The Creutzfeldt-Jakob disease (CJD) neurological status scale: a new tool for evaluation of disease severity and progression

Abstract

Objectives: To develop a scale sensitive for the neurological manifestations of Creutzfeldt-Jakob disease (CJD).

Methods: A 26-item CJD neurological status scale (CJD-NS) was created based on characteristic disease manifestations. Each sign was assigned to one of eight neurological systems to calculate a total scale score (TSS) and a system involvement score (SIS). The scale was administered to 37 CJD patients, 101 healthy first-degree relatives of the patients and 14 elderly patients with Parkinson's disease (PD).

Results: The mean TSS (±SD) was significantly higher in patients with CJD (13.19 ± 5.63) compared with normal controls (0.41 ± 0.78) and PD patients (9.71 ± 3.05). The mean SIS was also significantly different between the CJD (5.19 ± 1.22) and PD (2.78 ± 1.18 P ≤ 0.01) groups reflecting the disseminated nature of neurological involvement in CJD. Using a cutoff of TSS > 4 yielded a sensitivity of 97% for CJD, and specificity of 100% against healthy controls. All individual items showed excellent specificity against healthy subjects, but sensitivity was highly variable. Repeat assessments of CJD patients over 3-9 months revealed a time-dependent increase in both the TSS and the SIS reflecting the scale's ability to track disease progression.

Conclusions: The CJD-NS scale is sensitive to neurological signs and their progression in CJD patients.

Figure 1

CJD-NS: The Creutzfeldt-Jakob disease Neurological scale.

Figure 2. Progression of CNS-NS Total Severity Score (TSS) relative to elapsed time between evaluations

Progression of CNS-NS Total Severity Score (TSS) relative to time. Time is presented in months and TSS was calculated as described in the methods. (2A): TSS is presented for 14 patients with at least 2 examinations. Each point represents the change between first and last examination in each patient. (2B): The change in TSS relative to disease duration for 7 patients with 3 consecutive examinations and 7 additional patients with 2 consecutive examinations.

Figure 2. Progression of CNS-NS Total Severity Score (TSS) relative to elapsed time between evaluations

Progression of CNS-NS Total Severity Score (TSS) relative to time. Time is presented in months and TSS was calculated as described in the methods. (2A): TSS is presented for 14 patients with at least 2 examinations. Each point represents the change between first and last examination in each patient. (2B): The change in TSS relative to disease duration for 7 patients with 3 consecutive examinations and 7 additional patients with 2 consecutive examinations.

Figure 3. Progression of CJD-NS System Involvement Scores

Progression of CJD-NS System Involvement Scores (SIS) relative to disease duration in seven patients who had three or more evaluations. Each line represents the scores in one patient.