Five-year retention of the classically conditioned eyeblink response in young adult, middle-aged, and older humans

OBJECTIVE: To describe the clinical profile of demyelinating optic neuritis in African Americans. METHODS: The medical records of all patients with a diagnosis of optic neuritis examined at the Neuro-Ophthalmology Unit at the Emory University Eye Center (Emory) and at the Grady Memorial Hospital Eye Clinic (Grady), Atlanta, Ga, between 1989 and 1996 were retrospectively reviewed. PATIENTS: African American and white patients, aged 15 through 55 years, with a single initial episode of acute optic neuritis of unknown or demyelinative origin were included in the study. Study patients included 23 African American patients and 56 white patients examined at Emory as well as 10 African American patients examined at Grady. RESULTS: There were no significant differences among the African American study patients, the white study patients, and patients from the Optic Neuritis Treatment Trial (ONTT) regarding sex (P=.36), age (P=.73), or the presence of disc edema (P=.40), lesions found on magnetic resonance imaging (P=.43), or multiple sclerosis (P=.54) at the onset of an initial episode of optic neuritis. The Emory African American patients presented with more frequent severe visual loss (13 [93%] of 14 patients with a visual acuity < or =20/200) compared with Emory white patients (12 [39%] of 31 patients; P=.002) and with ONTT patients (161 [36%] of 448 patients; P<.001). At follow-up examination of at least 1 year, Emory African American patients had worse vision (9 [39%] of 23 patients <20/40, and 4 [17%] of 23 patients < or =20/200) compared with Emory white patients (5 [8%] of 63 patients <20/40, P=.001; 3 [5%] of 63 patients < or =20/200, P=.08), and with ONTT patients (29 [7%] of 409 patients <20/ 40, P=.0001; 12 [3%] of 409 patients < or =20/200, P=.01). Compared with ONTT patients, the Emory African American patients combined with the Grady African American patients had more frequent severe visual loss (visual acuity < or =20/200) at presentation (18 [90%] of 20 patients vs 161 [36%] of 448 patients; P<.001) and at follow-up examination of at least 1 year (6 [18%] of 33 patients vs 12 [3%] of 409 patients; P=.002). Seven (58%) of 12 African American patients with multiple sclerosis had a "neuromyelitis optica" presentation defined by the presence of neurological deficits limited to the optic nerves and spinal cord. CONCLUSIONS: The African American study patients with a single episode of demyelinating optic neuritis had visual acuities more severely affected at onset and after 1 year of follow-up compared with the white study patients and with patients in the ONTT. In the African American patients, multiple sclerosis occurred most frequently in a "neuromyelitis optica" form.