Pathology

Question 1

Pseudotumor cerebri

Answer 1

No tumor or obstruction of CSF flow, CSF reabsorption is decreased in the arachnoid villi

No mental status changes
Do have increased intracranial pressure (papilledema), and decreased CF protein
Present with headache and diplopia

Causes: All-trans-retinoic acid to treat APL, Hypothyroidism, Cushings disease, OCPs

Treatment: Carbonic anhydrase inhibitor or systemic corticosteroids

Question 2

Lewy Bodies

Answer 2

abnormal aggregates of protein that develop inside nerve cells in Parkinson’s disease and Lewy body dementia,

Question 3

Subfalcine herniation

Answer 3

cingulate gyrus herniates under the flax cerebri

compression of the anterior cerebral artery leads to infarction

Question 4

Uncal herniation

Answer 4

temporal lobe uncus herniates under the tentorium cerebelli (btw the cerebellum and the brainstem)

1. ) compresion of cranial nerve III leads to “down and out”
2. ) Compression of poeterioir cerebral artery leads to infarction of the occipital lobe (contralateral homonymous hemianopsia)
3. ) Rupture of the paramedian artery in the brainstem (Duret hemmorage)

Question 5

Tonsillar herniation

Answer 5

cerebellar tonsils displace into the foramen magnum

compression of the brainstem leads to cardiopulmonary arrest.

Question 6

communicating hydrocephalous

Answer 6

causes:
1. ) increased CSF production from a choroid plexus papilloma
2. ) Obstruction of CSF reabsorption by the arachnoid villi from a tumor, postmeningitic scaring, or subarachnoid hemorrhage.

Question 7

MC cause of noncommunicating hydrocephalus in newborns

Answer 7

Stricture of aqueduct of sylvius

causes paralysis of upward gaze (parinaud syndrome)

ventricles dilate, head circumference increases (only in newborns)

Question 8

Hydrocephalus ex vacuo

Answer 8

dilated appearance of ventricles when the brain mass is decreased from cerebral atrophy (ex in Alzheimer’s)

Question 9

Normal pressure hydrocephalus

Answer 9

Wet, wachy, wobbly (due to stretching of fibers near the ventricle)
Dilated ventricles, but normal CSF pressure

causes: idiopathic, prior subarachnoid hemorrhage, prior trauma, prior intracranial surgery

Question 10

Arnold-Chiari malformation

Answer 10

extension of the medulla and cerebellar vermis through the foramen magnum, usually results in hydrocephalus

associated with meningomyelocele (meninges and spimal cord) and syringomyelia

type 1 doesn’t go into the foramen magnum

Question 11

Dandy-Walker malformation

Answer 11

partial or complete absence of the cerebellar vermis
cystic dilation of the forth ventricle
noncommunicating hydrocephalus

Question 12

Syringomyleia

Answer 12

Cystic degeneration of the spinal cord, usually at C8-T1 (loss of pain and temp in the upper extremities, “cape-like distribution”)
damage to anterior white commissure- loss of pain and temperature sensation
If it expands to the anterior horns –> muscle atrophy and weakness

Question 13

Difference between syringomyleia and ALS

Answer 13

No sensory changes in ALS

Question 14

Neurofibromatosis 1

Answer 14

mutation on chromosome 17 for neurofibromin (tumor suppressor)

associated with: Cafe au late spots,optic gliomas, astrocytomas, pheochromocytoma, wilm’s tumor, axillary and ingunial freckling, pigmented plexiform nuerofibromas

Question 15

neurofibroma

Answer 15

benign nerve sheath tumor in the peripheral nervous system

Question 16

pigmented plexiform nuerofibromas

Answer 16

(only in NF1) - involve large nerve, can appear in children, can become cancerous

Question 17

pigmented cutaneous/subcutaneous neurofibromas

Answer 17

occur in NF1 and NF2
These Benign tumors grow from small nerves in the skin or just under the skin and appear as small bumps typically beginning around the time of puberty.
occur anywhere except for palms or soles

Question 18

Neurofibromatosis 2

Answer 18

mutation on chromosome 22 coding for merlin (tumor supressor gene)

associated with:
1.) Bilateral acoustic neuromas (SWANNOMA >90% of cases), benign CN VIII presenting with tumorsensorineural hearing loss

2. ) Meningiomas
3. ) Spinal schwannomas
4. ) juvenile cataracts

Question 19

Tuberous sclerosis

Answer 19

2nd most common neurocutaneous syndrome (phakomatoses)

1. ) mental retardation and seizures begining in infancy
2. ) Angiofibromas (adenoma sebaceum) on the face
3. ) shagreen patches or ash leaf spots (hypopigmented skin lesions, seen with wood lamp)
4. ) Angiomyolipomas in the kidney’s
5. ) Rhabdomyoma in the heart

Question 20

cerebral contusion

Answer 20

permanent damage to small blood vessels on the surface of the brain
usually secondary to acceleration deceleration injury
usually seen at the tips of the frontal and temporal lobes

Question 21

Epidural hematoma

Answer 21

fracture of temporalparietal bone causes severance of the middle meningeal artery
lucid interval may precede neurologic signs

Question 22

Subdural hemotoma

Answer 22

• bleeding btw the dura and the arachnoid membranes. -Bridging veins are torn ( conditions causing decreased brain mass increase the traction on the brides increasing the likelihood of a subdural hemotoma, e.x. elderly persons or alcoholics)
• Usually due to blunt trauma or coagulation deficiency
• consciousness level fluctuates, presents with progressive neurologic signs

Question 23

Global hypoxic injury

Answer 23

causes: cardiac arrest, hypovolemic shock, septic shock, chronic CO poisoning, (hypoglycemia can also present similarly)

Signs: cerebral atrophy is caused by apoptosis in layers 3,5&6 (neurons are most susceptible to hypoxic damage), produces laminar necrosis
Red neurons
Watershed infarcts

Question 24

Lacunar strokes

Answer 24

occur secondary to hyaline arteriolosclerosis (occurs with benign HTN or Diabeties). usually involves the lenticulostriate vessels.

• involvement of the internal capsule leads to a pure motor stroke
• involvement of the thalamus leads to a pure sensory stroke

Question 25

intracerebral hemorrhage

Answer 25

Classically due to rupture of Charcot-Bouchard microaneurysms of the lenticulostriate vessels (complication of HTN) Basal ganglia is the most common site symptoms: severe headache, nausea, vomiting, and eventual coma

Question 26

Subarachnoid Hemorrhage

Answer 26

Worst headache of my life, and nuchal rigidity lumbar puncture shows xanthochromia ( yellow hue due to bilirubin) usually due to berry aneurysm

Question 27

Berry aneurysm

Answer 27

thin walled saccular outpouchings that lacka media layer usually located at the anterior circle of Willis at branch point of anterior communicating artery associated with: Marfan syndrome and autosomal dominant polycytic kidney disease

Question 28

Thrombotic stroke locations

Answer 28

MC is middle cerebral artery | also internal carotid artery near the bifurcation

Question 29

Gliosis

Answer 29

reaction to injury to infarct astrocytes proliferate at the margins of the infarct microglial cells remove lipid debris cystic area area develops after 10 days to 3 weeks due to liquefactive necrosis

Question 30

Retinal TIA

Answer 30

amaurosis fugax, caused by microembolism of atherosclerotic material (Hollenhorst plaque) to a bifurcation of retinal arteries

Question 31

Strokes involving the Middle Cerebral Artery (MCA)

Answer 31

contralateral hemiparesis and sensory loss in the face and upper extremity expressive aphasia head and eyes deviate twds the side of the lesion

Question 32

Strokes involving the Anterior Cerebral Artery (ACA)

Answer 32

contralateral hemiparesis and sensory loss in the lower extremity

Question 33

Strokes involving the vertebrobasilar arterial system

Answer 33

Ataxia, vertigo Ipsilateral sensory loss in the face Contralateral hemiparesis and sensory loss in the trunk and limbs

Question 34

MC cause of viral meningitis

Answer 34

enterovirus, ex. coxsackievirus, poliovirus and echoviruses

Question 35

MC cause of neonatal meningitis

Answer 35

Group B strep

Question 36

MC cause of meningitis in adults

Answer 36

Streptococcus pneumoniae

Question 37

MC fungal CNS infection in AIDS

Answer 37

Cryptococcus neoformans causes both meningitis and encephalitis

Question 38

MC space-occupying lesion in AIDS

Answer 38

Toxoplasma gondii Ring enhancing lesion on CT causes Encephalitis

Question 39

Multiple Sclerosis

Answer 39

MC demyelinating disease Episodic course punctuated by acute relapses and remissions (80%-90% of cases) 1. ) Sensory dysfn 2. ) UMN dysfn 3. ) Autonomic dysfn ( urge incontinence[hyperactive detrusor muscle], bowel dysfn, sexual dysfn) 4. ) optic neuritis (blurry vision) 5. ) Cerebellar ataxia 6. ) Scanning speech 7. ) Intention tremor 8. ) Bilateral internuclear ophthalmoplegia (demyelination of MLF (slow progressive inability to move the eyes and eyebrows) 9. ) Flexion of the neck produces an electrical sensation down the spine

Question 40

Multiple Sclerosis Pathogenesis

Answer 40

1.) CD4 TH1 cells secrete interferon gamma, which activates macrophages--> produce TNF alpha TH17 cells release cytokines that recruit neutrophils and monocytes (type IV HSR) 2.) Antibodies produced against the myelin sheath & the oligodendrocytes (type II HSR)

Question 41

Multiple sclerosis microscopic findings

Answer 41

associated with: HLA-DR2 demyelinating plaques occur in white matter of brain/spinal cord Inflammatory infiltrate in plaques is composed predominantly of CD4 T cells, monocytes and microglial cells with phagocytosed lipid.

Question 42

Multiple sclerosis lab findings

Answer 42

Increased CSF leukocyte count (primarily C lymphocytes/monocytes) Increased CSF protein (from the gamma globulin)

Question 43

Central pontine myelinolysis

Answer 43

most often occurs in alcoholics who have hyponatremia | Rapid IV correction causes demyelination in the basis pontis

Question 44

Adrenoleukodystrophy

Answer 44

Enzyme deficiency in beta oxidation of fatty acids, cause accumulation of long chain fatty acids and subsequent loss of myelin in the brain and adrenal insufficiency X-linked recessive disorder

Question 45

Krabbe Disease

Answer 45

Galactocerebroside Beta-galactocerebrosidase defiency Brain shows large mutlinucleated, histiocytic cells (globoid cells) Autosomal recessive

Question 46

Sporadic early onset Alzheimer disease

Answer 46

related to apolipoprotein gene E allele e4

Question 47

Familial early-onset Alzheimer disease

Answer 47

mutation of amyloid precursor protein (APP) on chromosome 21 mutations in presenilin 1 on chromosome 14 mutations in presenilin 2 on chromosome 1

Question 48

Beta-amyloid (ABeta) and Alzheimers

Answer 48

Wnt activates GSK Activation of glycogen synthase kinase-3Beta (GSK) causes phosphorylation of ABeta--> neuronal and synaptic dysfn as well as positive feedback to GSK ABeta also deposits on the walls of cerebral vessels (amyloid angiopathy) Abeta stains positive with Congo Red Abeta is a metabolic product of APP. Alpha secretases cleave APP into fragments that cannot produce Abeta. Beta-secretases followed by gamma-secretases cleave APP into fragments that are converted to ABeta Insulin degrading enzyme is involved in the clearance of ABeta so those with DM2 have increased risk for Alzheimers disease.

Question 49

tau protein

Answer 49

normal function is to maintain microtubules in neurons. Activation of GSK causes hyperpolarization of tau, which results in nuerofibrillary tangles--> neuronal dysfn and death

Question 50

Gross and microscopic findings of Alzheimer Disease

Answer 50

Hydrocephalus ex vacuo Neurofibrillary tangles Senile (neuritic) plaques (core of ABeta surrounded by cell processes containing tau protein, microglial cells, and astrocytes amyloid angiopathy (increased risk for cerebral hemorrhage)

Question 51

Parkinsonism causes

Answer 51

1. ) idiopathic 2. ) Encephalitis, ischemia 3. ) CO poisoning (necrosis of globus pallidus) 4. ) Wilson Disease (copper not properly eliminated) 5. ) Addition to MPTP 6. ) Antipsycholtic drugs

Question 52

Parkinson disease

Answer 52

- degeneration/ depigmentation of neurons in the substainia nigra - neurons contain intracytoplasmic, eosinophilic bodies called lewy bodies (ubiquinated damaged neurofilaments)

Question 53

Clinical findings in parkinsons

Answer 53

``` cogwheel rigidity bradykinesia (slowness of voluntary movement) Resting tremor (ex pill rolling) Expressionless face Seborrheic dermatitis dementia (in some) ```

Question 54

Huntington's disease

Answer 54

CAG repeat on chromosome 4 Autosomal dominant Atrophy of striatal neurons ( caudate, putamen)

Question 55

Clinical findings in Huntington's disease

Answer 55

Chorea (irregular rapid nonstereotyped movements) Oculomotor abnormalities Parkinsonism in later stages Depression

Question 56

Friedreich ataxia

Answer 56

GAA repeat leads to frataxin deficiency --> impaired mitochondrial iron hemostasis makes cell more prone to apoptosis Sites of degeneration: dorsal root column posterior columns, spinocerebellar tract, lateral corticospinal tracts, large sensory peripheral neurons

Question 57

Clinical Findings in Friedreich ataxia

Answer 57

progressive gait ataxia loss of deep tendon reflexes loss of vibratory sensation and proprioception muscle weakness in the legs

Question 58

Amyotrophic lateral sclerosis

Answer 58

Degenerative disease of upper and lower motor nuerons due to a misfolded Superoxide dismutase (SOD) 1 leading to apoptosis

Question 59

Clinical findings in ALS

Answer 59

spasticity (UMN) weakness and eventual paralysis of respiratory muscles (LMN) NO sensory changes Preserved bowel and bladder function

Question 60

Wilson disease

Answer 60

defect in copper excretion in bile defect in the incorportation of copper into ceruloplasmin leads to liver cirrhosis (through the fenton reaction) and excess free copper in the blood CNS findings: Atrophy and cavitation of the basal ganglia sings of parkinsonism, chorea and dementia

Question 61

Acute Intermittent porphyria

Answer 61

Deficiency of uroporphyrinogen synthase proximal increase in PBG and ALA exposure to light oxidizes PBG to porphobilin producing port-wine color clinical presentation: recurrent sever abdominal pain, psychosis, peripheral neuropathy, dementia

Question 62

Vitamin B12 deficiency

Answer 62

posterior column and lateral corticospinal tract demylination clinical presentation: dementia, peripheral neuropathy

Question 63

Wernicke-Korsakoff syndrome

Answer 63

usually due to a thiamine deficiency (B1) hemorrhages of small vessels with hemosiderin deposits in the mammillary bodies and walls of the third and the forth ventricles neuronal loss gliosis and hemorrhages clinical presentation:confusion, ataxia, nystagmus, opthalmoplegia