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Infections in the differential diagnosis of Bell's palsy: a plea for performing CSF analysis
Katrin Henkel1,2, Peter Lange1, Helmut Eiffert3
1Departments of Neurology, University Medical Centre Göttingen (UMG), Robert-Koch-Straße 40, 37075, Göttingen, Germany.
Purpose:
Peripheral facial nerve palsy (FP) is the most common single nerve affection. Most cases are idiopathic, but a relevant fraction is caused by potentially treatable aetiologies including infections. Not all current diagnosis and treatment guidelines recommend routine cerebrospinal fluid (CSF) analysis in the diagnostic workup of this symptom. In this study, we evaluated frequency of aetiologies and relevance of CSF analysis in an interdisciplinary cohort.
Methods:
We retrospectively analysed all cases of newly diagnosed FP treated at a German university medical centre in a 3-year period. Diagnostic certainty was classified for infectious aetiologies according to clinical and CSF parameters.
Results:
380 patients with FP were identified, 63 children and 317 adults. Idiopathic Bell´s palsy was predominant in 61 %. 25 % of FP was attributed to infections, and other causes were identified in 14 %. Clinical presentation alone was not conclusive for infectious aetiology, in almost half of patients with infection-attributed FP the reported symptoms or clinical signs did not differ from common symptoms of idiopathic Bell`s palsy. Determination of C-reactive protein or white blood cell count was not helpful in the identification of infectious causes, and radiological imaging was performed in a high proportion of adult patients without conclusive results. Nuchal rigidity was found only in 7 % of patients with CSF pleocytosis. The predominant infectious agents were Borrelia burgdorferi, VZV and HSV, and in most of these cases diagnosis relied on the findings of CSF analysis.
Conclusions:
This study outlines the importance of careful differential diagnosis to identify infectious causes of facial nerve palsy. The high incidence and frequent unspecific clinical presentation of infectious FP underlines the importance of including CSF analysis in the diagnostic routine workup of FP.
Insights
Facial nerve palsy (FP) is often idiopathic, but infections are a treatable cause. Cerebrospinal fluid (CSF) analysis is crucial for diagnosing infectious FP, as symptoms can mimic idiopathic cases.
Area of Science:
- Neurology
- Infectious Diseases
- Diagnostic Medicine
Background:
- Peripheral facial nerve palsy (FP) is a common neurological condition.
- While often idiopathic (Bell's palsy), a significant portion results from treatable infections.
- Current guidelines do not uniformly recommend cerebrospinal fluid (CSF) analysis for FP diagnosis.
Purpose of the Study:
- To evaluate the frequency of different etiologies in facial nerve palsy.
- To determine the relevance and diagnostic utility of CSF analysis in FP workup.
- To assess the interdisciplinary cohort for FP causes and diagnostic approaches.
Main Methods:
- Retrospective analysis of newly diagnosed FP cases at a German university medical center over 3 years.
- Classification of diagnostic certainty for infectious etiologies based on clinical and CSF parameters.
- Inclusion of adult and pediatric patient data.
Main Results:
- 380 FP patients identified (63 children, 317 adults); 61% idiopathic Bell's palsy.
- 25% of FP cases were attributed to infections; 14% to other causes.
- Clinical presentation alone was often inconclusive for infectious etiology; CSF analysis was key for diagnosing Borrelia burgdorferi, VZV, and HSV infections.
Conclusions:
- Careful differential diagnosis is essential to identify infectious causes of facial nerve palsy.
- The high incidence and non-specific symptoms of infectious FP necessitate routine CSF analysis in its diagnostic workup.
