Review Articles
INSOMNIA: CASE STUDIES IN FAMILY PRACTICE
Mrs. Lee is now dependent on the benzodiazepine. Benzodiazepine dependence is defined by the appearance of a predictable withdrawal syndrome, the features of which include insomnia, agitation, muscle tension, irritability, nausea, malaise, sweating, nightmares, depression, hyperreflexia, tinnitus, delusions, and hallucinations. Abrupt withdrawal can result in seizures. The decision to take her off the hypnotic is, therefore, a major one and needs to be discussed with her, weighing the pros and cons. Considering her age and possible age-related cognitive decline, it may be advisable to wean her off the benzodiazepine under careful and regular supervision. Mrs. Lee’s consent must be sought.
Mrs Lee requests if it is possible for her to stop the hypnotic. What advice would you offer her? List down your strategy to withdrawal from the hypnotic.
Diazepam has to be discontinued very gradually over a period of several weeks on months in order to avoid the appearance of rebound symptoms (original symptoms with increased intensity), and appearance of new symptoms. With a long half-life benzodiazepine like diazepam, the onset of withdrawal symptoms may take 3 to 8 days after discontinuation. Reduction in dosage of diazepam should be made by 25% per week until 50% of the dose is reached. Then, dosage reduction is made by one-eighth every 4 to 7 days. The last period of discontinuation is usually the most difficult and some patients may never to stop the medication.
Adjunctive use of sedating tricyclic antidepressants e.g. dothiepin or antiseizure drugs e.g. valproic acid may be considered during the benzodiazepine tapering period. If insomnia is still a problem, behavioural measures can be considered. Short and intermediate acting hypnotics e.g. lorazepam, alprazolam can be allowed on difficult nights but the risk of dependence on these benzodiazepine remains. Alternatively, Zolpidem which is chemically unrelated to the benzodiazepine can be taken on a PRN basis when sleep difficulty is encountered. It has minimal anxiolytic and no muscle relaxant effects.
CASE 4
A 65 year old man with Parkinson’s disease and insomnia.
Encik Hamzah, a 68-year old man with Parkinson’s disease, complaints of difficulty falling asleep, frequent nocturnal awakenings and non-refreshing sleep. He also experiences daytime fatigue and spontaneous dozing. He goes to bed at 11 pm, takes an hour to fall asleep and is awake by 5 am. He is unable to sleep thereafter.
His is currently on levodopa and bromocriptine. He spends most of the day at home and does admit to feeling depressed. He has marked dystonia affecting his trunk andupper limbs after a recent increase in medication dosage. His wife has noticed him to be confused on some nights and talk in his sleep. He has not been observed to have sleep-related breathing difficulties.
What are the likely causes of insomnia in this patient?
- Several factors can contribute to depression in patients with Parkinson’s disease.8
- Sleep disturbances tend to increase with age and is particularly common in Parkinson’s disease. Difficulty falling asleep and difficulty remaining asleep are the most common complaints. Loss of dopaminergic neurons of the substantia nigra is responsible for most of the daytime features of Parkinson’s disease. Other neurochemical changes affecting cholinergic, serotonergic and noradrenergic systems are also involved and have been implicated in the sleep-wake disturbances in Parkinson’s disease. The precise role of these neurotransmitters in the disruption of the sleep-wake cycle is as yet unclear.
- Bradykinesia and rigidity – the reduction in number of normal body shifts during sleep, leading to discomfort and nocturnal awakenings, impaired ability to use toilet at night, pain may result from rigidity.
- Tremor in Parkinson’s disease is not completely abolished during sleep and medication induced myoclonus can result in increased arousals.
- Medication effects – e.g. levodopa, the biochemical precursor of dopamine and noradrenaline can cause frequent awakenings and reduced REM sleep.
- Depression and anxiety – difficulty falling asleep, early awakening. The on-off phenomena and presence of hallucinations can result in severe sleep disruption.
Dementia commonly accompanies late-stage Parkinson’s disease can be associated with nocturnal confusional episodes and vocalizations and awakenings.
REFERENCES
- International Classification of Sleep Disorders, Revised: Diagnostic and Coding Manual, Rochester, Minn: American Sleep Disorders Association; 2001. [Link]
- Partinen M, Hublin C. Epidemiology of sleep disorders. In: Kryger M.H, Roth T, Dement W.C. Principles and Practice of Sleep Medicine, 3rd.Ed. Philadelphia: WB Saunders; 558-563 [Link]
- Terzano MG, Parrino L, Cirignotta F, et al. Studio Morfeo: Insomnia in primary care, a survey conducted on the Italian population. Sleep Med. 2004 Jan;5(1):67-75 [PubMed]
- Walsh J. Insomnia: Assessment and management in primary care. Sleep. 1999 May 1;22 Suppl 2:S402-8 [PubMed]
- National Heart, Lung, and Blood Institute Working Group on Insomnia. Insomnia: assessment and management in primary care. Am Fam Physician. 1999 Jun;59(11):3029-38 [PubMed] [Full text]
- Ariff KM. Understanding insomnia and its management. Med J Malaysia. 2001 Sep;56(3):386-94 [PubMed]
- Zorick FJ, Walsh JK. Insomnia. In: Kryger M.H, Roth T, Dement W.C. Principles and Practice of Sleep Medicine, 3rd.Ed. Philadelphia: WB Saunders; 615-622 [Link]
- Aldrich MS. Parkinsonism. In: Kryger M.H, Roth T, Dement W.C. Principles and Practice of Sleep Medicine, 3rd.Ed. Philadelphia: WB Saunders; 1051-1057 [Link]