Muscle Cramps

Introduction

Muscle cramps are mostly idiopathic, commonly affecting the calf muscles and/or foot. Muscle cramps are usually short-lived and self-limited, but may be results from varieties of serious systematic disorders. Physical examination and review of medical history can rather quickly and simply rule out cramps caused by pathologies. Passive and/or active stretching of the affected muscle(s) is by far the most effective and safest non-pharmacology management for most acute idiopathic muscle cramps.

Definition

A muscle cramp is a sudden, involuntary, painful muscle contraction or spasm, associated with an increase in frequency of motor action potentials and can have persistent muscle soreness and swelling with a variable rate of improvement, often terminated by stretching.

Mechanism

The cramp is due to a reactivation of the nervous system. The part of the nervous system activated are motorneurons and sensory and this aspect distinguishes it from contracture which , however is electrical silent.

Etiology

• Idiopathic
• Pregnancy
• Strenuous exercise
• Haemodialysis
• Cirrhosis
• Metabolic or electrolyte disturbances
• Other chronic diseases

Assessment

Most people presenting with cramps have idiopathic cramps, which are usually diagnosed following clinical exam. Further investigations are only required if the cramp has atypical features or other associated conditions are suspected.

• Past medical history- Consider patient past medical that may increase suspicion of an organic cause.

• Blood test- serum or urine hCG, fasting serum metabolic panel, thyroid-stimulating hormone (TSH), HbA1c, serum liver function tests, prothrombin time (PT) and INR, serum myoglobin and urinalysis.
• Neurological examinations: may indicate nerve involvement with muscle wasting, weakness, fasciculations etc.
• other investigations: electromyogram, nerve conduction test, muscle biopsy, genetic studies etc.

Resources

Muscle cramps