Journal of Neurology, Neurosurgery, and Psychiatry, 1972, 35, 108-113 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.35.1.108 on 1 February 1972. Downloaded from Released involuntary laughter after temporal lobe infarction MICHAEL SWASH From the Department of Neurology, Section of Neurological Sciences, The London Hospital, London SUMMARY A case of sustained involuntary laughter is described, with accompanying alteration ot mood, due to infarction of the inferior and lateral aspects of the left temporal lobe. The lesion was localized by the clinical findings, by electroencephalography, by a radioisotope brain scan, and by angiography. The problem of the neurology of emotional behaviour is discussed in the context of the localization of the lesion in this case. Changes in emotional state are common in that she seemed to be continuously muttering and neurological disease but involuntary laughter laughing to herself. In this state loud laughterguest. Protected by copyright. occurring either as an epileptic event (gelastic occurred in response to any environmental stimulus. epilepsy) or as a released phenomenon in destruc- Any attempt at conversation, or even the noise of a and door slamming, induced a burst of loud, natural- tive lesions is very rare. Gumpert, Hansotia, sounding laughter which often continued for five or Upton (1970) have recently described one further 10 minutes. She seemed to understand what was case of gelastic epilepsy and have reviewed some said to her but her own speech was jumbled and of the previously reported instances of patho- incomprehensible, and when asked to write down logical laughter. They were unable to draw any what she wanted she wrote nonsense. During the firm conclusions about the nature of the under- night she was quiet, although her husband had lying mechanisms responsible for the production difficulty in preparing her for sleep because of her oflaughter in their patient, although they thought noisy laughter. The next morning she woke at that a hypothalamic lesion was the most likely the usual time, but immediately began to laugh cause. uncontrollably and with apparent amusement, and was brought to the hospital, still laughing and It is the purpose of this paper to present a case giggling. of sustained involuntary laughter, with accom- There was no history of previous physical or panying alteration of mood, due to left temporal psychiatric illness and there was no family history of lobe infarction. vascular disease. Menstruation had ceased seven years previously. http://jnnp.bmj.com/ On examination she was an obese woman lying on CASE REPORT her right side in a generally flexed posture chuckling Mrs. D.E.G. (LH 31891/57), aged 45 years, was and laughing to herself in a natural but wholly admitted to the London Hospital as an emergency. inappropriate manner. Frequent noisy yawns inter- She had been well until the evening before admission rupted her otherwise almost continual and often when she suddenly began to laugh. Her laughter was noisy laughter. She responded to simple questions by loud and continuous and although it was obviously nodding or shaking her head and with louder and inappropriate it seemed, in itself, to be like her usual more prolonged laughter. Sometimes she muttered on September 26, 2021 by laughter, so that her husband thought, at first, that inaudibly. If left alone she became drowsy and something had amused her. However, she continued drifted into a light sleep from which she could easily laughing and was unable to stand unaided or use her be awakened by calling her name. Her laughter was right arm to support herself. During the first hour so natural and so apparently enjoyable that it pro- her right arm flung wildly about in the air. She voked amusement and laughter among the physi- laughed almost continuously for the first three cians, nurses, and other patients who saw her, hours, with pauses only to draw breath, but then her although it was plain to them that her laughter was laughter gradually subsided and was replaced by both involuntary and pathological. Even her husband frequent giggles, low laughs, grimaces, and smiles so found it difficult not to laugh with her. She did not 108 Released involuntary laughter after temporal lobe infarction 109 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.35.1.108 on 1 February 1972. Downloaded from make puns or jokes and there was no word associa- Writing of remembered material-for example, her tion or flight of ideas. address-and of copied sentences showed similar She moved all limbs voluntarily and to command, errors. There was no gross limb apraxia or agnosia. but the right arm was consistently moved less than A right upper quadrantic visual field defect per- the left and the stretch reflexes were exaggerated in sisted and she often neglected right-sided visual and this limb. The right plantar response was extensor auditory stimuli. There was a mild right hemi- and the left flexor. There was a right facial weakness paresis, most marked in face and shoulder, and the of supranuclear type which was less obvious during right-sided stretch reflexes were brisk. The right the almost continuous mimetic facial movement plantar response was extensor. There was impair- than during voluntary movement. She responded less ment to all sensory modalities in the right limbs but well to painful stimuli in the right arm than elsewhere. perseveration and aphasia made detailed examina- The visual acuity was normal but there was a right tion impossible. upper quadrantic field defect to confrontation with The skull and chest radiographs and routine bilateral, simultaneously presented, stimuli. The haematological and urine tests were normal. An pupils were normal. The general examination was electroencephalogram showed poorly organized within normal limits and the blood pressure was background activity bilaterally and a focus of theta 115/75 mm Hg. and delta activity in the left fronto-temporal region. By the third day she was improved and could sit The brain scan (Tc99m) showed increased uptake of out in a chair. However, even at rest she still smiled radioisotope in the deep and inferior aspects of the and chuckled to herself without apparent cause and left temporal region (Figure) but an echoencephalo- when her attention was attracted by auditory or gram showed no shift of the midline echoes from the visual stimuli she burst into prolonged and hearty acoustical midline. A left carotid angiogram, per- laughter. Each laugh seemed to precipitate another, formed by left common carotid puncture, showed guest. Protected by copyright. so that louder and longer peals of laughter succeeded deformation of the stream of contrast medium by each other, speech was impossible, and her whole atheroma at the carotid bifurcation and reduction of body seemed to be taken up with laughter and the flow of contrast in the territory of an insular and respiration. It was possible, however, to modify the an anterior temporal branch of the left middle degree of her mirth. Even a faint smile from the cerebral artery (Dr. Leon Morris). Only the origin examiner provoked instant violent laughter but and proximal part of the anterior temporal vessel these outbursts could be slowly and partially sup- could be seen and filling of its terminal branches pressed by a serious or factual question or by an occurred retrogradely through leptomeningeal anas- emotionless expression on the part of the examiner. tomotic vessels. The CSF was clear and colourless She could not voluntarily suppress her laughter as and contained 30 mg protein/100 ml. The WR was when requested to 'stop laughing'. Such commands negative in both blood and CSF. The serum uric only increased the laughter. Her laughter was always acid and an oral glucose tolerance test were normal. accompanied by reddening of the face, an alteration offacial expression, by hand and arm movement, and PROGRESS Improvement continued during the next sometimes by tear formation appropriate to the month, although throughout this time prolonged degree of mirth. During these episodes of laughter bursts of loud, inappropriate laughter could be she would sometimes say 'funny, funny'. Inappro- elicited by sympathetic smiles or by slightly humour- priate crying, fear, or anger were not observed at ous stimuli presented either visually or verbally. She this or any other time in her illness. continued to smile and chuckle to herself without http://jnnp.bmj.com/ She was unable to describe the events of her illness apparent cause but this phenomenon gradually or to talk about her home and although she responded became less evident. On questioning she admitted to simple commands she failed to perform two-stage that her laughter was abnormal but could not requests. Perseveration, both of speech and of explain what it was that she found amusing or why gesture, was very marked and normal prosody was she laughed so easily. She was adamant that she was lost. She often spoke spontaneously, but in a soft actually amused during the act of laughing. She was mumbling voice, and her speech contained frequent rarely downcast and was never seen to be depressed, on September 26, 2021 by neologisms and repeated meaningless phrases. She or to cry, or weep, although she clearly understood could not repeat simple phrases either verbally or in that she had had a stroke. writing. There was a severe naming defect both to Six weeks after the onset ofher illness she returned visual and tactile tests, although it was clear that she from convalescence. She remembered and described knew the use of the objects presented. There was no the period of continuous laughter in detail and with echolalia. Calculations were performed inaccurately, amusement, although she realized that it was ab- but not out of proportion to the degree of aphasia, normal.