From the Guidelines
For evaluating numbness in feet and right hand weakness, an MRI of the brain and spinal cord is the most appropriate imaging modality. This recommendation is based on the fact that these symptoms suggest potential neurological issues affecting multiple limbs, which could be due to central nervous system lesions such as multiple sclerosis plaques, spinal cord compression, or stroke 1. MRI provides excellent soft tissue contrast and can accurately depict soft-tissue pathology, assess vertebral marrow, and assess the spinal canal patency, making it the imaging study of choice in the evaluation of suspected neurological deficits 1.
In the context of numbness in multiple extremities, which suggests a central rather than peripheral cause, imaging of the central nervous system is crucial for proper diagnosis and treatment planning. While CT scans can answer the question of whether or not spinal compression is present, they are less useful for this presentation unless there's suspicion of bony abnormalities or when MRI is contraindicated 1.
The use of MRI with contrast enhancement using gadolinium may be necessary to better visualize inflammatory or neoplastic processes, especially if there is a suspicion of underlying malignancy, infection, or inflammation 1. Additionally, nerve conduction studies and electromyography (EMG) should also be considered as complementary diagnostic tools to assess nerve and muscle activity, although these are not imaging studies 1.
Given the potential for multifocal deficits and progressive neurologic deficits, which can be caused by a number of noncompressive etiologies with some overlapping clinical features, a thorough evaluation with MRI is essential to guide treatment planning and improve patient outcomes 1.
From the Research
Imaging Options for Numbness in Feet and Right Hand Weakness
- Magnetic Resonance Imaging (MRI) is a widely used imaging technique to evaluate the spine and spinal cord 2.
- MRI of the spine enables the imaging specialist to evaluate a large anatomic region in multiple planes and can better examine the spinal cord 2.
- For patients with multiple sclerosis, brain MRI alone may be sufficient for monitoring disease activity, and the addition of spinal cord MRI may not provide significant additional information 3, 4.
- However, spinal cord MRI can provide relevant information to influence treatment decisions, especially in early treatment phases, compared to stand-alone brain MRI 5.
- Electrodiagnostic studies, such as nerve conduction and needle electromyographic studies, are essential in the evaluation of peripheral neuropathies and can help characterize the type and extent of nerve damage 6.
Considerations for Imaging Modalities
- The choice of imaging modality depends on the suspected underlying cause of numbness in feet and right hand weakness.
- MRI is suitable for evaluating the spine and spinal cord, while electrodiagnostic studies are more appropriate for assessing peripheral neuropathies.
- The combination of brain and spinal cord MRI may be useful in certain cases, such as multiple sclerosis, but the added value of spinal cord MRI is still a topic of debate 3, 5, 4.