Authors: Aliu Opeyemi Yakubu, et al.

Abstract: Clozapine is an atypical antipsychotic for treatment-resistant schizophrenia. Despite its efficacy, it is associated with many serious side-effects, including pericarditis. Clozapine-associated pericarditis may range from mild symptoms to life-threatening complications. Despite increasing case reports, a comprehensive synthesis is lacking.

In this review, fever (52.8%), breathlessness (50%), and tachycardia (44.4%) were the most common symptoms. Diagnostic tests consistently indicated elevated inflammatory markers, including C-Reactive Protein and erythrocyte sedimentation rate. Echocardiograms confirmed pericardial effusion in 88.9% of cases. Management strategies included colchicine (16.7%) and analgesics (19.4%), with cardiac recovery achieved in all but one case. Clozapine rechallenge was attempted in 16.7% of the cases, with successful outcomes in 83.3% of these cases.

Importance: “Clozapine-associated pericarditis is a rare but serious adverse event characterized by elevated inflammatory markers and diagnostic imaging abnormalities,” say the authors. “Prompt recognition and tailored management, including anti-inflammatory treatment and careful rechallenge, can lead to favorable cardiac and psychiatric outcomes.”

Authors: Tomoteru Seki, MD, et al.

Abstract: Higher body mass index (BMI) generally increases susceptibility to certain diseases. However, previous studies have shown that metformin, a medication for type 2 diabetes mellitus (T2DM), can improve various outcomes, including survival in obese patients. This indicates that the effectiveness of metformin on certain outcomes is more pronounced in those with a higher BMI. It remains unclear if the effects of metformin on delirium risk differ according to BMI.

This study analyzed 506 T2DM individuals. The authors compared delirium cases identified during hospitalization and survival curves among T2DM patients with and without a history of metformin use, stratified by BMI. Moreover, they investigated the influence of metformin use history and various other factors on cases of delirium identified during hospitalization and three-year mortality among T2DM patients in different BMI groups.

Importance: The authors concluded metformin use history was associated with a lower risk of delirium and mortality in the T2DM obesity group.

Authors: Sheue-Jane Hou, MD, et al.

Abstract: Evidence indicates that peripheral vestibular disorders (PVDs) are associated with depressive disorders. The authors aimed to elucidate temporal and causal relationships.

They examined PVD and its subtypes as both the cause and consequence of depressive disorders using data from the Taiwan National Health Insurance Research Database.

Patients with PVDs had a 4.29-fold higher risk of developing depression. Subgroup analyses based on PVD subtypes revealed that all four PVD subtypes (benign paroxysmal positional vertigo, Meniere’s disease, vestibular neuritis, and unspecified PVD) predicted higher risks of depressive disorders. Similarly, individuals with depressive disorders exhibited a 3.29-fold higher risk of developing PVDs.

Importance: The studies revealed a bidirectional relationship between PVDs and depression. As the authors say, further research is required to establish if these two conditions have common pathogenic mechanisms and if treating one effectively reduces the morbidity rate of the other.

Authors: Abigail Clark, MD, et al.

Abstract: Paradichlorobenzene (PDCB) is an active ingredient in mothballs and toilet bowl deodorizers. When PDCB is ingested, acutely or chronically, toxicity involving multiple organ systems, including the brain, kidney, liver, and skin, may result.

The authors describe the case of a 32-year-old woman who was admitted to a specialized medical and psychiatric inpatient unit with subacute cognitive decline, a diffuse ichthyotic rash, hyperreflexia, bowel and bladder incontinence, and upper extremity rigidity. Initial extensive serum, cerebral spinal fluid, and urine testing was only notable for iron deficiency anemia. Magnetic resonance imaging of the brain revealed periventricular leukoencephalopathy.

Collateral was then sought from her spouse, who disclosed she had been ingesting toilet bowel deodorizers for over a year before presentation. Subsequent serum and urine PDCB concentrations were elevated, and the patient was diagnosed with PDCB toxicity. She was provided supportive care, but ultimately, she developed severe cognitive decline, requiring a gastrostomy tube for nutritional support and was discharged to a skilled nursing facility. Her condition was unchanged six months after discharge.

The authors performed a systematic review of all reported cases of PDCB toxicity in humans and revealed that PDCB toxicity often results in significant but nonspecific neuropsychiatric, skin, and neuroimaging findings. Young women with iron deficiency anemia and substance use histories appear to be at particular risk of PDCB toxicity, though more research is needed to clarify these associations.

Importance: As the authors say, clinicians should maintain a high degree of suspicion for toxic ingestion and perform thorough collection of collateral history when the cause of encephalopathy is unknown. Greater attention should also be given to PDCB as a substance of abuse.