Pathology - S2B4 - Neuro 6

Front 1

Describe Type I muscles fibers

Back 1

Slow-twitch (red) fibers

rich in Mitochondria & Oxidative enzymes

Front 2

Describe Type II muscle fibers

Back 2

Fast-twitch (white) fibers

Poor in Mitochondria

Front 3

What determines the type of fiber a myocyte contains?

Back 3

Motor neuron

Front 4

Define Neurogenic Atrophy

Back 4

disease of the Anterior Horn cell or its axon

Front 5

Describe the pathology seen in Neurogenic Atrophy

Back 5

Initial: individual atrophic angular fibers

Later: Groups of atrophic angular fibers

Front 6

Neurogenic Atrophy

Back 6

What is seen here?

Front 7

What helps in diagnosis Neurogenic Atrophy?

Back 7

Fiber typing = after reinnervation, a cluster of Type I fibers are adjacent to a cluster of Type II fibers

Front 8

Fiber-typing used to diagnose Neurogenic Atrophy

Back 8

What is seen here?

Front 9

What diseases can cause Neurogenic Atrophy?

Back 9

1. ALS
2. Vasculitis
3. Trauma
4. Nerve compression (spinal cord disease)

Front 10

List 3 Inflammatory Myopathies

Back 10

1. Dermatomyositis
2. Polymyositis
3. Inclusion Body Myositis

Front 11

Dermatomyositis
-perifascicular pattern of injury

Back 11

What is seen here?

Front 12

What is the clinical presentation of Dermatomyositis?

Back 12

Rash + weakness + muscle pain

*has an association with Cancer (Lung CA)

Front 13

What is the immune target of Dermatomyositis? What is it mediated by?

Back 13

Capillaries

Antibodies + Complement

Front 14

Polymyositis = lack of skin involvement
-Endomysial process
-inflammation tends to occur within the meat of muscle
-nuclei are also sometimes not at the periphery

Back 14

What is seen here?

Front 15

Inclusion Body Myositis
-rimmed vacuoles that may contain Beta-amyloid & tau within

Back 15

What is seen here?

Front 16

Describe the clinical features of Inclusion Body Myositis

Back 16

1. occurs in Distal muscles first
2. Older subjects
3. Resistant to therapy = not responsive to steroids
4. Rimmed vacuoles

Front 17

pathology of Dystrophies
-fiber size variation
-increased central nuclei
-degeneration, necrosis
-regeneration
-fibrosis

Back 17

What is seen here?

Front 18

Describe the pathology of Dystrophy

Back 18

1. Fiber size variation
2. increased central nuclei
3. degeneration, necrosis
4. regeneration
5. fibrosis

Front 19

Dystrophy characterized by X-linked inheritance with a mutation in the dystrophin gene

Back 19

Duchenne & Becker Muscular Dystophy

Front 20

Central Core Disease (congenital myopathy)
-central pallor
-disorganized sarcomeres with deficiency of ATPase

Back 20

What is seen here?

Front 21

Nemaline Myopathy (congenital myopathy)
-Rod-like inclusions derived from the Z-disc

Back 21

What is seen here?

Front 22

Myotubular (Centronuclear) Myopathy
-desmin, loss of myofibrillar material (EM)

Back 22

What is seen here?

Front 23

Mitochondrial Myopathy
-aggregates of abnormal mitochondria
-Ragged red fibers
-Cytochrome oxidase negative fibers

Back 23

What is seen here?

Front 24

-aggregates of abnormal mitochondria
-Ragged red fibers
-Cytochrome Oxidase negative fibers

Back 24

Mitochondrial Myopathy

Front 25

Mitochondrial Myopathy

Proximal weakness
-other neurological symptoms
-lactic acidosis
-Cardiomyopathy

Back 25

What disease is this? What does it cause?