Case report: A case of anti-recoverin antibody-positive encephalitis exhibiting Cotard and Capgras delusions that was successfully treated with electroconvulsive therapy.

Recoverin is a neuron-specific calcium-binding protein that is mainly located in the retina and pineal gland. Few reports have described patients with anti-recoverin antibody-positive encephalitis, and no cases of psychosis associated with this encephalitis have been reported. We report a patient with anti-recoverin antibody-positive encephalitis with Cotard and Capgras delusions who was successfully treated with electroconvulsive therapy (ECT). The patient was a 25-year-old woman. She exhibited disorientation, executive function deficits, tremors in the upper limbs, generalized athetoid-like involuntary movements, hallucinations, incontinence, and fever, which led to her admission to our hospital. Upon admission, she complained of Cotard delusions. Various diagnostic tests, including cerebrospinal fluid analysis, antibody screening, and brain imaging, were unremarkable, except for positivity for serum anti-recoverin antibodies, non-specific general slowing on electroencephalography and decreased regional cerebral blood flow (rCBF) in the frontal and occipital lobes, and increased rCBF in the basal ganglia and pons on single-photon emission computed tomography. She was eventually diagnosed with encephalitis positive for anti-recoverin antibodies and treated with immunoglobulins and steroids. Her neurological symptoms improved temporarily, but three months later, psychiatric symptoms, i.e., suicidal thoughts and Cotard and Capgras delusions, were exaggerated. After ECT, her condition significantly improved. In conclusion, the present report suggests that pineal gland dysfunction due to anti-recoverin antibody or its cross-reactivity with neuron-specific calcium-binding proteins may contribute to the neuropsychiatric symptoms observed in anti-recoverin antibody-positive encephalitis and that ECT can be a viable treatment option if immunotherapy proves ineffective. Additionally, decreased rCBF in the prefrontal cortex may be associated with the clinical features of Capgras and Cotard delusions.

Regional cerebral blood flow in a patient with asystole episodes associated with anti-NMDA receptor encephalitis.

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is a rare and severe autoimmune encephalitis that displays neuropsychiatric symptoms and autonomic instability, e.g., hypoventilation and cardiac arrhythmia. Severe arrhythmia including asystole associated with this encephalitis is rare. Several causes have been suggested. Nevertheless, no report of the literature has described examination by functional brain imaging of a patient with asystole during anti-NMDA receptor encephalitis. This case is that of a 34-year-old woman diagnosed as having anti-NMDA receptor encephalitis. She repeatedly showed 10-20 s asystole episodes necessitating a temporary transvenous pacemaker. After resection of the bilateral ovarian cystic tumor, her symptoms improved. Regional cerebral blood flow (rCBF) was evaluated using single-photon emission computed tomography. The rCBF was increased in the amygdala, hypothalamus, anterior cingulate, hippocampus, and anterior temporal lobes, but decreased in the dorsolateral frontal lobes, parietal lobes, and occipital lobes. Findings in this case suggest that altered rCBF in the patient with asystole episodes associated with anti-NMDA receptor encephalitis was observed in several brain lesions. The rCBF increases in the central autonomic networks, i.e., the amygdala, hypothalamus, and anterior cingulate, might be associated with dysregulation of sympathetic and parasympathetic nervous systems leading to asystole.

Successful treatment by paroxetine of delusional disorder, somatic type, accompanied by severe secondary depression.

The case of a 42-year-old woman with delusional disorder, somatic type (DDST), with infestation delusion and delusions of body odor and halitosis accompanied by severe secondary depression is presented. These somatic delusions and depressive symptoms responded favorably to treatment with paroxetine 10 to 30 mg/d. Hypoperfusion in the left temporal and parietal lobes observed when she had marked clinical symptoms was improved at near recovery. The present report suggests that paroxetine is effective and a reasonable drug for DDST with secondary depression. It also supports previous observations that DDST is associated with hypoperfusion in the temporal and parietal lobes.

Extremely grotesque somatic delusions in a patient of delusional disorder and its response to risperidone treatment.

A 54-year-old man with delusional disorder, somatic type (DDST) showed extremely grotesque somatic delusions, i.e., the presence of another lower jaw with teeth and tongue accompanied by annoying sensations. These somatic delusions responded favorably to treatment with risperidone 2-3 mg/day. The single photon emission computed tomography taken when he had marked somatic delusions showed hypoperfusion in the temporal and parietal lobes. The present report suggests that delusion of reduplication of body parts, which has been generally associated with organic brain diseases, is also observed in DDST. This report also supports prior observations on the efficacy of risperidone for DDST and the association between this disorder and hypoperfusion in the temporal and parietal lobes.