Where would the lesion be located if a patient with suspected Multiple Sclerosis (MS) presents with bilateral upper and lower limb involvement, including a positive Babinski sign, despite a normal brain Magnetic Resonance Imaging (MRI)?

From the Guidelines

The lesion would likely be located in the spinal cord, given the patient's presentation with bilateral upper and lower limb involvement and a positive Babinski sign, despite a normal brain MRI.

Key Points

• The presence of a normal brain MRI does not rule out Multiple Sclerosis (MS), as spinal cord lesions can be present in the absence of brain lesions 1.
• Spinal cord imaging is recommended to define dissemination in space (DIS), particularly in patients who do not fulfill brain MRI criteria for DIS 2.
• The detection of spinal cord lesions can facilitate the diagnosis of MS and is predictive of conversion to clinically definite MS 1.
• Asymptomatic spinal cord lesions in patients with brain MRI findings suggestive of Radiologically Isolated Syndrome (RIS) herald an increased risk of short-term progression to either Clinically Isolated Syndrome (CIS) or primary progressive MS 1.

Diagnostic Considerations

• The 2010 McDonald criteria for MS diagnosis emphasize the importance of lesion location rather than lesion count, and allow for the concomitant presence of gadolinium-enhancing and non-enhancing lesions as evidence for dissemination in time (DIT) 3.
• The MAGNIMS consensus guidelines recommend the use of identical DIS and DIT MRI criteria for the evaluation of RIS and MS, and suggest that a diagnosis of MS can be made when a clinical attack occurs in RIS-DIT positive subjects 4, 2.

From the Research

Lesion Location in Multiple Sclerosis

If a patient with suspected Multiple Sclerosis (MS) presents with bilateral upper and lower limb involvement, including a positive Babinski sign, despite a normal brain Magnetic Resonance Imaging (MRI), the lesion is likely to be located in the spinal cord.

• The patient's symptoms, such as bilateral upper and lower limb involvement and a positive Babinski sign, suggest involvement of the central nervous system, particularly the spinal cord 5.
• A normal brain MRI does not rule out MS, as some patients may have normal brain MRI but abnormal spinal cord MRI 5.
• Spinal cord imaging is equally valuable to rule out spinal stenosis or tumor, and for detecting asymptomatic lesions when brain imaging is nondiagnostic in patients suspected of having MS 6, 5.
• The presence of lesions in the spinal cord can support the diagnosis of MS, especially in patients with clinical symptoms and signs referable to the spinal cord or optic nerves 5.

Diagnostic Considerations

The diagnosis of MS is based on the demonstration of dissemination of lesions in space (DIS) and in time (DIT), as well as on the exclusion of an alternative neurologic disorder.

• MRI is a core diagnostic tool in the detection of MS lesions and demonstration of spatial and temporal distribution of disease 6, 7.
• However, other white matter diseases can have similar appearances on MRI, and careful evaluation of associated findings on MRI, such as the presence of infarcts, microbleeds, meningeal enhancement, and calcifications, is necessary to suggest a diagnosis other than MS 8.