Can multiple sclerosis (MS) cause bone pain?

Can Multiple Sclerosis Cause Bone Pain?

Multiple sclerosis does not directly cause bone pain through demyelinating lesions, but MS patients frequently experience bone pain indirectly through osteoporosis, reduced bone mineral density, and immobility-related skeletal complications. 1, 2

Direct vs. Indirect Pain in MS

MS-related pain is classified into four categories, and bone pain falls into the "pain indirectly related to MS" category rather than neuropathic pain directly caused by demyelination 1:

• Neuropathic pain directly from MS includes burning dysesthesias, trigeminal neuralgia, and painful tonic spasms—these do not involve bone structures 1, 3
• Indirect pain from MS includes musculoskeletal pain from immobility, malposition, and reduced bone density—this is where bone pain originates 1, 2

Why MS Patients Develop Bone Problems

The primary mechanism linking MS to bone pain is immobility and reduced mechanical loading on bones, which is the major contributing factor for osteoporosis in MS patients 2, 4:

• 51% of MS patients with relapses have low bone mineral density (T-score <-1.0), even in relatively young and largely ambulatory patients 5
• Bone mineral density reduction is greatest at the hip, with a strong correlation between disability level (EDSS score) and BMD loss at the femoral neck 2
• The rate of BMD loss directly correlates with disability progression 2

Additional contributing factors include:

• Vitamin D deficiency affects 62% of MS patients experiencing relapses 5
• Glucocorticoid use for acute relapses, though pulsed corticosteroids do not significantly affect BMD with cumulative dosing 2
• Anticonvulsant medications used for neuropathic pain management 4

Clinical Presentation of Bone-Related Pain in MS

When MS patients report bone pain, consider these specific manifestations:

• Vertebral compression fractures causing localized back pain 6
• Hip and lower extremity pain from reduced femoral neck BMD 2
• Fracture risk increases with disability level, with falls and fractures more common than in healthy controls 2

Critical Distinction from Other MS Pain Syndromes

Do not confuse bone pain with these MS-specific pain syndromes that are not bone-related 1, 3:

• Central neuropathic pain: constant burning in lower limbs from demyelination, treated with tricyclic antidepressants or gabapentin
• Trigeminal neuralgia: extreme facial pain treated with carbamazepine
• Painful tonic spasms: treated with baclofen or benzodiazepines
• Musculoskeletal pain from spasticity: responds to antispastic agents and physiotherapy

Management Approach for Bone Pain in MS

Screen for osteoporosis with DEXA scanning in MS patients with EDSS ≥4.0 or those experiencing bone pain, as standard fracture risk tools like WHO FRAX are inadequate for this younger population 5, 4:

• Bisphosphonates with continued antihistamine use resolve bone pain and improve vertebral BMD 6
• Optimize vitamin D levels to at least 50 nmol/L, as 62% of MS relapse patients are deficient 5
• Denosumab serves as an alternative for patients not responding to bisphosphonates or with renal insufficiency 6
• Vertebroplasty or kyphoplasty for refractory pain from vertebral compression fractures 6

Common Pitfalls to Avoid

• Do not assume bone pain is neuropathic MS pain—it requires different diagnostic workup and treatment 1, 2
• Do not rely solely on age-based fracture risk calculators—MS patients have unique risk factors requiring DEXA scanning even when young 5, 4
• Do not overlook vitamin D screening—deficiency is present in the majority of MS patients and contributes to bone health deterioration 5
• Do not attribute all musculoskeletal pain to spasticity—underlying osteoporosis may be the primary cause requiring specific bone-directed therapy 1, 2