Targeting Sigma Receptors for the Treatment of Neurodegenerative and Neurodevelopmental Disorders

The sigma-1 receptor is a 223 amino acid-long protein with a recently identified structure. The sigma-2 receptor is a genetically unrelated protein with a similarly shaped binding pocket and acts to influence cellular activities similar to the sigma-1 receptor. Both proteins are highly expressed in neuronal tissues. As such, they have become targets for treating neurological diseases, including Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), multiple sclerosis (MS), Rett syndrome (RS), developmental and epileptic encephalopathies (DEE), and motor neuron disease/amyotrophic lateral sclerosis (MND/ALS). In recent years, there have been many pre-clinical and clinical studies of sigma receptor (1 and 2) ligands for treating neurological disease. Drugs such as blarcamesine, dextromethorphan and pridopidine, which have sigma-1 receptor activity as part of their pharmacological profile, are effective in treating multiple aspects of several neurological diseases. Furthermore, several sigma-2 receptor ligands are under investigation, including CT1812, rivastigmine and SAS0132. This review aims to provide a current and up-to-date analysis of the current clinical and pre-clinical data of drugs with sigma receptor activities for treating neurological disease.

Pseudobulbar Affect: An Overview

Pseudobulbar affect (PBA) is a disorder that develops in the context of a brain injury or underlying neurological dysfunction. It is characterized as an affective disorder of emotional expression. PBA manifests as frequent uncontrollable outbursts of laughing or crying, incongruent with the individual's internal emotional state. It can be challenging for clinicians to differentiate PBA from mood disorders, contributing to its high rate of misdiagnosis. This lack of recognition leads to ineffective and insufficient treatment, impacting patients' quality of life. The current article provides an overview of PBA, including its history, prevalence, pathophysiology, diagnostic criteria, clinical implications, and treatment. [Journal of Psychosocial Nursing and Mental Health Services, 58(9), 19-24.].

Treatment of pseudobulbar affect in a mixed neurodegenerative disorder with compounded quinidine capsules and dextromethorphan cough syrup

An elderly woman admitted in our geriatric inpatient unit suffered from disturbing outbursts of crying and, less frequently, episodes of laughing. The patient was diagnosed with pseudobulbar affect related to a mixed neurodegenerative disorder. This condition is often underdiagnosed and undertreated, despite being relatively frequent in patients with neurodegenerative disorders. This case report describes the treatment of pseudobulbar affect in this patient. The only available treatment in Canada for this condition, antidepressants, was not effective for our patient. Dextromethorphan/quinidine is a good accepted alternative, but the combination is not marketed in Canada. To manage this problem, we used compounded quinidine capsules and dextromethorphan cough syrup. The crying of our patient improved significantly and rapidly after the initiation of this treatment. This case will help professionals to review their central role in treating this complex and disabling condition.