A rare surgery was performed by a private Hyderabad hospital on a 3-year-old girl suffering from gelastic seizures, which used to make her have sudden bouts of laughter - for no obvious reason, situation, or cause.

Gelastic seizures are usually present in childhood, even in the newborn period, and are manifested by frequent attacks of inappropriate laughter resulting from seizure activity. Studies show that these are very rare and only one in every 200,000 children suffers from this abnormality. 

The child was evaluated when she had an abnormal laugh and was diagnosed to have gelastic seizures. She was found to have a sub-centimetre lesion in the hypothalamus (a part of the brain that houses a number of small nuclei that undertake a variety of functions), most probably hypothalamic hamartoma, and started on anti-seizure medications.

According to doctors, six months ago, the child used to get seizures once a month and it was lasting for 10 seconds, but recently the frequency increased to 5-6 times in a day and the duration of seizure to one minute. She also developed a new-onset squint in her left eye.

A team of a neurosurgeon, a neuro physician, a paediatrician and an endocrinologist evaluated the child. She underwent imaging (MRI brain plain and contrast) in high end 3T MRI which showed a large lesion extending from the hypothalamus with compression on major vessels and nerves (especially to vision and extraocular movements).

Endocrinologists diagnosed the child to have reached puberty stage (corresponding to 8 years of age) because neurons in the tumour function as a heterotopic hormone (GnRH) pulse generator. "The child's parents were explained about the condition, rarity of the disease, the requirement of surgery and risk involved. Parents were explained about other modalities of treatment. After thorough counselling, the child was taken for craniotomy and excision of the tumour using navigation under general anaesthesia.

Having navigation in our armamentarium helped us to do surgery in a minimally invasive manner without disturbing major structures especially nerves responsible for vision, extraocular movements and vessels. Post-surgery the frequency of seizures has significantly come down," said Dr. Ramesh, Consultant Neurosurgeon, Minimal Access brain and spine surgeon, Kamineni Hospitals.

"The most common areas of the brain which give rise to gelastic seizures are the hypothalamus that regulates the pituitary gland. A common cause of gelastic epilepsy is a small tumour in the hypothalamus. The majority of such tumours are benign. Children with hypothalamic hamartomas usually have gelastic seizures, cognitive malfunction, behavioural disorders. Early identification, proper diagnosis and management would help children to have better outcomes," he added.