually midline.
Behave like fat (bright on T1, hypodense on CT).
What are the imaging features of an arachnoid cyst?
Dark on FLAIR, will NOT restrict with diffusion
What are the MR features of an acute sinus thrombosis?
Isointense on T1 and hypointense on T2
What are the imaging features of HIV encephalopathy?
Symmetrical white matter changes (high T2, T1 can be normal)
Spares subcortical U-fibres
Cerebral atrophy present
What are the imaging features of progressive multifocal leukoencephalopathy?
Asymmetrical white matter changes
Involvement of the subcortical U-fibres
No cerebral atrophy
Which virus causes PML?
JC virus
What is the most common intramedullary spinal tumour in an adult?
Ependymoma
What are the contents of the foramen Ovale?
CN V3.
Accessory meningeal artery.
What are the contents of the foramen rotundum?
CN V2
What are the contents of the inferior orbital fissure?
CN V2
What are the contents of the superior orbital fissure?
CN 3.
CN 4.
CN V1.
CN 6.
What are the contents of the foramen spinosum?
Middle meningeal artery
What are the contents of the jugular foramen?
CN 9.
CN 10.
CN 11.
Jugular vein.
What are the contents of the hypoglossal canal?
CN12
What are the contents of the optic canal?
CN 2.
Ophthalmic artery.
What are the contents of the cavernous sinus?
CN 3.
CN 4.
CN V1/2.
CN 6.
Carotid artery.
What are the imaging features of intracranial hypotension?
Meningeal engorgement.
Distension of the dural venous sinuses.
Prominent intracranial vessels.
Engorgement of the pituitary.
Subdural haematoma/ hygroma.
What are the imaging features of idiopathic intracranial hypertension?
Meckel’s cave enlargement.
Optic disc protrusion.
Venous sinous stenosis.
Empty sella.
Slit-like ventricles.
Subfalcine herniation can result in compression of what structure?
Anterior cerebral artery, resulting in stroke
Duret haemorrhages at the pontomesencephalic junction are caused by what?
Descending transtentorial herniation
In which patients would you see acute disseminated encephalomyelitis (ADEM)?
Children/ adolescents following viral illness or vaccination.
What is the fulminant form of acute disseminated encephalomyelitis (ADEM)?
Acute haemorrhagic leukoencephalitis (Hurst disease)
What are the imaging features of posterior reversible encephalopathy syndrome?
Asymmetric cortical and subcortical white matter oedema.
Usually in parieto-occipital lobes.
Does NOT restrict diffusion.
What is the cause of Wernicke encephalopathy?
Thiamine deficiency
What are the imaging features of Wernicke encephalopathy?
Enhancement of the mamillary bodies.
Increased T2/ FLAIR signal in bilateral medial thalamus and peri-aqueductal grey matter.
What are the neurological imaging features of carbon monoxide poisoning?
CT hypodensity/ T2 bright globus pallidus (CO causes globus warming)
Which structure is involved in Marchiafava-Bignami, typically referred to as a “sandwich sign”.
Corpus callosum
Depressed blood flow and metabolism of the cerebellar hemisphere following a contralateral supratentorial insult. Diagnosis?
Crossed cerebellar diaschisis
Which dementia spares the mid posterior cingulate gyrus?
Dementia with Lewy bodies
What is the PETCT appearance of Huntington’s?
Low activity in the caudate nucleus and putamen
What is the most common neonatal TORCH infection?
CMV
Which TORCH infection is associated with periventricular calcifications and polymicrogyria?
CMV
Which TORCH infection are you most likely to see basal ganglia calcification and hydrocephalus?
Toxoplasmosis
Which TORCH infection are you most likely to see frontal lobe atrophy?
HIV
What is the most common fungal infection in patients with AIDs?
Cryptococcus
What are the imaging features of Cryptococcus?
Leptomeningeal enhancement.
Lesions in the basal ganglia with are T1 dark/ T2 bright and may ring enhance.
What are the imaging features of neurotoxoplasmosis?
T1 dark/ T2 bright/ ring enhancing lesions with NO restricted diffusion.
Thallium cold.
PET cold.
Decreased CBV on MR perfusion.
Which of the following, lymphoma or toxoplasmosis, is hot on Thallium?
Lymphoma
What would be the next step in the management of a patient with imaging suggestive of HSV encephalitis but HSV titer negative?
Investigation for lung malignancy.
Limbic encephalitis is a paraneoplastic syndrome (normally associated with small cell lung cancer).
Which virus can cause T2 bright basal ganglia and thalamus with corresponding restricted diffusion?
West Nile
What are the imaging features of CJD?
Gyriform cortical restricted diffusion.
Restricted diffusion in the dorsal medial thalamus or in the pulvinar.
What are the features of NF2?
Multiple schwannomas, meningiomas and ependymomas (MSME)
What are the CNS manifestations of NF1?
Optic gliomas.
Astrocytomas.
What are the CNS manifestations of tuberous sclerosis?
Cortical/ subcortical tubers.
Subependymal hamartomas.
Subependymal giant cell astrocytoma (SEGA).
What are the CNS manifestations of Von Hippel Lindau?
Haemangioblastomas.
Choroid plexus papilloma.
What is the differential for a cortical tumour?
Pleomorphic xanthoastrocytoma.
Dysembryoplastic neuroepithelial tumour (DNET).
Oligodendroglioma.
Ganglioglioma.
Calcified cortical frontal lobe lesion which expands the cortex with poorly defined margins. Diagnosis?
Oligodendroglioma
In regards to an oligodendroglioma, does a 1p/19q deletion have a better or worse outcome?
Better
Child presents with drug resistant seizures.
What imaging features would be consistent with a dysembryoplastic neuroepithelial tumour (DNET)?
“Bubbly” lesion in the temporal lobe which is high on T2.
Hypodense on CT and does not enhance.
Focal cortical dysplasia in 80%.
Where does the medulloblastoma tend to originate?
Roof of the 4th ventricle
Where does the ependymoma tend to originate?
Floor of the 4th ventricle
What are the imaging features of a medulloblastoma?
Heterogenous on T1/T2 with homogenous enhancement
What are the imaging features of an ependymoma?
Squeezes out 4th ventricle and out the foramen of Luschka and Magendie.
Heterogenous enhancement.
Calcifies more than the medulloblastoma.
Does a xanthogranuloma (benign choroid plexus mass) restrict diffusion?
Yes
What are the three most common cerebellar pontine angle masses?
Vestibular schwannoma.
Meningioma.
Epidermoid.
What is the difference between an epidermoid and a dermoid?
Dermoids behave like fat- bright on T1.
Dermoids are usually midline.
What is the difference between an epidermoid and arachnoid cyst?
Arachnoid cysts with be dark on FLAIR and will not restrict diffusion.
Posterior fossa cyst with a nodule in a paediatric patient. What is the most likely diagnosis?
Juvenile pilocytic astrocytoma
Posterior fossa cyst with a nodule in an adult patient. What is the most likely diagnosis?
Haemangioblastoma
Pontine lesion in a child which is T2 bright with subtle/ no enhancement and flattening of the 4th ventricle. Diagnosis?
Diffuse midline glioma, H3K27M-mutant
Dysplastic cerebellar gangliocytoma is also referred to as what?
Lhermitte-Duclos disease
What syndrome is associated with Lhermitte-Duclos disease?
Cowden syndrome
What are the imaging findings of dysplastic cerebellar gangliocytoma (Lhermitte-Duclos disease)?
Thickening and increased T2 signal of the cerebellar folia giving striated appearance
9 month old baby with a rapidly increasing head circumference. MRI revealed large supratentorial cystic tumour in the superficial cerebral cortex and leptomeninges.
What is the likely diagnosis?
Desmoplastic infantile ganglioglioma/astrocytoma
Dural lesion which looks like a meningioma but does not have any calcification and invades the skull rather than causing hyperostosis. What is the diagnosis?
Haemangiopericytoma
What is the most common primary to metastasise to the dura?
Breast cancer
What are the MR features of pituitary adenomas?
T1 dark, T2 bright
Pituitary apoplexy is typically what on T1 weighted imaging?
Bright
Which subtype of craniopharyngioma is most common?
Adamantinomatous (3-9 fold more common than papillary)
What are the features of adamantinomatous craniopharyngiomas?
Lobulated muti-cystic lesions referred to a “motor oil cysts”.
90% calcify.
90% enhance.
Where is the classic location of a hypothalamic hamartoma?
Tuber cinereum which is part of the hypothalamus located between the mamillary bodies and optic chiasm).
What symptoms might a child with a hamartoma of the tuber cinereum present with?
Gelastic seizures (laughing fits).
Precocious puberty.
Tumours of which region can cause vertical gaze palsy (dorsal parinaud syndrome)?
Pineal region (compression of the superior tectal plate).
What is the most common solid pineal region tumour?
Germinoma
Which pineal region mass can cause precocious puberty and is almost exclusively seen in boys?
Germinoma
There is a well established association of pineoblastomas with which other tumour?
Retinoblastoma
What is Parinaud syndrome?
Vertebral gaze palsy.
Papillary light-near dissociation.
Convergence-retraction nystagmus.
Results from compression of tectal plate.
“Exploded” calcification is seen in which pineal region tumours?
Pineocytoma and pineoblastoma
“Engulfed” calcification is seen in which pineal region tumours?
Germinoma
Choroid plexus carcinoma is associated with what syndrome?
Li-Fraumeni syndrome
Nevoid basal cell syndrome (AKA Gorlin) is associated with dural calcifications, odontogenic cysts, basal cell skin cancer following radiation and which intracranial tumour?
Medulloblastoma
Turcot syndrome (a polyposis syndrome) is associated with which CNS tumours?
Glioblastoma and medulloblastoma
Which extra-axial bleed can cross the midline?
Extra-dural haematoma
Which type of temporal bone fracture is more likely to cause conductive hearing loss and ossicular dislocation?
Longitudinal
Which type of temporal bone fracture is more likely to cause sensorineural hearing loss, facial nerve damage and vascular injury?
Transverse
What is the most sensitive sequence on MRI for acute subarachnoid haemorrhage?
FLAIR
Superficial siderosis from repeated episodes of subarachnoid haemorrhage can result in what symptoms?
Sensorineural hearing loss and ataxia.
When would you get vasospasm following subarachnoid haemorrhage?
4-14 days later
Moyamoya is progressive stenosis of which artery?
Supraclinoid ICA
Watershed infarcts in a child.
What is the most likely diagnosis?
Moyamoya
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) classically spares which part of the brain?
Occipital lobes
Failure to develop the cerebellar vermis with resultant transversely orientated single lobe cerebellum is termed what?
Rhombencephalosynapsis
Arhinencephaly (no olfactory bulbs or tracts) is seen in which syndrome?
Kallmann syndrome
“Molar tooth” appearance of the superior cerebellar peduncles is seen in which syndrome?
Joubert syndrome
Joubert syndrome is associated with what?
Retinal dysplasia.
Dysplastic kidneys.
If liver fibrosis: COACH syndrome
Which form of holoprosencephaly is the most severe?
Alobar, single large ventricle with fusion of the thalami and basal ganglia.
Which form of holoprosencephaly is associated with pituitary problems?
Lobar (mildest form of holoprosencephaly)
Which form of holoprosencephaly is associated with abscence of the olfactory tracts and bulbs?
Semi-lobar
What is the classic triad in Meckel-Gruber syndrome?
Holoprosencephaly.
Multiple renal cysts.
Polydactyly.
Smooth brain appearance with a “figure 8”, “hours glass” and “shallow sylvian fissures” appearances describes which CNS developmental anomaly?
Lissencephaly
What is the CNS developmental anomaly where there is a grey matter lined cleft that will extend through the entire hemisphere?
Schizencephaly
Which “cephalys” are secondary to encephaloclastic event?
Porencephaly.
Hydraencephaly (can be differentiated from hydrocephalus/ holoprosencephaly due to absence of cortical mantle).
What is a cephalocele?
Herniation of the cranial contents through a defect in the skull. Meningoencephalocele = brain and meninges. Meningocele = just meninges.
Chiari type 1 is associated with what?
Klippel-Feil syndrome
Syringohydromyelia (50%)
Which craniosynostosis would you find premature fusion of the sagittal suture?
Scaphocephaly (also called dolichocephaly)
Which craniosynostosis would you find premature fusion of the bilateral coronal and/ or lambdoid sutures?
Brachycephaly
Which craniosynostosis would you find premature fusion of a unilateral coronal suture?
Plagiocephaly (can get “Harlequin eye”)
Which craniosynostosis would you find premature fusion of the metropic suture?
Trigonocephaly
Which leukodystrophy has diffuse white matter involvement with a tigroid appearance?
Metachromatic
Which leukodystrophy, occurring in boys, has symmetrical involvement of the occipital and splenium of the corpus callosum white matter?
Adrenoleukodystrophy
Which leukodystrophy has frontal white matter involvement and large head?
Alexander disease
Where does the artery of Adamkiewicz arise?
Left side of the aorta between T8 and L1 (supplies lower 2/3 of cord)
What is Scheuermann’s?
At least 3 schmorl’s nodes resulting in kyphotic deformity.
Os odontoideum is associated with which syndrome?
Morquio’s syndrome
What would you find in a patient with anterior cord syndrome?
Loss of motor function and pain/temperature sensation.
Proprioception and vibration remain intact.
What would you find in a patient with central cord syndrome?
Upper extremity deficit worse than lower.
What would you find in a patient with central cord syndrome?
Upper extremity deficit worse than lower.
What would you find in a patient with posterior cord syndrome?
Loss of proprioception
What would you find in a patient with Brown sequard syndrome?
Motor loss on one side.
Sensory on the other (rotation injury or penetrating trauma).
What are open spinal dysraphisms (spina bifida aperta) associated with?
Diastematomyelia (split cord malformation) and Chiari II malformations.
Caudal regression is associated with VACTERL and Currarino triad.
What is the Currarino triad?
Anterior sacral meningocele.
Anorectal malformation.
Sacrococcygeal osseous defect (scimitar sacrum).
What are the typical imaging features of MS lesions of the cord?
Short segment.
Affects half of the cord.
What are the typical imaging features of transverse myelitis of the cord?
Long segment.
Both sides of cord.
Expanded/ swollen cord.
What are the typical imaging features of neuromyelitis optica (Devics)?
Long segment.
Full transverse diameter of cord.
What are the predisposing factors for Guillain Barre syndrome?
Campylobacter.
Recent surgery.
Lymphoma.
SLE.
What are the imaging features of Guillain Barre syndrome?
Enhancement of the nerve roots of the cauda equina, particularly anteriorly.
Facial nerve is the most common cranial nerve to be affected.
What is the differential for an intramedullary spinal tumour?
Astrocytoma.
Ependymoma.
Haemoangioblastoma.
What is the differential for an extra-medullary, intradural spinal tumour?
Schwannoma.
Meningioma.
Neurofibroma.
Drop met.
What is the differential for an extradural spinal tumour?
Disc disease.
Bone tumour.
Metastases.
Lymphoma.
What is the most common intramedullary spinal tumour in children?
Astrocytoma
What is the most common intramedullary spinal tumour in adults?
Ependymoma
What are the imaging features of an intramedullary spinal astrocytoma?
Favours cervical cord.
Eccentric.
Longer segment.
Dark T1/ bright T2, enhances.
What are the imaging features of an intramedullary spinal ependymoma?
Favours lower cord.
Central.
Shorter segment.
Can be haemorrhagic with T2 dark cap.
What are the differentiating features between an extramedullary schwannoma and neurofibroma?
Schwannoma does not envelop the nerve root (neurofibroma do). Schwannoma can have cytic/ haemorrhagic change. Neurofibroma can have “target sign”: T2 dark centre, bright rim.
“Caput medusa” appearance is a buzzword for what?
Developmental venous anomaly
What are the CT perfusion features of ischaemic but not infarcted brain?
Decreased cerebral blood flow
Elevated mean transit time
Normal or high cerebral blood volume (mismatch)
What are the CT perfusion features of infarcted brain?
Decreased cerebral blood flow
Increased mean transit time
Persistent decrease in cerebral blood volume (matched defect)
In stroke imaging, the volumetric mismatch between the perfusion weighted imaging and DWI is a marker of what?
Potentially salvageable tissue at risk
16 year old with extra-pyramidal symptoms, dementia and positive family history. T2-weighted MRI shows low signal intensity of the globus palladi surrounding a central small hyperintense area “eye of the tiger sign”. What is the most likely diagnosis?
Hallervorden- Spatz disease (neurodegeneration with brain iron accumulation)
What are the imaging features of Wilson disease?
High signal in the basal ganglia, thalamus and midbrain
What are the imaging features of methanol toxicity?
Optic nerve atrophy
Haemorrhage in the putamen
Subcortical white matter necrosis
What are the imaging features of HSV in adults and what is the most sensitive sequence?
Swollen medial temporal lobe with increased T2 signal
Spares basal ganglia
DWI most sensitive
Colpocephaly (asymmetric dilation of the occipital horns) is associated with what?
Corpus callosum agenesis
Pericallosal lipoma
What are the associations with schizencephaly?
Optic nerve hypoplasia
Absent septum pellucidum
Epilepsy
What are the associations with Chiari type 2?
Hydrocephalus
Myelomeningocele
Syringomyelia
Tectal plate beaking
Dysgenesis of the corpus callosum
