Pathological Laughter in a Female with Multiple Episodes of Stroke and Subdural Hematoma

Various brain areas in both cortical as well as subcortical locations are involved in pathological laughter. Pathological laughter may be seen as a prodromal symptom or acute manifestation or late sequel of stroke. Various other neuropsychiatric conditions attribute to stroke. It is often difficult to ascertain the cause of pathological laughter in the presence of multiple brain pathologies. Here, we highlight a case of a 55-year-old female, who had multiple episodes of stroke and subdural hematoma, presented with pathological laughter and other behavioral abnormalities.

Pathological laughter associated with paroxysmal kinesigenic dyskinesia: A rare presentation of acute disseminated encephalomyelitis

A 13-year-old boy presented with recurrent episodes of sudden brief posturing of the right upper and lower limbs accompanied by transient inability to speak and a tendency to smile which would sometimes break into laughter. Awareness was retained during the attack, and there was no associated emotional abnormality. The events were precipitated by walking and occurred several times in a day. The laughter was pathological in nature, and the abnormal posturing was akin to ‘paroxysmal kinesigenic dyskinesia’ (PKD). ‘Pathological laughter or crying’ is defined as an involuntary, inappropriate, unmotivated laughter, crying or both, without any associated mood change. It can occur as a result of cerebral lesions like tumors, trauma, vascular insults, multiple sclerosis and/or degenerative disorders. It can also be a component of gelastic epilepsy which is characterized by stereotyped recurrences, presence of interictal and ictal epileptiform discharges and absence of external precipitants. In our patient, however, there was no ictal or interictal EEG correlate. Paroxysmal kinesigenic dyskinesia is characterized by intermittent, involuntary movements triggered by kinesigenic stimuli and is usually familial but can also be secondary to metabolic and structural brain disorders. Magnetic Resonance Imaging (MRI), in our case, revealed multiple T2 and FLAIR hyperintense, non-enhancing lesions in the periaqueductal gray matter, pontine and midbrain tegmentum, bilateral thalami and left lentiform nucleus suggesting a diagnosis of ‘acute disseminated encephalomyelitis’, in which this unique combination of pathological laughter and PKD has not been described so far. Magnetic Resonance Spectroscopy (MRS) confirmed a demyelinating pathology, and the patient responded well to steroids.