Delayed Neurological Sequelae, called DNS, after carbon monoxide poisoning can result in additional hospital visits in the following weeks. Delayed symptoms can occur in the time following recovery of an acute carbon monoxide poisoning.
One of the worst aspects of carbon monoxide poisoning are the delayed neurological symptoms that occur after the accident. Brain damage does not occur immediately, but rather, takes weeks or months to show. Behavioral and neurological problems show between day two and day 40. A great deal of patients are discharged before dealing with the problems that come up in the following days, weeks, or months. DNS is an escalating pathology. That is why appropriate follow-up is so important. The toxic effects of this odorless, colorless gas persist weeks and even months after the exposure. This syndrome, DNS, can appear as any neurological or behavioral symptom, including memory loss, confusion, seizures, urinary incontinence, loss of bowel function, disorientation, hallucinations, psychosis, balance issues and dizziness.
It is believed that delayed symptoms are related to “brain lipid peroxidation” which may be a result of carbon monoxide triggering a Nitric Oxide formation in the blood stream.
It is vital that delayed symptoms in all CO cases be explained. The potential for Delayed Neurological Sequelae should be looked after carefully. Sufficient follow up with specialized medical professionals should be received. The longer a patient is unconscious, the more likely delayed symptoms may occur. There is also a dramatic increased risk of DNS with patients more than 30 years old. The prevalence of Delayed Neurological Sequelae is significantly understated because in the studies that have looked at neuropsychometric (neuropsychological testing) measures, versus strictly clinical manifestations, the percentage of those with DNS climbs to nearly 50 percent.
THE DIAGNOSIS OF PERMANENT BRAIN DAMAGE IS SUBTLE, AND IT CANNOT BE RULED OUT BY NORMAL NEUROLOGICAL EXAMS OR IMAGING STUDIES.