[Non-epileptic impaired consciousness in neurologic diseases]

Transient recurrent confusional and stuporous states of nonepileptic origin are clearly less frequent than epileptic ones. They are relatively common in diseases of disturbed vigilance, like narcolepsy, idiopathic hypersomnolence, and sleep apnea. These patients often suffer from attacks of hypovigilance, characterized by altered awareness, automatic behaviour and partial or complete amnesia for the attack. Because of the memory 'black outs' and the frequently associated hypnagogic hallucinations, the patients behave inappropriately and often appear confused. Confusional states also typically arise during basilar artery migraine attacks. This special form of complicated migraine predominantly affects young females and is characterized by symptoms and signs of brain stem dysfunction such as vertigo, ataxia, paresthesia, limb weakness, dysarthria; in 75% of the cases, disorders of consciousness dominate. Transient ischemic attacks are sometimes recurrent and, when involving the cranial basilar territory, may result in confusional states without significant motor dysfunction. Attacks of transient global amnesia are possibly also ischemic in nature and are assumed to arise from transient bilateral limbic failure. Affecting only memory functions, they are strictly spoken not confusional, but must nevertheless be taken into consideration when proper observation during the attack was not possible.