Patho-PNSCNS Flashcards
Most common cause of peripheral neuropathy
DM
Most common inherited peripheral neuropathy
Charcot-Marie Tooth disease
Symmetric ascending demyelinating polyradiculoneuropathy
Associated infections
Most prominent lesion of demyelination
GBS
Lymphoplasmacytic perivenjlar Nd endoneurial infiltrate
C. Jejuni, M. Pneumonia
CMV, EBV
Segmental demyelination
Most common form of Diabetic Neuropathy
Histology:
Axonal neuropathy
Hyaline arteriosclerosis
Regenerative axonal clusters
Distal sensorimotor polyneuropathy
2nd decade of life
Progressive distal sensorimotor neuropathy
Most common form
CHARCOT-MARIE-TOOTH DISEASE
Most common: CM1
Axonal: CM2, severe
Demyelinating: the rest
Differentiate Myasthenia Gravis and Lambert Eaton Myasthenic Syndrome in
Autoantibodies
Weakness with exertion
Muscle groups
Both are antibody mediated Type II
MG
- Postsynaptic AcH receptor
- fatigable weakness
- EOMs
LEMS
- presynaptic Ca channel
- improves with repetitive exertion
- extremities
Start with myalgia, then proximal weakness and eventually distal weakness
Differentiate dermatomyositis and polymyositis
Age
Skin changes
Pathogenesis
Mononuclear infiltrate
Dermatomyositis
- juvenile
- heliotrope rash - periorbital lilac discoloration
- gottron papules - dusky res patches over knuckles, knees and elbows
- CD4 mediated, INF-1
Polymyositis
- adult
- no skin changes
- CD8 mediated
- endomysial
Pelvic girdle weakness up to shoulders
Pseudohypertrophy of lower leg muscles
Arrhythmia, cardiomyopathy, mental retardation
Differentiate these 2 types in
- defect
- onset
- immunostaining
Duchenne
- total absence of dystrophin
- early, severe
Becker
- reduced activity of dystrophin
- late, mild
Early: segmental myofiber degeneration and regeneration
Late: Fatty replacement
PERIPHERAL NERVE SHEATH TUMORS
Identify:
- Plexiform (bag of worms), NF-1 associated, CD34 spindle cells in loose collagen stroma (shredded carrot)
- NF-2 associated, vestibular, Anton A (cellular, spindle cells in fascicles), Anton B (hypocellular, spindle cells in myxoid stroma), Verocay bodies, S100+
- Neurofibroma
2. Schwannoma
Differentiate herniation syndromes in
Herniating part
Herniation through
Compressed structure
Clinical manifestation
Subfalcine
-cingulate to falx cerebri, compressing ACA causing focal neurologic defecits
Transtentorial
-medial temporal to tentorium cerebelli compressing CNIII causing pupillary dilatation
Tonsillar
-cerebral tonsil to foramen magnum compressing the brainstem causing cardiac and respiratory depression
Cerebellar vermis hypoplasia
Cystic dilatation of 4th ventricle
Hydrocephalus
Dandy Walker malformation
Posterior fossa anomaly
Small posterior fossa with misshapen cerebellar tonsils
Aqueductal stenosis
Noncommunicating hydrocephalus
Low lying cerebellar tonsils
Clinically silent or hydrocephalus
ARNOLD CHIARI MALFORMATION
Chiari I
Chiari II
Rapidly evolving neurologic symptoms with lucid intervals
CT scan: biconvex, cross the midline, does not cross sutures
Dx?
Most common vessel involved
Epidural hematoma
Middle meningeal artery (usually from pterion fx)
Slowly evolving neurologic symptoms
CT scan: crescent shaped, can’t cross falx and tentorium
Dx?
Most common vessel involved
SUBDURAL HEMATOMA
Bridging veins
Worst headache of my life
Syncope
From ruptured saccular berry aneurysm
Dx?
Most common location?
SUBARACHNOID HEMORRHAGE
ACA-ACoA junction
May lead ti
- ischemic injury
- meningeal fibrosis > CSF outflow obstruction
CSF findings:
Dec sugar, inc protein, +culture
Dx
Common cause
ACUTE PYOGENIC MENINGITIS
infants: E. Coli > GBS > L. Monocytogenes
Adolescents: N. Meningitides
Adults: S. Pneumonia, L. Monocytogenes
CSF findings:
Normal sugar, inc protein, -culture
Dx
Common cause
ACUTE ASEPTIC MENINGITIS
Enteroviruses
Localized focus of necrosis of brain tissue with accompanying inflammation
Central liquefactivd necrosis surrounded by granulation tissue
Dx
Common cause
BRAIN ABSCESS
Staph and Strep: immunocompetent
Exudate on basal cister s and around cranial nerves
Present with tuberculomas
Obliterative endarteritis of vessels in SAS
Adhesive arachnoiditis
CSF: lymphocytic pleocytosis with markedly elevated protein
TUBERCULOIS MENINGIENCEPHALITIS
Cytoplasmic, round to oval, eosinophilic inclusions in pyramidal neurons of the hippocampus and Purkinje cells of the cerebellum
Widespread neuronal degeneration most severe in brainstem
RABIES
Microglial nodules, multinucleated giant cells
With microglial affectation that expresses CD4
Increased incidence of CNS lymphomas
HIV
Central foci of necrosis surrounded by tachyzoites and bradyzoites
CT scan: ring enhancing lesions
Brain abscess near the gray-white junction (cerebral cortex)
TOXOPLASMA
Gelatinous material within the subarachnoid space and small cysts in basal ganglia
Expanded perivascular (Virchow-Robin) spaces containing aggregates organisms
CRYPTOCOCCUS
Spongiform transformation in cerebral cortex and deep gray matter structures
-pathognomonic finding
CREUTZFELD-JAKOB DISEASE
Initial manifestation: unilaterL involvement of optic nerve
CSF: Increased IgG (oligoclonal)
Type IV hypersensitivity to myelin sheath
TRIAD: nystagmus, intention tremor, scanning speech
MULTIPLE SCLEROSIS
Charcot triad of MS
Neuritic plaques
Neurofibrillary tangles
Lewy body, alpha synuclein aggregates
Alzheimers
Parkinsons
- Ataxia
Confusion
Ophthalmoplegia
Acute
Can be reversed with thiamine
- Confabulation
Hallucinations
Amnesia
Chronic
Hemosiderin laden, dorsomedial nucleus
WERNICKE ENCEPHALOPATHY
KORSAKOFF SYNDROME
Rosenthal fibers
-eosinophilic granular bodies
Fried egg appearance
-round tumor cells with cytoplasmic halos
Perivascular Pseudorosettes
-regular, round to ovoid nuclei with abundant granular chromatin
Astrocytomas
-children: cerebellum, adults: cerebral cortex
Oligodendroglioma
-cerebral cortex
Ependymoma
- 1st 2 decades: cerebellum
- adults: spinal cord
Homer-Wright rosettes
Small, round, blue cells
Drop metastases
Most common poorly differentiated tumor
MEDULLOBLASTOMA
-radiosensitive
Most common CNS neoplasm in immunocompromised individuals
PRIMARY CNS LYMPHOMA
CNS tumor
-Psammoma bodies
MENINGIOMA
