br Case report A year old boy

Case report A 15-year-old boy complaining of unexplained fatigue was first attended by the pediatrics office on November 2010. Such discomfort started in June, two months after being vaccinated against the 2009 pandemic influenza A/H1N1 virus with Pandemrix™. Physical and neurological examinations were both negative and, at this time, pediatrician hypothesized secondary hypothyroidism which was not confirmed. By August, he gained additional 15kg due to increased appetite including food ingestion during the night time and early in the morning. Two months later (October) he presented with sleep attacks during calpain inhibitor 1 and poor sleep complains and after another two months (by December) he started showing a loss of muscular tone first affecting the perioral and periocular region, complaining of difficulties when trying to talk. Polysomnographic study was performed in February 2011 disclosing a total sleep time of 7h 35min with sleep efficiency of 93.7% and a sleep latency of two minutes and the first period starting in REM sleep with an absence of any other prevalent pathologic findings as sleep-related breathing disorders or periodic limb movements. The MSLT immediately after the PSG test documented 4 sleep onset rapid eye movement periods (SOREMPs) with latencies up to 5min (1.31min in average). Identification of HLA-DQ6 was made by the PCR-SSP technique in February 2012. CSF hypocretin level could not be determined because this test was not available at that time in our hospital. Based on the clinical findings and objective measures it was diagnosed as narcolepsy with cataplexy. The patient started treatment with metilphenidate (10mg 3 times/day) for hypersomnolence. Despite subjective improvement on daytime sleepiness, a new MSLT in April 2011 showed no significant differences compared with the previous one. The patient was instructed to follow some sleep hygiene important roles as regular schedules and scheduled short naps in order to improve excessive sleepiness and was advised to avoid situations, which may lead to emotional stimulation and thus catapletic attacks. No pharmacologic treatment was initiated for cataplexy since related symptoms were not severe and this was not a major concern for the patient. In February 2012 the patient showed some worry about side effects of metilphenidate like alopecia, sudoresis, increased frequency of headaches and cutaneous irritation, which led to the decision to abandon therapy. The patient is now 18 years old and is studying in university completing the first year. As the major part of his classes is in the afternoon, he can sleep at home during the morning. However, when he has classes during the morning he often falls asleep. Teachers are however aware of his condition. Currently he is followed in the sleep consultation department of our hospital.
Discussion In 2010, first cases about a possible relationship between H1N1 flu vaccination and narcolepsy with cataplexy were reported in the north of Europe [11]. Almost at the same time additional cases were independently reported in France, Canada and the United States [8] and by January 2011, there were 162 reported cases of narcolepsy after vaccination with Arepanrix™ [12]. Biological mechanisms behind this link are not clear, but an immunitary response to the vaccine adjuvant used in this patient is most likely since side effects suggestive of strong immune stimulation were reported after A/H1N1 vaccination, particularly with Pandemrix™ [13]. In those cases reported in the literature the onset of symptoms ranged from two days to five months after vaccination and many of them received vaccines with ASO3 as an adjuvant, which is the same adjuvant used in Pandmrix™. This supports the immunitary role and the link between vaccination and development of narcolepsy symptoms. The present case evolved after A/H1N1 vaccination with Pandemrix™. Diagnosis of narcolepsy was carried out according to the current guidelines and the short time that elapsed between vaccination and emergence of the clinical symptoms makes plausible the hypothesis of a link between both events. One important limitation of this work must be mentioned and it is regarding the fact that a single case was presented and thus the establishment of a probable association between H1N1 vaccination and narcolepsy can be indeed criticized with the argument that it can configure a subjective inference. On the other hand, it remains crucial to understand the widespread distribution of this relationship around the globe as well as its particular characteristics and mechanisms for what these reports can be of major relevance.