Neuro (2) Flashcards
(58 cards)
CJD - progressive rapid dementia, ataxia, myoclonus.
MRI findings high T2/FLAIR
- putamen
- Caudate nuclei
+/- pulvinar thalamic nuclei (hockey stick). Varient CJD.
Important points - no white matter involvement, no enhancement and can cause diffusion restriction.
Huntington disease
MRI findings -
Caudate head atrophy
Compensatory frontal horn prominence
‘BOX’ like appearance
Parkinson’s - neuronal loss in substantial migration (pars compacta)
MRI - blurring of intermediate signal line separating two adjacent low intensity structures (pars reticulata of SN and RN)
DAT (Dopamine Active Transfer) - loss of uptake in posterior putamen. Loss of comma sign.
Wilson’s disease - disorder of copper metabolism
White matter atrophy
T2 high signal basal ganglia and thalami.
Describe pattern in Wilsons, Huntington, Parkinson, Wernicke’s.
Differentiate Progressive multi focal leukoencephalopathy (PML) - JC and HIV encephalopathy
Toxoplasmosis v Lymphoma in HIV patients
Cerebral tuberculosis - Can be difficult to differentiate from toxoplasmosis or lymphoma
Target lesions in corticomedullary regions
Can CALCIFY with treatment
Co-existent MENINGEAL ENHANCEMENT
Cryptococcus - yeast like fungus
Non enhancing low density lesions in basal ganglia
These show high signal on T2
Differentiated from VR spaces on FLAIR where VR spaces suppress.
Can get a granulomatous meningitis.
Functional Imaging in Dementia
Tc99 HMPAO SPECT + FDG PET
FDG PET preferred
1.Alzeimhers - Disproportionate effect to anterior temporal lobes, hippocampi + Sylvia’s fissure. Reduced uptake precuneus + posterior cingulate gyrus + frontal/temporal parietal lobes. Sparing of occipital lobes.
3.Lewy body - SPARES hippocampi. Involves occipital cortex. Preservation of metabolism in mid-posterior cingulate gyrus. Affects temporal-parietal region.
2.Vascular dementia
Toxic Poisoning
Typically produces high T2 signal in basal ganglia (and low T1)
Methanol - Putamen
Carbon monoxide - Globus pallidus
Cerebral amyloid angiopathy (CAA)
- 1/3 pts over 60
- beta-amyloid protein deposition
-causes microhaemorrhage _ blooming artefact on T2*/SWI
Generally involves cortical/subcortical regions
Spares deep white matter and basal ganglia.
Chronic hypertensive encephalopathy
-end arteries affected - thalamic and lenticulostriate perforators
Stages of MS
1. Oedematous peri-vascular inflammation
2. Demyelination with proliferation of astroglia in chronic phase
Causes oblong elliptical plaques high callososeptal T2 signal
Other high yield
1.middle cerebellar peduncle is highly specific
2. Lesions can cross midline
3. T2>FLAIR in post. Fossa
4. Acute lesion can enhance (incomplete ring) + diffusion restrict
Thalamic involvement rare - think ADEM
Neurocysticercosis - Tapeworm infection carried by pigs.
Particular involvement of the basal ganglia
Cause rice like calcification on plain film. Orientated along the muscle fibres.
Stages - note 1) cyst in a dot, 4)calcification 1-10yrs.
Sheehan syndrome - consequent on obstetric hypovolaemia. Pituitary becomes atrophied.
Pituitary apoplexy
- pituitary infarction which can be secondary to haemorrhage (>50% patients have underlying macro adenoma)
- can cause empty sella sign in chronic stage
Sheehan - pituitary apoplexy secondary to hypovolaemic shock post delivery
Acute idiopathic transverse myelitis (diagnosis of exclusion)
- inflammation of spinal cord which results in motor, sensory and autonomic dysfunction.
- High T2 centrally expanded cord over multiple vertebral levels. At least 2/3 cord.
MS spinal plaques - confined to 1-2 vertebral levels. Confined to 1-2 vertebral levels. <1/2 cord cross section. High T2.
ADEM - days/weeks after viral infection
Mostly white matter but spinal cord can be affected. Grey matter in basal ganglia also.
Usually affects young children - respond well to steroid.
ADEM
Neurodegeneration with iron accumulation
(HAllervorden - Spatz syndrome)
Eye of tiger sign
Low T2 in globus pallidus
Tuberculosis meningitis v Sarcoidosis meningitis
- sarcoidosis shows nodular enhancement
Carcinomatous meningitis usually from breast ca (also lung, melanoma) - zuckergrass ‘sugar’ coating with thin subarachnoid enhancement following Gyral pattern
-also shows leptomeningeal nodularity.
HIV related brain disease
CADASIL
Cerebral autosomal arteriopathy with subcortical infarcts and leukoencephalopathy
30-50s
Recurrent TIA/stoke + depression/psychosis
Classically affects anterior temporal lobe and external capsules.
Moyà Moyà
Unilateral progressive occlusion/arteritis distal ICA
- large network of tiny collateral vessels on angiogram
-puff of smoke.
Herpes simplex encephalitis
T2 high signal unilateral white matter medial temporal lobe and insular region.
Also has a predilection for limbic system too.
It can diffusion restrict (differentiates it from Japanese encephalitis)
differential is low grade glioma.
AUTOIMMUNE AND LEIGH’S SYNDROME
Superficial Siderosis
Haemosiderin deposition pliable an depends all surfaces.
Secondary to recurrent SAH.
Congenital Infections - TORCH
CMV (most common) —peri-ventricular calcification+ polymicrogyria.
Toxoplasmosis —2nd, basal ganglia calcification and hydrocephalus.
