Sleep Disorders

INTRODUCTION

Approximately half of the population report a sleep-related problem in 12 mths. Normal ideal sleep in a fit, young person is 7.5–8 h, with a latency less than 30 mins.

PRIMARY INSOMNIA

321–2

PERIODIC LIMB MOVEMENTS

Also referred to as nocturnal myoclonus or ‘leg jerks’, they tend to occur in the anterior tibialis muscles of the leg. Most people are asymptomatic—the diagnosis is often made during sleep studies. If troublesome, referral to a sleep clinic is appropriate.

Medication (if symptomatic)

• Levodopa + carbidopa (e.g. Sinemet 100/25, 2 tabs before bedtime) or

• Clonazepam 1 mg (o) nocte increasing to 3 mg (o) nocte or

• Sodium valproate 100 mg (o) nocte

RESTLESS LEGS SYNDROME

416

NARCOLEPSY

459

SLEEP PARALYSIS

The temporary inability to move or speak when falling asleep or upon awakening, with intact consciousness. It can be terrifying but is not dangerous. Treatment is educational and preventive with optimal sleep hygiene.

SLEEP APNOEA

Sleep apnoea refers to cyclical brief interruptions of ventilation (breathing) resulting in hypoxaemia and related biochemical effects and terminating in sleep arousal, which is often not recognised by the patient. The main type is obstructive sleep apnoea, which refers to the presence of apnoeas and hypopnoeas during sleep together with daytime dysfunction, especially sleepiness.

Predisposing causes include:

• diminished airway size (e.g. obesity, tonsillar–adenoidal hypertrophy)

• upper airway muscle hypotonia (e.g. alcohol, neurological disorders)

• nasal obstruction

Clinical effects include daytime somnolence and neuropsychiatric disturbances (e.g. depression, personality change).

The other type is central sleep apnoea, which is characterised by periodic loss of breathing during sleep. Due mainly to neurological causation.

Management Referral to a sleep disorder centre is advisable. General principles and methods:

1. lifestyle modification (e.g. weight loss, no smoking)

2. continuous +ve airway pressure (CPAP) delivered by nasal (or facial) mask

3. corrective surgery (e.g. tonsillectomy, nasal obstruction)

4. oral appliance (e.g. the mandibular advancement splint)

5. medication (e.g. amitriptyline)

PARASOMNIAS

These are dysfunctional episodes associated with sleep, sleep stages or partial arousal. More common in children.

Nightmares (dream anxiety) These occur ...