The chronic neurologic symptoms and signs in 27 patients with previous signs of Lyme disease and current evidence of immunity to Borrelia burgdorferi are reported from the Departments of Neurology and Medicine, Tufts University School of Medicine, New England Medical Center, Boston, MA. The median age was 49 years with a range of 25-72 years. Signs and symptoms of chronic neurologic abnormalities included encephalopathy in 89% with memory loss, depression, sleep disturbance, irritability, and difficulty finding words; polyneuropathy in 70% with spinal or radicular pain, distal paresthesia, and sensory loss; leukoencephalitis in 4%; and miscellaneous symptoms including fatigue (74%), headache (48%), hearing loss (15%), fibromyalgia (15%), and tinnitus (7%). Seventeen patients (63%) had abnormalities of both the central and peripheral nervous systems, seven (26%) had encephalopathy alone, two (7%) had polyneuropathy alone, and the remaining patient (4%) had leukoencephalitis. At the time of examination chronic neurologic abnormalities had been present from three months to 14 years, usually with little progression. Six months after a two week course of intravenous Ceftriaxine (2 g daily), 17 patients (63%) had improved, 6 (22%) had improved and then relapsed, and 4 (15%) had no change in their condition. The early signs of infection were erythema migrans (85%), and headache and neck stiffness in 41%. The most common early neurologic abnormality was a facial palsy in 30%. Arthritis had occurred in 70% before the chronic neurologic symptoms developed and it was still present in ten patients (37%) when the chronic neurologic abnormalities were noted. 
COMMENT. The criteria for case inclusion in this study were previous signs of Lyme disease, neurologic symptoms lasting at least three months that could not be attributed to another cause, and current evidence of humoral or cellular immunity to B. burgdorferi, as shown by elevated serum IgG or IgM antibody titer of at least 1:400, five or more IgG antibody bands to spirochetal polypeptides, or a stimulation index of 10 or more in response to Borrelia antigens. The chronic neurologic abnormalities began months to years after the onset of infection, sometimes after long periods of latency and similar to the course of neurosyphilis. The most common form of chronic CNS involvement was subacute encephalopathy affecting memory, mood, and sleep sometimes with subtle disturbances in language. Diagnosis could be difficult because of the nonspecific nature of the symptoms. Although this report concerns adults, the findings might be pertinent to Lyme disease contracted during childhood.