sleep apnoea and narcolepsy

what is obstructive sleep apnoea syndrome

• recurrent episodes of upper airway obstruction leading to apnoea (stopping breathing) during sleep

• usually associated with heavy snoring

• typically unrefreshing sleep

• daytime somnolence/ sleepiness

• poor daytime concentration

what are other possible symptoms of sleep apnoea

• walking with a transient choking sensation

• lethargy or tiredness

• headache on waking

• nocturnal polyuria

• reduced libido

what are signs of sleep apnoea

1. loud snoring- often interrupted by pauses in breathing

2. choking or gasping during sleep

3. restless sleep- frequent tossing and turning

4. morning headaches- due to low oxygen levels

5. dry mouth or sore upon waking

what are the three main causes of sleep apnoea

• muscle relaxation

• narrow pharynx

• obesity

how long does apnoea last

10 seconds

hypopnea

when the airway closes but not fully

breathing is shallow or abnormally slow due to a partial blocking of upper airway

why is OSAS impoortant

• impaired quality of life

• marital disharmony

• increased risk of RTAs

• associated with hypertension, increased risk of stroke and probably increased risk of heart disease

what is the prevalence of OSA

2% of adult men and 1% of adult women

how is OSAS diagnosed

• clinical history and examination

• epsworth questionnaire

• overnight sleep study

  • pulse oximetry

  • limited sleep studies

  • full polysomnography

what is the Epsworth sleep scale

get asked 8 question and have to rank each one

0- would never dize

1- slight chance of dozing

2- moderate chance of dozing

3- high chance of dozing

what are the questions you get asked in an Epsowth sleepiness sclae

chance of dozing when

1. sitting and reading

2. watching TV

3. sitting inactive in a public place

4. as a passenger in a car for an hour without a break

5. sitting and talking to someone

6. lying down when circumstances permit

7. sitting quietly after lunch without alcohol

8. in a car while stopped for a few mins in traffic

interpretation of epsowrths sleepiness scale

0-5 normal

6-10- mild

11-14- moderate

15-24- severe

what can you record with polysomnography

• oronasal airflow

• thoracoabdominal movement

• oximetry

• body position

• Electropherogram- records brain waves

• audiovisual recording

• EOG

• EMG

• ECG

OSA severity

0-5 normal

5-15- mild

15-30- moderate

>30 severe

treatment of OSA

• identify exacerbating factors

  • weight reduction

  • avoidance of alcohol

  • diagnose and treat endocrine disorders

• continuous positive airways pressure- CPAP

• mandibular repositioning splint- like a mouthguard that pushes the tongue and mandibular forward

• positional therapy device- stops patient lying on their back- as apnoea is worse here

driving with OSA

should advise patients with sleep apnoea and excess daytime somnolence not to drive or restrict driving and to inform DVLA of their condition

what are clinical features of narcolepsy

• cataplexy- sudden loss of muscle control that occurs a state of full consciousness

• excessive daytime somnolence

• hypnagogic/ hypnopompic hallucinations

• sleep paralysis

investigation of narcolepsy

• PSG

• MSLT- multiple sleep latency test- used to evaluate excessive daytime sleepiness- measures how quickly you fall asleep during naps

• Low CSF orexin

Treatment of narcolepsy

• modafinil

• dexamphetamine

• venlafaxine

• sodium oxybate