Ruptured aneurysm of the artery of Adamkiewicz as a rare cause of spinal cord injury

Background

The most common cause of non-traumatic subarachnoid haemorrhage (SAH) is ruptured cerebral aneurysm.1 Alternatively, haemorrhage of spinal cord origin can cause SAH although this is far less common with an incidence of less than 3 per 100 000 person-years.2 Trauma, arteriovenous malformations (AVMs) and cavernomas are the leading causes of isolated spinal cord haemorrhage.3 4 Isolated rupture of a spinal cord aneurysm is exceedingly rare. Only 12 previous cases have been published describing ruptured aneurysms of the artery of Adamkiewicz as a cause of spinal cord haemorrhage.

Case presentation

A man in his 60s with paroxysmal atrial fibrillation on aspirin initially presented to a community emergency department with progressive back pain, headaches, malaise and urinary retention after undergoing an ocular surgery for retinal detachment earlier in the day. He was hypoxic and found to be in atrial fibrillation with rapid ventricular response. Initial physical examination in the emergency department was notable for diaphoresis and anxiety. No focal neurological deficits were noted at that time. The patient was retired and living at home with his spouse. He was functioning at the independent level for mobility and activities of daily living (ADLs) prior to admission. His vision had declined over several months and he had undergone two separate procedures with his ophthalmologist to repair his detached retina the week of admission.

Initial ECG showed the patient to be in atrial fibrillation with rapid ventricular response. He was found to have a leucocytosis (white cell count=18.6) and an elevated creatinine. Troponins were elevated and he was started on a heparin drip due to concern for a myocardial infarction. While awaiting admission, he developed progressive dysarthria, altered mental status and weakness with less than antigravity strength in the right lower limb. There were no sensory deficits, and cranial nerves were intact bilaterally.

Differential diagnosis

Investigations

Following the development of right lower extremity hemiparesis and altered mental status, non-contrast CT of the head was performed. CT of the head showed trace of SAH centred in the basilar cisterns, around the brainstem (figure 1). The heparin drip was stopped, and cerebral angiogram was performed to rule out a ruptured aneurysm. Cerebral angiogram was normal and showed no evidence of aneurysm or AVM.

The patient’s condition continued to decline, and on hospital day 3, he was intubated for respiratory failure. He underwent cervical, thoracic and lumbar spine MRI, which demonstrated scattered, multilevel intradural blood products. Most notably, there was a haematoma at T10 causing mass effect on the right anterior spinal cord (figure 2). It was suspected that the right lower extremity weakness was a result of compression of the cord rather than ischaemia given the correlation between the location of the haematoma and nearby lateral corticospinal tract.

Although the MRI findings explained this patient’s symptoms, the aetiology of the haemorrhage was still unknown. Diagnostic considerations at that point included occult spinal AVM versus occult dural arteriovenous fistula and spinal artery branch aneurysm rupture. This prompted further investigation with a diagnostic spinal angiogram which was performed by interventional radiology on hospital day 6. Spinal angiogram demonstrated a short segment fusiform aneurysmal dilatation of the artery of Adamkiewicz, branching off of the right T11 posterior intercostal artery (figure 3).

Treatment

The patient was then transferred to a different hospital for neurosurgical evaluation. Neurosurgery elected to manage conservatively due to risk of paraplegia with sacrifice of the vessel. Repeat MRI of the spine during acute hospitalisation showed no increase in haemorrhage, and the patient’s neurological status improved. He was discharged to an inpatient rehabilitation facility on hospital day 39.

Outcome and follow-up

On admission to an inpatient rehabilitation facility, the patient was found to have 2/5 strength with right lower extremity strength testing (hip flexion, knee extension, ankle dorsiflexion, great toe extension, ankle plantarflexion) and impaired sensation to light touch at L4–S5 dermatomes on the right. His urinary retention continued throughout his rehabilitation course and intermittent straight catheterisation (ISC) was implemented for emptying. The patient was started on tamsulosin and had occasional spontaneous voids. Post-void residuals measured following spontaneous voids showed elevated bladder volumes raising suspicion that spontaneous voids were due to overflow. Initially, the patient had some difficulty with ISC due to his visual deficits but he was comfortable performing ISC on his own at the time of discharge from inpatient rehabilitation. He participated in inpatient rehabilitation for 11 days following discharge from acute care to address functional deficits with ambulation, transfers and toileting. On hospital day 50, he was discharged home at the modified independent level of function with transfers and ambulation using a roller walker. He continued outpatient physical therapy after discharge.

He followed up with his neurosurgeon 11 weeks after his initial presentation. At this appointment, his strength had improved to 5/5 in proximal muscles of the right leg with 3/5 ankle dorsiflexion and 4/5 ankle plantarflexion. The patient had progressed to ambulating community distances without an assistive device. The patient underwent repeat MRI 11 weeks after initial symptom onset which showed resolving haematoma with interval development of web-like arachnoid adhesions and syrinx formation at T2–3 and T9–10 (figure 4). Repeat spinal angiogram at 15 weeks after initial presentation showed spontaneous resolution of the previous aneurysm of the artery of Adamkiewicz. There was opacification of the anterior spinal artery with improved visualisation of collaterals from right T11 intercostal artery.