Rasmussen encephalitis: Predisposing factors and their potential role in unilaterality

Abstract

Objective: Rasmussen encephalitis (RE) is a progressive and destructive inflammatory disease of one hemisphere. Its cause is unknown. We investigated comorbidity and laterality factors that might predispose to RE. Methods:We retrospectively compared the histories of 160 RE patients to those with genetic generalized epilepsy (n = 154) and those with focal cortical dysplasia Type II (FCD II; n = 148). Results:The median/mean age at symptom onset in RE was 7/10 years (range = 1-53 years), and 58.1% of the patients were female. The female sex predominated in RE patients, with age > 7 years at disease manifestation. The left hemisphere was affected in 65.6%. Perinatal complications (preterm birth, twin pregnancies, early acquired brain lesions) were more frequent in RE than in control patients.Ipsilateral facial autoimmune conditions (scleroderma en coup de sabre, uveitis, or chorioretinitis) were only observed in RE patients (6.9%). Onset of RE was more frequently associated with fever than that of FCD II. In 33.1% of RE patients, ≥1 potential risk factor was found. Interestingly, 11.9% of patients had onesided early brain lesions or facial autoimmune lesions ipsilateral to subsequent RE; none had such a lesion contralaterally.Significance: Perinatal complications and facial autoimmune conditions may act as predisposing factors for RE. Fever might trigger RE manifestation. Further genetic or infectious contributors may be identified in the future. Single or combined hits may be required to elicit or facilitate the start of the disease. Ipsilateral early comorbid lesions or facial autoimmune processes might in part explain the enigmatic unilaterality of RE.

Epilepsy, Immunity and Neuropsychiatric Disorders

“…Similar to clinical evolution, RE also evidences a neuropathological progression, dealing with four stages with the progressive cortical injury sustained by T-lymphocyte and neuroglial activation [ 19 ]. A retrospective series of 160 RE cases showed that perinatal complications and other autoimmune conditions (like scleroderma, uveitis, and chorioretinitis) might predispose to RE [ 27 ]. Treatment in RE syndrome aims to reduce seizure frequency and improve motor and long-term cognitive outcomes.…”

Retos en el diagnóstico y tratamiento de la Encefalitis de Rasmussen de inicio tardío: Reporte de tres casos

“…Posterior al desarrollo de la EPC su hemiparesia secuelar empeoró y se acentuó un poco más tras la cirugía. Respecto a ello, se ha descrito que lesiones cerebrales unilaterales adquiridas a temprana edad son más frecuentes en pacientes con ER comparados a pacientes sanos y que estas lesiones son ipsilaterales al hemisferio afectado por ER (15). De la misma forma, la paciente 3 presentó 2 lesiones identificadas en las neuroimágenes, sin que estas patologías pudieran explicar su cuadro clínico; pues los angiomas venosos no suelen asociarse al desarrollo de epilepsia y las calcificaciones residuales no se asocian a epilepsia farmacorresistentes; en ambos casos podrían ser silentes.…”

Progress in pathogenesis and therapy of Rasmussen's encephalitis

“…In 2005, Bien et al proposed formal diagnostic criteria of the European consensus statement for RE, which described Part A and Part B 14 . The diagnosis of RE requires the fulfilment with either all three criteria of Part A or two out of three criteria of Part B. Scholars suggest that the positive histopathology (B3 in Part B) plus two of three A criteria could also be diagnosed as RE for improving the sensitivity of the criteria and this modified criteria was applied in a retrospective study by Bien 15,16 …”