1. Teaching NeuroImages Neurology Resident and Fellow Section © 2014 American Academy of Neurology A 67 year-old man with progressive facial diplegia and gait imbalance

2. Vignette A 67-year-old man presents with progressive diplopia, dysarthria, dysphagia, and gait imbalance. Neurological examination revealed ophthalmoplegia, facial diplegia, and areflexia without signs of respiratory failure. CSF showed albuminocytologic dissociation. Initial spirometry yielded falsely low values due to air leakage and resulted in ICU admission, which may have been avoided with a better test. Kramer et al. © 2014 American Academy of Neurology

3. Kramer et al. Video © 2014 American Academy of Neurology

4. Kramer et al. Imaging © 2014 American Academy of Neurology

5. Table: Pulmonary Function Tests In Patient With Facial Diplegia Using Traditional Mouthpiece And With Facemask Forced Vital Capacity (mL) Maximal Inspiratory Pressure (mmH 2 O) Maximal Expiratory Pressure (mmH 2 O) Tidal Volume (mL) Using Spirometry With Traditional Mouthpiece Trial 1700+8-24100 Trial 26500-24125 Trial 3660+6-24115 Using Spirometry With Facemask Trial 12,750+38-42375 Trial 22,800+45-42350 Trial 32,800+42-38300 Kramer et al. © 2014 American Academy of Neurology

6. How to Unmask Respiratory Strength Confounded by Facial Diplegia Spirometry measures diaphragmatic strength in acute neuromuscular disorders and often directs patient triage. Facial weakness can confound readings with a conventional mouthpiece due to poor seal. Facemask spirometry in patients with motor neuron disease 1 and normals 2 improves values by reducing leak. We demonstrate unequivocally that mask spirometry surmounts spurious readings in acute facial diplegia. Kramer et al. © 2014 American Academy of Neurology