Suggested distinguishing features between hereditary and inflammatory neuropathy and main findings indicative of overlap
| Typical for hereditary | Typical for inflammatory | Main features in overlap | |
|---|---|---|---|
| Clinical | |||
| Dysmorphic features | Yes | No | Yes |
| Weakness | Distal/no proximal | Symmetrical, proximal and distal | Proximal (recent change) |
| Positive sensory symptoms | No | Yes | Yes (recent change) |
| Progression | Slow | Stepwise or rapid | Acute, subacute or stepwise deterioration |
| Electrophysiological | |||
| Demyelinating | Yes (if demyelinating form, eg, CMT1, FAP) | Yes | Yes |
| Internerve motor slowing | Homogeneous | Heterogeneous motor conduction slowing, distal latency prolongation and F-wave prolongation | + Heterogeneous (new vs comparative studies) |
| Conduction block or temporal dispersion | No, except at entrapment sites | Yes, outside entrapment sites | Yes (new vs comparative studies) |
| Cerebrospinal fluid | |||
| CSF protein | Normal or mildly elevated (<1 g/L) | Elevated CSF protein above normal range, >0.50 g/L | Raised; with suggested cut-off >1 g/L or 0.50–1 g/L, if highly suggestive clinical context |
| Imaging (MRI) | |||
| Thickened nerve roots | Yes | Yes | Yes |
| Enhancing nerve roots/plexus with gadolinium | No | Yes | Yes |
| Histopathological (nerve biopsy) | |||
| Demyelinating: onion bulbs, loss of myelinated fibres | Yes | Yes | Yes |
| Inflammatory cells | No | Yes; macrophage-induced demyelination ++ | Yes; macrophage-induced demyelination ++ |
CMT, Charcot-Marie-Tooth disease; FAP, familial amyloid polyneuropathy.