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Thursday, May 23, 2013
I work nightshift, and have been told by family and my husband that if they wake me up to talk to me, or tell me something, that I seem that I am awake, my eyes are open, and I will talk to them. If they ask me a yes or no question, my answer is always yes. For example one time my brother had asked me when he said I looked awake if he could borrow my van to go somewhere, and I said yes, but when I awoke I had no memory of talking to him. I got dressed to go somewhere only to find out my van was gone! I called him to say I thought it was stolen, and he told me he borrowed it, and that I knew about it! This seems to happen a lot where someone talks to me, but when I awake I don`t remember any of the conversation. They say I answer like when I am fully awake any other part of the day. Is there a reason I don`t remember anything afterward? Am I really sleep talking or is there another condition it can be?
Based on the information you provided in your question, it’s likely that you have at least 2 separate but related sleep problems. The first is that you are probably suffering from partial sleep deprivation due to your night shift work (this is a well-known phenomena). The second is that you are probably having episodes of sleep inertia or “sleep drunkenness” when awakened in the middle of your sleep episode. The two are likely related in that your sleep schedule may well be contributing to worsening of the sleep inertia and difficulty awakening.
Shift work is quite common in modern society due to the 24/7 nature of world. As a result, about 20% of the population is involved in some form of shift work and about 15% of these individuals will have problems with sleep. There a couple of major sleep issues with shift work schedules. First, shift workers tend not to get enough sleep. Due to the fact that they are sleeping off-cycle from their normal internal rhythm, coupled with interruptions and social pressures to be awake during the daytime, shift workers tend to short themselves by 1-2 hours per day of needed sleep. This can have long-term consequences on health and well-being. Second, while it would be ideal to be able to totally invert your circadian cycle (sleepy during the day and awake at night), most shift workers are unable to do this despite best efforts. Thus, many shift workers do not to feel optimal as a result of the mismatch between their internal clock and their need to be awake at night.
Sleep inertia or sleep drunkenness refers to periods of confusion following awakening from sleep or from a nap. This impairment may be severe, lasting from minutes to hours and occurs when there is gradual disengagement from sleep to wakefulness. Also, short-term memory seems to be unreliable near sleep onset. Not remembering a conversation or some news that you were told in the middle of your sleep episode would be typical for this.
The underlying mechanism is believed to be state-dissociation. During state-dissociation the brain is partially awake and partially asleep. The brain is awake to perform such complex behavior as holding a conversation or turning off alarm clocks, but asleep enough that the person does not realize what they are doing. Sleepiness and worsening of sleep inertia can be caused by:
- Reduced sleep time, mostly seen in otherwise healthy adults (the most common reason)
- Disrupted sleep, such as in sleep apnea
- Intake of sedating drugs or alcohol
- Discontinuation of alerting drugs
- Many neurologic disorders
- Biologic clock misalignment, like in shift workers or in jet lag
Sleep inertia may be more pronounced if one is awakened from deep sleep, or slow wave sleep. This stage of sleep occurs most frequently in the young and decreases with aging. However, with sleep deprivation, or erratic sleep schedules, slow wave sleep “rebound,” or increased time spent in slow wave sleep may occur. As such, your irregular sleep schedule may be predisposing you to developing sleep inertia when attempts to awaken you are made.
To improve your situation, I recommend you start with getting adequate regular sleep. You need to establish a regular sleep schedule that allows for enough sleep time. You should also discuss with your family and friends that awakening you in the middle of your sleep to have meaningful conversations in not in either of yours best interest and should be avoided.
If your problem is not improved with the above measures, then I recommend you discuss it with your doctor. An evaluation by a Sleep Specialist may be necessary to determine how best to manage your sleep issues.
For additional information regarding sleep and sleep disorders, visit the American Academy of Sleep Medicine website. This website also contains a list of Sleep Centers across the country so you can locate one near you if need it. Good luck, and sleep well.
Dennis Auckley, MD
Associate Professor of Medicine
School of Medicine
Case Western Reserve University