Diagnosing Functional Neurological Disorder through History and Physical Examination: A Case Report

Differentiating between stroke and stroke mimics (i.e., non-vascular conditions) is a major challenge, as they often involve similar presenting symptoms. A common type of stroke mimic is functional neurological disorder (FND), a somatic disorder caused by severe stress, emotional conflict, or a psychiatric disorder usually presenting with one or more neurologic symptoms. This condition is associated with voluntary motor and sensory symptoms that are internally inconsistent with identifiable neurological diseases and lack structural lesions. We describe a 54-year-old female with a history of transient ischemic attack resulting in bilateral blindness and recent social stressors, who presented with right-sided facial and extremity motor and sensory deficits, bilateral diplopia, and dysphagia. Her left upper and lower extremities had 2 out of 5 motor strength, a weak hand squeeze, and a positive Babinski reflex on the contralateral side of her weakness, which resolved the next day. In addition, decreased sensation to light touch and temperature over the right arm and leg were appreciated without a dermatomal pattern. Given the negative stroke work-up, atypical physical exam findings, prior history of blindness, and in the setting of recent psychological stressors, her acute motor and sensory deficits were diagnosed as FND after evaluation by the Neurology service. The current case demonstrates the following important features of making a FND diagnosis: 1) careful history taking in eliciting potential psychological stressors; 2) a comprehensive neurological examination assessing the presence of findings specific for FND (e.g., greater weakness with active rather than passive movements, fluctuating weakness); 3) multidisciplinary collaboration with neurology and psychiatry providers to aid in performing a comprehensive assessment.