13.13.1 Central neuropathic pain attributed to multiple sclerosis (MS)

Identification: Female patient, 34 years old, with a diagnosis of relapsing-remitting MS for 5 years, presents with chronic neuropathic pain for 8 months.

History of Present Illness:
Pain Symptoms:
Location:
- Right lower limb (lateral aspect of the thigh and leg)
- Lumbosacral region

Characteristics:
- Continuous pain: Burning (6-8/10 VAS)
- Exacerbations: Electric shocks (9/10), 5-15 episodes/day

Neuropathic Phenomena:
- Allodynia to touch of fabric (clothes, sheets)
- Hyperpathia to mild heat

Course:
- Onset coinciding with spinal flare-up (L2-L4)
- Persistence after resolution of other deficits

MS History:
- 3 previous relapses (2 optic, 1 spinal)
- On fingolimod for 2 years

Physical/Neurological Examination:
Sensory Evaluation:
- Thermal and pain hypoesthesia in "shotgun" pattern (right L2-L4)
- Mechanical hyperesthesia (von Frey brush 4.17)

Motor Function:
- Muscle strength preserved (5/5)
- Brisk reflexes in lower limbs (negative Babinski)

Coordination:
- Mild dysdiadochokinesia on the right

Complementary Exams:
Spinal Cord MRI (T2/T1 with contrast):
- Active demyelinating plaque in the conus medullaris (L2-L4)
- Post-gadolinium ring enhancement

Somatosensory Evoked Potentials:
- Increased latency in right tibial nerves (P40: 48ms)

Cerebrospinal Fluid:
- Positive IgG oligoclonal bands
- Elevated IgG index