Dear Editor,

Pathological laughter is described as a sudden outburst of uncontrollable, spontaneous, and inappropriate laughter when a subjective feeling of euphoria is ruled out.[ 1 ] Pathological laughter is a rare but distinct presenting symptom associated with pathologies such as benign and malignant intra- and extra-axial brain tumors, ischemic insult to the brainstem, epileptic phenomenon, and degenerative disorders.[ 5 ] Its association with petroclival meningioma is an unusual and rare finding. The exact physiology of normal and “pathological” laughter remains poorly understood since the mechanism of normal laughing is complex.[ 8 ]

We report a case of a 42-year-old male who presented with complaints of pathological laughter for 6 weeks followed by headache, unsteady gait, weakness in the left upper and lower limbs, and difficulty in swallowing liquids for 15–20 days. On examination, his mental status was normal. He had a Glasgow Coma Scale score of 15/15 with left upper and lower limb power of 4/5 and pathological laughter. He had grade 2 facial weakness with an absent gag reflex. Cerebellar signs were positive. Preoperative contrast-enhanced magnetic resonance imaging of the brain revealed a well-defined globular extra-axial lesion in the left petroclival region, which was T1 isointense, T2 iso to hyperintense, measuring 3.5 × 4.2 × 4.0 cm with homogenous postcontrast enhancement [ Figure 1 ]. The lesion was expanding the pontomedullary cistern and displacing the midbrain and pons toward the right side. Posteriorly, the lesion was causing a mass effect over the left cerebellar hemisphere and left middle cerebellar peduncle. The aqueduct of Sylvius was completely displaced, and the 4^th ventricle was effaced [ Figure 1 ]. The patient underwent right-sided Frazier’s point medium pressure ventriculoperitoneal shunt followed by left retromastoid suboccipital craniotomy and gross total excision of the lesion 3 days later [ Figure 2 ]. Postoperatively, his pathological laughter resolved completely.

Figure 1:

Preoperative magnetic resonance imaging brain (a - T1 axial, b - T2 axial, c - T2 coronal, d - contrast) suggestive of left petroclival meningioma with upper brainstem compression.

Figure 2:

Postoperative noncontrast computed tomography scan of the brain (a - axial, b - coronal) suggestive of complete excision of the tumor with resolved brainstem compression.

Pathological laughter has been reported in lesions causing anterior and anterolateral compression and distortion of the upper brainstem. The etiopathogenesis for pathological laughter in our case can be postulated as follows:

Compression of the pontomesencephalic brainstem and its distortion.[ 3 , 7 ]

We have reported this case to highlight the significance of pathological laughter as an early localizing symptom for petroclival meningioma and its complete resolution after surgery.

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Conflicts of interest

There are no conflicts of interest.

Use of artificial intelligence (AI)-assisted technology for manuscript preparation

The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.

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The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.

References

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