From the Guidelines
Muscle spasms are caused by a variety of factors, including electrolyte imbalances, particularly hypokalemia, hypomagnesemia, and hypophosphataemia, as well as metabolic disorders and inflammatory conditions 1.
Common Causes of Muscle Spasms
- Electrolyte imbalances: such as hypokalemia, hypomagnesemia, and hypophosphataemia 1
- Metabolic disorders: such as thyrotoxic hypokalaemic periodic paralysis 1
- Inflammatory conditions: such as inflammatory myositis 1
- Drug-induced toxic myopathy: caused by medications such as colchicine, chloroquine, emetine, or statins 1
- Mitochondrial disease 1
- Muscle fatigue, overuse, or strain
- Underlying medical conditions: such as multiple sclerosis, where medications like baclofen may be used to alleviate symptoms 1 Certain medications, such as diuretics like furosemide, can also contribute to muscle spasms by causing electrolyte imbalances, particularly hypokalemia and hypomagnesemia 1.
Treatment of Muscle Spasms
Medications like baclofen, at a dose of 10-20 mg three times daily, may be used to alleviate symptoms of muscle spasms in conditions like multiple sclerosis 1. Additionally, tizanidine and dantrolene may be used to treat spasticity that results in pain, poor skin hygiene, or decreased function 1. It is essential to identify and address the underlying cause of muscle spasms to provide effective treatment and prevent further complications.
From the FDA Drug Label
Diazepam is a useful adjunct for the relief of skeletal muscle spasm due to reflex spasm to local pathology (such as inflammation of the muscles or joints, or secondary to trauma), spasticity caused by upper motor neuron disorders (such as cerebral palsy and paraplegia), athetosis, and stiff-man syndrome The causes of muscle spasm include:
- Reflex spasm to local pathology, such as:
- Inflammation of the muscles
- Inflammation of the joints
- Trauma
- Spasticity caused by upper motor neuron disorders, such as:
- Cerebral palsy
- Paraplegia
- Athetosis
- Stiff-man syndrome 2
From the Research
Causes of Muscle Spasm
The causes of muscle spasm can be attributed to various factors, including:
- Pathophysiological factors that increase the activation of smooth muscle contractile mechanisms, resulting in long-lasting contractions-spasms 3
- Dehydration or electrolyte depletion, although recent literature suggests that the neuromuscular mechanism may prevail as the trigger event of muscle cramps 4
- A confluence of unique intrinsic and extrinsic factors, rather than a singular cause, contributing to exercise-associated muscle cramps (EAMCs) 5
- Changes in motoneuron excitability and synaptic inhibition, rather than synaptic excitation, in individuals with spinal cord injury 6
Underlying Mechanisms
The underlying mechanisms of muscle spasm can be complex and involve:
- Increased intercellular concentration of calcium ions and/or increased affinity of thin contractile filaments for them 3
- Imbalance between the rising excitatory drive from the muscle spindles and the decreasing inhibitory drive from the Golgi tendon organs 4
- Impaired inhibitory inputs to motoneurons, leading to increased motoneuron excitability and persistent inward currents 6
Types of Muscle Spasms
Different types of muscle spasms can occur, including: