Pathological Laughing and Crying Is Associated with Posterior Fossa Lesions in Multiple Sclerosis
Objectives: To examine the relationship between lesions in the posterior fossa and PLC in PwMS.
Methods: This retrospective chart review from the London (ON) MS Clinic identified PwMS between 2012 and 2016 who had completed the Center for Neurologic Study-Liability Scale (CNS-LS) and had an MRI for clinical reasons on the same 1.5T MRI machine within six months of each other. Brainstem and cerebellar lesions were counted and measured. Chi-square analysis was used to compare the number of posterior fossa lesions (brainstem and cerebellum) in PwMS who were positive on the CNS-LS (scores of ≥ 17) with those who were negative on the CNS-LS (scores 0-16). Next, the same analysis was performed when the sample was restricted to PwMS without depressive symptoms (Hospital Anxiety and Depression Scale, Depressive subscore (HADS-D) < 8) due to the confounding effect of depression on CNS-LS scores.
Results: Of the charts reviewed, 80 potential cases were identified with an MRI and CNS-LS within six months of each other. Three cases were excluded, due to CIS diagnosis (n=2) or no HADS-D scores (n=1). The mean age of the cohort was 39.3 (± 11.0) years, the majority were women (51, 66.2%), and the mean years since diagnosis was 5.3 (± 7.3). Most of the cohort had a relapsing form of MS (66, 85.7), the median EDSS was 2.0 (0.0-6.5) and 37 (48.1%) were on a disease modifying therapy. The mean CNS-LS score was 13.9 (± 5.0), with 22 (28.6%) in the positive range for PLC symptoms. On MRI, 42 (54.5%) had lesions in the posterior fossa, ranging from 0 to 35 (brainstem 0-10, cerebellum 0-12). The number of lesions was not significantly different in PwMS without PLC (CNS-LS ≤ 16) compared to PwMS with PLC (CNS-LS ≥ 17) (X2 (11, N=77) = 12.903, p = 0.3). When the analysis was restricted to PwMS without evidence of depression (HADS-D < 8), there was a significant difference (X2 (9, N=57) = 17.882, p = 0.037).
Conclusions: In PwMS, the number of posterior fossa lesions on MRI is associated with the presence of PLC. Further studies into the relationship between these lesions and PLC symptoms are needed.