There are certain conditions that can affect the brain and compromise sleep. Some of these are quite serious, and one of the most fearsome is Creutzfeldt-Jakob disease (CJD). What is CJD, and what causes it? What are the symptoms? How does CJD impact sleep? Learn about the relationship between CJD and sleep.
What is CJD?
Creutzfeldt-Jakob disease (CJD) is an extremely rare neurological condition that affects the central nervous system, especially the brain. It is estimated to occur in just 1 in a million people. There are both classic and variant forms of the condition; classic CJD may run in families or occur randomly (such as in sporadic cases), with symptoms often appearing in the late 50s. The variant form of CJD is extremely rare, with only 200 cases reported worldwide. It tends to affect younger people, and is related to mad cow disease.
CJD is caused by a misfolded protein called a prion. This misfolded protein induces other proteins to misfold, and as a result, the proteins may become dysfunctional. Exposure to prions may lead to the variant form of the disease, making it an infectious condition. It has previously occurred in the setting of contaminated tissues or instruments as part of corneal transplant, blood transfusion, or brain surgery. Extreme caution is now used to prevent the disease from spreading from infected people. Prions may also cause other diseases, including fatal familial insomnia.
What Are the Symptoms of CJD?
There are a few symptoms that are highly characteristic of CJD. The most common presentation is a rapidly progressive dementia that evolves over a period of weeks or months which may be accompanied by sudden, jerking movements called myoclonus. Myoclonus may be elicited by a surprising noise like sudden clapping, a so-called "startle response." Other symptoms associated with CJD include:
- Difficulty walking
- Personality changes
- Difficulty speaking
- Muscle twitches or stiffness
- Blurry vision (occasionally)
CJD and the Effects on Sleep
One of the most common sleep-related symptoms in CJD is sleepiness. Research studies demonstrate that half of people with CJD experience insomnia. These changes may prompt further evaluation with a sleep study.
When people with CJD are evaluated with a sleep study called a polysomnogram, marked changes in sleep are noted. The electroencephalogram (EEG), which is used to evaluate brain waves, has characteristic findings. A neurologist with an expertise in reading EEG will recognize periodic sharp wave complexes with a background of generalized slowing and low-voltage waves. These sharp waves may appear in sleep 1 to 3 months before other symptoms occur.
Overall, the sleep patterns also become very disorganized, with rapid transitions between sleep stages. Fewer normal patterns are seen, such as sleep spindles or K complexes, that are typically seen in stage 2 sleep. The amount of slow-wave sleep and rapid eye movement (REM) sleep decreases.
Dream-related confusion and aggressive behaviors may occur, similar to REM behavior disorder. Sleep apnea also seems to commonly occur.
Treatment and Prognosis in CJD
The long-term prognosis in CJD is poor. Most people die from the disease in 4 to 8 months, but up to 10% of people may survive 2 years or more. Significant impairment rapidly ensues, so an early diagnosis may help to establish appropriate supportive care.
If you have a loved one who has symptoms suggestive of CJD, including a rapidly progressive dementia that unfolds over weeks or months, you should seek evaluation by a neurologist. Further examination and testing will rule out other causes of the condition and ensure the proper diagnosis. As CJD can be associated with specific sleep disorders, these may need to be addressed as well.
"Creutzfeldt-Jakob disease". PubMed Health. Accessed: January 30, 2013.
Kryger, MH et al. "Principles and Practice of Sleep Medicine." Elsevier, 5th edition, pp. 1042.