AANEM Connect

Hi everyone,
Looking for your thoughts on a puzzling case.

I'm seeing a 54-year-old right-handed woman on long-term disability.

Her history includes type 2 diabetes, hypertension, hypothyroidism, OSA (on CPAP), nodular thyroid hyperplasia, DVT/PE and, most importantly, a lateral medullary stroke in 2021. She also underwent bariatric surgery and has bilateral knee prostheses.

She is a past smoker, and drinks only rarely.

After her stroke, she had stable non-painful hypoesthesia of the right face and left hemibody. However, in late May 2025, she experienced rapid onset (over a few days) of paresthesias in all fingertips, followed shortly by paresthesias in the soles of both feet. She also reported left hand weakness—mainly grip issues, such as difficulty holding a knife. Around the same time, she developed new low back pain (not clearly radicular), worsening balance (now needs two canes instead of one), and four falls in the span of a few weeks—whereas she hadn't fallen at all in the preceding year.

She has long-standing urinary urgency since her stroke, but feels it has worsened; more concerningly, she now reports new-onset fecal incontinence. No orthostatic hypotension is present. MRI cervical spine showed only mild spondylosis, without myelopathy. Brain MRI revealed no new findings.

On exam, there’s mild atrophy of the left first dorsal interosseous with 2/5 weakness in that muscle, the ADM, and APB on the left. The rest of the motor exam is intact. Reflexes are symmetric at 2+ except for an absent right Achilles. Light touch is reduced over the fingertips bilaterally and soles of the feet. Vibration at the toes lasts 6–7 seconds.

EMG/NCS revealed severe bilateral median neuropathies at the wrist (markedly prolonged distal motor latencies, at 13-14 ms, and collapsed CMAPs), bilateral ulnar neuropathies at the elbow (more severe on the left, with both demyelinating and axonal features), and absent median and ulnar SNAPs. Tibial and right fibular motor responses are intact, as well as radial, sural (6-7 microvolts) and superficial fibular sensory responses.

Needle EMG showed chronic neurogenic changes in the left FDI and APB, with normal C5-C7 muscles. In the legs, there were chronic neurogenic changes in bilateral TA and medial gastroc, with the left TA and right MG more affected and showing active denervation. There were also changes in the left vastus lateralis, equivocal findings in the left tensor fascia lata, and mild denervation in the left L5 paraspinals.

Altogether, we’re looking at:

• Bilateral median and ulnar entrapment neuropathies 

• Axonopathic changes suggestive of chronic L5 > S1 > L4 involvement (bilateral, asymmetric), possibly radicular in origin

I interpreted the relatively robust sural amplitudes (6–7 µV) as not suggestive of an obvious large-fiber polyneuropathy.

Although the simplest hypothesis would be a combination of mechanical entrapment neuropathies and lumbar radiculopathies, I remain somewhat puzzled by the rapid and simultaneous onset of symptoms in all four limbs, which seems hard to reconcile with purely mechanical explanations like cane use.

It makes me wonder whether something more systemic is at play, amyloidosis being one of the possibilities I'm considering, especially given the massively prolonged median motor latencies and fecal incontinence. 

My plan is to pursue a workup for amyloidosis (including serum protein electrophoresis, free light chains, etc.), inflammatory/vasculitic workup, and to push for expedited carpal tunnel release surgery with biopsy of the flexor retinaculum—though this isn’t always straightforward to obtain in my setting.

I would appreciate any insights—particularly on whether you'd explore additional imaging, consider nerve biopsy, or look into other systemic causes. Any suggestions or advice would be very welcome.

Many thanks!

MB