Figure 1.
Reciprobit plot of saccade latencies from a healthy volunteer.
Cumulative probability is plotted on the y axis on a probit scale. Using this scale, plotting a normal distribution results in a straight line. Latency is plotted on the x axis using a reciprocal scale. The reciprocals of the latencies are equally spaced along this scale. Additionally this scale is mirrored, so that short latencies are to the left and long to the right: infinite latencies, whose reciprocals are zero, therefore form the right hand margin. Because their reciprocal latencies are normally distributed, with mean mu and standard deviation sigma, most latencies lie on a straight line (red), the main distribution, whose median and slope correspond to mu and sigma. In addition, under some conditions there may be a sub-population of early saccades (blue) that lie on a line of shallower slope, corresponding to a third parameter early sigma.
Figure 2.
Baseline scores and annualised rates of change for motor tests.
Row A shows baseline scores on each test. In order that all graphs show decline as lower values, the scores have been transformed by subtracting the participants’ score from the maximum for the test (see methods). Blue diamonds are controls, red squares are patients with PSP. Black triangles mark the baseline score for patients who could not complete interval testing. Row B shows the difference in score between baseline and interval, in those patients who completed both assessments. The score has been adjusted so that it shows the change in score over twelve months Negative values represent worsening of function. In both sets of graphs, the x axis represents a nominal value. In line A the x axis is arranged so that controls are on the left, patients who completed interval assessments are in the middle and patients who did not complete the interval assessment are on the right. In line B the scores are arranged randomly. Tests are named at the top of each column. UPDRS is the Unified Parkinson’s Disease Rating Scale motor sub scale; PSPRS is the PSP rating scale and PSPRS stage is the stage sub score of the PSPRS. All tests are marked “–inv” to signify that the scale for these tests has been inverted representing deficit from normal.
Figure 3.
Baseline scores and annualised rates of change for cognitive tests.
Tests are named at the top of each column. FAB is the Frontal Assessment battery; Hayling A-inv is the number of correct category A answers in the Hayling test; Hayling B-inv is the number of correct category B answers on the Hayling test; ACE-R is the Addenbrookes Cognitive Examination - Revised. Row A shows baseline scores on the test. Blue diamonds are controls, red squares are patients and black triangles mark the baseline score for patients who could not complete the interval testing. Hayling A and Hayling B scores have been transformed so that a higher score represents a better function (see methods). Row B shows the difference in score between baseline and interval, in those patients who completed both assessments. The score has been adjusted so that it shows the change in score over twelve months. Negative values represent worsening of function. In both sets of graphs, the x axis represents a nominal value. In line A the x axis is arranged so that controls are on the left, patients who completed interval assessments are in the middle and patients who did not complete the interval assessment are on the right. In line B the scores are arranged randomly.
Figure 4.
Baseline scores and annualised rates of change for visual and oculomotor tests.
Tests are named at the top of each column. VOSP is the Visual Object and Space Perception battery and mu is the reciprocal of the latency as measured by saccadometry. Row A shows baseline scores on the test. Blue diamonds are controls, red squares are patients and black triangles mark the baseline score for patients who died before interval testing. A lower value on the y axis for the mu graph corresponds to a lengthening of latency between stimulus presentation and saccade initiation. Row B shows the difference in score between baseline and interval, in those patients who completed both assessments. The score has been adjusted so that it shows the change in score over twelve months, irrespective of how far apart the assessments were. Negative values represent worsening of function. In both sets of graphs, the x axis represents a nominal value. In line A the x axis is arranged so that controls are on the left, patients who completed interval assessments are in the middle and patients who did not complete the interval assessment are on the right. In line B the scores are arranged randomly.
Figure 5.
Graph showing annualised and normalised rates of change for different aspects of disease.
Green squares are the change in scores for the Addenbrookes Cognitive Examination Revised, green triangles are rates of change for mu (reciprocal latency), purple squares are the change in scores for the Unified Parkinson’s Disease Rating Scale (UPDRS) motor subsection and the purple triangles are the change in scores for the PSP rating scale (PSPRS). The horizontal black lines are the mean rate of change for each test. Values below the x axis represent worsening of patients’ conditions and those above the x axis are improving.
Figure 6.
Graph showing the rate of change for individual items (A) and section totals (B) of the PSP rating scale (PSPRS).
Bars extending to the right of the y axis are those parts of the scale where there has been a worsening of symptoms, those to the left an improvement of symptoms. The scale on the x axis refers to annualised normalised rates of change. The black vertical line on Figure A corresponds to the mean change of the overall total of the PSPRS scale.