MR-201 is a novel formulation of a well known NMDA-antagonist being developed for pseudobulbar affect. 

Pseudobulbar affect (PBA), is a condition that is characterized by uncontrollable crying and/or laughing that happens suddenly and frequently. PBA occurs secondary to a neurologic disorder or brain injury, such as TBI (traumatic brain injury), Alzheimer's disease/dementia, Stroke, Multiple sclerosis(MS), Lou gehrig's disease (ALS) and Parkinson's Disease (PD), that affect the way the brain controls emotion. A person having a PBA crying or laughing spell may cry or laugh when they don’t feel sad or amused, i.e, the episode may be mood-incongruent. While there are almost 2 million people in the US with neurologic conditions or traumatic brain injury who have PBA, over 7 million people in the US have symptoms that may suggest PBA. PBA can be extremely embarrassing and disruptive to social life of the patient. The frontal lobe of the brain normally keeps emotions under control. In PBA, there is a disconnect, due to nerve problems, between the frontal lobe (which controls emotions) and the cerebellum and brain stem (where reflexes are mediated). In particular, PBA is now understood to be a disinhibition syndrome in which specific pathways involving serotonin and glutamate are disrupted or modulated causing reduced cortical inhibition of a cerebellar/brainstem-situated “emotional” laughing or crying focal center. The PBA is not curable but it is treatable. The main aim of treatment is to reduce the severity and frequency of emotional outbursts. The only FDA-approved drug for the treatment of PBA is NUEDEXTA® (Dextromethorphan HBr (20 mg) and Quinidine Sulfate (10 mg) combination). Despite of being a first and only treatment for PBA, NUEDEXTA has a serious limitation of drug-drug interaction and QTc prolongation due to usage of quinidine sulfate.