Neuropathology 2 Flashcards
What is chorea?
Diseases associated?
Involuntary, jerky, purposeless movements that arise from basal ganglia lesions
Inherited disorders: HD, Neuroacanthocytosis, Wilson’s disease
Infectious - strep infection - rheumatic fever
Drug induced chorea - neuroleptics (phenothiazines, haloperidol), phenytoin, oral contraceptives in women with SLE, L-dopa and DA agonists, cocaine
What is athetosis
Not fixed, snake like writhing, especially of the fingers
Basal ganglia lesions, antipsychotics e.g. haloperidol
What is hemiballismus? Causes
Treatments?
Sudden, uncontrolled flailing of one limb due to lesions in contralateral STN (subthalamic nucleus)
Interrupts inhibitory indirect pathway
Treatments: Haloperidol, phenothiazine
Broca’s aphasia?
Motor/nonfluent/expressive aphasia - occurs in inferior frontal gyrus, brodmann 44, patients are nonfluent, with good comprehension, impaired repetition, speak in short monosyllabic words, aware of deficit, frustrated
Assoc. contralateral arm and face weakness
Lesions in superior left MCA
Wernicke’s aphasia?
Superior temporal gyrus, brodmann 22,
Sensory/fluent/auditory aphasia - with impaired comprehension, neologisms, paraphasic errors, and impaired repetition
Speech is fluent but nosensicl ‘word salad”
Unaware of deficit
Assoc. visual deficit, contralateral RU quadrantanopia, due to meyer’s loop in temporal lobe, alexia
Conduction aphasia?
Lesions to arcuate fasciculus that connects the two language centers, poor repetition with intact comprehension and fluent speech
Cannot name objects
Global aphasia?
Both speech and comprehension affected, large perisylvian or separate frontal and temporal lesions
Assoc. right hemiplegia, right hemianesthesia, and homonymous hemianopia
Degenerative diseases
Classic symptoms with cerebrum lesions?
CST? Basal ganglia? cerebellum?
CST - motor deficits
Cerebrum - personality changes, memory loss, seizures cognitive dysfunction
Basal ganglia -movements disorders
Spinocerebellar/cerebellum lesions - manifest in ataxia
Name 3 diseases associated with motor neuron lesions?
- ALS
- Werdnig-Hoffman syndrome (floppy baby)
- Poliomyelitis
What is ALS? Features?
- Amyotrophic Lateral Sclerosis - associated with UMN and LMN signs sparing sensation, 40-60 years age of onset, assoc. chr. 21, SOD1 gene
- UMN signs - spasticity, +Babinski, hyperreflexia
- LMN signs - thenar atrophy, muscle weakness, denervation atrophy
- Rapidly fatal due to resp. failure - use Riluzole to delay ventilator/tracheostomy use
What is Werdnig-Hoffman disease?
Features? Pathology?
- Autosomal “recessive inheritance that manifests at birth as “floppy baby syndrome”
- Tongue fasciculations, LMN disease
- Degeneration of anterior horn cells
- no UMN, or CST degeneration
- congenital variant of ALS with only LMN signs
- Defect in gene turns of peri-natal apoptosis
- Median age of death - 7 years
Poliomyelitis? features? causes? treatment?
-Follows infection (fecal-oral) with poliovirus
Replicates in oropharynx and small intestine before hematologic spread to CNS, presents with LMN signs
-CSF with lymphocytic pleocytosis, slight increase in protein
-virus recovered from stool or throat
-Degeneration of anterior horn cells
-Treatment: hospitalize with strict bed rest to reduce paralysis, ventilation to treat resp. muscle weakness
Alzheimer’s disease? features? presentation?
- Slow progressive mental deterioration with loss of short term memory, anosmia, language difficulties and planning skills, decline in executive function
- Spares primary sensory and motor areas
- Generalized cerebral atrophy –> widened sulci, hydrocephalus ex vacuo
- Most common dementia in elderly
Alzheimer’s disease? Inheritance?
- Familial form (10%) associated with early onset (before 40 yrs)
- Genetic causes - presenilin 1 and 2 on chr. 1 and 14 - causing hyperphosphorylated tau and neurofibrilliary tangles, APOE4 allele on chr. 19, p-APP on chr. 21
- p-APP increases amount of APP, trisomy 21 is assoc. with early -onset AD (30-40 yrs)
Alzheimer’s disease? Pathology?
- senile plaques (Beta-amyloid surrounded by dystrophic neuritis in extracellular space
- neurofibrillary tangles (intracellular abnormal tau protein, silver stain positive)
- Beta-amyloid is toxic when deposited on neurons and cerebral blood vessels (cerebral amyloid angiopathy) causing intracranial hemorrhage
- decreased ACh due to loss of cholinergic nuclei in forebrain nucleus basalis of Meynert
Alzheimer’s disease? Treatment?
- Donezepil - ACE inhibitors that cross BBB
- NMDA receptor antagonists - memantine reduce glutamate -mediated excitotoxicity
- Not disease modifying
Name 3 diseases assoc. with cerebral cortex lesions?
- Alzheimer’s Disease
- Pick’s disease
- Vascular dementia (multi-infarct)
Pick’s disease? features? pathology? treatment?
- First sign is personality changes (disinhibition, dementia, impaired judgement, with aphasia)
- Frontal -temporal atrophy with gliosis, loss of white matter
- Has aspects of AD but with early onset (
Multi-infarct (vascular dementia) -features?
-2nd common cause of dementia
-Progressive, stepwise decline in functioning (instead of gradual cause in AD)
secondary to atherosclerosis
-Treatment underlining vascular cause, stroke prevention
Name 4 diseases associated with Basal ganglia lesions?
- Huntington’s disease
- Parkinson disease
- Wilson’s disease
- Dementia with Lewy bodies (DLB)
Huntington’s Disease: Features?
-Autosomal dominant with complete
penetrance
-Progressive devo. of athetoid chorea in all
four limbs (writhing), dementia, and
emotional disturbances. Onset at
35-45 years with anticipation.
-Atrophy of the caudate (head)
and putamen-- lateral
ventricles enlarged ("bat-wing" frontal horns).
-Hydrocephalus ex vacuo
-spared memoryHuntington’s disease: Pathology?
-Atrophy of striatum –> loss of
medium spiny (GABAergic) neurons
-Expansion of CAG triplet repeats
(polyglutamine) in huntingtin
gene on chr. 4 –>aggregation of mutant huntingtin – toxic
-Expansion of CAG repeats (anticipation).
Caudate loses ACh and GABA.
Huntington’s disease: Treatment?
-Symptomatic treatment with
haloperidol effective in
suppressing movement disorder
-Incurable, progressive decline, death in 15-20yrs, increase rates of suicide
-allele more unstable during spermatogenesis
Parkinson disease: Clinical features?
Tremors Rigidity Akinesia/bradykinesia Postural instability Shuffling gait Expressionless face, flat affect Dementia (late) -en bloc turning -small handwriting
Parkinson disease: Pathology
-Degenerative disorder of CNS associated with Lewy bodies (composed of α-synuclein—intracellular eosinophilic inclusions and loss of dopaminergic neurons (i.e., depigmentation) of substantia nigra pars compacta.
Parkinson Disease: Treatment
BALSA:
Bromocriptine - DA agonist
Amantadine -increase DA release, decrease DA reuptake
Levodopa (with carbidopa) —carbidopa
blocks peripheral conversion of l-DOPA
to dopamine by inhibiting DOPA decarboxylase.
Selegiline (and COMT inhibitors) -blocks conversion of dopamine into 3-MT by selectively inhibiting MAO-B.
Antimuscarinics - Benztropine, improves
tremor and rigidity
Wilson’s disease: pathology?
-(hepatolenticular degeneration) results from
autosomal recessive mutations in a membrane-bound copper transporter that overwhelms copper capacity because of an inability to
excrete copper into bile.
-Copper is deposited in the putamen and
globus pallidus, liver, eyes
-liver biopsy and copper quantification
Wilson’s disease: Features
Characterized by: -Decreased -Ceruloplasmin -Cirrhosis -Corneal deposits (Kayser-Fleischer rings), -Copper accumulation -Carcinoma (hepatocellular) -Hemolytic anemia -Basal ganglia degeneration (parkinsonian symptoms) -Asterixis -Dementia, Dyskinesia, Dysarthria “Copper is Hella BAD.”
Wilson’s disease: tx?
-Zinc, penicillamine (copper chelator) \+ pyridoxine to prevent anemia effective at preventing progression of neurologic symptoms; low-copper diet. -Liver transplant
Dementia with Lewy bodies: features? tx?
-Initially dementia and visual hallucinations
(“haLewycinations”) followed by parkinsonian
features.
-α-synuclein defect (Lewy bodies, primarily
cortical) -substantia nigra, limbic system, NBM
-Selegiline and other MAO inhibitors
Progressive Supranuclear Palsy: features?
-widespread neuronal loss and subcortical gliosis that notably spares the cerebral and cerebellar cortices
-Presents in 60s, difficulty in vertical movement of gaze, pseudobulbar palsy (dysarthria, dysphagia, hyperactive jaw jerk and gag
reflexes, and uncontrollable laughing or crying unrelated to emotional state)
-axial dystonia with repeated falls, and bradykinesia without resting tremor
(“atypical Parkinsonism”) .
-Memory and intellect intac
-prominent neurofibrilliary tangles
Friedreich ataxia? features?
-Autosomal recessive trinucleotide repeat disease (GAA) involving frataxin gene, with onset of symptoms in the first decade of life.
-Loss of proprioception, decreased
deep tendon reflexes, positive Babinski sign.
Friedreich ataxia? associations?
-Associated with myocarditis, hypertrophic cardiomyopathy, scoliosis, hearing/vision impairment, and high plantar arches (pes cavus).
Friedreich ataxia? pathology?
- “Atrophy of spinal cord,” diffuse damage to dorsal columns, spinocerebellar tracts, and lateral corticospinal tracts.
- poor prognosis, no definitive treatment
Multiple sclerosis: presentation?
-Autoimmune inflammation and demyelination
of CNS (brain and spinal cord).
-Patients can present with optic neuritis (sudden loss of vision resulting in Marcus Gunn pupils), INO, hemiparesis, hemisensory symptoms, bladder/ bowel incontinence.
-Relapsing and remitting
course.
-Most often affects women in their
20s and 30s; more common in whites living
further from equator.
MS: Classic triad? tx?
Charcot classic triad of MS is a SIN: ---> Scanning speech ---> Intention tremor (also Incontinence and Internuclear ophthalmoplegia) ---> Nystagmus
Tx: Slow progression with disease-modifying therapies (e.g., β-interferon, natalizumab).
-Treat acute flares with IV steroids.
MS: Findings
-Increased protein (IgG) in CSF.
-Oligoclonal bands are diagnostic.
-MRI is gold standard. Periventricular
plaques (areas of oligodendrocyte loss and reactive gliosis) with destruction of axons. -Multiple white matter lesions separated in space and time.
Acute inflammatory
demyelinating
polyradiculopathy (AIDP): features?
-Most common subtype of Guillain-Barré
syndrome. Autoimmune condition that
destroys Schwann cells –> inflammation
and demyelination of peripheral nerves and
motor fibers.
-Results in symmetric ascending muscle weakness/paralysis beginning in lower
extremities.
Acute inflammatory
demyelinating
polyradiculopathy (AIDP): findings? assoc.? tx?
-Findings: increased CSF protein with normal cell count
(albuminocytologic dissociation). protein
may cause papilledema
-Associated with infections (e.g., C. jejuni, viral) –> autoimmune attack of PNS myelin due to molecular mimicry, inoculations, and stress, but no definitive link to pathogens.
-Respiratory support is critical until recovery.
-Additional treatment: plasmapheresis, IV
immunoglobulins.
—— viruses causes these ——- demyelinating diseases
- Viral infection of oligodendrocytes is the key feature of subacute sclerosing panencephalitis (measles paramyxovirus) and progressive multifocal leukoencephalopathy (JC virus).
— (disease) affects only white matter, — affects both white and gray matter, — affects only gray matter
- Only white matter is affected in PML (Progressive Multifocal Leukoencephalopathy) -subacute sclerosing panencephalitis, affects both white and gray matter -rabies, affects only gray matter.
