Path: Demyelinating/Neurodegenerative and Metabolic Dz Flashcards
What are the signs of Wernicke encephalopathy; caused by?
How can it be alleviated?
- Thiamine (B1) deficiency
- Acute; psychotic symptoms or opthalmoplegia
- May reverse w/ Thiamine
Mutations in the gene encoding ______ are a more common cause of autosomal dominant PD
LRRK2 (leucine-rich repeat kinase 2)
In the absence of a toxic or other known etiology the presumptive diagnosis of PD can be based on the presence of the central triad of parkinsonism, which includes?
How is this diagnosis confirmed?
1) Tremor
2) Rigidity
3) Bradykinesia
- Confirmed by symptomatic response to L-DOPA replacement therapy
Why is severe cognitive impairment not a usual feature of MS?
Gray matter is relatively spared
When is the onset of Ataxia-Telangiectasia?
What are the common symptoms?
- Ataxic-dyskinetic syndrome beginning in early childhood w/ recurrent sinopulmonary infections and unsteadiness in walking
- Later on, dysarthria and eye movement abnormalities
- Subsequent development of telangiectasias in the conjunctiva and skin along w/ immunodeficiency
B12 deficiency causes what?
- Subacute combined degeneration of the spinal cord –> defect in myelin formation
- Degeneration of both ascending and descending spinal tracts
Which disease is characterized by extrapyramidal rigidity, asymmetric motor disturbances (jerking movements of limbs), and imparied higher cortical functioning?
Corticobasal Degeneration (CBD)
What chromosome is the HTT gene encoding the protein huntingtin found on?
Chromosome 4p16.3
What is the characteristic pattern of atrophy seen in Pick disease?
- Asymmetric, atrophy of the frontal and temporal lobes w/ sparing of the posterior 2/3 of superior temporal gyrus
- Reduction of gyri to a wafer-thin (“knife-edge”) appearance
Central pontine myelinolysis (aka osmotic demyelination disorder) most commonly arises when?
- 2-6 days after rapid correction of hyponatremia
- Low to high, the pons will die
What is the diagnostic hallmark of PD and what is the major component of this diagnostic indicator?
Lewy body; major component is α-synuclein
What is the clinical presentation of Central pontine myelinolysis (aka osmotic demyelination disorder)?
- Rapidly evolving quadriplegia, which may be fatal
- “Locked-in” syndrome, in which patients are fully conscious yet unresponsive
Cerebral amyloid angiopathy (CAA) is an almost invariable accompaniment of _______
AD
Which chromosome is the mutated ATM gene associated with Ataxia-Telangiectasia located on?
Function of this gene?
- Chromosome 11q22-q23
- Encodes kinase critical for repair of double-stranded DNA breaks
- Fails to remove cells with DNA damage
Which missense mutation and on what gene is the most common cause of ALS in the US?
A4V mutation of SOD1 on chromosome 21
Structures of which lobe are involved earliest in the AD and are usually severely atrophied in the later stages?
Medial temporal lobe, including hippocampus, entorhinal cortex and amygdala
Diffuse plaques seen in AD have no _____ and are predominantly made up of Aβ____
Diffuse plaques seen in AD have no amyloid core and are predominantly made up of Aβ 42
Loss of axons and gliosis are seen where in Friedreich Ataxia?
- Posterior columns
- Corticospinal tracts
- Spinocerebellar tracts
Friedreich ataxia is associated with what expansion?
GAA trinucleotide repeat of gene on chromosome 9q13 that encodes frataxin
What is seen morphologically in an active plaque of a patient with MS?
- Abundant macrophagescontaininglipid-rich, PAS-positive debris
- Perivascular (small veins) inflammatory infiltrate (mononuclear) at outer edge of plaqe
- Relative preservation of axons within plaque and depletion of oligodendrocytes
Accumulation of what is seen in FTLD-tau?
- Accumulation of tau and NOT Aβ are characteristic
- Smooth contoured inclusions —> Pick bodies
When is the onset of Friedreich Ataxia and how does it manifest?
How do the symptoms progress and what do most affected individuals develop?
- First decade of life beginning with gait ataxia, followed by hand clumsiness and dysarthria
- DTRs are depressed or absent, but extensor plantar reflex is typically present
- Joint position and vibratory senses impaired
- Most will develop pes cavus and kyphoscoliosis
- Cardiomyopathy later in life associated w/ arrhythmia and CHF
What is progressive musclar atrophy vs. primary lateral sclerosis in terms of findings in patients w/ ALS?
- Progressive muscular atrophy: applied to uncommon cases where LMN involvement predominates
- Primary lateral sclerosis: cases where UMN involvement predominates
What is the age of onset most commonly seen with Huntington Disease?
Fourth and fifth decades (30-50 yo)
A higher number of (plaques/tangles) correlates better with the degree of dementia seen in AD?
Number of neurofibrillary tangles correlates better with the degree of dementia
What are Pick Cells vs. Pick Bodies?
How do Pick bodies stain?
- Pick cells = swollen cells
- Pick bodies = cytoplasmic, round to oval, filamentous inclusions that are weakly basophilic and stain strongly with silver
What is Bergmann gliosis and who is it seen in?
- Advanced cases of chronic alcoholism
- Loss of purkinje cells and proliferation of adjacent astrocytes = Bergmann gliosis
Single or multiple cytoplasmic, eosinophilic, round to elongated inclusions that often have a dense core surrounded by a pale halo describes what feature found in PD?
Lewy Bodies
Inclusions containing SOD1, TDP-43, and FUS are associated with that neurodegenerative disease?
ALS
Which MHC halotype increases risk for developing MS?
HLA-DR2
Wernicke encephalopathy is characterized by foci of hemorrhage and necrosis where?
With time there is infiltration by?
- Mammillary bodies and walls of the 3rd and 4th ventricles
- Hemosiderin-laden macrophages
Metachromatic Leukodystrophy can be observed using what stain?
What is a sensitive method of establishing diagnosis?
- Toluidine blue
- Metachromatic material in the urine = sensitive
What is the most severe form w/ the earliest onset of Spinal Muscular Atrophy?
Onset and prognosis?
- SMA type 1, Werdnig-Hoffmann disease
- Onset during first year of life w/ death by 2
What type of hydrocephalus may be seen with AD?
Hydrocephalus ex vacuo
Which neurodegenerative disorder is characterized by loss of myelin in a roughly symmetric pattern involving the basis pontis and portions of the pontine tegmentum, including myelin loss WITHOUT evidence of inflammation?
Central pontine myelinolysis (aka osmotic demyelination disorder)
Which condition is characterize by synchronous bilateral optic neuritis and spinal cord demyelination?
Neuromyelitis optica (aka Devic disease)
Demyelinating diseases of the CNS are acquired conditions characterized by preferential damage to ________ w/ relative preservation of ______.
Demyelinating diseases of the CNS are acquired conditions characterized by preferential damage to myelin w/ relative preservation of axons.
Which Ig is found in increased levels in the CSF of patients with MS?
What is seen on immunoelectrophoresis?
- IgG
- Oligoclonal IgG bands
What is the prognosis of Huntington Disease?
Relentlessly progressive and uniformly fatal, average course of 15 years
Which T cells are the major players in causing damage to the myelin in persons w/ MS?
CD4+ TH1 and TH17
Which chromosome contains the ApoE locus?
Chromosome 19
Clinical features of PD can be remembered with mnemonic TRAPS, which includes?
T = tremor (“pill rolling” tremor at rest)
R = rigidity
A = akinesia and bradykinesia
P = postural instability (stooped posture)
S = shuffling gait (festinating gait)
Internculear opthalmoplegia (INO) often seen in MS is due to damage to what?
Medial longitudinal fasciculus (MLF)
What is progressive bulbar palsy (Bublar ALS) associated with some patients with ALS?
Prognosis?
- Some pts will have degeneration of the lower brainstem cranial motor nuclei occuring early and rapidly progessing
- Problems with deglutination and phonation dominate; clinical course is inexorable during 1-2 year period; 50% alive at 2 years
Which disease is characterized by distinct episodes of neuro deficits separated in time due to white matter lesion that are separated in space
Multiple Sclerosis
What is commonly found in the CSF of patients with Neuromyelitis Optica?
White cells, often including neutrophils
What are the CSF findings in MS?
- Midly elevated protein
- Moderate pleocytosis in 1/3 cases
- IgG increased