Neurologic Involvement in Primary Immunodeficiency Disorders.

The nervous system may be affected in primary immune deficiency (PID) syndromes through infectious, autoimmune, neoplastic mechanisms, or as a primary feature of the syndrome. However certain neurologic problems do not conform to these etiopathogenetic groups. We retrospectively examined PID patients seen in neurology consultation between 2014 and 2017 in order to determine the spectrum of nervous system involvement. Among patients with confirmed neurologic problems (n = 35), common manifestations were encephalopathy and global developmental/cognitive delay. In 13 (37%) instances, the neurologic signs had no apparent relation with a treatment-related, infectious, or vascular complication and were considered as primary findings: acquired microcephaly, central nervous system malformation, or peripheral neuropathy. The diagnosis of PID was made after, and based on, the neurologic manifestation in 6 of 35 (17%) patients. Neurologic presentation may constitute the initial manifestation in some types of primary immune deficiency.