Insomnia and sleep-disordered breathing in FKRP-related limb-girdle muscular dystrophy R9. The Norwegian LGMDR9 cohort study (2020)

Limb-girdle muscular dystrophy R9 (LGMDR9) is a progressive and disabling genetic muscle disease. Sleep is relevant in the patient care as it impacts on health, functioning, and well-being. LGMDR9 may potentially affect sleep by physical or emotional symptoms, myalgia, or sleep-disordered breathing (SDB) through cardiorespiratory involvement. The objective was to investigate the occurrence of insomnia and unrecognized or untreated SDB in LGMDR9, associated factors, and relationships with fatigue and health-related quality of life (HRQoL). All 90 adults in a Norwegian LGMDR9 cohort received questionnaires on sleep, fatigue, and HRQoL. Forty-nine of them underwent clinical assessments and 26 without mask-based therapy for respiration disorders additionally underwent polysomnography (PSG) and capnometry. Among 77 questionnaire respondents, 31% received mask-based therapy. The prevalence of insomnia was 32% of both those with and without such therapy but was significantly increased in fatigued respondents (54% vs 21%). Insomnia levels correlated inversely with mental HRQoL. Among 26 PSG candidates, an apnea-hypopnea index (AHI) ≥ 5/h was observed in 16/26 subjects (≥ 15/h in 8/26) with median 6.8 obstructive apneas and 0.2 central apneas per hour of sleep. The AHI was related to advancing age and an ejection fraction < 50%. Sleep-related hypoventilation was detected in one subject. Fatigue severity did not correlate with motor function or nocturnal metrics of respiration or sleep but with Maximal Inspiratory Pressure (r = - 0.46). The results indicate that insomnia and SDB are underrecognized comorbidities in LGMDR9 and associated with HRQoL impairment and heart failure, respectively. We propose an increased attention to insomnia and SDB in the interdisciplinary care of LGMDR9. Insomnia and pulmonary function should be examined in fatigued patients.

Is obstructive sleep apnea syndrome associated with headache?

OBJECTIVE

Obstructive sleep apnea syndrome (OSA) is a common disorder in the general population. Although the mechanisms remain obscure, an association with headache has been reported. We aimed to assess the frequency of OSA in a population of headache patients based on a stratified sampling technique using questionnaire and polysomnography (PSG).

METHODS

The survey was provided to new outpatients examined by a neurologist for headache over a 2-year period of time. The patients completed a headache diary during 30 days and those at risk of OSA went through a PSG examination.

RESULTS

Of 903 headache patients, 75 reported heavy snoring and episodes of interrupted nocturnal breathing (8%). Among 43 patients examined with PSG, 14 (1.5% of the total study population) had an apnea/hypopnea index of 5 or higher. Eleven of the patients reported morning headache.

CONCLUSION

The frequency of OSA in a patients referred to specialist for headache problems is not higher than what is reported for the general population. The relatively low rate of OSA in this selected group of patients with headache referred to neurology for second opinion does not support the notion that OSA brings about headache.