Spontaneous Spinal Epidural Hematoma Mimicking Stroke and Its Outcome post Intravenous Thrombolysis

Intravenous thrombolysis (IVT) is the mainstay of treatment for acute ischemic stroke (AIS). The limited time frame and aim to shorten door-to-needle time prompt clinicians to make decision on treatment instantaneously, rendering insufficient time for observation of clinical progressions to confirm the diagnosis.

Most of the time, it was safe with small bleeding risk even when IVT was given to stroke mimics like migraine and Bell’s palsy (risk of symptomatic intracerebral hemorrhage (sICH) compared with patients with AIS was significantly lower with risk ratio = 0.33) [1]. It was further reassuring that even for AIS attributing to intracranial dissection, IVT was reported to be relatively safe [2].

However, it had come to our recognition that for a hemorrhagic condition – spontaneous spinal epidural hematoma (SSEH), IVT may be potentially harmful when given inadvertently. Yet it was at the same time difficult to differentiate from true AIS, especially for cervical SSEH.

SSEH is a rare neurological emergency with incidence estimated to be 0.1 patients per 100,000 patients per year [3]. It is defined to be SSEH if blood accumulates in the spinal epidural space spontaneously without an obvious traumatic or iatrogenic cause, as proposed by Lonjon et al. [4]. It was commonly presented with acute neck or back pain, followed by neurological symptoms ranging from pure sensory symptoms to a full-blown cord compression syndrome. Yet of note, 15% was painless and 3 out of 13 patients in a case series presented with hemiparesis [5], which would be potentially mistaken as AIS when presented hyper-acutely.

The outcome and management of SSEH after administration of IVT were unclear. The purpose of this study was to enhance our understanding toward SSEH and its outcome and potential treatment options through review of cases.

We had identified all patients admitted to United Christian Hospital, a tertiary hospital in Hong Kong, from 1 January 2008 to 31 March 2021 for suspected AIS with IVT given. We aimed to identify those with SSEH as stroke mimics.

A literature search was performed using PubMed, Ovid, and Google Scholar to identify cases of SSEH who had been given IVT. The inclusion criterion for literature review was SSEH given IVT. Cases that had spinal epidural hematoma diagnosed as a consequence of IVT were excluded. The definition of SSEH was adapted as mentioned earlier. We reviewed their demographical characteristics, clinical features, radiological findings, treatment, and outcome. This study was approved by KEC Ethics Committee.

From January 2008 to March 2021, a total of 940 patients were treated with IVT. Around half were male, with a median age of 74 (range = 21–97) years. Among them, 2 were diagnosed with SSEH, accounting for 0.21% of all IVT-treated cases.

A 61-year-old woman with good past health presented with sudden-onset neck pain and left hemiparesis. Other neurological examinations were normal. There was no trauma or neck manipulation. Computed tomography (CT) of the brain was unremarkable, and CT angiogram showed no major artery dissection.

IVT was given with power improved from grade 0 to 3/5, but neck pain persisted. Subsequent MRI and MRA of the brain were unremarkable, while MRI of the cervical spine showed epidural hematoma from C2 to T1 (Fig. 1). Retrospective review of initial CT angiogram noted tiny SSEH at C2 (Fig. 2). MRA of the spine showed no underlying arteriovenous fistula or arteriovenous malformation.

She was managed conservatively. MRI showed resolution of hematoma with improved mobility to walking with aid and managed daily activities at 3-month follow-up.

A 58-year-old man with good past health presented with sudden onset left-sided numbness and weakness. He did not complain of any neck pain or trauma, and neurological examination was unremarkable, except for left hemiparesis with grade 0/5 for the upper limb and 4/5 for the lower limb. IVT was given after brain CT was revealed normal. The patient progressed to become tetraplegic with acute retention of urine upon observation after an hour of thrombolysis. Urgent whole spine MRI showed epidural hematoma at C4-7 level. Fresh frozen plasma, platelet concentrates, and cryoprecipitate were given, and urgent decompressive surgery was carried out. The patient had good recovery with power back to full 4 weeks after surgery. To further understand SSEH patients given IVT, a literature search was performed, and a total of 10 cases were extracted from 5 eligible case reports [6-10]. Along with the 2 cases we presented, all 12 cases are summarized in Table 1. Presentation, investigation modality, and outcome were listed. Outcome was defined as the maximal resolution of neurological deficit.

All cases presented with hemiparesis, and the location of SSEH was at the cervical region. Pain was present in most of the cases (9 in 12). Of note, in cases 1, 3, and 4 where neck pain was present, and urgent head and neck CT angiogram was performed to rule out dissection before IVT was given. In all 3 cases, retrospective review of the initial CT film revealed epidural hematoma at the cervical region.

Of the 12 cases, 8 were treated surgically and 4 were treated conservatively. Of those treated surgically, 6 out of 8 had good recovery, while those treated conservatively, 3 out of 4 had good recovery. None of the cases suffered from major adverse events from IVT, like symptomatic intracerebral hemorrhage or other major bleeding.

This is a single-center retrospective study spanning over 12 years. In this long period of time, the occurrence of stroke mimics was relatively low. SSEH remains a rare cause, with only 2 cases seen, accounting for 0.21% of all IVT-treated cases.

This was to date the first case review on SSEH as stroke mimics with IVT given. Extensive literature searches only revealed a total of 10 cases with SSEH given IVT erroneously.

It was of note that in cases presented with neck pain, 3 of them had head and neck CT angiogram performed, and the diagnosis of spinal epidural hematoma was missed. This illustrated despite a window for diagnosis of SSEH before the administration IVT, it was missed due to lack of awareness to the condition.

The largest literature review on SSEH to date recruited 65 cases from 12 studies [11]. Up to 50% of cases did not fully recover and continued to have some level of sensorimotor deficiency. Disease-related mortality was up to 5.7%.

Overall, compared with general SSEH cases in the review mentioned, the outcome of all 12 cases was not particularly worsened due to IVT. On contrary, it was relatively favorable, with none severely disabled or died. Overall, 66.7% (8 out of 12) had full neurological recovery or just mild deficit without significant disability. It showed no obvious preference toward surgical or conservative treatment. In the literature review, the degree of preoperative neural deficit is the major prognostic factor and conservative management has been proven effective, although it was feasible only if spontaneous recovery is manifested. This rationale appeared to hold true for SSEH patients, despite given IVT.

With the increasing use of IVT and mechanical thrombectomy, it is believed we would encounter more cases with SSEH presenting as stroke mimics in the future. This warrants the attention of physicians to be cautious and consider the possibility of SSEH before commencing IVT.

There are a few limitations in this study. First, this is a retrospective study and patients’ follow-up timing was different depending on decisions by treating physicians. Second, not all patients underwent spinal imaging; hence, it was possible that spinal pathologies were underdiagnosed. Third, due to rarity of the disease, the sample size was small.

SSEH is a rare stroke mimic accounting for 0.21% cases in our 12-year cohort receiving IVT. Awareness toward SSEH should be enhanced to prevent erroneous administration of IVT and delay in treatment.

This study was approved by KEC Ethics Committee (Reference No.: KC/KE-21-0096/ER-1). Written informed consent was obtained from the patients for publication for this case report and any accompanying images.

The authors have no conflicts of interest to declare.

There is no funding involved.

Dr. Szeto was responsible for case collection, reviewing cases from literature, drafting, and writing the manuscript. Dr. Hui was responsible for supervising and providing critical feedback for the manuscript.

All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.