Neuro - Neuromuscular Disease

Question 1

1. Major symptoms of motor unit dysfunction?
2. Where do sympathetic preganglionic nerves arise from? Enter?
3. Where do preganglionic parasympathetic neurons arise? Axons end where?

Answer 1

1. Motor unit dysfunction: muscle weakness, wasting, fatigue, cramps, pain, and stiffness
2. Sympathetic preganglionic arise from IML cell column of SC and enter ganglia; postganglionic innervate BV or viscera
3. Preganglionic parasympathetic neurons arise in the brainstep or sacral SC; axons end in viscera, special sensory organs, and skin where postganglionic cells arise and terminate

Question 2

1. Symptoms of autonomic nerve dysfunction?
2. Symptoms of peripheral nerve disease?

Answer 2

1. Autonomic dysfunction: postural dizziness, impotence in men, abnormal cardiac/visceral/ocular function, changes in sweating, dry eyes/mouth (=sicca syndrome) can be seen in Sjogrens syndrome associated with sensory neuropathy
2. Peripheral nerve disease: decreased sensation (hypesthesia), abnormal sensation (parasthesia), and painful sensation (dyesthesias)

Question 3

Electromyography:

1. What disorders show spontaneous activity?
2. Difference between fibrillation and fasciculation?
3. Denervation motor unit potentials versus myopathy motor units?

Answer 3

Electromyography:

1. Spontaneous activity: myotonic disorders, inflammatory myopathies, and denervated muscle
2. Fibrillation: spontaneous activity of a single muscle fiber - loss of innervation; Fasciculation: spontaneous activity of an entire motor unit - motor neuron disease (anterior horn)
3. Denervation motor unit potentials appear larger and fire faster to produce force; Myopathy motor units are smaller and more are recruited earlier to produce force

Question 4

Repetitive stimulation:

1. What happens in disorders of the neuromuscular junction with repetitive stimulation? What is this seen with?
2. Describe Lambert-Eaton myasthenic syndrome in response to repetitive stimulation.

Answer 4

Repetitive stimulation:

1. NMJ disorders may have normal amplitude but with repetitive stimulation at a great enough rate, the amplitude declines by the 4th stimulus; seen in Myasthenia gravis
2. Lambert-Eaton: the response starts small and increases with repetitive stimulation

Question 5

**Disorders of the anterior horn cell:

1. What is the most common acquired motor neuron disease?
2. Describe the pathology of the disease in question 1.

Answer 5

**Disorders of the anterior horn cell:

1. Amyotrophic lateral sclerosis (ALS) is the most common acquired motor neuron disease
2. ALS has degeneration of BOTH the UMNs and LMNs

Question 6

**Disorders of the anterior horn cell:

1. What is it called if only the upper motor neurons have degenerated?
2. What if only the lower motor neurons are affected?
3. Basic signs of ALS?

Answer 6

**Disorders of the anterior horn cell:

1. UMN - Primary lateral sclerosis
2. LMN - Spinal muscular atrophy (hereditary disorder)
3. ALS - combined signs of spasticity and hyperreflexia and progressive muscle wasting and weakness, no loss of sensation

Question 7

Plexopathy:

1. What is brachial plexopathy?
2. What could cause brachial plexopathy?
3. What is Lumbosacral plexopathy?
4. What causes Lumbosacral plexopathy?

Answer 7

Plexopathy:

1. Brachial: weakness, wasting, pain, and sensory loss in shoulders and arms
2. Brachial: MOST COMMON with auto-immune inflammatory cause but also tumor invasion and radiation necrosis
3. Lumbosacral: pain and weakness in anterior more than posterior thigh
4. Lumbosacral: MOST COMMON in diabetes, malignancy, radiation or hemorrhage. Much less auto-immune

Question 8

**What are sompe patterns of peripheral neuropathy? Causes? (5)

Answer 8

**Patterns of peripheral neuropathy:

a. Symmetric length dependent: diabetes, drugs, toxins, or metabolic causes
b. Symmetric proximal and distal: Acute or chronic inflammatory demyelinating polyradiculoneruopathy (Guillane Barre)
c. Asymmetric nerve or plexus: diabetic amyotrophy, nomoneuritis multiplex, idiopathic
d. Asymmetric unusual: porphyria or leprosy
e. Autonomic unusual: amyloid

Question 9

Mononeuropathies:

1. Nerve of carpal tunnel? Where is ulnar palsy?
2. **What is meralgia paresthetica? Where? What occurs?
3. What is mononeuritis multiplex? Result? Causes?

Answer 9

Mononeuropathies:

1. Carpal tunnel: median nerve; Ulnar palsy: at elbo or wrist
2. **Meralgia paresthetica: MOST COMMON PURE SENSORY NEUROPATHY; from the lateral femoral cutaneous nerve passing under or through the inguinal ligament; often a stretching injury common in obese patients - lateral thigh distribution with intense burning
3. Mononeuritis multiplex: scattered single nerves and could cause foot/wristdrop; can be seen in diabetes, RA, polyarteritis nodosa, or other vasculitidis

Question 10

Polyneuropathies:

1. Most commonly known polyneuropathy?
2. What occurs?
3. Treatment?

Answer 10

Polyneuropathy:

1. Guillain-Barre
2. Weakness typically symmetrically affects limb often in an ascending pattern with a loss of reflexes. Often begins with tingling in the limbs followed by weakness and backpain. May progress rapidly to cause respiratory insufficiency
3. Treatment: plasma exchange or IVIG

Question 11

Hereditary neuropathies:

1. Common hereditary neuropathy? Types?
2. What occurs in each type?
3. “historical” hints? (often misdiagnosed as arthritis or poliomyelitis because of what signs?)

Answer 11

Hereditary neuropathy:

1. Charcot-Marie-Tooth: Type 1 and 2
2. Type 1: due to dysmyelination causing slowing of nerve conduction, high arches, thin calves, distal weakness/numbness, and hammer toes; Type2: milder axonal form
3. Hints: difficulty running, high arched feet, hammer toes, claw hands, wasting of muscles, chronic foot troubles, use of brases, and chronic difficulty walking on heels or toes

Question 12

Diabetic neuropathies:

1. Most commone one?
2. Ophthalmic involvment can cause what?
3. Early signs?

Answer 12

Diabetic neuropathies:

1. Most common: distal symmetric stocking/glove territory
2. Opthalmic involvment is common in CN II/VI = diplopia
3. Early signs: burning/tingling

Question 13

Myopathies:

1. Which are inherited?
2. Which are acquired?

Answer 13

Myopathies:

1. Hereditary: muscular dystrophy, congenital, myotonia, metabolic, mitochondrial
2. Acquired: inflammatory, endocrin/metabolic, associated with systemic illness or drug induced

Question 14

Name several types of muscular dystrophies:

Answer 14

Muscular dystrophies:

a. Duchenne/Becker (dystrophin)
b. Limb girdle - multiple subtypes
c. Fascioscapulo MD
d. Oculopharyngeal MD
e. Myotonic dystrophy TI and TII (myotonin protein kinase most common adult MD)
f. Congenital and distal MDs

Question 15

Congenital myopathy:

1. Defined by?
2. What is seen at birth?
3. Characteristics?

Answer 15

Congenital myopathy:

1. Defined by biopsy appearance
2. At birth: hypotonia (but relatively nonprogressive)
3. Characteristics: decreased muscle bulk, slender build, long narrow face, high arched palate, pectus excavatum, kyphoscoliosis, dislocated hims, pes vacus, slow growth, and absent or decreased deep tendon reflexes

Question 16

Mitochrondrial myopathy:

1. Characteristic biopsy seen?
2. Pathology?
3. Inheritance?

Answer 16

Mitochondrial myopathy:

1. Biopsy: Ragged red fibers (MERRF!!)
2. Slow progressive weakness of proximal limbs and extraocular muscles with abnormal fatigability. May have elevated lactic acid at rest
3. Maternally inherited or autosomal/x linked because 95% of mitochondrial proteins are encoded from nuclear genes

Question 17

Inflammatory myopathy:

1. Examples of types that are idiopathic?
2. Other causes?

Answer 17

Inflammatory myopathy:

1. idiopathic: dermatomyositis, polymyositis, and inclusion body myositis
2. Other: CT diseases (SLE/RA), sarcoid, eosinophilic, and infections (bacterial/viral/parasitic/fungal)

Question 18

Drug induced myopathy:

1. Inflammatory can be caused by?
2. Acute muscular necrosis caused by?
3. Malignant hyperthermia caused by?
4. What else?

Answer 18

Drug induced myopathy:

1. Inflammatory: cimetidine and penicillamine
2. Muscular necrosis: statins, alcohol, and cocaine
3. Malignant hyperthermia: halothane ethylene and succynylcholine
4. Other: AZT, chloroquine, and colchicine

Question 19

DISEASES OF THE SPINAL CORD: HE TOLD US IN CLASS

Question 20

What destroyes cells associated with the anterior SC (UMN)/brainstem and is characterized by ASYMMETRICAL paralysis?

Answer 20

Poliomyelitis

Question 21

Conus medullaris vs. Cauda Equina:

1. Motor weakness symmetry?
2. Sensory loss pattern?
3. Presence/absence of pain?
4. Reflexes?
5. Bowel/bladder issues?
6. Where do cauda equina injuries occur? What is involved? Signs?

Answer 21

Conus medullaris vs. Cauda equina:

1. Motor weakness: CM: symmetric CE: asymmetric
2. Sensory loss: CM and CE: both have saddle pattern
3. Pain: CM: uncommon CE: common
4. Reflexes: CM: increased CE: decreased
5. Bowel/bladder: CM: retention is common CE: not common
6. CE: BELOW L2; LMN signs, anterior horn cells, no longer at cord level, distal nerve roots involved; thigh flexion is preserved

Question 22

Brown Sequard Syndrome:

1. What is it caused by?
2. Result?

Answer 22

Brown Sequard:

1. Caused by cord hemisection due to tumor or trauma
2. Result:
   a. Loss of pain/temp contralateral (1-2 below)
   b. Los of vibration/proprioception ipsilaterally
   c. Weakness and UMN signs (eg. weakness/spasticity) ipsilateral to the lesion