Topics in Brain

• Anatomy

  • Cisterns

    • Premedullary cistern

    • Prepontine cistern

    • Cerebellopontine cistern

    • Cisterna magna

    • Superior cerebellar cistern

    • Interpeduncular cistern

    • Ambient cistern

    • Quadrigeminal cistern

    • Suprasellar cistern

  • Surface Anatomy

    • Frontal lobe

      • Superior

      • Middle

      • Inferior

        • Pars orbitalis

        • Pars triangularis (44) Broca

        • Pars opercularis (45) Broca

      • Precentral gyrus

    • Parietal lobe

      • Superior lobule

      • Intraparietal sulcus

      • Inferior lobule

        • Supramarginal

        • Arcuate

      • Postcentral gyrus

    • Midsagital

      • Corpus callosum

      • Callosal sulcus pars marginalis

      • Cingulate gyrus

      • Cingulate sulcus

      • Superior gyrus

      • Paracentral lobule

      • Parietoocciptial sulcus

      • Calcarine sulcus

      • H-shaped subparietal sulcus

      • Precuneus

      • Cuneus

      • Lingual

• Congenital and malformations

  • Septum Pellucidum Variations

    • Cavum septum pellucidum

    • Cavum vergae

    • Cavum veli interpositi

  • Neurophakomatoses

    • NF1

      • Findings: Cafe-au-lait spots, Lisch nodules in the iris, plexiform neurofibromas, axillary/ingiunal freckling, bone dysplasias, pseudoarthroses, optic pathway gliomas

      • Astrocytomas may arise in the basal ganglia, optic radiations, cerebellar gray or white matter, or brain stem at the sites of high intensity foci on T2WI.

    • NF2

      • Bilateral CN VIII schwannomas.

      • CN V is the second most common site of schwannomas

      • Ependymomas

      • Meningiomas

    • TS

      • Periventricular subependymal nodules, cortical and subcortical peripheral tubers, white matter hamartomas, subependymal giant cell astrocytomas (rare)

      • renal cysts and RCC, adenoma sebaceum, retinal hamartomas, shagreen patches, ungal fibromas, rhabdomyomas of the heart, angiomyoliomas of the kidney, cystic skeletal lesions

    • SW

      • Port-Wine stain

      • Leptomeningeal capillary-venous angiomatosis

    • vHL

      • Hemangioblastomas

      • Renal cysts, RCC

    • Meningiomatosis

    • Neurocutaneous melanosis

      • Melanotic thickening of the meninges (high signal intensity on T1WI)

    • Hereditary hemorrhagic telangiectasia

      	NF1	NF2	TS	VHL
      Skin	Cafe-au-lait spots, NF		Angiofibromas
      Eyes	Lisch nodules		Retinal hamartomas	Hemangioblastoma
      Brain	Optic and other gliomas, BO in basal ganglia	Vestibular schwannoma, meningioma	Tubers, Nodules, SGSA	Hemangioblastoma
      Spine	NF, dural ectasia	Schwannomas, Meningiomas, Ependymomas		Hemangioblastoma
      Chest	Coarctation of aorta		LAM
      Renal	Renal artery stenosis		AML, renal cysts, RCC	Renal cysts, RCC

• Infection

  • Epidural abscess is usually dorsal to the spinal cord due to anatomy of the venous plexus, but can be anterior due to diskitis

  • Meningitis

    • Basal - TB

    • Leptomeningitis - bacterial infection

    • Pachymeningitis

      • Intracranial hypotension

      • Mets to dura

      • Sarcoid

      • Infection less likely

  • Pyocephalus

    • Rupture of abscess into ventricles

  • Toxoplasmosis

    • Predilection for basal ganglia

    • Edema is out of proportion to the lesion size

    • Target sign on T2 - dark, bright, dark

  • AIDS

    • Basal ganglia calcifications

  • Listeria

    • Mesenrhombencephalitis

• Demyelinating conditions

  • ADEM lesions are synchronus, MS lesions can be in different stages

  • MS

    • Diffusion restriction indicates that lesion is acute

    • Enhancing lesions are subacute

    • Incomplete ring sign

• Hydrocephalus

  • Terminology

    • Obstructive

      • Non-communicating

      • Communicating

    • Non-obstructive

      • Ex vacuo

• Brain Herniations

  • (1) Cingulate herniation under the falx cerebri,

  • (2) Downward transtentorial (central) herniation,

  • (3) Uncal herniation over the edge of the tentorium, or

  • (4) Cerebellar tonsillar herniation into the foramen magnum.

  • Coma and ultimately death result when (2), (3), or (4) produces brain stem compression.

• Vascular malformations and anomalies

  • Developmental venous anomaly

    • Old term: venous angioma

    • May co-exist with cavernoma

  • Cavernoma

    • Old term: cavernous angioma

  • Capillary telangiectasia

  • Pial AVM

    • Supplied by internal carotid or vertebral circulation

  • Dural AVM

    • Supplied by external carotid

  • AV fistula

    • Drains into dural venous sinus

  • Aneurysm