Symptom Finder - Fasciculations
FASCICULATIONS
This sign is generally considered pathognomonic for anterior horn cell or root disease. It may occur, however, in certain cases of peripheral neuropathy, in electrolyte disturbances, and in myasthenia gravis, especially under treatment. It is also found in healthy states, most commonly in the twitching of the orbicularis oculi muscle from nervous tension or eyestrain. Fasciculations must be distinguished from fibrillations that are not visible, are detected only with EMG, and are caused by muscle disease. The causes can easily be recalled by visualizing the anterior horn cells and nerves and applying the mnemonic VINDICATE to this area.
V—Vascular conditions include anterior spinal artery occlusion and
intermittent claudication from peripheral vascular disease.
I—Inflammatory diseases include poliomyelitis, viral encephalomyelitis,
tetanus, syphilis, and diphtheria.
N—Neoplasm suggests intramedullary tumors of the cord such as
ependymomas, and extramedullary tumors such as meningioma,
Hodgkin lymphoma, metastatic carcinoma, and multiple myeloma must
be considered.
D—Degenerative diseases are the most important causes of
fasciculations. They include progressive spinal muscular atrophy,
amyotrophic lateral sclerosis, Werdnig–Hoffmann disease, and
syringomyelia.
I—Intoxication includes lead poisoning and alcoholism.
C—Congenital disorders suggest Werdnig–Hoffmann disease, spondylolisthesis, and other anomalies of the spinal cord that may compress the anterior horn and roots.
A—Autoimmune disorders recall transverse myelitis, myasthenia gravis (under treatment), periarteritis nodosa, and Guillain–Barré syndrome.
T—Trauma suggests herniated discs and fractures that compress the anterior horn or roots.
E—Endocrine and metabolic diseases include hypoparathyroidism and other causes of tetany, magnesium deficiency and other electrolyte disturbances, diabetic myelopathy, and hypothyroid myopathy (more commonly the cause of fibrillations which can only be detected by EMG).
Approach to the Diagnosis
Deciding on the cause of fasciculations will usually be based on other neurologic symptoms and signs. Muscular atrophy without sensory changes suggests progressive muscular atrophy, whereas atrophy and fasciculations with sensory changes suggest syringomyelia, peripheral neuropathy, and root compression (e.g., a herniated disc). Treatable neurologic disorders should be considered first. Thus, x-rays of the spine, spinal fluid analysis, and MRI should be performed to rule out a spaceoccupying lesion. EMG is useful in detecting which level is involved and in following the progress of the disease. Serum electrolytes, calcium, phosphorus, and magnesium levels are useful in selected disorders.
Other Useful Tests
1. Blood lead level (lead poisoning)
2. Glucose tolerance test (diabetes mellitus)
3. Serum protein electrophoresis (polyclonal gammopathy)
4. Antinuclear antibody (ANA) analysis (collagen disease)
5. Nerve conduction velocity (NCV) test (peripheral neuropathy)
6. Free thyroxine and sensitive thyroid-stimulating hormone (S-TSH)
levels (hypothyroid myopathy)
7. Acetylcholine receptor antibody titer (myasthenia gravis)
8. CT scan of the thoracic or lumbar spine (space-occupying lesion)
9. MRI of the cervical, thoracic, or lumbar spine (space-occupying
lesion)
10. Neurology consult
11. Muscle biopsy
This sign is generally considered pathognomonic for anterior horn cell or root disease. It may occur, however, in certain cases of peripheral neuropathy, in electrolyte disturbances, and in myasthenia gravis, especially under treatment. It is also found in healthy states, most commonly in the twitching of the orbicularis oculi muscle from nervous tension or eyestrain. Fasciculations must be distinguished from fibrillations that are not visible, are detected only with EMG, and are caused by muscle disease. The causes can easily be recalled by visualizing the anterior horn cells and nerves and applying the mnemonic VINDICATE to this area.
V—Vascular conditions include anterior spinal artery occlusion and
intermittent claudication from peripheral vascular disease.
I—Inflammatory diseases include poliomyelitis, viral encephalomyelitis,
tetanus, syphilis, and diphtheria.
N—Neoplasm suggests intramedullary tumors of the cord such as
ependymomas, and extramedullary tumors such as meningioma,
Hodgkin lymphoma, metastatic carcinoma, and multiple myeloma must
be considered.
D—Degenerative diseases are the most important causes of
fasciculations. They include progressive spinal muscular atrophy,
amyotrophic lateral sclerosis, Werdnig–Hoffmann disease, and
syringomyelia.
I—Intoxication includes lead poisoning and alcoholism.
C—Congenital disorders suggest Werdnig–Hoffmann disease, spondylolisthesis, and other anomalies of the spinal cord that may compress the anterior horn and roots.
A—Autoimmune disorders recall transverse myelitis, myasthenia gravis (under treatment), periarteritis nodosa, and Guillain–Barré syndrome.
T—Trauma suggests herniated discs and fractures that compress the anterior horn or roots.
E—Endocrine and metabolic diseases include hypoparathyroidism and other causes of tetany, magnesium deficiency and other electrolyte disturbances, diabetic myelopathy, and hypothyroid myopathy (more commonly the cause of fibrillations which can only be detected by EMG).
Approach to the Diagnosis
Deciding on the cause of fasciculations will usually be based on other neurologic symptoms and signs. Muscular atrophy without sensory changes suggests progressive muscular atrophy, whereas atrophy and fasciculations with sensory changes suggest syringomyelia, peripheral neuropathy, and root compression (e.g., a herniated disc). Treatable neurologic disorders should be considered first. Thus, x-rays of the spine, spinal fluid analysis, and MRI should be performed to rule out a spaceoccupying lesion. EMG is useful in detecting which level is involved and in following the progress of the disease. Serum electrolytes, calcium, phosphorus, and magnesium levels are useful in selected disorders.
Other Useful Tests
1. Blood lead level (lead poisoning)
2. Glucose tolerance test (diabetes mellitus)
3. Serum protein electrophoresis (polyclonal gammopathy)
4. Antinuclear antibody (ANA) analysis (collagen disease)
5. Nerve conduction velocity (NCV) test (peripheral neuropathy)
6. Free thyroxine and sensitive thyroid-stimulating hormone (S-TSH)
levels (hypothyroid myopathy)
7. Acetylcholine receptor antibody titer (myasthenia gravis)
8. CT scan of the thoracic or lumbar spine (space-occupying lesion)
9. MRI of the cervical, thoracic, or lumbar spine (space-occupying
lesion)
10. Neurology consult
11. Muscle biopsy