Scales and Scores

Ullrich Meier

Clinical classification of special clinical pictures should, on the one hand, take into account the specific symptoms and, on the other, provide or enable an evaluation of the individual course of the disease, while also allowing for an interindividual comparison. An assessment of the individual symptoms, according to their importance for the patient and bearing in mind the pathophysiologic, occupational medicine, and psychosocial aspects is, in this context, indispensable. With regard to practicality in the context of everyday hospital routine, clinical grading must be constructed in a lucid manner, as far as possible without inclusion or exclusion criteria, as well as being easy to use. From this perspective, we investigated three different scales for assessing the course of disease in patients with normal pressure hydrocephalus (NPH): the Black Grading Scale for shunt assessment,¹ the clinical grading scheme of Kiefer et al.^2,3,4 and the index for the postoperative improvement in findings for patients with idiopathic normal pressure hydrocephalus (iNPH) of Krauss et al.^5,6 The description of the Stein–Langfitt scale⁷ was taken from the literature.

13.1 Black Grading Scale

The Black Grading Scale for shunt assessment¹ grades different forms of clinical improvement following a shunt operation, but it does not allow any distinction between an unchanged course of the disease and clinical worsening. This fact has a negative consequence in a comparative consideration of patient groups on differentiating the results of follow-up. A positive attribute of the Black Grading Scale for shunt assessment¹ is a clear subdivision of the scale into six groups, which are defined as excellent, good, gradual, time-limited improvement, bad, and death. In this way, the gradation is simple and can be used without any inclusion or exclusion criteria.

The Black Grading Scale for shunt assessment¹ is well suited for use in patients with pressure hydrocephalus. For this patient group, the individual symptoms do not so much dominate in the clinical course following a shunt operation, but the results of the operation as such are to be taken into account without consideration of the preoperative condition of the patient. For interindividual comparison of patients in relation to the course of the disease with internal hydrocephalus, the Black Grading Scale for shunt assessment¹ is, in our experience, well suited.^8,9 In addition to providing an undifferentiated summary when the course of the disease is unchanged and when there is worsening of the clinical symptoms, the Black Grading Scale for shunt assessment¹ also does not consider the specific symptoms of the clinical picture of NPH. Taking into account these two negative attributes, the Black Grading Scale for shunt assessment¹ can only be conditionally recommended for assessing the individual course in patients with iNPH (▶ Table 13.1).⁸

**Table 13.1** Black Grading Scale for shunt assessment¹
Assessment	Level of activity following the shunt operation
Very good	Achieved the same level of activity as before the illness, without restrictions
Good	Achieved the same level of activity as before the illness, with restrictions
Moderate	Improvement, but cannot carry out a job
Moderate/temporary	Temporary improvement
Bad	No improvement or worsening
Death	Died within 6 weeks following the operation or because of the operation

13.2 Index for Postoperative Improvement

From postoperative observations of the clinical course of 50 patients with iNPH in whom, following a careful preselection during 1989 to 1994, a shunt operation was carried out in Freiburg, Germany, Krauss et al⁵ reported the calculation of an index intended to clarify the extent of postoperative improvement in findings. In this, an index of 0 indicates no or minimal improvement, and an index of 1 indicates an excellent improvement in findings for all cardinal symptoms. To calculate the index, the postoperative changes in three cardinal symptoms are evaluated separately on a three-point scale. The index is produced by the quotients of the actual improvement in findings and the maximum possible improvement in findings. In patients with two preoperative cardinal symptoms, an index between 0/4 and 4/4 is possible, and in patients with three cardinal symptoms, an index between 0/6 and 6/6 is possible.^5,6 The scientific approach to the calculation of the index for the postoperative improvement in findings in patients with iNPH⁵ is similar to that of the clinical grading of Kiefer et al.⁴ In the latter, in addition to the cardinal symptoms for NPH, headaches and symptoms of dizziness are also evaluated, as well as a clear gradation of the individual symptoms, which is undertaken according to their degree of severity. For this reason, we believe that the index for postoperative improvement in findings for patients with iNPH proposed by Krauss et al⁵ is unsuitable for clinical practice.⁸

13.3 Stein–Langfitt Scale

With the Stein–Langfitt scale,⁷ patients are judged both preoperatively as well as postoperatively according to their clinical condition and, in particular, to their residual abilities. The Stein–Langfitt scale⁷ does not take into account the specific symptoms of the clinical picture of iNPH. Since most patients with iNPH are found to be in stages 1 or 2, a substantial lack of discrimation power has to be stated compared to other scales. In addition, there are problems with the allocation of grades. For example, a patient with mild gait ataxia and urinary incontinence would be allocated to both grades 1 and 2. Consequently, the Stein–Langfitt scale⁷ can only be conditionally recommended for assessing the individual course in patients with iNPH (▶ Table 13.2).⁸

**Table 13.2** Stein–Langfitt scale⁷
Grade	Clinical condition
0	No neurological deficit; the patient is able to work
1	Slight neurological deficit; the patient is able to get home alone
2	At times, the patient requires to be cared for at home
3	Care of the patient at home is necessary, despite the patient having some remaining residual ability
4	The patient is not able to take care of himself/herself alone