The Diagnosis and Treatment of Rasmussen’s Encephalitis: A Case Report

Rasmussen’s encephalitis is a very rare type of chronic inflammatory disease of the brain. We report a case of a nine-year-old male patient who presented with seizures and cognitive impairment for six years. An MRI of the brain revealed significant cerebral hemiatrophy. The patient was on immunoglobulin therapy. We also engage in a review of the existing literature on Rasmussen’s encephalitis.


Introduction
Rasmussen's encephalitis is a rare neurological disorder. It usually affects only one hemisphere of the brain, and the involvement of both hemispheres is extremely rare. It occurs in the adolescent age group and presents as an autoimmune disease. It is a gradually progressive disease that usually manifests with refractory seizures and cognitive impairment. It is diagnosed by MRI of the brain and the treatment involves corticosteroids, immunoglobulins, or surgery.

Case Presentation
A nine-year-old male, born out of a non-consanguineous marriage, presented with complaints of flexion deformity of the right hand and intermittent episodes of generalized status epilepticus for six years. The patient was on treatment for seizures under a local practitioner and had never undergone an MRI brain before. He had a history of poor scholastic performance, but there was no history of fever or trauma. On general examination, the patient was conscious and well-oriented. He was able to count objects, state his full name, ride a tricycle, and draw a circle. As per the clinical examination, he had achieved the milestones by the age of three years, suggestive of delayed milestones. The patient was vitally stable and systemic examination was within normal limits. Immunization was up to date. The patient's mother had not undergone ultrasound scans during her ANC period. She neither had a history of fever during pregnancy, nor a history of miscarriage. The patient had been born full-term by normal vaginal delivery and weighed 3 kg at the time of birth. He had immediately cried after birth.
The patient was advised to undergo an MRI brain for further evaluation. On MRI brain axial sections, altered signal intensity appearing hypointense on T1 weighted imaging (T1WI) and fluid-attenuated inversion recovery (FLAIR) and hyperintense on T2 weighted imaging (T2WI) were noted at the frontoparietal lobe on the left side, with the loss of gray-white matter junction as well as encephalomalacia and gliotic changes with dilatation of anterior horn and body of ipsilateral lateral ventricle suggestive of significant left-sided partial cerebral hemiatrophy. Atrophy of the splenium of the corpus callosum, lentiform nucleus, basal ganglia, and internal capsule on the left side was noted (Figures 1-3). 1 1 1 1

FIGURE 3: MRI brain axial FLAIR image
Altered signal intensity is noted at the frontoparietal lobe on the left side with the loss of gray-white matter junction, encephalomalacia, and gliotic changes with dilatation of anterior horn and body of ipsilateral lateral ventricle appearing hypointense on FLAIR No evidence of restriction was noted at the frontoparietal lobe on the left side on diffusion-weighted imaging (DWI) (Figure 4), corresponding to the high apparent diffusion coefficient (ADC) value ( Figure 5).
For certain cases, a brain biopsy is not necessary because the diagnosis can also be obtained without one. Therapy aims to reduce inflammation, regain functional ability, and manage seizures. Pharmacological, immunotherapeutic, surgical, and rehabilitative procedures are some of the different therapy modalities that can be used to accomplish these objectives [3]. The early institution of long-term immunotherapy to prevent functional decline is the recommended mode of therapy [2].

Conclusions
Rasmussen's encephalitis is an uncommon type of brain malformation characterized by chronic inflammatory changes of the unilateral cerebral hemisphere; it can be diagnosed accurately by MRI. Steroids, immunoglobulins, and surgery are the most effective treatment modalities for this condition.

Additional Information Disclosures
Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.