Entzündliche Erkrankungen des Rückenmarks und der Nervenwurzeln in der MRT

Zusammenfassung

Entzündliche Erkrankungen des Rückenmarks und der Nervenwurzeln werden aus klinischer und radiologischer Sicht in eine (Meningo)-Myeloradikulitis und eine Meningoradikulo-(Myelitis) beim immunsupprimierten und immunkompetenten Patienten eingeteilt, was teilweise Rückschlüsse auf die zugrundeliegende Ätiologie erlaubt. Der immunsupprimierte Patient leidet vor allem an viralen (Herpes simplex, Herpes zoster, Zytomegalie, HIV-Virus) sowie an bakteriellen (Tuberkulose, selten Syphilis), aber nur selten an parasitären Infektionen. Der immunkompetente Patient erkrankt vor allem an bakteriellen Infektionen (Borreliose) sowie an immunologisch bedingten entzündlichen Erkrankungen (Sarkoidose) und an demyelinisierenden Läsionen. Häufig ist auch die idiopathische Myelitis. Virale Infektionen sind selten. Die MRT-Morphologie der entzündlichen Läsionen wird durch sekundäre ischämische und demyelinisierende Veränderungen kompliziert, wodurch die Differentialdiagnose sehr erschwert sein kann, da das gesamte Spektrum von demyelinisierenden bzw. ischämischen und entzündlichen Erkrankungen miteinbezogen werden muß. Zudem können auch tumoröse Prozesse eine Myelitis bzw. Radikulitis nachahmen.

Summary

Purpose: To evaluate characteristic and reliable MRI patterns of different inflammatory lesions of the spinal cord and the nerve roots in immunologically compromised and immunologically competent patients in order to be able to establish a correct diagnosis based on MRI findings. Material and methods: The MRI examinations of 52 patients (27 men, 25 women, mean age 38.5 years, range 14–75 years) with proven inflammatory lesions (39 patients) or tumorous/postactinic lesions of the spinal cord (6 patients) and vascular malformations of the spinal cord (7 patients) were retrospectively analyzed. All examinations were performed on a 1.5 T MR unit, using bi- or triplanar T 1-w pre- and postcontrast as well as T 2-w SE sequences. Additionally, a review of the common medical literature concerning inflammatory lesions of the spinal cord was included. Results: Clinical and radiological examinations allow a subdivision of inflammations of the spinal cord and the nerve roots into (meningoradiculo) myelitis and meningoradiculo (myelitis) in immunologically suppressed or competent patients. The MRI patterns of these two inflammatory subtypes vary: meningoradiculitis presents with an enhancement of the nerve roots and the leptomeninges; myelitis itself is characterized by single or multiple, diffuse or multifocal, with or without nodular, patchy or diffusely enhancing intramedullary lessions, with or without thickening of the cord and leptomeningeal inflammation. This differentiation helps to determine the underlying etiology in some of the patients. The immunologically suppressed patient suffers from viral infections (especially herpes simplex, varicella-zoster virus, cytomegalovirus), bacterial infections (tuberculosis), but rarely from parasitic infections. The immunologically competent patient suffers from bacterial (borreliosis), but rarely viral infections, sarcoidosis and demyelinating diseases. Idiopathic myelitis is also common. Conclusions: Secondary ischemic and demyelinating processes result in a complex morphology of inflammatory lesions on MRI, and therefore the whole spectrum of demyelinating, ischemic and inflammatory lesions has to be included in the differential diagnosis. Even tumors may imitate inflammatory myelitis and radiculitis. Most commonly, meningoradiculitis can be separated from myelitis. A reliable diagnosis of a specific inflammatory lesion is difficult and is mostly achieved in patients with multiple sclerosis and in patients with HIV-associated cytomegalovirus infection.