List the 3 main features of the blood brain barrier
Tight junctions between endothelial cells
Continuous basement membrane
Astrocyte podocytes
What is leptomeningitis? Common routes of infection?
Inflammation surrounding the subarachnoid space
Blood-borne
Directly from middle ear, mastoid/nasal sinuses, dural venous sinus, skull fracture
What is the most common benign primary CNS tumour in adults? What is it derived from?
Meningioma - arachnoid cap cells of arachnoid villi
When testing reflexes, what myotome is involved in knee, ankle, and plantar (Babinski) reflexes?
Knee - L3, L4
Ankle - S1, S2
Plantar - L5, S1, S2
Where are the Broca's and Wernicke's areas located? What do they control?
Broca's in frontal lobe - expressive speech and fluency
Wernicke's in temporal lobe - comprehension
List 4 opportunistic CNS infections that can occur in someone with HIV
Any 4 of:
Describe some characteristics/features of a pilocytic astrocytoma?
Benign, well-circumscribed, cyst-mural nodule
Usually in cerebellum
What reflexes are tested in an upper limb neuro exam? Can you name the myotomes?
Biceps - C5, C6
Triceps - C6, C7
Supinator - C5, C6
Finger jerk - C8
What nerves exit through the superior orbital fissure?
CN III, IV, V1, VI
List some viruses that cause meningitis/encephalitis
Enteroviruses
Herpes Simplex Viruse
CMV, EBV
Arboviruses - JEV, WNV
Which tumour secretes CSF?
Choroid plexus papilloma (benign) or choroid plexus carcinoma (malignant)
Hypersecretion of CSF = hydrocephalus
Demonstrate how you would test someone's upper limb dermatomes?
Describe the flow of CSF
Lateral ventricle (cerebral hemispheres)
Interventricular foramina
3rd ventricle (diencephalon)
Cerebral aqueduct
4th ventricle (dorsal to pons)
Lateral (2) and median (1) apertures
Subarachnoid space
Reabsorbed into venous circulation through dural venous sinuses through the arachnoid granulations
What are the causative agents in chronic and granulomatous meningitis?
Mycobacterium tuberculosis
Treponema pallidum
Cryptococcus neoformans
Borrelia burgdoferi
Glioblastoma - derivative, location, spread?
Derived from astrocytes
Usually in cerebral hemispheres
Can cross the corpus callosum = 'butterfly tumour' but does not metastasise outside nervous system
Differentiate between myelitis vs encephalitis clinically
Myelitis - inflamed spinal cord, motor and sensory signs
Encephalitis - inflammation of brain, confusion and reduced consciousness
What cranial nerves are involved in the following:
Pupil light reflex
Jaw jerk
Gag reflex
Pupil light reflex - CN II afferent, CN III efferent
Jaw jerk - CN V3 afferent and efferent
Gag - CN IX afferent, CN X efferent
Self-limiting, benign disease
Fever, meningism (headache, neck stiffness, photophobia), altered mental state
CSF - clear, normal glucose, mildly elevated protein, lymphocytes +++
What are the phakomatoses?
Familial disorders in which there are developmental abnormalities associated with hamartomas and neoplasms, affect organs of ectodermal origin (skin, CNS, eyes)
Neurofibromatosis 1 - neurofibromas (benign tumours of peripheral nerves, multiple polypoid skin nodules), cafe au lait spots
NF2 bilateral acoustic neurofibromatosis - bilateral schwannomas of CN VIII
Von Hippel-Lindau syndrome - haemangioblastoma (secretes EPO), renal cell carcinoma, phaeochromocytoma
Clinical features of raised intracranial pressure?
Cushing triad = HTN, bradycardia, irregular breathing
Altered consciousness
Headache
Nausea, vomiting
Papilloedema