There was no restriction in her visual field and no scotoma. Disturbance of movement vision
LMs impression of movement depended on the direction of the movement (horizontal vs vertical), the velocity, and whether she fixated in the center of the motion path or tracked the object with her eyes. Circular light targets were used as stimuli.In studies, LM reported some impression of horizontal movement at a speed of 14 degrees of her predetermined visual field per second (deg/s) while fixating in the middle of the motion path, with difficulty seeing motion both below and above this velocity. When allowed to track the moving spot, she had some horizontal movement vision up to 18 deg/s. For vertical movement, the patient could only see motion below 10 deg/s fixated or 13 deg/s when tracking the target. The patient described her perceptual experience for stimulus velocities higher than 18 and 13 deg/s, respectively as "one light spot left or right" or "one light spot up or down" and "sometimes at successive positions in between", but never as motion. Motion in depth
To determine perception of motion in depth, studies were done in which the experimenter moved a black painted wooden cube on a tabletop either towards the patient or away in line of sight. After 20 trials at 3 or 6 deg/s, the patient had no clear impression of movement.
Bolivian hemorrhagic fever (BHF), also known as black typhus or Ordog Fever, is a hemorrhagic fever and zoonotic infectious disease originating in Bolivia after infection by Machupo mammarenavirus.BHF was first identified in 1963 as an ambisense RNA virus of the Arenaviridae family, by a research group led by Karl Johnson. The mortality rate is estimated at 5 to 30 percent. Due to its pathogenicity, Machupo virus requires Biosafety Level Four conditions, the highest level.During the period between February and March 2007, some 20 suspected BHF cases (3 fatal) were reported to the Servicio Departamental de Salud (SEDES) in Beni Department, Bolivia. In February 2008, at least 200 suspected new cases (12 fatal) were reported to SEDES. In November 2011, a second case was confirmed near the departmental capital of Trinidad, and a serosurvey was conducted to determine the extent of Machupo virus infections in the department. A SEDES expert involved in the survey expressed his concerns about the expansion of the virus to other provinces outside the endemic regions of Mamoré and Iténez provinces. Epidemiology
History
The disease was first encountered in 1962, in the Bolivian village of San Joaquín, hence the name "Bolivian" Hemorrhagic Fever. When initial investigations failed to find an arthropod carrier, other sources were sought before finally determining that the disease was carried by infected mice.