Lumbosacral radiculoplexus neuropathy: Incidence and the association with diabetes mellitus.

OBJECTIVE

To determine the previously unknown incidence of lumbosacral radiculoplexus neuropathy (LRPN) and its association with diabetes mellitus (DM).

METHODS

LRPN defined by clinical and electrophysiologic criteria was identified among Olmsted County, Minnesota, residents during a 16-year period (2000-2015) using the unique facilities of the Rochester Epidemiology Project. DM was ascertained using American Diabetes Association criteria.

RESULTS

Of 1,892 medical records reviewed, 59 patients (33 men, 26 women) were identified as having LRPN. The median age was 70 years (range 24-88 years) and the median time of onset of symptoms to diagnosis was 2 months (range 1-72 months). DM was more frequent in patients with LRPN than in controls (39/59 vs 35/177, < 0.001) but not in those with pre-DM (10/20 vs 55/142, = 0.336). LRPN recurred in 3 patients with DM resulting in 62 LRPN episodes during the study period. The overall incidence of LRPN was 4.16/100,000/y (95% confidence interval [CI] 3.13-5.18). The incidences of LRPN among DM and non-DM groups were 2.79/100,000/y (95% CI 1.94-3.64) and 1.27/100,000/y (95% CI 0.71-1.83), respectively. The odds of LRPN among patients with DM and pre-DM was 7.91 (95% CI 4.11-15.21) and 1.006 (95% CI 1.004-1.012), respectively.

CONCLUSIONS

LRPN incidence in Olmsted County of 4.16/100,000/y makes LRPN a common inflammatory neuropathy and is higher than that of other immune-mediated neuropathies (acute or chronic inflammatory demyelinating polyradiculoneuropathy, brachial plexus neuropathy) assessed within the same population. DM is a major risk factor for LRPN and thus justifies the continued classification of LRPN into diabetic and nondiabetic forms.