MSA. Sleep disorders MULTIPLE SYSTEM ATROPHY AND NOCTURNAL STRIDOR 1/26/2015. Alex Iranzo Neurology Service Hospital Clinic de Barcelona Spain

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1 MULTIPLE SYSTEM ATROPHY AND NOCTURNAL STRIDOR Alex Iranzo Neurology Service Hospital Clinic de Barcelona Spain MSA Neurodegenerative disease Parkinsonism, cerebellar, dysautonomia Mean survival is less than 10 years Casuses of death are bronchopneumonia (48%), sudden death (wake and sleep) (21%) Sleep disorders Poor and reduced sleep Hypersomnia REM sleep behavior disorder Sleep disordered breathing 1

2 Sleep disordered breathing Central Peripheral Impaired control of laryngeal function Laryngeal narrowing during inspiration leading to the obstruction of the upper ariway 1) Stridor 2) Obstructive sleep apnea 3) Dyspnea during wakefulness 4) Respiratory failure Stridor Harsh high pitched sound Reflects upper airway obstruction at the larynx during inspiration 2

3 Snoring Other noises during sleep Bruxism Cathatrenia (nocturnal groaning) Stridor in MSA Stridor during sleep occurs in 13-42% May be the first symptom of the disease No relation with disease severity and duration No relation with the MSA subtype Patient are unaware, may coexist with snoring May be followed by diurnal stridor Gaig et al. JNNP 2008;79:

4 Stridor in MSA Associated with OSA + vocal cord paresis (Iranzo 2000 and 2004) Associated with sudden death during sleep (Munschaucher 1990) Marker of short survival if untreated (Silber and Levine 2000) (Yamaguchi 2003) Nucleus ambiguus It is located in the medulla It is the origin of the vagus nerve Degenerates in MSA Vagus Nerve It is the origin of the laryngeal nerve Innervates the muscles of the larynx In MSA - Axonal loss of the laryngeal nerves - Denervation of the muscles of the larynx 4

5 Normal movements of the vocal cords 1) Abduct fully during inspiration 2) Adduct on expiration and phonation Stridor in MSA Produced by vocal cord abduction restriction during inspiration Bilateral (complete or partial) or less often unilateral (complete) This restriction can be observed in many cases with laringoscopy during wakefulness Polysomnography in MSA Stridor (n=14) No stridor (n=26) AHI = 16 CT90 = 28 AHI = 9 CT90 = 5 (Iranzo, Neurology 2004) 5

6 What is the cause of stridor in MSA? 1) Neuronopathy of the laryngeal nerve Neuronal loss in the nucleus ambiguus Loss of large myelinated nerve fibers of the recurrent laryngeal nerve Selective neurogenic atrophy of the posterior crycoarytenoid muscles What is the cause of stridor in MSA? 2) Dystonia of the adductors EMG (awake) shows increased thyroarytenoid activity in patients with nocturnal stridor Botulinum toxin into the thyroarytenoid muscle ameliorates stridor What is the cause of stridor in MSA? 3) Increased reflex contraction of adductors due to paresis of the abductors In normal conditions, if there is an obstruction in the upper airway the vocal cord adductors increase their activity during inspiration as a reflex In MSA, since there is an abductor paralysis and laryngeal narrowing, the airway resistance increases because the activation of the adductors Explains the overactivity in TA in EMG studies Explains why moderate CPAP pressures abolish stridor Explains why botulinum toxin into the TA opens the vocal cords 6

7 Stridor during sleep needs to be treated Laryngeal narrowing Obstructive sleep apneas Sudden death during sleep Progresses to during wakefulness Respiratory failure Marker of short survival Treatment of stridor in MSA CPAP Tracheostomy Cordectomy Botulinum toxin in the adductors Nasal CPAP Iranzo et al. Lancet

8 Nasal CPAP Non-invasive Abolishes nocturnal stridor (5-10 cm H 2 0) Opens the glottic aperture May cause facial discomfort Iranzo et al. Neurology ,0 Survival: no stridor vs stridor without CPAP,8,6 Supervivencia acum,4,2 0,0 P=0.02 CPAP Stridor w ithout CPAP No stridor Months from disease onset 8

9 1,0 Survival,8,6 Supervivencia acum,4,2 0, P= CPAP Stridor w ith CPAP Stridor w ithout CPAP 120 Months since disease onset 1,0 Survival: non stridor vs. stridor with CPAP,8,6 Supervivencia acum,4,2 0,0 P= 0.7 CPAP Stridor w ith CPAP No stridor Months since disease onset Tracheostomy Effective By-passes v. cord obstruction Invasive Frequently refused Local complications 9

10 Cordectomy and vocal cord lateralization Effective Opens the glottic space Limited experience in MSA Invasive (requires anesthesia) Risk of aspiration Impaired phonation Botulinum toxin Only one study involving 3 patients in whom in 2 stridor was eliminated Increases risk of bronquial aspiration, dysphonia Requires EMG guidance Repeated injections Management of stridor in MSA First option CPAP When CPAP is not tolerated Tracheostomy When stridor progresses to wakefulness Tracheostomy 10

11 Conclusions Stridor is frequent in MSA Vocal cord laryngeal obstruction Risk of sudden death during sleep Associated with short survival Conclusions Early stages of MSA: CPAP Advanced stage: CPAP /Tracheostomy Awakening stridor: Tracheostomy Not recomended: Botulinum toxin in the adductors and cordectomy 11