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What percentage of amyotrophic lateral sclerosis (ALS) cases are genetic?
What percentage of amyotrophic lateral sclerosis (ALS) cases are genetic?
Cognition is affected in patients with amyotrophic lateral sclerosis (ALS).
Cognition is affected in patients with amyotrophic lateral sclerosis (ALS).
False
What is the primary structure that degenerates first in amyotrophic lateral sclerosis (ALS)?
What is the primary structure that degenerates first in amyotrophic lateral sclerosis (ALS)?
Anterior horn cell (AHC)
The category of ALS that involves both upper and lower motor neurons is known as _____ motor neuron disease.
The category of ALS that involves both upper and lower motor neurons is known as _____ motor neuron disease.
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Match the following clinical features with their descriptions in ALS:
Match the following clinical features with their descriptions in ALS:
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Which of the following symptoms are associated with X-linked SMA?
Which of the following symptoms are associated with X-linked SMA?
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Benign Monomelic Amyotrophy primarily affects young females.
Benign Monomelic Amyotrophy primarily affects young females.
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What is another name for Benign Monomelic Amyotrophy?
What is another name for Benign Monomelic Amyotrophy?
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X-linked SMA is associated with __________ insensitivity.
X-linked SMA is associated with __________ insensitivity.
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Match the following conditions with their associated symptoms:
Match the following conditions with their associated symptoms:
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Which of the following drugs is known to exacerbate Myasthenia Gravis?
Which of the following drugs is known to exacerbate Myasthenia Gravis?
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The Lambert-Eaton Myasthenic Syndrome (LEMS) is associated with antibodies against postsynaptic membrane receptors.
The Lambert-Eaton Myasthenic Syndrome (LEMS) is associated with antibodies against postsynaptic membrane receptors.
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What is the first-line treatment for a first attack of Myasthenia Gravis?
What is the first-line treatment for a first attack of Myasthenia Gravis?
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Symptoms of a cholinergic crisis include DUMBELLS, which stands for Diarrhea, Urination, ______, Bradycardia.
Symptoms of a cholinergic crisis include DUMBELLS, which stands for Diarrhea, Urination, ______, Bradycardia.
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Match the following treatments with their indications:
Match the following treatments with their indications:
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Which tract is primarily responsible for transmitting pain and temperature sensations?
Which tract is primarily responsible for transmitting pain and temperature sensations?
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The ventral root is a part of the sensory input pathway.
The ventral root is a part of the sensory input pathway.
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What type of myelopathy is caused by a tumor such as an ependymoma?
What type of myelopathy is caused by a tumor such as an ependymoma?
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The ________________ tract is responsible for proprioception.
The ________________ tract is responsible for proprioception.
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Match the spinal cord pathways to their primary functions:
Match the spinal cord pathways to their primary functions:
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What symptom would you expect at the level of a spinal cord lesion?
What symptom would you expect at the level of a spinal cord lesion?
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Syringomyelia is classified as a non-compressive myelopathy.
Syringomyelia is classified as a non-compressive myelopathy.
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Describe a characteristic symptom of a L4 spinal segment lesion.
Describe a characteristic symptom of a L4 spinal segment lesion.
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Which of the following symptoms is specific for Myasthenia Gravis (MG)?
Which of the following symptoms is specific for Myasthenia Gravis (MG)?
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The Peek sign indicates normal eyelid closure strength.
The Peek sign indicates normal eyelid closure strength.
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What test shows the improvement of symptoms after the administration of a cholinesterase inhibitor?
What test shows the improvement of symptoms after the administration of a cholinesterase inhibitor?
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Myasthenia Gravis symptoms include _____ diplopia and ophthalmoplegia.
Myasthenia Gravis symptoms include _____ diplopia and ophthalmoplegia.
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Match the following tests with their corresponding characteristics:
Match the following tests with their corresponding characteristics:
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Which cranial nerves are primarily involved in Bulbar Palsy?
Which cranial nerves are primarily involved in Bulbar Palsy?
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In Pseudobulbar Palsy, the gag reflex is typically absent.
In Pseudobulbar Palsy, the gag reflex is typically absent.
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What type of motor neuron lesion is associated with Bulbar Palsy?
What type of motor neuron lesion is associated with Bulbar Palsy?
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Patients with ALS may experience ____ due to thenar atrophy.
Patients with ALS may experience ____ due to thenar atrophy.
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Match the following symptoms with their associated conditions:
Match the following symptoms with their associated conditions:
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What is the primary function of the spinal cord?
What is the primary function of the spinal cord?
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The spinal cord is 70 cm long.
The spinal cord is 70 cm long.
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What is the upper limit of the spinal cord's extent?
What is the upper limit of the spinal cord's extent?
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The spinal cord extends from the junction between L1 and L2 in _____ and from L3-L4 in _____ individuals.
The spinal cord extends from the junction between L1 and L2 in _____ and from L3-L4 in _____ individuals.
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Match the vertebrae with their level of segments:
Match the vertebrae with their level of segments:
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Which of the following symptoms is NOT associated with Conus Medullaris Syndrome?
Which of the following symptoms is NOT associated with Conus Medullaris Syndrome?
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Sensation is consistently completely lost in Cauda Equina Syndrome.
Sensation is consistently completely lost in Cauda Equina Syndrome.
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What is the primary pathology associated with Cauda Equina Syndrome?
What is the primary pathology associated with Cauda Equina Syndrome?
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The length of the Filum Terminale is approximately __________ cm.
The length of the Filum Terminale is approximately __________ cm.
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What sensation is primarily affected by complete hemisection of the spinal cord?
What sensation is primarily affected by complete hemisection of the spinal cord?
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Match the spinal roots with their corresponding actions:
Match the spinal roots with their corresponding actions:
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Sacral sparing occurs with intradural or extramedullary lesions.
Sacral sparing occurs with intradural or extramedullary lesions.
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What type of neuropathy is characterized by stocking and glove sensory loss?
What type of neuropathy is characterized by stocking and glove sensory loss?
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The lateral spinothalamic tract is responsible for transmitting _______ sensations.
The lateral spinothalamic tract is responsible for transmitting _______ sensations.
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Match the following pathologies with their descriptions:
Match the following pathologies with their descriptions:
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What is the first peak age range for Myasthenia Gravis, particularly in females?
What is the first peak age range for Myasthenia Gravis, particularly in females?
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Thymoma is present in 80% of seropositive Myasthenia Gravis cases.
Thymoma is present in 80% of seropositive Myasthenia Gravis cases.
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What is the primary characteristic of the pure motor syndrome in Myasthenia Gravis?
What is the primary characteristic of the pure motor syndrome in Myasthenia Gravis?
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In Myasthenia Gravis, thymic hyperplasia is present in _____% of seropositive cases.
In Myasthenia Gravis, thymic hyperplasia is present in _____% of seropositive cases.
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Match the antibodies involved in Myasthenia Gravis with their descriptions:
Match the antibodies involved in Myasthenia Gravis with their descriptions:
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What is the typical gender ratio observed in early onset Myasthenia Gravis cases?
What is the typical gender ratio observed in early onset Myasthenia Gravis cases?
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Neck extensor weakness is a feature associated with Myasthenia Gravis.
Neck extensor weakness is a feature associated with Myasthenia Gravis.
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The drug commonly used to treat Myasthenia Gravis is called _____
The drug commonly used to treat Myasthenia Gravis is called _____
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What percentage of Myasthenia Gravis cases are classified as generalized MG?
What percentage of Myasthenia Gravis cases are classified as generalized MG?
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What is the prognosis for thymectomy in adult onset generalized Myasthenia Gravis?
What is the prognosis for thymectomy in adult onset generalized Myasthenia Gravis?
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Study Notes
Amyotrophic Lateral Sclerosis (ALS)
- ALS is a neurodegenerative disease affecting upper and lower motor neurons.
- 90% of cases are sporadic and 10% are genetic, often due to copper-zinc superoxide dismutase defects.
- ALS typically affects individuals over 50 years old, with males affected more frequently than females.
- Average survival after onset is 3 years.
- Primary structures affected include the anterior horn cells, lower motor neurons in brainstem nuclei, upper motor neurons in the corticospinal tract, and the corticobulbar tract.
- Clinical features include distal asymmetric upper limb atrophy, fasciculations, cramps, brisk reflexes, and loss of dexterity or tone.
- Cognition, the autonomic nervous system, and sensory systems remain intact.
Spinal Cord
- The spinal cord is a continuation of the medulla, extending from the upper border of the atlas (C1) to the junction between L1 and L2 in adults, or L3-L4 in children.
- 31 spinal cord segments correspond to the 31 pairs of spinal nerves.
- Each spinal nerve root is composed of a dorsal and ventral root.
- The spinal canal is 70 cm long, accommodating the spinal cord and its surrounding meninges (dura mater, arachnoid mater, and pia mater).
Spinal Cord Tracts
- Fasciculus cuneatus and fasciculus gracilis: Sensory tracts, involved in proprioception, fine touch, and pressure.
- Lateral corticospinal tract (pyramidal tract): Major motor pathway for voluntary movements.
- Dorsal spinocerebellar tract and ventral spinocerebellar tract: Carry sensory information related to proprioception.
- Lateral spinothalamic tract: Carries pain and temperature sensations.
- Ventral spinothalamic tract: Carries pressure and touch sensations.
- Rubrospinal tract: Influences movement.
- Lateral reticulospinal tract, ventral reticulospinal tract, and vestibulospinal tract: Involved in motor control and balance.
- Tectospinal tract: Controls reflexes related to eye and head movements.
Myelopathies
- Myelopathies are spinal cord diseases causing sensory, autonomic, and motor symptoms.
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Types of myelopathies:
-
Compressive:
- Intramedullary: e.g. tumors (ependymoma) and syringomyelia.
- Extramedullary: e.g. disc compression.
- Non-compressive: e.g. transverse myelitis.
-
Compressive:
-
Lesion Presentation:
- Above the level of the lesion: Normal function.
- At the level of the lesion: Symptoms depend on the involvement of anterior horn cells.
- Below the level of the lesion: Motor (UMN-type) and sensory loss.
Grey Matter
- Anterior horn cells: Motor neurons responsible for voluntary movement.
-
Level of lesion symptoms:
- Motor symptoms (LMN-type): Absent reflexes are a key diagnostic feature.
- Sensory symptoms: Vary based on the location of the lesion.
X-linked SMA (ALS Variants)
- Characterized by spinobulbar involvement, proximal muscle wasting, tongue wasting, and perioral fasciculations.
- May be associated with androgen insensitivity.
Benign Monomelic Amyotrophy (BMA)
- Also known as Hirayama disease.
- Primarily affects young males, causing weakness and atrophy in the upper extremity.
- Symptoms improve with rest and neck extension.
Myasthenia Gravis (MG)
- Autoimmune neuromuscular disorder affecting the neuromuscular junction.
- Characterized by fluctuating weakness in skeletal muscles.
- Primary cause is antibodies against the acetylcholine receptor (AChR) at the neuromuscular junction.
- 85% of cases are generalized MG.
- 50% of cases are ocular myasthenia.
- 10-20% of cases are generalized MG with negative anti-AChR antibodies.
- May involve thymus hyperplasia or thymoma in a significant proportion of cases.
- Thymectomy in adult-onset generalized MG has a good prognosis.
Lambert-Eaton Myasthenic Syndrome (LEMS)
- Autoimmune disorder affecting the release of acetylcholine from presynaptic motor neurons.
- Primarily affects proximal lower limbs and autonomic nervous system.
- Associated with small cell lung cancer in a significant number of cases.
- Antibodies target voltage-gated calcium channels on the presynaptic membrane.
- Treatment includes 3,4-diaminopyridine and supportive measures.
Myasthenia Gravis: Clinical Features
- Initial weakness, fatigue, and ptosis are characteristic features.
- Can involve bulbar muscles causing difficulty with speech and swallowing.
- Diurnal variation with worsening symptoms towards the evening.
- Muscle weakness increases with repetitive activity and improves with rest.
- Associated antibodies can be detected.
- Thymectomy can be beneficial in specific cases.
- Treatment options include cholinesterase inhibitors, immunosuppressants, and plasmapheresis.
Myasthenia Gravis: Investigations
- Clinical tests: Ice pack test, edrophonium test, and neostigmine test.
- Immunological tests: Anti-AChR antibody, anti-muscle specific kinase antibody, and anti-LRP4 antibody.
- Electrophysiological studies: Single nerve fiber electromyography, repetitive nerve stimulation test, and nerve conduction studies.
Bulbar vs. Pseudobulbar Palsy
- Bulbar palsy: Affects lower motor neurons of cranial nerves 9, 10, 11, and 12, causing dysphagia, dysarthria, and tongue fasciculations.
- Pseudobulbar palsy: Affects upper motor neurons to cranial nerves 9, 10, 11, and 12, resulting in spastic dysarthria, exaggerated reflexes, and emotional lability.
Conus Medullaris
- The terminal portion of the spinal cord located at the level of L1/L2 in adults and L3/L4 in children.
- Conus medullaris syndrome: Affects the sacral nerve roots and the conus medullaris, causing sacral sensory loss, urinary incontinence, and sphincter dysfunction.
- Cauda equina syndrome: Affects the lower lumbar and sacral nerve roots, leading to asymmetric radiculopathy, motor weakness, and variable sensory loss.
Anatomy of Spinal Cord
- The spinal cord extends from the medulla to the tip of the coccyx.
- Cervical enlargement houses the nerve roots for the upper limbs.
- Lumbar enlargement houses the nerve roots for the lower limbs.
- The filum terminale is a fibrous extension of the pia mater that extends from the conus medullaris to the coccyx.
- The dorsal tract (posterior column) carries sensory information for proprioception and tactile discrimination.
- The lateral spinothalamic tract carries pain and temperature sensations.
- Note:* This is a broad overview of the content. The text you provided does not include comprehensive explanations of specific syndromes and their management, so this summary focuses on highlighting key facts and anatomical features. Further research would be necessary for obtaining a complete understanding of these topics.
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Description
This quiz covers essential aspects of Amyotrophic Lateral Sclerosis (ALS) and spinal cord anatomy. Learn about the neurodegenerative effects of ALS, its clinical features, and the structure of the spinal cord. Test your knowledge on key facts related to motor neurons and survival statistics.
