Pathological Yawning, Laughing and Crying.

Yawning, laughing, and crying are normal physiological behaviors of humans in good health. As with all physiological behaviors, their deregulation can reveal disorders. Pathological yawning occurs in salvos of 10-20 successive yawns, and the number of yawns per day can exceed one hundred. After listing the functional etiologies, we will give the clinical keys for differentiating the most serious causes: iatrogenic, tumors, strokes, amyotrophic lateral sclerosis, and intracranial hypertension. Sudden, uncontrollable episodes of emotional display involving pathological laughing and crying (PLC) may be encountered in various neurological diseases: amyotrophic lateral sclerosis, multiple system atrophy (cerebellar), cerebrovascular disease, traumatic brain injuries, mass lesions in the cerebellopontine junction, and epilepsy. After describing the pathophysiology of PLC and the use of diagnostic scales for PLC, we will discuss the current treatments.