From the Guidelines
Multiple Sclerosis (MS) symptoms are triggered by specific CNS areas, including the brainstem, spinal cord, and optic nerves. The symptoms that occur with nerve damage below C5 without brain involvement are typically related to the spinal cord and can include weakness, numbness, or tingling in the legs, bladder and bowel dysfunction, and sexual dysfunction.
CNS Areas Triggering Specific MS Symptoms
- Brainstem: lesions in the brainstem can cause diplopia (double vision), nystagmus (abnormal eye movements), and ataxia (loss of coordination) 1
- Spinal Cord: lesions in the spinal cord can cause weakness, numbness, or tingling in the legs, bladder and bowel dysfunction, and sexual dysfunction 1
- Optic Nerves: lesions in the optic nerves can cause optic neuritis, which can lead to vision loss or blindness 1
Symptoms with Nerve Damage below C5 without Brain Involvement
- Weakness, numbness, or tingling in the legs: due to damage to the spinal cord below C5 1
- Bladder and bowel dysfunction: due to damage to the spinal cord below C5, which can affect the autonomic nervous system 1
- Sexual dysfunction: due to damage to the spinal cord below C5, which can affect the autonomic nervous system 1
It's worth noting that spinal cord lesions are often small, covering less than two vertebral segments, and usually less than half of the cord area 1. Additionally, spinal cord atrophy measures can define and predict MS severity, with cervical cord area being an important marker of disability status in MS 1.
From the Research
CNS Areas and MS Symptoms
- The central nervous system (CNS) areas that trigger specific MS symptoms include the optic nerve, brainstem, and spinal cord 2.
- The symptoms of MS are related to a loss of function due to a failure of axonal conduction at the site of the lesion(s) 3.
- The disease can exhibit an exceptionally wide variety of symptoms due to the semi-random distribution of lesions in the CNS 3.
Nerve Damage Below C5
- Nerve damage below C5 without brain involvement can occur in MS, and the peripheral nervous system (PNS) can be involved in the disease 4.
- Studies have shown that the PNS is functionally affected during MS, and the disease might be part of a spectrum of demyelinating disorders instead of being a distinct entity 4.
- Spinal cord atrophy is a significant predictor of disability progression in MS, and isolated spinal cord atrophy can exert a similar effect on motor disability as concomitant brain and spinal cord atrophy 5.
Symptoms Without Brain Involvement
- Some symptoms in MS can occur without brain involvement, such as those related to nerve damage below C5 4.
- These symptoms can be due to demyelination, inflammation, and axonal degeneration in the spinal cord and PNS 4.
- The symptoms can include paresthesias, Lhermitte's sign, and other sensory and motor symptoms 3.