Non-Convulsive Status Epilepticus in the Presence of Catatonia: A Clinically Focused Review

Introduction: Catatonia is classically associated with psychiatric conditions but may occur in medical and neurologic disorders. Status epilepticus (SE) is a seizure lasting more than five minutes or two or more seizures within a five-minute period without interictal recovery of consciousness. Non-convulsive status epilepticus (NCSE) is SE without prominent motor activity that may present with catatonic symptoms. The relevance of NCSE as a potential etiology for catatonia is not clear in the literature. Methods: A systematic review was completed to evaluate the literature on NCSE presenting with catatonia. PubMed and PsycInfo databases were searched and articles were reviewed for the presence of catatonia and NCSE. Results: 15 articles describing 27 cases meeting inclusion criteria were identified. The authors add 1 case to the literature. The most common catatonic symptoms identified in NCSE were mutism and stupor. Clinical features frequent in NCSE presenting with catatonia included new catatonic symptoms, age over 50 years, comorbid neurological conditions, or a change in medications that affect seizure threshold. A documented psychiatric history was also common and may contribute to delayed diagnosis. Discussion/Conclusion: It is important to consider NCSE in the differential diagnosis of new catatonic symptoms. A suggested approach to diagnostic evaluation is provided.