As discussed last week, a neurodisability score (NDS) has been proposed for use in dogs with meningitis of unknown origin (MUO). The goal is to help grade the clinical signs more objectively and, hopefully, prognosticate more accurately. The score was developed by Drs. Goncalves et al (https://doi.org/10.1111/jvim.16717) from the UK and published in 2023.
A retrospective evaluation of medical records was performed to identify common clinical signs at presentation. Subsequently these signs were grouped in to the following categories for prospective use: seizure activity, ambulatory status, posture and cerebral, cerebellar, brainstem and visual signs. For the prospective part, the score was tested on 31 dogs diagnosed with MUO. Table 2 of the published article has an outline of the scoring system which I would suggest you look at if you have time. As an example, under the “ambulatory status” section the options are “normal, mild paresis or ataxia but ambulatory without falling, moderate/severe paresis or ataxia with frequent falling, and nonambulatory”. Each of these options is given a numeric score from 0 (least severe) to 3 (most severe). As the categories are worked through, points will be accrued based on their neurologic exam. The maximal score is 21, indicating he most severe disease. According to the article, the mean score at presentation was 8 +/- 2.85 points. All of the things that you imagine would affect this score such as concurrent disease, treatment prior to referral, and evaluator skill must be considered here (which the authors did consider, for the most part). In the end, they found a significant difference in dogs that survived to discharge (median 8; range 3-14) and those that did not (median 12.3; range 8-13). You can see as well as I can that there is marked overlap between the ranges which makes it difficult in a clinical patient to draw conclusions. Furthermore, the study did not evaluate validity (did the test measure what it was supposed to be measuring) and did not find an association at a specific cut-off value related to long-term outcome. The study presented in last weeks TidBit Tuesday suggested a cut off value of 7 would be used to predict death by 6 months for dogs with MUO. I’m ecstatic that this work is being done but caution you to use it with care. Euthanizing a pet simply based on this score feels inappropriate at this time. Predicting a poorer possible outcome at 6 months and relaying this information to a client would be an appropriate use of the NDS. It IS encouraging that we may have a universally available tool for ALL VETS (i.e. not a specialty tool like an MRI, or a neurofilament in CSF) that we can use to talk about MUO in objective terms. As with most of the TidBit Tuesdays there will be much more to come on this topic over time so stay tuned!
Thanks for reading! Changes to my schedule are once again upon us as the summer sets in. My schedule varies WEEKLY so please reach out if you have a case that needs to be seen but cannot find a suitable time on the schedule; I may have more flexibility than what is listed, so please ask. I will be closed at the end of June for a few days for a family wedding, and mid-July for the Dane County Fair but otherwise anticipate high availability for you this summer. Enjoy the beautiful spring weather and the delicious smells of blooming things this week!