Neuro Pathology Flashcards
What is Dementia?
Dec in cogntive ability, memory or function w/ intact consciousness
Who is at risk of developing Alzheimers dz?
Elderly & Down Synd
Which proteins are altered in the familial form of Alzheimer’s dz?
- Eary onset: APP (21), presenilin-1 (14), Presenlin-2 (1)
- Late onset: ApoE4 (19)
Which protein is protective against Alzheimers?
ApoE2
What are the histo findings w/ Alzheimers?
- Widespread cortical atrophy
- Dec ACh
- Senile plaques
- Neurofibrillary tangles
What are Senile plaques?
Extracellular ß-amyloid core
(synthesized by cleaving amyloid precursor protein)
What can Senile plaques cause?
May cause amyloid agniopathy→ intracranial hemorrhage
What is Pick’s dz (frontotemporal dementia)?
- Dementia
- Aphasia
- Parkinsonian aspects
- Change in personality
What is spared in Pick’s dz?
Parietal lobe & posterior 2/3 of superior temporal gyrus
What are the histo findings in Pick’s dz?
- Pick bodies: spherical tau protein aggregates
- Frontotemporal atrophy
What is Lewy Body dementia?
Parkinsonism w/ demntia & hallucinations
What are the histo findings in Lewy body dementia?
Alpha-synuclein defect
What is Creutzfeldt-Jakob dz (CJD)?
Rapidly progressive (wk to mo) dementia w/ myoclonus (“startle myoclonus”)
What are the histo findings of CJD?
- Spongiform cortex
- Prions (ß-pleated sheet resistant to proteases)
What are some causes of dementia?
- Multi-infarct (2nd MCC of dementia in elderly behind alzheimers)
- Syphilis
- HIV
- Vit B1, 3 or 12 def
- Wilson’s dz
- NPH (normal press hydrocephalus)
What is Multiple sclerosis?
Autoimmune inflam & demyelination of CNS
How do pts w/ MS present?
- Optic neuritis (sudden loss of vision)
- MLF synd (internuclear opthalmoplgeia)
- Hemiparesis
- Hemisensory sx
- Bladder/bowel incontinence
Who gets MS?
Women in 20-30’s
MC in whites
What are the clinical findings in MS?
- Inc protein (IgG) in CSF
- Oligoclonal bands are dx
What is the gold standard for MS imaging?
MRI
What are periventricular plaques?
Areas of oligodendrocyte loss & reactive gliosis w/ destruction of axons
What is the tx of MS?
- ß-interferon
- Immunosuppression
- Natalizumab
- Sx tx for neurogenic bladder, spacitity & pain
What is Charcot’s classic triad of MS?
- Scanning speech
- Intention tremor, incontinence & internuclear opthalmoplegia
- Nystagmus
- “SIN”
What is Acute inflam demyelinating polyradiculopathy?
Autoimmune cond that destroys Schwann cells→ inflam & demyelination of peripheral nerves & motor fibers
MC variant of Guillian-Barré synd
What does acute infalm demyelinating polyradicuopathy result in?
Symmetric ascending muscle weakness/paralysis beginning in LE.
Facial paralysis in 50%
Autonomic function may be severely affected
What is the outcome of pts w/ acute inflam demyelinating polyradiculopathy?
Almost all pts survive
Majority recover completely after wks to mo
What are the clinical findings in acute inflam demyelinating polyradiculopathy?
- Inc CSF protein w/ normal cell count
- Inc protein→ papilledema
What is acute inflam demyelinating polyradiculopathy assoc w/?
Infections: Campylobacter jejuni & CMV→ autoimmune attack of peripheral myelin
What is the tx for acute inflam demyelinating polyradiculopathy?
- Resp support critical
- Plasmapheresis
- IV immune globulins
What is Progressive multifocal leukoencephalopathy (PML)?
Demyelination of CNS d/t destruction of oligodendrocytes
What is PML assoc w/?
JC virus
Seen in AIDs pts
What is the outcome in PML pts?
Rapidly progressive, usually fatal
What is Acute disseminated (postinfectious) encephalomyelitis?
Multifocal perivenular inflam & demyelination after infection (measles or VZV) or vaccinations (rabies, small pox)
What is Metachromatic leukodystrophy?
AR lysosomal storage dz, MC d/t arylsulfatase A def
What does build up of sulfatides in Metachromic leukodystrophy lead to?
Impaired prodution of myelin sheath
What is Charcot-Marie-Tooth dz also known as?
Hereditary motor & sensory neuropathy (HMSN)
What is Charcot-Marie-Tooth dz?
Group of hereditary nerve disorders related to the defective prod of proteins involved in the structure & funct of peripheral nerves or the myelin sheath
What is Krabbe’s dz?
AR lysosomal storage dz d/t def of galactocerebrosidase
Build up of galactocerebroside→ destroys myelin sheath
What are seizures characterized by?
Synchronized, high-freq neuronal firing
What are Partial (focal) seizures?
- Affect 1 area of brain
- Simple partial
- Complex partial
- Epilepsy
- Status epilepticus
Where do partial seizures orginiate?
MC in medial temporal lobe
Proceded by seizure aura
What is a simple partial seizure?
Conciousness intact
(motor, sensory, autonomic, psychic)
What is a complex seizure?
Impaired consciousness
What is Epilepsy?
Disorder of recurrent seizures
What is Status epilepticus?
Continuous seizure for >30min or recurrent seizures w/o regaining consciousness b/w seizures for >30 min
Medical emergency
What are the causes of seizures in children?
- Genetic
- Infection (febrile)
- Trauma
- Congenital
- Metabolic
What are the causes of seizures in adults?
- Tumors
- Trauma
- Stroke
- Infection
What are the causes of seizures in elderly?
- Stroke
- Tumor
- Trauma
- Metabolic
- Infection
What are the types of Generalized seizures?
- Absence (petit mal)
- Myoclonic
- Tonic-clonic (grand mal)
- Tonic
- Atonic
What is an Absence (petit mal) seizure?
3 Hz, no postictal confusion, blank stare
What is a Myoclonic seizure?
Quick, repetitive jerks
What are Tonic-clonic (grand mal) seizures?
Alternating stiffening & movement
What is a tonic seizure?
Stiffening
What is an Atonic seizure?
“Drop” seizures (falls to floor)
commonly mistaken for fainting
What are Cluster headaches?
Unilateral brief headaches w/ excrutiating periorbital pain w/ lacrimation & rhinorrhea
What can cluster headaches induce?
Horner’s synd
Who gets cluster headaches?
MC in males
What is the tx for cluster headaches?
Inhaled O2 & sumatriptan
What are Tension headaches?
Bilateral w/ steady pain
NO photophobia, phonophobia or aura
What are Migraines?
Pulsating pain w/ nausea, photophobia or phonophobia
may have aura
What is the cause of Migraines?
Due to irritation of CN V, meninges or BV
What is Vertigo?
Sensation of spinning while stationary
What is Peripheral Vertigo?
MC; inner ear etiology
(Semicurcular canal debris, vestibular nerve inf, Meniere’s dz)
What is Central vertigo?
Brain stem or cerebellar lesion
What are the findings in Central vertigo?
- Directional change of nystagmus
- Skew deviation
- Diplopia
- Dysmetria
What happens in positional testing of Peripheral vertigo?
Delayed horizontal nystagmus
What happens in positional testing of Central vertigo?
Immediate nystagmus in any direction; may change direction
What are the Neurocutaneous disorders?
- Sturge-Weber synd
- Tuberous sclerosis
- Neurofibramtosis type I (von Recklinhausen’s dz)
- von Hippel-Lindau dz
What is Sturge-Weber synd?
Congenital disorder w/ port-wine stains, typically in the V1 opthalmic distribution, ipsi leptomenigeal angiomas & pheochromocytomas
What can Sturge-Weber synd cause?
- Glaucoma
- Seizures
- Hemiparesis
- Mental retardation
What are the HAMARTOMAS assoc w/ Tuberous sclerosis?
- Hamartomas in CNS & skin
- Adenoma sebaceum
- Mitral regurg
- Ash-leaf spots
- cardiac Rhabdomyoma
- (Tuberous sclerosis)
- Autosomal dOminant
- Mental retardation
- renal Angiomyolipoma
- Seizures
What is Neurofibromatosis type I (von Recklinghausen’s dz)?
- Cafe-au-lait spots
- Lisch nodules (pigmented iris hamartoma)
- Neurofibromas in skin
- Optic gliomas
- Pheochromocytoma
What is the cause of Neurofibromatosis type I?
AD, 100% penetrant, variable expression
Mutated NF1 gene on chr 17
What is von Hippel-Lindaue dz?
- Cavernous hemangiomas in skin, mucosa & organs
- Bilateral renal cell CA
- Heangioblastoma in retina, brain stem, cerebellum
- Pheochromocytoma
What is the cause of von-Hippel Lindau dz?
AD; mutated tumor suppressor VHL gene on chr 3
Where are Glioblastoma multiformes found?
Found in cerebral hemispheres
Can cross corpus callosum (“ Butterfly glioma”)
What is found on histology of a Glioblastoma multiforme?
“Pseudopalisading” pleomorphic tumor celss–border central areas of necrosis & hemorrhage
Stain astrocytes for GFAP
What is the prognosis of Glioblastoma multiforme?
Malignant w/ <1 year life expectancy
What is the MC primary brain tumor?
Glioblastoma multiforme (grade IV astrocytoma)
What is the 2nd MC primary brain tumor?
Meningioma
Where do Meningiomas occur?
Convexities of hemispheres (near surface of brain) & parasagittal region
Adjacent to brain attached to dura
Where do Meningiomas arise from?
Arachnoid cells, are extra-axial (external to brain parenchyma( & may have a dural attachment (“trail”)
What are the clinical features of a meningioma?
Typically benign & resectable
Often asx; may present w/ seizures or focal signs
What is found on histo of a Meningioma?
Spindle cells concentrically arranged in a whorled pattern; psammona bodies (laminated calcifications)
What is the 3rd MC primary brain tumor?
Schwannoma
What do Schwannomas arise from?
Schwann cells
Where are Schwannomas localized?
Usually found at cerebellopontine angle
CN VIII→ acoustic schwannoma (aka acoustic neuroma)
What is the marker for a Schwannoma?
S-100 +
What are Bilateral acoustic schwannoma assoc w/?
Neurofibromatosis type 2
What are the clinical features of a Schwannoma?
- Hearing loss
- Tinnitus
- Loss of balance
What is the prognosis of an Oligodendroglioma?
Relatively rare, slow growing
What are the histo findings of Oligodendroglioma?
- Chicken-wire capillary pattern
- Oligodendrocytes= “fried egg” cells–round nuclei w/ clear cytoplasm
- Cells often calcified
Where are Oligodrogliomas located?
Frontal lobes
What is the MC pituitary adenoma?
Prolactinoma
What are the clinical features of a Pituitary adenoma?
Bitemporal hemianopia & hyper or hypopituitarism
Where are Pilocytic (low-grade) astrocytomas located?
- Well Circumscribed
- In children found in posterior fossa
- May be Supratentorial
What is the prognosis of Pilocytic astrocytoma?
Benign; good prognosis
What is found on histo in Pilocytic astrocytoma?
GFAP +
Rosenthal fibers–eosinophilic, corkscrew fibers
Cystic + solid (gross)
What is a Medulloblastoma?
Highly malignant cerebellar tumor
Form of primitive neuroectodermal tumor
What is found on histo in Medulloblastoma?
- Homer-Wright rosettes
- Solid
- Small blue cells
- Radiosensitive
What are the clinical features of Medulloblastoma?
- Can compress 4th ventricle causing hydrocephalus
- Can send “drop mets” to SC
Where are Ependymomas found?
4th ventricle
What can Ependymomas cause?
Hydrocephalus
What is the prognosis of an Ependymoma?
Poor
What will be found on histo in an Ependymoma?
- Perivascular pseudorosettes
- Rod-shaped blepharoplasts (basal ciliary bodies) found near nucleus
Where are Hemangioblastomas found?
Cerebellar
What are Hemangioblastomas assoc w/?
vvon Hippel-Lindaue synd when found w/ retinal angiomas
What can Hemangioblastomas produce?
EPO→ 2° polycythemia
What is found on histo in Hemangioblastoma?
Foamy cells & high vascularity are characteristic
What is a Craniopharyngioma?
Benign childhood tumor, confused w/ a pituitary adenoma (may cause bitemporal heminopia)
What is the MC childhood supratentorial tumor?
Craniopharyngioma
What are Craniopharyngiomas derived from?
Remnants of Rathke’s pouch
What is found on histo in Craniopharyngioma?
Calcification is common (enamel-like)