Neuropsychiatric adverse reactions in patients treated with denosumab: two case reports and a review of data from the FDA Adverse Event Reporting System (FAERS)

Denosumab is a human monoclonal antibody indicated for patients with osteoporosis and a high risk of fractures. It targets RANKL, the receptor activator of NF-κB (RANK) ligand, blocking RANKL-RANK interaction and leading to rapid osteoclast-mediated bone resorption inhibition. But RANK is widely expressed in neurons, microglia, and astrocytes. RANKL/RANK/NF-κB system can play an important role in the neuroinflammatory response, depressive behavior, memory impairments, and neurotrophism. We present two well-documented case reports of recurrent neuropsychiatric manifestations in patients treated with denosumab and a descriptive review of similar cases reported to the Food and Drug Administration Adverse Event Reporting System (FAERS) database between 2012 and 2022. Only those reported by healthcare professionals, coding denosumab as the only suspected drug, were retained. An 81-year-old woman with pre-existing mild cognitive impairment suffered two acute confusional episodes and another 81-year-old woman with depression in remission suffered two depressive recurrences with anxiety and psychomotor inhibition, in both cases following sequential administrations of denosumab without underlying calcium/phosphate imbalance. Scores on Naranjo Adverse Drug Reaction Probability Scale were 6 and 7, respectively, suggesting a probable causal relationship. Of the 91,151 cases with denosumab exposure reported to FAERS, 5.7% were related to psychiatric/neurological disorders and 23.8% of these corresponded to cognitive impairment, depressive/mood disturbances, or psychomotor retardation. Denosumab may cause transient but severe neuropsychiatric symptoms by several mechanisms involving RANKL blockade and subsequent immuno-inflammatory changes, at least in subjects with pre-existing neurobiological vulnerability. We recommend caution and careful monitoring of these patients following denosumab administrations.

Clinical features and outcomes of COVID-19 patients hospitalized for psychiatric disorders: a French multi-centered prospective observational study

BACKGROUND

Patients with psychiatric disorders are exposed to high risk of COVID-19 and increased mortality. In this study, we set out to assess the clinical features and outcomes of patients with current psychiatric disorders exposed to COVID-19.

METHODS

This multi-center prospective study was conducted in 22 psychiatric wards dedicated to COVID-19 inpatients between 28 February and 30 May 2020. The main outcomes were the number of patients transferred to somatic care units, the number of deaths, and the number of patients developing a confusional state. The risk factors of confusional state and transfer to somatic care units were assessed by a multivariate logistic model. The risk of death was analyzed by a univariate analysis.

RESULTS

In total, 350 patients were included in the study. Overall, 24 (7%) were transferred to medicine units, 7 (2%) died, and 51 (15%) patients presented a confusional state. Severe respiratory symptoms predicted the transfer to a medicine unit [odds ratio (OR) 17.1; confidence interval (CI) 4.9-59.3]. Older age, an organic mental disorder, a confusional state, and severe respiratory symptoms predicted mortality in univariate analysis. Age >55 (OR 4.9; CI 2.1-11.4), an affective disorder (OR 4.1; CI 1.6-10.9), and severe respiratory symptoms (OR 4.6; CI 2.2-9.7) predicted a higher risk, whereas smoking (OR 0.3; CI 0.1-0.9) predicted a lower risk of a confusional state.

CONCLUSION

COVID-19 patients with severe psychiatric disorders have multiple somatic comorbidities and have a risk of developing a confusional state. These data underline the need for extreme caution given the risks of COVID-19 in patients hospitalized for psychiatric disorders.

Acute Confusional State Revealing Moyamoya Disease in the Emergency Department: A Rare Entity

A 54-year-old woman was admitted to the emergency department for an acute, fluctuating altered mental status and reduced perceptual awareness of her surroundings as well as disorganized thinking. Blood tests, including for drugs, were normal. A CT scan of the brain was normal. Magnetic resonance imaging and CT angiography of the supra-aortic vessels were both were consistent with moyamoya disease. The patient was hospitalized for further investigations.

LEARNING POINTS

Moyamoya disease should be considered in the differential diagnosis of middle-aged patients presenting with an acute confusional state of unknown aetiology in the emergency department.The absence of focal examination findings does not exclude neurological disease as the cause of acute confusion, requiring further neuroimaging tests.

Dopaminergic Hyperactivity in Neurological Patients with Delirium

BACKGROUND

Delirium has important etiological, prognostic, and therapeutic implications. The study of neurochemical markers in this condition is relevant to the understanding of its pathophysiology. The assessment of the dopamine system is particularly relevant, as dopamine antagonists are the most used drugs in delirium.

AIM

To analyze neurotransmission markers in patients with delirium, focusing in the dopamine metabolite, homovanillic acid.

METHODS

A case-control study was performed at the National Institute of Neurology and Neurosurgery, Mexico, including hospitalized patients in which lumbar puncture was obtained for diagnostic purposes. Cases were selected if they fulfilled DSM-5 criteria for delirium. Age-paired controls were patients in which delirium was ruled out, selected at the same clinical scenario, during the same period. Neurological and systemic diagnoses were registered. Delirium was assessed using the DRS-98-R instrument. The dopamine metabolite, homovanillic acid (HVA), was measured by means of high-performance liquid chromatography. Other neurotransmission markers were also measured (5-hydroxyindoleacetic acid, glutamate, aspartate, GABA, glycine, arginine, citrulline, nitrites, and nitrates). A logistic regression model was used to determine pathogenic factors associated with the presence of delirium.

RESULTS

68 neurological patients with delirium and 68 patients without delirium were included. Higher homovanillic acid levels in cerebrospinal fluid were significantly associated with delirium. This result was significant after a subanalysis in patients without exposure to antipsychotics. Male gender and autoimmune limbic encephalitis were also associated with the presence of delirium.

CONCLUSIONS

In hospitalized neurological patients, dopaminergic hyperactivity and autoimmune limbic encephalitis are pathogenic factors associated with the presence of delirium.

A Clinical Approach to Diagnosing Encephalopathy

Encephalopathy refers to dysfunction of the level or contents of consciousness due to brain dysfunction and can result from global brain insults or focal lesions. The underlying causes of encephalopathy include both primary neurologic and systemic conditions. This article discusses the differential diagnosis of encephalopathy, with a focus on primary neurologic causes. A practical schema for organizing the differential diagnosis is to group etiologies by their pace of onset and evolution (eg, sudden, acute, subacute, chronic).

A neurologist's approach to delirium: diagnosis and management of toxic metabolic encephalopathies

Toxic metabolic encephalopathies (TMEs) present as an acute derangement in consciousness, cognition and behavior, and can be brought about by various triggers, including endocrine and metabolic disturbances, exogenous toxins, pain and infection. Also referred to as "delirium" or "acute confusional states," TMEs are characterized by (1) an altered level of consciousness and activity, (2) global changes in cognition with inattention, (3) a fluctuating course with disturbances in the sleep-wake cycle, and (4) asterixis and myoclonus. The pathophysiology of this syndrome is poorly understood. Imbalanced neurotransmitter signaling and pathologically heightened brain inflammatory cytokine signaling have been proposed as candidate mechanisms. Focal brain lesions can also occasionally mimic TMEs. A neurological examination is required to identify the presence of focal findings, which when present, identify a new focal lesion or the recrudescence of prior ischemic, inflammatory or neoplastic insults. Diagnostic testing must include a search for metabolic and infectious derangements. Offending medications should be withdrawn. Magnetic resonance imaging, cerebrospinal fluid analysis and electroencephalography should be considered in select clinical situations. In addition to being an unpleasant experience for the patient and family, this condition is associated with extended hospital stays, increased mortality and high costs. In individuals with diminished cognitive reserve, episodes of TME lead to an accelerated decline in cognitive functioning. Starting with an illustrative case, this paper provides a neurologist's approach to the diagnosis, differential diagnosis and management of toxic metabolic encephalopathies.

Episodic confusional state: Due to insulinoma

This case report deals with 45-year-old male who came for consultation in the psychiatry department for the persisting symptoms, after consulting various departments with no relief. He had episodes of confusion with disorganized behavior, restlessness, and symptoms like talking irrelevantly once a week lasting up to 10-30 min in the preceding six months. Investigations like computerized tomography scan, electroencephalogram were not contributory. While under observation in our ward for evaluation and diagnosis, one such episode with intense sweating and clouding of consciousness was witnessed and helped in clinching the diagnosis of insulinoma. The case is reported for its rarity and as one of the causes of episodic confusional state.