Neurologic manifestations of ulcerative colitis

Ulcerative colitis (UC) has traditionally been considered to be an inflammatory disease limited to the colonic mucosa. However, since it has been shown that UC is frequently accompanied by various extraintestinal disorders, there is increasing evidence that UC may also manifest in the nervous system. The following review focuses particularly on these possible manifestations of UC, both in the peripheral (PNS), and in the central nervous system (CNS). A systematic literature search according to the MEDLINE database was performed for this purpose. Although a reliable differentiation may clinically not always be possible, three major pathogenic entities can be differentiated: (i) cerebrovascular disease as a consequence of thrombosis and thromboembolism; (ii) systemic and cerebral vasculitis; (iii) probably immune mediated neuropathy and cerebral demyelination. With the exception of thromboembolism and sensorineural hearing loss, evidence for a causal relationship relies merely on single case reports or retrospective case series. Considering the CNS-manifestations, similarities between UC-associated disorders of the white matter and acute disseminated encephalomyelitis (ADEM) are obvious. Epileptic seizures, unspecified encephalopathies and confusional states are most likely epiphenomena that have to be regarded symptomatic rather than as own entities. A prospective study on the neurologic aspects of UC would be very welcome.