Neuropathies related to hepatitis E virus infection: A prospective, matched case-control study.

BACKGROUND: Acute hepatitis E virus (HEV) infection has recently emerged as a potential trigger for acute dysimmune neuropathies, but prospective controlled studies are lacking. AIMS: To compare the frequency of concomitant acute HEV infection in patients with neuralgic amyotrophy (NA), Guillain-Barré syndrome (GBS), and Bell's palsy with a matched control population. METHODS: Swiss multicenter, prospective, observational, matched case-control study over 3 years (September 2019-October 2022). Neurological cases with NA, GBS, or Bell's palsy were recruited within 1 month of disease onset. Healthy controls were matched for age, sex, geographical location, and timing of blood collection. Diagnostic criteria for acute hepatitis E were reactive serum anti-HEV IgM and IgG assays (ELISA test) and/or HEV RNA detection in serum by real-time polymerase chain reaction (RT-PCR). RT-PCR was performed on sera to confirm IgM positivity. RESULTS: We included 180 patients (59 GBS, 51 NA, 70 Bell's palsy cases) and corresponding matched controls (blood donors) with median age 51 years for both groups and equal gender distribution. Six IgM+ cases were detected in the NA, two in the GBS, and none in the Bell's palsy group. Two controls were anti-HEV IgM-positive. At disease onset, most cases with acute HEV infection had increased liver enzymes. A moderate association (p = 0.027, Fisher's exact test; Cramér's V = -0.25) was observed only between acute HEV infection and NA. CONCLUSION: This prospective observational study suggests an association between concomitant acute HEV infection and NA, but not with GBS or Bell's palsy.

Muscle ischaemia in patients with orthostatic hypotension assessed by velocity recovery cycles.

OBJECTIVE: Patients with orthostatic hypotension may experience neck pain radiating to the occipital region of the skull and the shoulders while standing (so-called coat-hanger ache). This study assessed muscle membrane potential in the trapezius muscle of patients with orthostatic hypotension and healthy subjects during head-up tilt (HUT), by measuring velocity recovery cycles (VRCs) of muscle action potentials as an indicator of muscle membrane potential. METHODS: Eight patients with multiple system atrophy (MSA), orthostatic hypotension and a positive history for coat-hanger pain and eight normal controls (NCs) were included in this study. Repeated VRCs were recorded from the trapezius muscle by direct muscle stimulation in the supine position and during HUT for 10 min. RESULTS: Muscle VRC recordings did not differ between MSA patients and NCs in the supine position. During HUT, early supernormality decreased progressively and relative refractory period increased in MSA patients whereas VRC measures remained unchanged in NCs. Ten minutes after the start of HUT, early supernormality was reduced by 44% and relative refractory period was increased by 17%. CONCLUSIONS: Muscle membranes in patients with orthostatic hypotension become progressively depolarised during standing. Membrane depolarisation is most likely the result of muscle ischaemia, related to the drop in perfusion pressure caused by orthostatic hypotension. Coat-hanger ache is most likely a consequence of this muscle ischaemia.