Cellular immune response in prognosis of Bell’s palsy and its relation to clinical and electrophysiological findings

Objective: To determine the cellular immune response in Bell’s palsy (BP) and its prognostic value in relation to clinical and electrophysiological findings. Methods: Twenty patients with BP were subjected to: Facial nerve paralysis assessment according to House–Brackmann (H&B) grading system, bilateral facial nerve conduction study with electroneurography (ENoG) quotient calculation, blink reflex, and needle electromyography (EMG) for the affected side; one week from the onset. Before the start of medical treatment, peripheral blood mononuclear cell subsets were analyzed to reveal the percentage of total T cells (CD3+), T helper/inducer cells (CD4+), T cytotoxic (CD8+) and B cells (CD19+). Patients were followed up by H&B, ENoG and needle EMG up to 3 months from the onset (end point). Fifteen age and sex matched healthy control subjects for the electrophysiological study and laboratory tests were included. Results: The percentages of CD3+, CD4+ & CD8+ were significantly depressed in BP patients than in control. CD19+ percentage did not show significant difference between them. On follow up, H&B revealed significant improvement. Neither electrophysiological parameters nor ENoG showed significant difference between initial and follow up assessments. Initial CD4+ percentage correlated negatively with disease duration. While Initial CD8+ percentage correlated positively with follow up compound muscle action potential (CMAP) amplitude of orbicularis oris muscle and ENoG of orbicularis oculi and nasalis muscles. Initial CD19+ percentage correlated negatively with follow up H&B and R1 & R2 responses of follow up blink reflex. Initial CD3+ percentage did not correlate with any of the follow up measures. Conclusion: Decreased percentage of peripheral blood CD3+, CD4+ & CD8+ in BP patients emphasizes the role of cell mediated autoimmune pathogenesis in the acute stage of the disease. These cells have a prognostic significance for prediction of the disease duration and outcome. Analysis of T lymphocytes subsets may provide an additional parameter to differentiate patients with favorable from those with poor prognosis.