Reviewer 1 Comments

1. The rate of symptom progression was described qualitatively in patients who developed neurological deficits in the literature. For instance, a case with a 4-day evolution of symptoms was reported previously. Hence, it would be informative to know the duration of symptoms before diagnosis. 
    ResponseThe duration was 6 days. This information has been added to the manuscript.
    
2. Patients with catheter tip granulomas may be exposed to different drugs (i.e. morphine or hydromorphone, either alone or as a drug admixture), dosages, or drug concentrations before diagnosis. It is useful to know about the intrathecal drugs that were administered at the time a mass was diagnosed.
    ResponseThe patient was only on morphine at 20 mg/ml without any changes in the last 4 years. This information has been added to the manuscript.
    
3. Delayed diagnosis and treatment has been found to be associated with residual neurological disabilities. However, it is unclear that whether neurological outcome correlates with the type of treatment for patients with catheter tip granulomas. Removal or revision of the drug administration system is one of the therapeutic options. Case records suggest that patients with a mass that did not fill the spinal canal or cause neurological impairment may be treated by stopping or emptying the drug infusion pump or by refilling it with preservative-free normal saline to run at a minimal infusion rate (approximately 0.1 ml/d). Nevertheless, in the literature, most of the cases underwent surgery to relieve spinal cord or cauda equina compression. Was there any contraindication of surgical intervention for the patient?  
    ResponseThe neurosurgery team preferred observation over surgical option, since the patient did not have any motor deficit or cauda equina syndrome.


4. Contamination of intrathecal drugs or diluent solutions with bacterial endotoxins or pyrogens is another potential microbiological hypothesis. Did the patient undergo her CSF analysed using the Bacterial Endotoxins Test or the Limulus amoebocyte lysate test for endotoxins? Did she experience meningitis symptoms, or CSF pleocytosis consistent with an endotoxic or pyrogenic reaction?
    ResponseAs the cerebrospinal fluid analysis was normal and cultures were negative for infection, no further investigation was pursued on CSF.

Reviewer 2 Comments

1. This is a very interesting case, however, the authors need to explain what this case adds to the existing literature on the subject.
    ResponseThis case is submitted as a brief report in the Images in Neurology section. Authors hope to refresh this clinical entity to the readers with impactful images. This case responded to the conservative treatment which could be an option in mild presentation, rather than surgery.

Jain G, Rizk NN. Spinal cord compression due to a catheter tip granuloma of an intrathecal morphine pump. Neurol Neurosci Res 2018;1(1):5. https://doi.org/10.24983/scitemed.nnr.2018.00066