Case report

In 1993, a 46-year-old woman presented to our Sleep Clinic with poor sleep, nocturnal choking episodes and daytime fatigue. She denied habitual snoring and hypersomnolence. Her medical history was unremarkable except for severe LM rhombencephalitis in 1977. At that time, the patient had been hospitalised in the intensive care unit following the acute onset of fever, influenza-like symptoms, meningism, facial palsy and nystagmus. Blood and cerebral spinal fluid samples were positive for LM on direct microscopic exam as well cultures. Treatment was initiated but the patient acutely deteriorated, exhibiting tetra paresis, bilateral pontomedullary syndrome, impairment of vigilance, and experienced a cardiac arrest. She was successfully resuscitated and remained in the intensive care unit with gradual and slow recovery. After a lengthy hospital stay, she was eventually discharged from the hospital and resumed a normal life, with few neurological sequelae such as dysphagia and mild facial palsy. To investigate the patient's sleep complaints, an in-laboratory full polysomnography was obtained and revealed central sleep apnoeas and hypopnoeas (Apnoea–Hypopnoea index (AHI)=50 events/hour) with severe nocturnal hypoxaemia. Morning arterial blood gases revealed alveolar hypoventilation with partial pressure of arterial CO₂ or PaCO₂ of 6.7 kPa and PaO₂ of 9.5 kPa. The patient refused further investigations and therapy but agreed to return to clinic for a follow-up in 1 year. In 1994, polysomnography and arterial blood gases showed persistent sleep apnoea and daytime hypoventilation but the patient continued to decline treatment. The patient was then lost to follow-up until 2011, when she presented for the third time to the Sleep Clinic complaining of daytime fatigue, unrefreshing sleep, choking episode during sleep and …