The Spectrum Between Catatonia and Functional Neurologic Disorder Superimposed on Post-Infectious Encephalitis in a Marine Recruit

Catatonia, a neuropsychiatric condition characterized by abnormal speech, volition, and movement, is primarily thought of as a symptom of a primary psychiatric pathology, but there are a variety of non-psychiatric medical conditions that must be considered. As a result of symptomatic complexity and the wide range of differential diagnoses, catatonia-like symptoms can cloud the clinical evaluation and complicate treatment regimens. Within the realm of catatonic-like diagnoses is functional neurological disorder because of its vast range of potential presentations. Functional neurologic disorder can be diagnosed by evidence of incompatibility between neurologic symptoms and recognized neurological or medical conditions. Clinical uncertainty is further intensified in the presence of co-morbid medical etiologies because of inability to neatly delegate symptoms to a specific diagnosis. The blurred spectrum between catatonia and functional neurologic disorder is highlighted in this patient's complex clinical presentation while being further obscured in the setting of a possible overlying encephalitis exacerbating the presentation. This case report presents a unique case of a Marine recruit whose inconsistent catatonic symptoms caused diagnostic uncertainty and were ultimately decided to have neurologic and psychiatric contributions, highlighting that diagnoses are not mutually exclusive and should be continually re-assessed as new data become available. This report also showcases the distinctiveness of U.S. Marine culture and possible physical manifestations because of imposed psychological stress.