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.