Risk factors for nonidiopathic and idiopathic facial nerve palsies: findings of a retrospective study.

BACKGROUND: Idiopathic (IF) and nonidiopathic facial (NIF) nerve palsies are the most common forms of peripheral facial nerve palsies. Various risk factors for IF palsies, such as weather, have been explored, but such associations are sparse for NIF palsies, and it remains unclear whether certain diagnostic procedures, such as contrast agent-enhanced cerebral magnetic resonance imaging (cMRI), are helpful in the differential diagnosis of NIF vs. IF. METHODS: In this retrospective, monocentric study over a five-year period, the medical reports of 343 patients with peripheral facial nerve palsy were analysed based on aetiology, sociodemographic factors, cardiovascular risk factors, consultation time, diagnostic procedures such as cMRI, and laboratory results. We also investigated whether weather conditions and German Google Trends data were associated with the occurrence of NIF. To assess the importance of doctors' clinical opinions, the documented anamneses and clinical examination reports were presented and rated in a blinded fashion by five neurology residents to assess the likelihood of NIF. RESULTS: A total of 254 patients (74%) had IF, and 89 patients (26%) had NIF. The most common aetiology among the NIF patients was the varicella zoster virus (VZV, 45%). Among the factors analysed, efflorescence (odds ratio (OR) 17.3) and rater agreement (OR 5.3) had the highest associations with NIF. The day of consultation (Friday, OR 3.6) and the cMRI findings of contrast enhancement of the facial nerve (OR 2.3) were also risk factors associated with NIF. In contrast, the local weather, Google Trends data, and cardiovascular risk factors were not associated with NIF. CONCLUSION: The findings of this retrospective study highlight the importance of patient history and careful inspections to identify skin lesions for the differential diagnosis of acute facial nerve palsy. Special caution is advised for hospital physicians during the tick season, as a surge in NIF cases can lead to a concomitant increase in IF cases, making it challenging to choose adequate diagnostic methods.

Antiganglioside antibody frequency in routine clinical care settings.

BACKGROUND AND PURPOSE: Antiganglioside antibodies (AGAs) might be involved in the etiopathogenesis of many neurological diseases, such as Miller-Fisher syndrome (MFS) and Guillain-Barré syndrome (GBS). Available comprehensive reference data regarding AGA positivity rates and cross-responsiveness among AGAs (where one line immunoblot is positive for ≥1 AGA) during routine clinical care are scant. METHODS: In this 10-year monocentric retrospective study, 3560 immunoglobulin (Ig) G and IgM line blots (GA Generic Assays' Anti-Ganglioside Dot kit) obtained using cerebrospinal fluid (CSF) and serum samples from 1342 patients were analyzed for AGA positivity in terms of 14 diagnosis categories and AGA cross-responsiveness. RESULTS: Of all 3560 line blots 158 (4.4%) and of all CSF samples 0.4% (4/924) CSF line blots were AGA positive. For serum IgG, blots with positivity rates higher than the standard deviation of 15.6% were associated with MFS (GD3, GD1a, GT1a and GQ1b) and acute motor axonal neuropathy (AMAN) (GM1, GD1a and GT1a). For serum IgM, blots with positivity rates higher than the standard deviation of 8.1% were associated with AMAN (GM2, GT1a and GQ1b), MFS (GM1, GT1a and GQ1b), multifocal motor neuropathy (MMN) (GM1, GM2 and GQ1b) and chronic inflammatory demyelinating polyneuropathy (CIDP) (GM1). Cross-responsiveness was observed in 39.6% of all positive serum AGA. CONCLUSIONS: Testing for AGAs during routine clinical care rarely led to positive findings, both in serum and even less in CSF, except for the diagnoses AMAN, MFS, MMN and CIDP. Nonspecific findings found as cross-responsiveness between different AGA samples occur frequently, impacting the positivity of most AGA subtypes.