Remission of psychosis in Lambert–Eaton myasthenic syndrome after electroconvulsive therapy

Introduction

Psychotic symptoms have rarely been described in Lambert-Eaton myasthenic syndrome, and the underlying mechanism remains uncertain. The case previously reported raised the possibility of a shared autoimmune or channelopathy-related substrate, but the longitudinal psychiatric response had not yet been fully described.

Aims

To report the clinical evolution of a young woman with Lambert-Eaton myasthenic syndrome and persistent psychosis, focusing on response to sequential antipsychotic trials, clozapine, electroconvulsive therapy, and ancillary etiological investigations.

Methods

This is a single-case longitudinal report based on clinical records, neurological and psychiatric assessments, and collateral information from caregivers. No standardized symptom scales were used, so response was judged by repeated bedside clinical observation and caregiver report. Because of the case-report design, no inferential statistical analysis was performed; data are presented descriptively as clinically observed outcomes over time. Work-up included cerebrospinal fluid studies, serum neuronal antibody testing, oncological screening, and genetic testing for microdeletions associated with neurodevelopmental syndromes, including 22q11.2 deletion syndrome.

Results

The patient, a 21-year-old woman, developed Lambert-Eaton myasthenic syndrome at age 17 and later presented with multisensory psychotic phenomena, including auditory, haptic, kinesthetic, and somatic passivity experiences. During follow-up, she underwent multiple antipsychotic adjustments, with only slight and unstable clinical improvement. Given the persistence of psychotic symptoms, clozapine was introduced and titrated to 75 mg/day; however, the response remained limited and was judged only mildly beneficial on clinical grounds. Because of the poor control of psychosis, electroconvulsive therapy was started. After 12 sessions, there was a marked clinical improvement, with remission of psychotic symptoms. At the current follow-up, more than 1 month after the last session, no recurrence had been observed. Previous investigations had excluded autoimmune encephalitis and paraneoplastic disease, and genetic testing for microdeletions, including 22q11.2 deletion, was negative.

Conclusions

This case suggests that severe psychosis may coexist with Lambert-Eaton myasthenic syndrome and may remain refractory to several antipsychotic strategies, including clozapine at a modest dose. Electroconvulsive therapy was followed by a clinically meaningful remission in this patient, although causality cannot be established from a single case and spontaneous fluctuation cannot be fully excluded. The negative immunological, oncological, and genetic investigations reduce but do not eliminate the likelihood of a defined secondary cause. Ongoing follow-up is needed to determine the durability of remission and to further clarify whether this presentation reflects a shared neuroimmune pathophysiology or an unusual comorbidity. From a clinical perspective, the temporal relationship between refractory psychosis and subsequent robust response to electroconvulsive therapy is notable, particularly in the context of persistent neurological disease and prior limited response to pharmacotherapy. Although the case does not prove an autoimmune origin, it supports systematic medical reassessment in atypical or treatment-resistant psychosis and suggests that electroconvulsive therapy may be a useful option when antipsychotic strategies are insufficient.

References

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