Related Experiment Video
Updated: Aug 15, 2025
08:16
Utility of Dissociated Intrinsic Hand Muscle Atrophy in the Diagnosis of Amyotrophic Lateral Sclerosis
Published on: March 4, 2014
32.1K
Finger Flexor Weakness in Myasthenia Gravis.
Mohammed H Alanazy1,2, Hisham Alkhalidi
1Department of Internal Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
Summary
A rare presentation of myasthenia gravis (MG) involved severe finger flexor weakness. This case highlights the need for early recognition and aggressive immunotherapy for myasthenia gravis relapses.
Area of Science:
- Neurology
- Immunology
- Clinical Medicine
Background:
- Myasthenia gravis (MG) typically affects ocular, bulbar, and proximal limb muscles.
- Distal limb muscle involvement, particularly isolated finger flexor weakness, is uncommon in MG.
Observation:
- A 35-year-old woman with acetylcholine receptor-antibody positive generalized MG presented with severe, asymmetric finger flexor weakness during an MG relapse.
- Intrinsic hand muscles and finger extensors were spared.
- Repetitive nerve stimulation showed significant decremental responses (>10%).
Findings:
- Muscle imaging revealed increased signal intensity in volar forearm muscles.
- Electromyography showed neurogenic changes, including fibrillations and abnormal motor unit potentials.
- Muscle biopsy confirmed neurogenic features, and myositis-specific autoantibodies were negative.
Implications:
- This case underscores that severe finger flexor weakness can be a manifestation of MG relapse.
- Clinicians should consider MG in patients presenting with such focal weakness.
- Early and aggressive immunotherapy may be crucial for favorable outcomes in these specific MG presentations.
Related Concept Videos
01:28Disorders of the Skeletal Muscle
1.0K
The clinical conditions affecting the skeletal muscle tissue are broadly categorized as musculoskeletal and neuromuscular disorders.
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...
1.0K
01:15Myasthenia Gravis: Diagnostic Tests
1.2K
Myasthenia gravis is an autoimmune condition affecting neuromuscular transmission, causing generalized weakness in skeletal muscles. Initial diagnoses rely on patients' signs, symptoms, and medical history. The challenge lies in distinguishing myasthenia from other muscular dystrophies. An important diagnostic feature is the significant improvement of symptoms after administering anticholinesterase inhibitors.
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
1.2K
01:20Myasthenia Gravis: Overview and Treatment
1.8K
Myasthenia gravis is a neuromuscular transmission disorder characterized by weakness and increased fatigability of skeletal muscles. It is an autoimmune disease affecting approximately one in 2000 people, where antibodies against the α1 subunit of nicotinic acetylcholine receptors are produced.
These antibodies interfere with the function of the nicotinic receptors in three ways: by binding to the receptor and disrupting acetylcholine binding; by causing cross-linking of receptors which...
These antibodies interfere with the function of the nicotinic receptors in three ways: by binding to the receptor and disrupting acetylcholine binding; by causing cross-linking of receptors which...
1.8K
01:26Chemical Synapses
9.0K
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
9.0K
01:10Muscle Contraction
6.7K
In skeletal muscles, acetylcholine is released by nerve terminals at the motor endplate—the point of synaptic communication between motor neurons and muscle fibers. The binding of acetylcholine to its receptors on the sarcolemma allows entry of sodium ions into the cell and triggers an action potential in the muscle cell. Thus, electrical signals from the brain are transmitted to the muscle. Subsequently, the enzyme acetylcholinesterase breaks down acetylcholine to prevent excessive...
6.7K
01:17Muscles of the Forearm that Move the Hand and Fingers
1.2K
The muscles of the forearm that move the wrist, hand, and digits are numerous and diverse. They can be classified into two groups based on their location and function — the anterior and posterior compartment muscles.
Anterior Compartment
The anterior compartment muscles originate from the humerus. They primarily function as flexors and are also known as flexor muscles. They typically insert on the carpals, metacarpals, and phalanges. The superficial layer includes the flexor carpi...
Anterior Compartment
The anterior compartment muscles originate from the humerus. They primarily function as flexors and are also known as flexor muscles. They typically insert on the carpals, metacarpals, and phalanges. The superficial layer includes the flexor carpi...
1.2K