Table 2.
Summary routine ancillary investigations
| Patient | NCS(EFNS/PNS criteria are not fulfilled) | MRI(brachial plexus) | CSF protein content, mg/dL | Supportive criteria EFNS/PNSa | Diagnostic criteria EFNS/PNS |
|---|---|---|---|---|---|
| 1 | CMAP↓ median bilateral, right tibial + left fibular nerves | Normal | 37 | 1 (treatment) | Not compatible |
| 2 | CMAP ↓ of left and absent on right fibular nerve | Normal | 103 | 2 (CSF, treatment) | Not compatible |
| 3 | SNAP↓ right median, both sural nerves | Normalb | … | 1 (treatment) | Not compatible |
| 4 | DML↑ and SNAP↓ of right median nerve (CTS), CMAP↓ fibular and tibial nerves, SNAP↓ sural nerves | Normal | 54 | 2 (CSF, treatment) | Not compatible |
| 5 | Only chronodispersion F‐waves (median, ulnar, fibular + tibial) | Normal | 52 | 2 (CSF, treatment) | Not compatible |
| 6 | SNAP↓ right median, ulnar and radial, absent CMAP fibular and tibial nerves + SNAP both sural nerves | Enlargement + hyperintense T2‐signal right trunks | 42 | 2 (MRI, treatment) | Not compatible |
Abbreviations: …, data not available; CMAP, compound muscle action potential; CSF, cerebrospinal fluid (elevated protein content was defined as >40 mg/dL, indicated in bold type); CTS, carpal tunnel syndrome; DML, distal motor latency; EFNS/PNS, European Federation of Neurological Societies and the Peripheral Nerve Society; NCS, nerve conduction study; SNAP, sensory nerve action potential.
a
Abnormal MRI brachial plexus (enlargement and/or T2 hyperintense signal (nerve)root(s), gadolinium contrast enhancement), increased CSF protein, objective improvement following treatment, and in the case of MMN, presence of anti‐GM1 antibodies.
b
Additionally diagnosed with non‐Hodgkin lymphoma.