Pathological laughter as a presenting symptom of acoustic schwannoma: report of two cases

Pathologic Laughter as an Early and Unusual Presenting Symptom of Petroclival Meningioma: a Case Report and Review of the Literature

BACKGROUND

Pathologic laughter is inappropriate, involuntary, and unmotivated laughter episodes that may or may not be associated with mirth or amusement. Although associated with many diffuse brain pathologies, its association with intracranial focal mass lesions causing ventrolateral brainstem compression, like petroclival meningioma, is very rare. The exact pathophysiology of this interesting and unusual clinical symptom is unknown, but probably involves disinhibition and release of the so-called coordination center located in the upper brainstem due to compression by the tumor.

CASE DESCRIPTION

A 26-year-old woman presented with recurrent episodes of inappropriate and involuntary laughter, which significantly affected her quality of life, for 2 years. These episodes did not resolve, and a magnetic resonance imaging of the brain showed a giant petroclival meningioma causing upper brainstem compression. Near-total excision of the tumor was done using an extended middle fossa approach. To our surprise, the pathologic laughter subsided immediately after surgery.

CONCLUSIONS

Pathologic laughter may be the only symptom of a focal mass lesion causing ventrolateral upper brainstem compression, like petroclival meningioma, well before other neurological sign/symptoms appear. Tumors causing ventral brainstem compression must be ruled out before the patient is sent for a psychiatric evaluation.

The epidemiology and pathophysiology of pseudobulbar affect and its association with neurodegeneration

Pseudobulbar affect is a disorder resulting from neurologic damage manifesting as sudden, stereotyped affective outbursts that are not reflective of internal emotion. A literature review was completed to examine the current understanding of the epidemiology, characterization, diagnosis, pathophysiology, and treatment of pseudobulbar affect. This review revealed that it is common in neurodegenerative disorders but is poorly recognized, placing significant impacts on patients and their families. The disorder appears to result from a disruption of the cortico-limbic-subcortical-thalamic-pontocerebellar network involved in emotional expression and regulation with resulting disruptions of neurotransmitter systems. Effective treatment is available with agents such as selective serotonin reuptake inhibitors and dextromethorphan combined with quinidine, but further well-designed comparative studies are needed. Advances in technology such as neuroimaging may enhance knowledge about the pathophysiology of this disorder, and help guide future interventions.

Pathological laughter in trigeminal schwannoma: case report and review of the literature

Pathological laughter is an uncommon manifestation of neurosurgical diseases. Very few cases of trigeminal schwannoma have been reported in the literature presenting with pathological laughter as a predominant symptom. We are reporting on a case of multi-compartmental trigeminal schwannoma presenting as pathological laughter and discuss a review of the literature. A 23-year-old lady presented with pathological laughter, along with symptoms pertaining to other cranial nerves and cerebellar dysfunction. Magnetic resonance imaging (MRI) of the brain was suggestive of a dumbbell-shaped mass in the middle and posterior cranial fossa on the left side, causing significant compression of the pons. She was investigated and operated for multi-compartmental trigeminal schwannoma. Following surgery, abnormal laughter disappeared immediately and no recurrence of symptoms was -present for a follow-up of 16 months. This case supports the role of the brainstem, especially the pons, in the control of laughter and, perhaps, of the medial temporal lobe too.