Neuromuscular Disorders Flashcards Preview

Central Nervous System Pathology > Neuromuscular Disorders > Flashcards

Flashcards in Neuromuscular Disorders Deck (15)
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1
Q

Primary Myopathy

A
  • Weakness (proximal > distal; ex: deltoid, ilopsoas, hip flexors)
  • Normal reflexes
  • Normal tone
  • Muscle atrophy may occur with disease progression
2
Q

Neuromuscular Junction Disorder

A
  • Weakness which fatigues → fluctuates throughout the day: Can feel good in the AM, then slur your words later
  • Normal reflexes
  • Normal tone
  • No muscle atrophy
  • e.g., Myasthenia Gravis
3
Q

Peripheral Neuropathy

A
  • These nerves have a motor and sensory component so there will be motor and sensory deficits
  • Longest nerves affected the most
  • Muscle weakness (distal > proximal)
  • Sensory loss (usually a stocking/glove distribution)
  • Parasthesias, dysesthesias (can be very painful or absent feeling)
  • Decreased or absent reflexes
4
Q

Myasthenia Gravis

A
  • Most common NMJ disorder

Mech: Autoantibodies (made in thymus) to postsynaptic Ach receptor

Clinical:

  • Ptosis
  • Diplopia
  • Weakness that worsens with muscle use

Dx: Repetitive stimulation testing

Tx: Acetycholinesterase Inhibitor; Immunosupression; thymectomy

5
Q

Inflammatory Myopathies

A
  • Polymyositis
  • Dermatomyositis
  • Inclusion body myositis
6
Q

Polymyositis

A
  • inflammatory myopathy with Proximal weakness, dysphagia, weakness of neck flexion
  • NO SKIN RASH
  • Inflammatory injury to heart
  • Endomesial inflammation with invasion of non-necrotic fibers
7
Q

Dermatomyositis

A
  • inflammatory myopathy that is similar to polymyositis, but younger onset and more systemic disease
  • WITH SKIN RASH (Heliotrope rash on face)
8
Q

Inclusion body myositis

A
  • inflammatory myopathy that has slowly progressive proximal and distal weakness
  • Involves quads and finger flexors first
  • Late adulthood onset
  • Doesn’t respond to immune modulation therapy
9
Q

Amyotrophic Lateral Sclerosis

A
  • Degeneration of UMN (Lateral corticospinal tract) and lower motor neurons (Anterior motor horn)
  • Mixture of atrophy, hyper- and hyporeflexia, fasciculations
  • Atropy and weakness of hands is an early sign
  • Normal sensation; the lack of sensory impairment distinguishes ALS from syringomyelia (loss of Pain & Temp)
10
Q

Poliomyelitis

A
  • Damage to the anterior motor horn due to poliovirus infection
  • presents with lower motor neuron signs
11
Q

Duchenne’s muscular dystrophy

A
  • X-linked recessive
  • Absence of dystrophin gene: results in muscle wasting and replacement of skeletal muscle with adipose tissue
  • Onset in childhood → delayed walking, calf hypertrophy
  • Toe walking, waddling, lordosis
  • Gower’s sign: use his hands and arms to “walk” up his own body from a squatting position due to lack of hip and thigh muscle strength –> indicates proximal weakness
12
Q

Guillain Barre syndrome

A
  • Acute inflammatory demyelinating polyneuropathy: autoimmune destruction of Schwann cells
  • Ascending paralysis beginning in lower extremities
  • Respiratory compromise
  • Autonomic dysfunction
  • almost all patients survive, with complete recovery after weeks to months
13
Q

Wallerian degeneration

A
  • nerve fiber is cut or crushed from neuron cell body
  • Leads to degeneration of the separated axon distal to the injury
  • Conduction is blocked
14
Q

Segmental demyelination

A
  • loss of myelin around axon
  • Increased distal latency
  • Conduction velocity is reduced
15
Q

Axonal degeneration

A
  • usually due to toxins
  • Results decreased amplitude of signal
  • Speed of conduction is normal