A case of leucine-rich glioma-inactivated 1 antibody encephalitis with schizophrenia-like symptoms as an initial clinical manifestation

Abstract

Leucine-rich glioma-inactivated 1 (LGI-1) antibody encephalitis is a type of limbic encephalitis characterized by faciobrachial dystonic seizure and short-term memory loss as initial clinical symptoms. We present a case initially misdiagnosed as schizophrenia and finally diagnosed as LGI-1 antibody encephalitis. A 41-year-old female presented to the neurology clinic with a 4-month history of anxiety and disoriented speech and a new onset headache. Her explanation of symptoms was unclear, and she was unable to answer questions properly. Her brain magnetic resonance imaging (MRI) showed no specific lesions. After 6 months, depersonalization, place disorientation and memory impairment were noted. Her symptoms continue to progress, experiencing visual/auditory hallucinations. She was diagnosed with schizophrenia and admitted to a closed psychiatric ward. In the hospital, she showed mild fever, and her memory loss worsened faster than her psychiatric symptoms, unlike in schizophrenia. Follow-up MRI scans showed a diffusely enlarged right hippocampus with a 2.5 × 1.3-cm mass lesion. Electroencephalogram showed rhythmic theta activities/interictal spikes in the right frontal lobe, for which she was treated with an antiepileptic drug. Cerebrospinal fluid analysis results showed pleocytosis. Based on this, autoimmune encephalitis was diagnosed, and steroid pulse treatment and immunoglobulin treatment were performed. Positivity for LGI-1 antibody was reported and finally led to diagnosis of LGI-1 antibody encephalitis. Clinical symptoms gradually improved, and the lesion had shrunk considerably on MRI performed 6 months after immunoglobulin treatment. She reports persistent amnesia for 6 months but has returned to her daily life under follow-up observation.

Anti‐LGI1 encephalitis preceded by psychiatric symptoms: A case report

“…7 Moon et al reported the case of a 41-year-old woman who presented with anxiety for 4 months, followed by hallucinations 6 months later, and was diagnosed with schizophrenia. 8 Taken together, the present and the previous cases indicate diversity in the characteristics, age of onset, and the duration of isolated psychiatric symptoms. [6][7][8] In the present case, the main symptoms at the first visit to our hospital were hallucinations and delusions, and acute psychotic disorder was also a differential diagnosis.…”

“…8 Taken together, the present and the previous cases indicate diversity in the characteristics, age of onset, and the duration of isolated psychiatric symptoms. [6][7][8] In the present case, the main symptoms at the first visit to our hospital were hallucinations and delusions, and acute psychotic disorder was also a differential diagnosis. Anti-NMDA receptor encephalitis tends to develop more frequently in young women and is associated with tumors.…”

“…Furthermore, in patients with anti-LGI1 encephalitis with FBDSs, ictal changes may not be seen on EEG, 10,11 and FBDSS may even be misdiagnosed as psychogenic seizures. 11 In fact, the previous reports showed that patients developing isolated psychiatric symptoms in the initial phase were diagnosed with psychiatric disorders, [6][7][8] and there was a long interval before anti-LGI1 encephalitis was diagnosed. 6,8 The MRI findings of anti-LGI1 encephalitis are characterized by abnormal findings in the medial temporal lobes, 1 although approximately half the cases of anti-LGI1 encephalitis accompanied by FBDSs do not show abnormal findings in the medial temporal lobes.…”

“…11 In fact, the previous reports showed that patients developing isolated psychiatric symptoms in the initial phase were diagnosed with psychiatric disorders, [6][7][8] and there was a long interval before anti-LGI1 encephalitis was diagnosed. 6,8 The MRI findings of anti-LGI1 encephalitis are characterized by abnormal findings in the medial temporal lobes, 1 although approximately half the cases of anti-LGI1 encephalitis accompanied by FBDSs do not show abnormal findings in the medial temporal lobes. 11 In addition, abnormal findings in the basal ganglia on MRI are associated with the onset of FBDSs.…”

“…Approximately 70% of patients with anti‐NMDA receptor encephalitis present with psychiatric symptoms, such as agitation and psychosis, at the time of initial diagnosis, 4 and approximately 4% of patients reportedly develop isolated psychiatric symptoms in the initial phase 5 . With regard to anti‐LGI1 encephalitis, there are only a few reports of isolated psychiatric symptoms in the initial phase 6–8 …”