Spontaneous healing of an isolated posterior inferior cerebellar artery dissection without stroke: a case report
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Isolated posterior inferior cerebellar artery dissections can cause subarachnoid hemorrhages or infarctions. Surgical and endovascular treatments for hemorrhagic stroke cases and medical treatments using antithrombotic agents for ischemic stroke cases have been performed, but there are very few reports on nonstroke isolated posterior inferior cerebellar artery dissections, and the treatment strategy for nonstroke cases has not been established.
A 48-year-old healthy male felt a severe, throbbing headache on the right side and came to our clinic on the fourth day following onset. MRI examinations revealed a right posterior inferior cerebellar artery dissection and showed no infarctions or hemorrhages. He was observed carefully with continuous monitoring of blood pressure, hydrated sufficiently, and given analgesic anti-inflammatory agents. Two weeks later, the dissected vessel’s diameter grew to the maximum size, though the patient’s headache rapidly improved around that day. Surgical or endovascular treatments for prevention of subarachnoid hemorrhage were recommended, but careful conservative therapy was continued in accordance with the patient’s wishes. Gradually, the dissection finding improved. Four months later, MRI examinations showed his right posterior inferior cerebellar artery was almost normal in size and shape.
This is the first detailed report on a nonstroke isolated posterior inferior cerebellar artery dissection that spontaneously occurred and healed, observed by serial high-resolution MRI examinations.
KeywordsIsolated posterior inferior cerebellar artery (PICA) dissection Spontaneous healing Headache High-resolution MRI
Basi-parallel anatomical scanning
Computed tomographic angiography
Digital subtraction angiography
Diffusion weighted image
Fluid-attenuated inversion recovery
High-resolution vessel wall imaging
Isolated posterior inferior cerebellar artery dissection
Maximum intensity projection
Magnetic resonance arteriogram
Magnetic resonance imaging
Numerical rating scale
Vertebral artery dissection
Isolated posterior inferior cerebellar artery dissections (iPICADs) can cause subarachnoid hemorrhages or infarctions . The incidence of iPICAD had been thought to be very rare. The reports of iPICAD with stroke, however, are increasing with the advancement of high-resolution MRI techniques. Surgical and endovascular treatments for hemorrhagic stroke cases and medical treatments using antiplatelet or anticoagulant agents for ischemic stroke cases have been reported. The treatment strategy for iPICADs without stroke, however, is not yet established because the reports on nonstroke iPICADs are still rare. Herein, a nonstroke iPICAD case that spontaneously healed is reported.
Discussion and Conclusions
Diagnostic criteria for cervicocephalic arterial dissection
1. “Double lumen” or “intimal flap” demonstrated on either DSA, MRI, MRA, CTA, or duplex ultrasonography
2. “Pearl and string sign” or “string sign” demonstrated on DSA
3. Pathological confirmation of arterial dissection
4. “Pearl sign” or “tapered occlusion” demonstrated on DSA
5. “Pearl and string sign,” “string sign,” or “tapered occlusion” demonstrated on MRA
6. “Hyperintense intramural signal” (corresponding to intramural hematoma) demonstrated on T1-weighted MRI
7. Change in arterial shape demonstrated on either DSA, MRI, MRA, CTA, or duplex ultrasonography
8. No other causes of arterial abnormalities
Presence of one or more major criteria, or presence of one or more minor criteria and both of 2 additional criteria
Presence of one or more minor criteria
Conventional angiography may have provided useful information to confirm the patient’s PICA condition; however, for this patient, serial high-resolution MRI examinations, including HRVWI, were sufficient to confirm the condition of the vessel. T1-weighted HRVWI was used to confirm the intraluminal size change. The outer diameter was followed by basi-parallel anatomical scanning (BPAS), one type of T2-weighted HRVWI .
Among cervicocephalic artery dissections, vertebral artery dissections (VADs) are common, and the therapeutic strategy for VAD has been established . The reports of iPICAD with stroke are increasing with the advancement of high-resolution MRI techniques, but those without stroke are still limited. In the last decade, over 70 cases of iPICAD have been found in the literature, but almost all the cases included subarachnoid hemorrhages  or infarctions . There have been only two nonstroke iPICAD cases reported, and one of these was diagnosed with coexisting VAD . As mentioned above, PICAD is often a tiny finding, even with high-resolution MRI techniques, and can therefore be overlooked unless accompanied by a symptomatic stroke. The patient in the present case was fortunately suspected to have iPICAD at the beginning of the clinical course and was followed using high-resolution MRI examinations, though he presented only with headache.
It is interesting that the severity of the patient’s headache might be related to the chronological changes of the MRI findings. The patient felt a severe, throbbing headache continuously while MRI findings of PICAD were worsening. After the occipital pain was relieved, his PICAD finding stopped worsening and gradually improved on MRI examinations.
Conservative therapy is usually selected for nonstroke VAD, whereas the therapeutic strategy for nonstroke iPICAD is not yet determined. The other case of the reported two iPICAD without stroke was surgically treated to prevent subarachnoid hemorrhage because the dissection finding by radiological examination was progressive . It might be permissible to perform any surgical and/or endovascular treatments in such a case. However, as in the present case, it is also possible that nonstroke iPICAD may heal spontaneously.
This is the first detailed report on a nonstroke iPICAD that spontaneously occurred and healed, observed by MRI examinations. In this case, serial high-resolution MRI examinations clearly showed the spontaneous healing course of iPICAD without stroke.
YK was responsible for the clinical management of the patient, collected and interpreted the data, wrote the manuscript, and prepared the figures.
Ethics approval and consent to participate
This manuscript was approved by the institutional review board (OIKE Clinic ethics committee, approval reference number 18–01), and informed consent for participation was obtained from the patient.
Consent for publication
Written informed consent was obtained from the patient for publication of this report and any accompanying images.
- 2.Minematsu K, et al. Cervicocephalic arterial dissection in Japan: analysis of 454 patients in the spontaneous cervicocephalic arterial dissection study I (SCADS-I) (abstract). Stroke. 2008;39:567.Google Scholar
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