Never Miss Sleep Disorder in Children with Drop Attacks

Abstract

To the Editor: Drop attacks refer to sudden falls without impairment of awareness or consciousness followed by complete recovery [1]. Causes of drop attacks are myoclonic seizures, atonic seizures, movement disorders, sleep disorders, and psychiatric disorders [1]. An 8-y-old girl presented with excessive daytime sleepiness (EDS), multiple drop attacks precipitated by laughter and scholastic deterioration. She was treated elsewhere with antiepileptic medications without any clinical response. There was no facial dysmorphism, tonsillar enlargement or focal neurological deficit. Possibilities of subacute sclerosing panencephalitis, progressive myoclonic epilepsy, and narcolepsy were considered. Magnetic resonance imaging of brain and electroencephalography were normal. HLA-DQB1 was identified. Cerebrospinal fluid (CSF) and serum antimeasles antibody titre was not significant. Polysomnography (PSG) revealed a mean sleep latency of 7.7 min on multiple sleep latency test (MSLT) and two sleep onset rapid eye movement period (SOREMPs) confirming the diagnosis of narcolepsy. Sleep hygiene measures were emphasized and the child was treated with modafinil and venlafaxine following which there was a significant clinical improvement. Narcolepsy is characterized by EDS and at least one of following features such as cataplexy, CSF hypocretin deficiency, night PSG revealing a rapid eye movement sleep latency ≤ 15 min, or MSLT confirming a mean sleep latency ≤ 8 min with ≥ 2 SOREMPs [2]. Sleep disorders in children may be screened using “BEARS (B = Bedtime Issues, E = Excessive Daytime Sleepiness, A = Night Awakenings, R = Regularity and Duration of Sleep, S = Snoring)” sleep screening tool [3]. Treatment of narcolepsy includes behavioural modification such as scheduled daytime naps and short naps before activities demanding high attention span and pharmacotherapy. EDS may be managed with sodium oxybate, dextroamphetamine, methylpehnidate, modafinil, armodafinil, and pitolisant [4]. Drugs used in management of cataplexy are sodium oxybate, clomipramine, imipramine, fluoxetine, and zimelidine [4]. Though epilepsies remain the common cause of drop attacks in children, other causes such as cataplexy and movement disorders should not be missed. A high index of clinical suspicion with emphasis on sleep history often helps in early diagnosis and management of narcolepsy.