A Novel Adult-Onset, Progressive MAO-A Hypofunction

We describe a previously undocumented adult-onset, progressive form of monoamine oxidase A (MAO-A) hypofunction in a patient who is one of the authors (hereafter referred to as SB). SB, a 45-year-old male computational neuroscientist, experienced 16 years of progressive symptoms consistent with MAO-A hypofunction producing excess intracellular noradrenaline (NA), serotonin (5HT), and tyramine in the peripheral sympathetic nervous system [1]. Symptoms included constant “fight or flight” response, heart rate and blood pressure spikes after ingesting high-tyramine foods, hyperreflexia, and insomnia, among others. Symptoms were relieved via treatment with either rasagiline or selegiline, which increase MAO-A expression [2], and adrenergic blockade with carvedilol.