4.1 Spot Sign And Functional Outcomes
This study is the first to focus on the association of the spot sign and functional outcomes in primary ICH survivors. Our results demonstrated that patients with a spot sign tended to be severely dependent in ADL at discharge and were more likely to require surgical intervention. In addition, patients with a higher spot sign score had a significantly longer hospital stay. ICH survivors, whose numbers are steadily increasing over the decades, are candidates for long-term neuro-rehabilitation, and analyses focusing on this group have important clinical implications. Detection of a spot sign may have great benefit for designing personalized and intense rehabilitation programs for ICH survivors.
Our results demonstrated that in primary ICH survivors, the presence of a spot sign within 24 h of ICH onset may be associated with detrimental functional status at discharge. Although the data did not reach statistical significance, notably, none of the patients positive for a spot sign achieved functional independence. Earlier studies have revealed that the spot sign is associated with higher mortality, hematoma expansion, and worse functional outcomes in patients with ICH, indicating the predictive value of the spot sign. However, these studies determined the endpoint of functional outcome solely based on the mRS score and the study population included patients who died (mRS = 6) during the acute disease phase, which might obscure the predictability of the spot sign in ICH survivors[9, 15]. In the present study, we determined functional outcomes based on both BI and mRS scores, which are better in characterizing ADLs. Both parameters revealed that patients with a spot sign tended to have worse outcomes (BI: OR = 2.87, p = 0.15; mRS: OR = 2.31; p = 0.24). The OR for worse outcome defined based on the mRS score (≥ 4) was similar to previous studies, which reported ORs of 2.40 and 2.50[7, 9]. The nonsignificance of the OR in the present study could be attributed to the small sample size, due to strict inclusion/exclusion criteria, and the selection of patients admitted to rehabilitation, neurology, and neurosurgery wards to retrieve consistent functional evaluation records.
4.2 Spot Sign, Surgery, And Length Of Hospital Stay
Essentially, two-thirds of the patients positive for a spot sign required cranial surgery compared with only one-fourth of the patients negative for a spot sign (66.67% vs 24.56%; OR = 6.14; p = 0.01). Indication for surgery is often an ominous sign of the profound mass effect of hematoma, although numerous factors, such as location of hematoma and baseline condition of patients, may confound the decision. On the contrary, although the benefit of surgery in terms of mortality and functional outcomes remains unclear in primary ICH[16], recent studies have reported that early neurosurgery is predictive of longer survival and better functional outcomes in patients with severe primary ICH[17]. Thus, early identification of patients with ICH in whom surgical intervention has a positive impact is of great clinical importance.
In addition to functional outcomes, multiple linear regression demonstrated that patients with a higher spot sign score had a longer mean hospital stay (p = 0.013). Essentially, all the patients in this study were covered by the National Health Insurance program, which covers 99.9% of the citizens of Taiwan, attenuating the influence of private health insurance and socioeconomic status on the length of hospital stay. The duration of hospitalization may reflect the severity of diseases, complications rates, and medical costs. Furthermore, studies in geriatric and general populations indicate that prolonged hospitalization is associated with increased functional dependence, infection, and comorbidities[18–20].
4.3 Implications
Early CTA serves as an important tool to diagnose and evaluate ICH, and an earlier study reported that a CTA spot sign could be precisely detected across multiple medical centers[21]. Extending its association with functional outcomes, as is shown in our results, the spot sign is a potential indicator for prognosis in patients with primary ICH. Furthermore, the spot sign helps identify ICH survivors who might require surgical intervention and longer in-patient treatment course. Combining the CTA spot sign with other prognostic tools is also an option[15], but more research on this topic is warranted.
4.4 Limitations
This study has several limitations. First, the sample size was relatively small. CTA was not routinely performed in patients with ICH. Limited case number hinders further stratification according to BI and mRS scores. Second, the follow-up period was short and not standardized in all the patients because of the retrospective study design. Further large-scale prospective studies with longer follow-up durations are warranted to comprehensively verify the predictive value of the spot sign. Third, in our retrospective review, we found no clear protocol for when and on whom to perform CTA in patients with ICH. CTA was performed when the cerebral hemorrhage seemed atypical for primary hypertensive ICH, which was determined by neurologists or neurosurgeons. This could have caused a selection bias that not all patients with primary ICH have CTA data available, and the criteria for prescribing a CTA may differ between physicians. Despite these limitations, our study still provides important evidence of the association of an early spot sign and deleterious outcomes in primary ICH survivors.