Case Report: When catatonia-like symptoms are not catatonia: Guillain–Barré syndrome in a patient with schizophrenia

Introduction: Schizophrenia is a severe psychiatric disorder. Catatonia is relatively common in schizophrenia; its main manifestations include catatonic stupor, mutism, negativism, and other psychomotor symptom clusters. Patients with schizophrenia are at increased risk of infections, which are also recognized triggers for Guillain-Barré syndrome (GBS). GBS typically presents with limb weakness, paresthesia, facial weakness, respiratory muscle paralysis, and autonomic symptoms, and may similarly result in severe immobility and impaired communication. Consequently, when schizophrenia (especially with catatonic features) coexists with GBS, history taking and clinical assessment can be challenging, increasing the risk of misdiagnosis or delayed diagnosis. Case presentation: We report a 28-year-old man with a 3-year history of schizophrenia who was found after 2 weeks of lost contact and admitted emergently. His first episode featured hallucinations, persecutory delusions, and catatonia, which remitted with antipsychotic and other medications treatment. He subsequently relapsed twice after discontinuing medication; both relapses presented mainly with hallucinations and delusions without catatonia and remitted after re-treatment, followed by regular risperidone maintenance. In the current episode, hallucinations and delusions recurred and progressed to apathy, reduced speech and activity, and eventually complete mutism, immobility, and inability to perform self-care. Schizophrenia was initially diagnosed per DSM-5 criteria and risperidone was initiated. Further evaluation revealed pulmonary infection with limb weakness and decreased tendon reflexes, differing from the increased muscle tone typical of catatonia. Cerebrospinal fluid showed albuminocytologic dissociation (protein 0.61 g/L; leukocytes 1.2×10^6/L), and comorbid Guillain-Barré syndrome was considered. He was transferred to neurology and treated with intravenous immunoglobulin (25 g/day for 5 days) plus rehabilitation, with gradual improvement. During the 1-year follow-up, the patient continued risperidone 4 mg as maintenance to prevent psychiatric relapse; his symptoms had essentially resolved, and he returned to normal work and daily life. Conclusion: In psychiatric practice, mutism and immobility are often attributed to primary psychiatric illness, particularly in patients with established diagnoses, which can lead to missed or delayed detection of medical conditions. This case underscores the importance of thorough neurologic examination and timely investigations in uncooperative patients, especially after antecedent infection, including consideration of lumbar puncture to evaluate for comorbid neurologic disorders such as Guillain-Barré syndrome.