Compressive and Demyelinating Illness

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Questions and Answers

What is the most common cause of unilateral facial paralysis?

Radiculopathy

Sciatica

Meralgia paresthetica

Bell’s Palsy (correct)

Which virus is thought to be responsible for the reactivation leading to Bell’s Palsy?

Hepatitis virus

Herpes virus (correct)

Influenza virus

Human papillomavirus

What is the characteristic clinical feature of Bell’s Palsy?

Gradual onset of symptoms

Bilateral facial paralysis

Vision disturbances

Hyperacusis (increased sensitivity to sound) (correct)

Why is surgery not a primary treatment for Bell’s Palsy?

Ineffective in resolving symptoms Signup and view all the answers

Which of the following is NOT a symptom of Bell’s Palsy?

Blurred vision Signup and view all the answers

What is the proposed mechanism of nerve compression in Bell’s Palsy?

Edema and inflammation Signup and view all the answers

Which population group is more commonly affected by Bell’s Palsy?

Older adults Signup and view all the answers

What percentage of Bell’s Palsy cases tend to resolve spontaneously over time?

>80% Signup and view all the answers

What is the Uhthoff sign associated with in multiple sclerosis (MS)?

Blurry vision Signup and view all the answers

Which symptom is NOT common in MS patients?

Loss of bowel control Signup and view all the answers

What can cause a temporary worsening of neurological function in MS patients?

All of the above Signup and view all the answers

What is a stereotyped worsening of neurological function among MS patients associated with?

Core body temperature increase Signup and view all the answers

Which of the following symptoms is NOT commonly worsened by heat in MS patients?

Constipation Signup and view all the answers

MS patients can experience an "electric shock" running down their back and legs in an unpleasant manner. What is this phenomenon called?

L'hermitte's phenomenon Signup and view all the answers

What is the most common mechanism of injury in central nervous system demyelination?

Autoimmune mechanism affecting oligodendrocytes Signup and view all the answers

Which type of neuropathy involves damage to Schwann cells in the peripheral nervous system?

Guillain-Barre syndrome Signup and view all the answers

What is the main pathophysiologic mechanism involved in nerve compression-related neurological damage?

Vascular injury leading to nerve ischemia Signup and view all the answers

Which term refers to a condition characterized by self-reactive antibodies or T-cells damaging Schwann cells in the peripheral nervous system?

Guillain-Barre syndrome Signup and view all the answers

What defines multiple sclerosis (MS) as an immune-mediated disease in the body?

Autoimmune response directed against the CNS Signup and view all the answers

Which of the following is the most common demyelinating disease?

Multiple sclerosis Signup and view all the answers

What distinguishes between the pathologic appearance of an active and an inactive plaque in central nervous system demyelination?

The inflammatory activity in active plaques Signup and view all the answers

Which condition involves genetic deficits impairing Schwann cells' ability to produce myelin sheaths?

Hereditary sensory and motor neuropathy Signup and view all the answers

What is the typical presentation of Guillain-Barre Syndrome?

Acute polyradiculopathy Signup and view all the answers

What happens to the Schwann cells after 2-3 weeks of demyelination in Guillain-Barre Syndrome?

They begin to proliferate Signup and view all the answers

Which nerve is most at risk of being involved in Guillain-Barre Syndrome if the condition progresses to a life-threatening state?

Phrenic nerve Signup and view all the answers

What is the treatment approach for severe Guillain-Barre Syndrome cases that can progress to loss of function including cervical spinal cord?

Plasmapheresis Signup and view all the answers

What is a common feature of most compressive neuropathies in the peripheral nervous system?

Reduction or loss of motor function Signup and view all the answers

What is a distinguishing characteristic regarding the progression of symptoms in Guillain-Barre Syndrome compared to other conditions?

Ascending muscle weakness Signup and view all the answers

What is the genetic etiology of multiple sclerosis?

HLA-II gene (DRB1/DRB15) responsible for 10% of disease risk Signup and view all the answers

What is a characteristic of inactive plaques in multiple sclerosis?

Loss of axons with limited leukocytic infiltration Signup and view all the answers

What is the role of helper T-cells in the pathogenesis of active plaques in MS?

Recruit cytotoxic T-cells and macrophages into white matter Signup and view all the answers

What do hematoxylin and eosin (H&E) stains show in MS inflammation?

Perivascular infiltration of inflammatory cells Signup and view all the answers

How do acute flares in MS contribute to worsened neurological symptoms?

Attack on white matter components by helper T-cells and cytotoxic T-cells Signup and view all the answers

What is a common feature of active plaques in multiple sclerosis?

Presence of MBP-specific B-lymphocytes producing anti-MBP antibodies Signup and view all the answers

Which immune cells are involved in initiating an immune response against myelin in MS?

$CD4+$ Th cells and B cells Signup and view all the answers

Which of the following is NOT an autoimmune disease?

Charcot Marie Tooth disease Signup and view all the answers

Match the following symptoms with their descriptions in compressive neurological damage:

Weakness or flaccid paralysis = Loss of muscle strength or tone Numbness or anaesthesia = Loss of sensory function resulting in inability to feel touch or pain Tingling or dysaesthesia = Pins-and-needles sensation Urinary retention or erectile dysfunction = Loss of autonomic nervous system function Signup and view all the answers

Match the theories of compressive nerve damage with their descriptions:

Direct mechanical damage to the nerve = Results in loss of axonal function, especially in crush injuries Compression of the vessels in the perineurium = Causes decreased blood flow and reduced nerve function due to ischemia Impingement of the nerve = Inability for the nerve to glide along its course, leading to position-dependent symptoms Compressive defects in axonal transport = Prevent proper transport of proteins from cell body to axon, affecting nerve function Signup and view all the answers

Match the potential consequences of compressive neurological damage with their descriptions:

Death of the nerve = Occurs only in severe cases of direct mechanical damage Survival of the nerve = Usually happens unless compression is severe Decreased blood flow to the nerve = Results from compression of vessels in the perineurium Inability for proper protein transport = Caused by compressive defects in axonal transport Signup and view all the answers

Bell's palsy is caused by compression of _______ nerve

Facial Signup and view all the answers

MS symptoms progress in a gradual manner

False Signup and view all the answers

Guillian Barre Syndrome is characterized by acute and rapid radiculopathy

True Signup and view all the answers

Guillian barre syndrome typically occrus after an ______

infection Signup and view all the answers

Hammer toe is characteristic of.....

Charcot Marie Tooth Disease Signup and view all the answers

______ is a very common feature of most compressive neuropathies

Pain Signup and view all the answers

Study Notes

Here are the study notes:

Demyelinating Diseases

Demyelination can occur in the central or peripheral nervous system
Central demyelination: damage to oligodendrocytes or their processes that myelinate axons, commonly caused by autoimmune mechanisms (multiple sclerosis)
Peripheral demyelination: damage to Schwann cells, commonly caused by genetic deficits or autoimmune mechanisms

Multiple Sclerosis (MS)

Immune-mediated disease directed against the central nervous system
Genetic polygenic etiology: candidate genes include HLA-II gene (DRB1/DRB15) responsible for antigen presentation, and variations in IL-2, IL-7, and IL-17 genes
Other factors: link to viral infections (e.g., Epstein-Barr virus), and reduced vitamin D levels
Pathogenesis: two phases - active plaques (inflammation, demyelination, and axon damage) and inactive plaques (loss of axons, oligodendrocytes, and myelin)
Gross pathology: well-circumscribed, irregularly shaped plaques in white matter areas
Signs and symptoms: vision problems, weakness, numbness, fatigue, heat and activity intolerance, Uhthoff sign
Diagnosis: clinical diagnosis, aided by characteristic lesions on brain and spinal MRI, and presence of certain antibodies in CSF
Treatment and prognosis: no cure, immunomodulators can be used for chronic treatment, steroids for acute flares, prognosis varies depending on the pattern of progression

Guillain-Barre Syndrome

Acute onset immune-mediated demyelinating neuropathy
Pathogenesis: typically occurs after an infection, immune system mistakenly attacks the nerves
Clinical features: acute onset of weakness or flaccid paralysis, loss of autonomic nervous system function, loss of sensory function
Diagnosis, treatment, prognosis: clinical diagnosis, EMG and nerve conduction studies, treatment with plasmapheresis and immunoglobulins, prognosis generally good

Compressive Neurological Damage

Theories of compressive nerve damage: direct mechanical damage, ischemia, and impingement of the nerve
Examples of compressive disorders: carpal tunnel syndrome, ulnar nerve entrapment, thoracic outlet syndrome, and disk herniation

Other Neurological Disorders

Charcot-Marie-Tooth disease: hereditary sensory and motor neuropathy, characterized by demyelination of peripheral nerves
Bell's palsy: idiopathic paralysis of the facial nerve, thought to be caused by compression of the facial nerve during inflammation

I hope this helps! Let me know if you need any further clarification.

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