From the Guidelines
The typical location of a Multiple Sclerosis (MS) lesion causing intermittent lower limb heaviness is in the cervical spinal cord, specifically in the lateral or dorsal columns of the spinal cord, and can also affect the anterior white matter and central grey matter 1.
Key Characteristics of MS Lesions
- MS lesions are often small, covering less than two vertebral segments and usually less than half of the cord area 1
- They are focal, with clearly demarcated borders, and can be cigar-shaped on sagittal images and wedge-shaped on axial images 1
- MS lesions are hyperintense on T2-weighted sequences and may be hypointense on T1-weighted images, especially when imaged with higher field strengths 1 ### Location of MS Lesions
- MS lesions can occur along the entire spinal cord, but the cervical portion is more frequently involved 2
- Lesions are often located in the periphery of the spinal cord, mainly in the lateral or dorsal columns 1
- Focal lesions strictly confined to the grey matter are unusual in MS 1 ### Diagnostic Considerations
- The presence of multiple short-segment spinal cord lesions is highly specific for MS and only rarely occurs in other inflammatory CNS diseases 1
- Red flags for spinal cord lesions include longitudinally extensive lesions, prominent involvement of the central grey matter, and leptomeningeal or nerve root involvement 1
From the Research
Location of MS Lesions Causing Intermittent Lower Limb Heaviness
- The location of Multiple Sclerosis (MS) lesions causing intermittent lower limb heaviness is not explicitly stated in the provided studies 3, 4, 5, 6, 7.
- However, studies suggest that MS lesions can occur in various locations, including the periventricular, (juxta)cortical, infratentorial, and subcortical regions 5.
- Lesion location can be associated with specific symptoms and cognitive deficits, such as sensory and coordination functional system deficits correlating with lesion accumulation in distinct anatomically plausible regions, like the thalamus and middle cerebellar peduncule 6.
- The presence of peripheral pons lesions can discriminate between MS and vascular risk factor-related small vessel disease, with MS patients being more likely to have peripheral pons lesions 7.
- It is essential to note that the correlation between MRI lesion load and disability is only modest, and strategic lesion location might partially account for this 'clinico-radiologic paradox' 6.
Lesion Location and Symptom Development
- Lesion probability mapping supports the association of specific lesion locations with symptom development in MS, but only to a limited extent 6.
- The location of lesions in the central nervous system (CNS) can affect the symptoms exhibited by MS patients, with most lesions occurring in apparently "silent" areas in the brain, causing no detectable symptoms 4.
- The disease is therefore much more active than a mere clinical monitoring would suggest, and most symptoms are related to a loss of function due to a failure of axonal conduction at the site of the lesion(s) 4.