Muscle cramps in cancer patients can be classified based on:
(1) cause
(2) reversible vs irreversible
(3) anatomic site affected (peripheral nerve, nerve root, anterior horn cell, muscle, etc)
Causes of muscle cramps:
(1) drug-induced (neuropathy, myopathy, metabolic)
(1a) chemotherapy (vincristine, cisplatin, other)
(1b) hormone therapy
(1c) amphotericin B
(1d) diuretic therapy
(1e) cimetidine
(1f) lithium
(1g) clofibrate
(2) nutritional deficiency
(2a) vitamin B12 deficiency
(2b) vitamin B1 deficiency
(3) endocrine
(3a) diabetes
(3b) hypothyroidism
(4) metabolic
(4a) electrolye imbalance (calcium, magnesium, potassium)
(4b) uremia
(4c) dehydration
(4d) hemodialysis
(5) myopathy
(5a) paraneoplastic (dermatomyositis)
(5b) toxic
(5c) infection
(6) neurological involvement
(6a) compression or infiltration by tumor
(6b) compression by nontumor tissue (fibrous tissue, bone, etc)
(6c) radiation-associated
(6d) amyotrophic lateral sclerosis (ALS)
(7) autoimmune
(7a) Guillain Barre syndrome
(7b) paraneoplastic
(8) idiopathic
(8a) effort cramps
(8b) rest cramps
Determining the cause of muscle cramping is essential for deciding how to control them.
