Elevated cerebrospinal fluid IgG index in acute cerebellitis presenting with sudden onset headache

Acute cerebellitis is a rare inflammatory syndrome and is one of the important causes of acute cerebellar dysfunction in children. The cerebrospinal fluid (CSF) IgG index is most often tested clinically in the diagnosis of multiple sclerosis. However, it is not specific to multiple sclerosis, and can be elevated in a variety of neurologic diseases. A 7-year-old boy with acute cerebellitis presenting with sudden onset headache and subtle cerebellar dysfunction demonstrated an elevated CSF IgG index (1.1) and an absence of oligoclonal bands. On the seventeenth day, the follow-up CSF IgG index was 0.71. Two-month and one-year follow-up magnetic resonance imaging revealed cerebellar atrophy, although the patient showed no neurologic deficit. To the best of our knowledge, this case report is the first to describe acute cerebellitis accompanied by an elevated CSF IgG index and an absence of CSF oligoclonal IgG bands. These findings suggest that a breach in the blood-brain-barrier might occur in acute cerebellitis. Neurology Asia 2014; 19(2) : 211 – 213 Address correspondence to: Kyung Yeon Lee, MD, Department of Pediatrics, Ulsan University Hospital, 877, Bangeojinsunhwando-ro, Dong-gu, Ulsan 682-714, Republic of Korea. Tel: +82-52-250-8980, Fax: +82-52-250-8071, E-mail: [email protected] INTRODUCTION In contrast to acute cerebellar ataxia, acute cerebellitis can be diagnosed when cerebellar lesions are detected on neuroimaging. Although its typical clinical features are cerebellar dysfunction such as ataxia and dysmetria, it can also present with nonspecific neurologic symptoms such as headache and vomiting with minimal or no cerebellar signs. Meanwhile, the cerebrospinal fluid (CSF) IgG index is most often used in the diagnosis of multiple sclerosis. However, it can also be elevated in various neurologic diseases, such as bacterial and viral central nervous system (CNS) infection and Guillain-Barre syndrome. In the case reported here, a patient with acute cerebellitis presenting with sudden onset headache and subtle cerebellar dysfunction demonstrated an elevated CSF IgG index and was oligoclonal band-negative.