Neurology lists Flashcards
Chiari malformations
Chiari 1
- most common
- peg like cerebellar tonsils, displaced into the upper cervical canal
Chiari 1.5
- caudal descent of the cerebral tonsils and brain stem
Chiari 2
- displacement of the medulla, fourth ventricle and cerebellar vermis
- associated with a myelomeningocele
Chiari III
- similar to II but with high cervical encephalocele
Chiari IV
- severe cerebellar hypoplasia without displacement through the foramen magnum
Chiari V
- absent cerebellum, hernia of the occipital lobe through the foramen magnum
MRS - What does creatinine represent
Cellular energy stores
MRS - Peaks occur in what order?
Alphabetical
Choline, creatinine, NAA
Which disorder increases NAA?
Canavan disease - demyelinating disorder
When is a lactate doublet seen?
High grade tumour
- anaebolic metabolism
Periventricular enhancement Ddx
- Primary CNS lymphoma
- rarely involves meninges
- systematic lymphoma commonly involves menenges
- Necrotic in immunocompromised
- Enhances homogenously in the immunocompetent patient
- Infectious ependymitis
- Primary glial tumour
- Multiple sclerosis
Gyriform enhancement - DDx
- Herpes encephalitis
- Decreased diffusion
- Meningitis
- Subacute infarct
- PRES
Ring enhancement ddxx
- Mets
- Abscess
- glioma
- infarc
- contusion
- demyelination
- radiation
Ddx Pachymeningeal enhancement
- Intracranial hypotension
- Postoperative
- post lumbar puncture
- Meningeal neoplasm
- Granulomatous disease
- Sarcoid
- TB
- Fungal
- Occurs at the basal meninges
Letpomeningeal enhancement ddx
- Meningitis
- Letpomeningeal carcinomatosis
- Viral encephalitis
- slow flow vascular
How to differentiate between intra and extra axial mass
Abscence of intervening gray matter between the mass and white matter
Tumours hypointense on T2 weighted imaging
- Containing dessicated mucin
- Hypercellular tumours
- Lymphome
- medulloblastoma
- germinoma
- glioblastoma
Tumours hyperintense on T1 weighted imaging
- Metastatic melanoma
- Fat containing tumours
- Haemorrhagic metastases
- renal cell
- thyroid
- choriocarcinoma
- melanoma
Metastataic disease to the brain
- Lung
- Breast
- Melanoma
Posterior fossa mass in a child
- Medulloblastoma
- Juvenile pilocytic astrocytome
- Epdendymoma
- Haemangioblastoma
- ATRT (atypical teratoid/rhabdoid tumour)
Posterior fossa mass in an adult
- Metastasis
- Haemangioma
- Astrocytoma
- Medulloblastoma
CP angle masses
- Schwannoma
- Meningioma
- Arachnoid cyst
- Aneurysm
- Epidermoid cyst
- Intra-axial neoplasm
Intrinsic pituitary mass
- Macroadenoma
- Microadenoma
- Lymphocytic hypophystitis
- Granulomatous hypophysitis
- sarcoid
- Wegner
- TB
- Rathke’s cleft cyst
Suprasellar mass
- Sarcoid/suprasellar extension of an adenoma
- Aneurysm
- Teratoma
- Craniopharyngioma
- Hypothalamic glioma/Hypothalamic harmatoma
- Meningioma/Mets
- Optic nerve glioma
Intrinsic pineal mass
- Germ cell tumour
- Germinoma
- Teratoma
- Pineal cyst
- Pineocytoma
- Pineoblastoma
- Mets
Pineal regiom masses
- Gliomas
- Vein of galen aneurysm
- Meningioma
- Quadrigeminal plate lipoma
DAI Grading
- Only grey white matter junction
- CC
- Dorsolateral midbrain
Dural AV fistula classification (Cognard classification)
- I - no cortical venous drainage
- IIA - Reflux into dural sinus but not cortical veins
- IIB -Reflux into cortical veins - 10-20% haemorrhage
- III - Direct cortical venous drainage: 40% haemorrhage rate
- IV - direct cortical venous drainage with venous ectasia 66% haemorrhage rate
- V - spinal venous drainage
Fisher grading of SAH
- Gr I - ve on CT
- II - <1mm thick
- III >1mm thick
- IV = diffuse or IV/parenchymal extension
What area of the brain is seen in superior sagittal sinus thrombosis?
Parasagittal high convexity cortex
What area of the brain is seen in deep venous system thrombosis?
Infarction of bilateral thalami
What area of the brain is seen in transverse sinus thrombosis?
Posterior temporal lobe infarct
Causes of intraparenchymal haemorrhage
- Hypertensive haemorrhage
- Amyloid angiopathy
- Aneurysmal haemorrhage
- AVM
- dAVF
- Cavernous malformation
- Venous thrombosis
- Haemorrhagic neoplasm
- Haemorrhagic infarct
- CNS vasculitis
- Moyamoya
Dilated perivascular spaces ddx
- Mucopolysaccharidoses
- Gelatinous pseudocysts in cryptococcal meningitis
- atrophy
Brain myelination
- Babies are born with the brainstem and posterior limb of the internal capsule myelinated
- Order of myelination
- inferior to superior
- posterior to anterior
- Central to peripheral
- sensory before motor
Sinus development
- Maxillary (5 months)
- Ethmoid (1 year)
- Sphenoid (6 years)
- Frontal (4 years)
Chiari 1 differentials
Chiari type II malformation: Chiari type II malformation presents with deformity of the brainstem and enlargement of the foramen magnum. It is associated with myelomeningocele.
• Spinal hypotension syndrome: This is characterized by downward displacement of the cerebellar tonsils secondary to low pressure within the spinal canal. The brainstem and 3rd ventricle “sag” inferiorly, and the pituitary gland is upwardly convex. If contrast is administered, dural thickening and enhancement are demonstrated