A 40-year-old man presented with peripheral vision loss. A severe headache three days earlier had woken him up, but his pain had eased with ibuprofen. His headache was completely gone, but he continued to have vision loss and was bumping into things on his right side.
His only symptom was loss of vision on the right, and he currently had no headache, weakness, chest pain, shortness of breath, abdominal pain, nausea, vomiting, diarrhea, dysuria, or fever.
The patient said he had been punched in the face 10 years earlier, and fell backwards and hit his head, causing a subdural hematoma that required a craniotomy. He also reported frequent drinking (about one bottle of hard liquor every three days) and frequent marijuana use.
His blood pressure was 146/95 mm Hg, temperature was 98.2°F, heart rate was 69 bpm, and respiration was 12 breaths per minute with 100% oxygen saturation on room air .
The patient was resting comfortably and his pupils were of equal size and responsive bilaterally, with full strength and intact feeling of his face. The extraocular movements were intact, but visual field examination revealed that he appeared to have a right sided visual field cut, predominantly right superior quadranopia. He had no dysarthria or facial asymmetry, and another assessment of the cranial nerves was otherwise normal. The patient had full strength and sensation in extremities, coordination was intact, and gait was normal.
Given the patient’s history, what type of imaging would you order? What is the diagnosis?
Find a discussion on the next page.
Diagnosis: intraparenchymal hematoma with FAV and MAV
Arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) are abnormal vascular structures that provide communication between the arterial and venous circulations. The pathogenesis of AVMs and AVFs is not well understood, but cerebral arteriovenous malformations have traditionally been associated with congenital lesions, with hereditary hemorrhagic telangiectasia being the most common genetic cause. (Stroke. 2012;43:72; https://bit.ly/3knvFLj.)
Both AVMs and AVFs occur infrequently after trauma, with documented cases of post-traumatic AVMs of the temporal artery (J Vasc Innov Tech Surgery Case. 2020;6:50; https://bit.ly/3xZzVsp) and peripheral traumatic AVF, although traumatic AVF is often secondary to stab or gunshot wounds. (Phlebology. 2012;27:124.)
The clinical presentation of cerebral AVMs and AVFs can vary. Symptomatic patients may present with intracranial hemorrhage, seizures, headache, or focal neurological deficit. (Curr Neurol Neurosci Representative. 2013;13:324.) Intracranial hemorrhage is usually intraparenchymal, but isolated intraventricular or subarachnoid hemorrhages have also been documented. (Stroke. 2017;48:e200; https://bit.ly/3rXKXLf.) The size and location of the AVM often influences the location of the hemorrhage and the focal neurological deficit.
The first choice of imaging, as with any suspected intracranial hemorrhage, is CT scan of the head without contrast. Further diagnosis of AVM or AVF can be obtained by CT angiography or magnetic resonance angiography. The sensitivity and specificity of CTA are 95 and 99%, respectively, making it a reasonable initial choice for ED imaging. (Cochrane Database System Rev. 2014;2014:CD009372; https://bit.ly/3LpKTLD.) Catheter contrast angiography is also an integral part of procedural management, planning, and diagnosis of AVMs and AVFs.
The treatment of AVMs and AVFs largely depends on the clinical presentation. Acute intracranial hemorrhage is managed based on the size and severity of the bleed. A large ICH requires urgent intervention, while smaller AVMs with minimal deficits can be managed conservatively. Seizure activity can be managed with antiepileptic drugs. AVMs themselves can be managed by microsurgical excision or radiosurgery, particularly if the AVM has ruptured. Accidental AVMs or those that have not ruptured can be managed conservatively. (N English J med. 2017;376:1859.)
A lab workup in the emergency department revealed no major abnormalities for this patient. A cranial CT scan showed a left parieto-occipital parenchymal hematoma with intraventricular extension and slight surrounding vasogenic edema. A CTA was obtained due to concerns about a subarachnoid hemorrhage and it showed prominent veins suspicious of AVM and AVF. Neurosurgery was consulted at this time and the patient’s blood pressure was monitored in the emergency department to maintain a systolic reading below 140 mm Hg.
The patient was admitted to neurosurgical intensive care and eventually went to interventional radiology for cerebral angiography, which demonstrated left parieto-occipital AVM, left MCA MCA and left sphenopalatine AVF. An MRI prompted the decision to delay repeat imaging due to the size of the AVM relative to the intraparenchymal hematoma.
The patient continued to improve. He was started on levetiracetam 1000 mg twice daily and physical and occupational therapy, and his pain was controlled. The patient was discharged from the hospital in stable condition with plans to repeat CTA to assess a possible nidus that could be resected. The patient has persistent right upper quadranopia on visual field examination.
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Dr Petzis a first-year resident in emergency medicine andDr Selbyis an Associate Professor of Emergency Medicine at the University of Kansas School of Medicine and the University of Kansas Medical Center. Read the quick reference columns athttp://bit.ly/EMN-QuickConsult.