Sensory Deficit in Multiple Sclerosis with C4 Demyelinating Plaque

Anatomical Basis for the Sensory Deficit

The spinothalamic tract carries pain and temperature sensations from the body to the brain, with fibers crossing to the opposite side at the level they enter the spinal cord, then ascending in the contralateral spinothalamic tract, as described by the American College of Radiology 1, 2, 3, 4
A lesion affecting the lateral spinothalamic tract at C4 on the right side would therefore affect sensations coming from the left side of the body below the level of the lesion, according to the American College of Radiology 2, 3

The patient would likely report decreased pain and temperature sensation on the left side of the body below the C4 dermatome, with decreased sensation to pinprick and temperature in the left arm, trunk, and leg, as reported by the American College of Radiology 1, 2, 3, 4
Proprioception and vibration sense would likely be preserved unless the lesion extends medially, according to the American College of Radiology 3, 5

MS commonly affects the cervical spinal cord, with 80-90% of MS patients showing cervical cord involvement, as stated by the American College of Radiology 4, 6
The sensory deficit pattern helps localize the lesion and can be correlated with MRI findings to confirm the relationship between the structural lesion and clinical symptoms, according to the American College of Radiology 3, 4

Careful sensory testing should be performed to map the exact distribution of sensory loss, with specific testing for pinprick and temperature sensation on both sides of the body to detect the contralateral deficit, as recommended by the American College of Radiology 2, 3, 4
The presence of this specific sensory deficit pattern can help distinguish MS from other conditions that might cause similar symptoms, according to the American College of Radiology 4