James is a Neuromuscular and EMG trained neurologist who graduated Auckland medical school in 1996 before leaving for the US in 1998. There he trained in internal Medicine and Neurology, and took up a faculty position at the University of Rochester, NY in 2004. He and his wife (also a neurologist) moved back to NZ to Waikato in 2006. James has worked at Waikato Hospital (2006-2010), Auckland City Hospital (2010-2018), and now Tauranga Hospital (2018-). He runs a private practice based in Cambridge, and specialises in nerve conduction studies and neuromuscular disease. He has 2 secondary school aged children and in his spare time renovates a car and does the odd bit of fishing and DIY engineering, and is a keen craft brewer.
Peripheral Neuropathy - When And When Not To Order Nerve Conduction Studies
Peripheral neuropathy is a common presentation to General Medical and Neurology Clinics, with a prevalence estimated at 8% of the general population over 55 years of age (Martyn and Hughes, 1997).
Many cases are clinically mild, indolent, and will present little threat to independence during prolonged follow up. In such cases at least 30-40% are idiopathic, and a detailed investigation beyond excluding reversible causes is often unrevealing. Nerve conduction studies (NCS), beyond confirming the presence of a neuropathy and its severity, often leads to little advancement of the diagnosis beyond a careful clinical examination. This is particularly relevant in the 80+ age group, where the range of normal is sufficiently broad that the specificity of NCS is significantly reduced.
However, there are several instances where NCS are particularly valuable in determining severity, physiology (axonal vs demyelinating), and pattern (focal, multifocal, generalised). This can facilitate rapid diagnosis, assist in selection of targets for biopsy, assess response to treatment, and help differentiate between inherited and acquired causes.
This session will focus on discussing the utility of NCS with Illustrative cases, with the following objectives: (1) developing practical tools for the General Physician (rather than focusing on rare entities seen by neurologists), and (2) recognising neuropathic conditions that herald underlying general medical conditions (e.g. amyloidosis, paraprotein-related neuropathy, toxic neuropathies, and paraneoplastic disorders). Management of these conditions is beyond the scope of this presentation.
Martyn, C.N.; Hughes, R.A. Epidemiology of peripheral neuropathy. J. Neurol. Neurosurg. Psychiatry 1997, 62, 310–318