PMC9411636_01
Recording from both orbicularis oculi muscles, stimulating the supraorbital nerve on each side. (A) Stimulating the left side results in a normal R1 response while ipsilateral and contralateral R2 components are absent. Stimulating the right side results in a normal R1 component, while the ipsilateral R2 response is delayed and the contralateral R2 component is absent. This feature is related to a bilateral alteration of the multisynaptic pathway between the nucleus of the spinal tract of V cranial nerve in the ipsilateral pons and medulla and interneurons forming connections to the ipsilateral and contralateral facial nuclei. (B) The blink reflex is normal.
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Nerve conduction studies, F-response, and H-reflex resulted normal while blink reflex showed an abnormal pattern suggesting brainstem dysfunction ( Figure 1A ). Six weeks after disease onset, the blink reflex resulted normal ( Figure 1B ).
Timeline with selected events. EEG, electroencephalogram; ENG, electroneurography; IVIg, intravenous immunoglobulin; IVMP, intravenous methylprednisolone; MRI, magnetic resonance imaging.
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After 2 weeks, he was able to walk without assistance and the neurological examination was normal ( Figure 2 ).