Sleep and neurology

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Sleep and neurology

• AWAKE group meeting
• 11/05/2008
• Eric Frenette MD FRCP(C)?
• Neurologist and Sleep medicine
• Stanford Sleep Clinic

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Sleep and neurology

• Sleep is a reversible behavioral state of
  perceptual disengagement from and
  unresponsiveness to the environment
• Carskadon and Dement, Principles and practice of
  sleep medicine, 4th edition, Elsevier-Saunders,
  p. 13

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Sleep and neurology

• We record sleep during an all-night sleep study,
  called polysomnography (PSG).
• We analyze
• Brain waves (EEG)?
• Eye movements
• Breathing (flow and effort)?
• Muscle tone
• Heart rhythm
• Oxygen saturation
• Leg movements

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Sleep and neurology

• Normal sleep for an adult
• Between 7-9 hours
• 4-5 sleep cycles
• Sleep cycle
• Consists of NREM and REM sleep
• 4 stages of NREM sleep (1-2-3-4) and then REM
• More slow-wave sleep at beginning of the night
  (3-4)?
• More REM sleep at the end of the night

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Sleep and neurology

• STROKE
• Defintion
• Sudden brain dysfunction induced by a blood flow
  disruption
• Strokes can be either ischemic (lack of blood
  flow) of hemorragic (blood vessel rupture)?
• Anatomy
• There are four major blood vessels supplying the
  brain 2 carotids and 2 vertebral arteries.
• The carotids supply the major part of the brain,
  while the vertebral arteries supply the
  brainstem, cerebellum and posterior part of the
  brain.

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Sleep and neurology

• STROKE
• Epidemiology
• Prevalence of stroke is about 1
• 3rd cause of mortality and major cause of
  disability
• Significant proportion of strokes occur during
  sleep
• Obstructive sleep apnea (OSA) and ischemic stroke
• Moderate to severe OSA increases risk of stroke
  by up to 2-3 folds compared to control groups
• OSA is an independent risk factor for stroke
• OSA is present in up to 60 of patients in the
  post-stroke period and 50 at 3 months

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Sleep and neurology

• STROKE
• Treatment
• Using CPAP reduces the markers of atherosclerosis
  in severe OSA
• Take home message
• OSA is a potentially reversible risk factor for
  stroke
• Risk is significantly increased for
  moderate-severe OSA
• Mild OSA?

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Sleep and neurology

• EPILEPSY
• Definition
• Electrical brain dysfunction that manifests
  itself by seizures
• Seizures can be simple, complex, generalized
• Epidemiology
• Prevalence is 1 of population
• OSA is not, per se, a risk factor for epilepsy,
  although untreated OSA can affect seizure
  frequency.

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Sleep and neurology

• EPILEPSY
• Treatment
• CPAP usage in patient with OSA and poorly
  controlled epilepsy reduces the number of
  seizures without the need of changing the
  antiepileptic drug regimen
• How?
• Reducing sleep fragmentation
• Increasing blood oxygen saturation

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Sleep and neurology

• EPILEPSY
• Seizures frequently occur during sleep and may
  manifest themselves as
• Confusional arousal
• Bizarre behavior
• Sleep walking (wandering)?
• All these manifestations can be mistaken for
  parasomnia, especially in children
• Polysomnogram plus EEG monitoring might be
  required to make the distinction

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Sleep and neurology

• EPILEPSY
• Take home message
• Undertreated OSA can exacerbate epilepsy (seizure
  frequency)?
• Nightime manifestations of seizures may mimic
  parasomnias
• PSG and EEG monitoring might be necessary to
  differentiate one from another

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Sleep and neurology

• PARKINSON
• Definition
• Neurodegenarative disease caused by an overall
  reduction of dopamine production, particularly by
  the substantia nigra
• Epidemiology
• Affects 1 in 100 person above 70 yo
• Clinical manifestations
• Tremor (rest)?
• Rigidity (cog-wheeling)?
• Akinesia
• Posture changes

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Sleep and neurology

• PARKINSON
• REM sleep behavior disorder
• Sleep symptoms can be prominent particularly REM
  sleep behavior disorder, or RBD
• RBD occurs in REM sleep and can be characterized
  by acting-out dreams, especially dreams with
  aggressive overtones.
• Normally, in REM sleep, there is a loss of muscle
  tone except for the diaphragm and the eyes

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Sleep and neurology

• PARKINSON
• Diagnosis is made with the help of the clinical
  history (bed partner)?
• In RBD, the muscle tone is increased in REM
  sleep, leading to muscle twitches and sometimes
  to the full blown syndrome
• This can be documented with PSG
• Treatment
• Clonazepam is the drug of choice

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Sleep and neurology

• MULTIPLE SCLEROSIS
• Definition
• Intermittent and recurrent affection of the
  central nervous system nerve sheaths, probably
  caused by an immune disorder, that creates
  neurological symptoms.
• Epidemiology
• Affects predominantly women
• Peak age of onset between 20-40 yo.
• Prevalence is 1 or 2 per 1000

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Sleep and neurology

• MULTIPLE SCLEROSIS
• Clinical manifestations
• Loss of vision (optic neuritis)?
• Balance problems (ataxia)?
• Leg spasticity, sphincter problems, tingling
  (transverse myelitis)?
• Fatigue is a common symptom, even in otherwise
  unaffected individuals
• Sleep disruption common (insomnia, pain, leg
  movements)?
• Treatment is symptomatic

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Sleep and neurology

• NEUROMUSCULAR DISORDERS
• Amyotrophic Lateral Sclerosis (ALS, Lou Gehrig)?
• Myotonic dystrophy (Steinert)?
• Sleep disordered breathing common
• Sleep related hypoventilation also seen with
  weakness of respiratory muscles
• Bilevel a better choice than CPAP
• Some report evidence of secondary narcolepsy (MD)?

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Sleep and neurology

• SUMMARY
• Sleep disorders very common in neurological
  diseases
• Patients with sleep disorders (OSA, RBD) at risk
  for neurological problems (stroke, Parkinson)?
• Treating the sleep problem may help avoid the
  neurological consequences