Management of pathologic laughter and crying in patients with locked-in syndrome: a report of 4 cases

Abstract

Emotional lability and pathologic laughter and crying (PLC) have been frequently mentioned in patients with locked-in syndrome (LIS) without giving any detail about the clinical characteristics and possible consequences in terms of symptoms burden, functional impact, and recovery. In the present report, we describe our approach and management of 4 patients with LIS and PLC. PLC caused discomfort to the patients and hindered the different components of their rehabilitation program, limiting communication, the execution of swallowing testing and training, and the improvement of any residual motor function. PLC was unrelated to depression, did not ameliorate after pharmacologic treatment, and improved with cognitive-behavior treatment. Our findings suggest that, in LIS patients, laughter and crying alterations do not represent symptoms of a mood disorder but are the result of the same pontine lesion that causes LIS. In relation to the complex pathway regulating laughter and crying, we hypothesized that, in patients with LIS, PLC may be the result of a direct damage to the pontine center or of an alteration in the ponto-cerebellar pathway linking emotional behavior to contextual information. Presence of PLC in patients with LIS severely affects their intelligent adaptation to the environment. Direct explanation to the patients of the origin of PLC may be helpful as a cognitive-behavior treatment, with resulting benefits to the entire rehabilitation program.