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

ABSTRACT

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.