The Heterogeneity of Cidp

The clinical picture of a slowly progressive sensory and motor peripheral neuropathy with loss of tendon refl exes certainly fi ts the diagnosis (Burns 2004). The early sensory symptoms in the territory of individual peripheral nerves is compatible although they would also be consistent with a vasculitic neuropathy. The severe pain is unusual and, although not unknown in CIDP, is again more suggestive of vasculitic neuropathy. The occurrence of intermittent fever is not a recognized part of CIDP, although Dr BodleyScott’s own enquiries suggest that this may require further consideration. The diagnosis depends critically on the nerve conduction studies and these, we are told, showed clear-cut evidence of demyelination, presumably marked slowing of nerve conduction, partial conduction block or dispersion of elicited compound muscle action potentials, or a combination of all three. The negative sural nerve biopsy certainly does not rule out the diagnosis of CIDP as it is often unhelpful, showing either no change or nonspecifi c axonal degeneration and loss of axons. Only about 25% of biopsies show the diagnostic hallmarks of endoneurial lymphocytic infi ltration, macrophage-associated demyelination and ‘onion bulb’ formation. His renal failure is unlikely to have contributed because it does not cause a demyelinating sensory and motor neuropathy, and he worsened following the institution of haemodialysis.