The World Federation of Neurological Surgeons Scale for Subarachnoid Haemorrhage: Aphasia should be removed from the classification
BI Ogungbo, Presented to the Society of British Neurological Surgeons. August 2002.
The World Federation of Neurological Surgeons (WFNS) grading scale for Subarachnoid Haemorrhage (SAH) was publicized in 1988 via letters from the committee of the WFNS. (2, 11) The scale has achieved worldwide acceptance and common usage by being easy and, compatible with formerly employed scales. (3) Overall, despite some attempts to modify or combine it, in various ways, it has proved robust and remains applicable by a diverse group of observers. (1, 6-10)
The WFNS Scale is based upon the well-known Glasgow Come Score (5) (GCS) and on the finding of a motor focal deficit. The scales are not reiterated here and knowledge is assumed. The GCS for patients in WFNS 2&3 is similar (GCS=13 or 14). The finding of aphasia and or motor deficit in a patient with GCS 13 or 14 was used to downgrade the patient to WFNS grade 3. My gripe is with the usage of the word "aphasia".
Aphasia might denote that the patient is not making any verbal communication and under the GCS verbal score classification, such a patient should be scored as V1. In this regard the maximum total GCS for that particular patient would be 11.
So a patient with aphasia should not be classifiable into WFNS 2 or 3. Such a patient has GCS 11, and therefore belongs to WFNS grade 4. On the other hand, some may decide that a patient with a localized focal deficit involving language function but who looks intact neurologically should be scored higher on the verbal GCS. But how high? If such a person is scored as V5 then certainly the GCS should be 15 and such a person grouped into WFNS grade 1.
There also seems to be differences in the interpretation and application of the grade by medical practitioners and researchers. It has been suggested that patients with confused verbal responses should be graded lower than those who are oriented, even when they have the same total score. (4) In the same vein some have suggested that the presence of dysphasia should be applied (instead of aphasia!), to downgrade patients with GCS 13 or 14 into WFNS 3. One notes as well that some interchange aphasia and dysphasia, believing, as it is, that they are part of a continuum. Yet, it does matter whether you are dysphasic or globally aphasic.
In my opinion, it is probably better to be half-blind than completely blind and they are not interchangeable. In the first instance, dysphasia could be sensory or motor or both and this immediately conjures up difficulties. Should we use motor dysphasia (motor deficit!) or sensory dysphasia? Does it matter which is applied? Which of the three correlates more with poor outcome, if any? How do you differentiate a comatose patient with confusion and disorientation from one with receptive or expressive dysphasia? I suggest that it is difficult and much more that simply asking if such a patient recognizes your tie or not.
Furthermore a patient making incomprehensible sounds is not necessarily aphasic but may be severely dysarthric. Linguistic fluency is easier to evaluate in patients with clear consciousness (GCS 15) and for me, the degree of consciousness influences clinical evaluation greatly.
Alterations in level of consciousness, motivation and drive leads to disturbed communication and affect the patients' general behaviour. Neurologists have suggested that the term aphasia is used only if the deficit leaves the other higher mental functions basically intact. I agree with this.
Scientific communication in medicine can be effective only if reports are based on unequivocal criteria for clinical conditions or specific diagnoses (12). We have to be applying the scales in a uniform and clear manner. However, there are these subtle differences in the application of the WFNS scale by different people as discussed above.
The value of a scale is directly related to the division of patients into discrete groups, which correlate directly with outcome. In this regard, there is currently no ideal scale. Specifically, with regard to the WFNS scale, many papers have failed to show a difference in outcome between the WFNS grades 2 and 3. A gradation of the outcome with regard to the middle admission grades has not been identified. (1, 4) It is conceivable that the use of aphasia and dysphasia is directly or indirectly responsible for this. So where do we go from here?
I believe that this is worthy of debate. Personally, I am of the opinion that it was wrong to have included aphasia as part of the motor deficit to be used in creating a difference between WFNS 2&3.
It is my submission that a modification of the scale by the simple elimination of "aphasia" is long overdue.
