Isolated choroid plexus infarction caused by multiple occlusive cerebrovascular lesions.

The choroid plexus is the secretory tissue responsible for cerebrospinal fluid production in the brain. Ischemia of the choroid plexus is rare because of its abundant blood supply from multiple arterial systems, including the anterior and posterior choroidal arterial anastomoses. It is not clear under what circumstances isolated choroid plexus infarction occurs. A 56-year-old woman presented to our hospital after experiencing several episodes of paroxysmal dizziness and weakness in her right upper extremity that lasted several hours. She had a 10-year history of hypertension, diabetes mellitus, and hyperlipidemia, which were very poorly controlled. Magnetic resonance imaging confirmed isolated right choroid plexus infarction. Magnetic resonance angiography showed severe stenosis of the cavernous portion of the right internal carotid artery, occlusion of the distal portion of the right posterior cerebral artery, and occlusion of the contralateral left internal carotid artery. Thus, we hypothesized that isolated choroid plexus infarction was caused by ischemia due to both atherosclerotic changes in large vessels spanning multiple vasculatures and microangiopathy around the choroid plexus due to diabetes, hypertension, and hyperlipidemia. In choroid plexus infarction, both occlusive changes in multiple large vessels and microangiopathy may be involved, and the underlying cause of these changes should be thoroughly investigated. Although choroid plexus infarction may not be significant neurologically, it may shed light on further pathogenesis in this complex structure.

Significance of upper cervical epidural venous engorgement on head computed tomography in the initial diagnosis of spontaneous intracranial hypotension: patient series.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a rare condition characterized by positional headache, for which contrast-enhanced magnetic resonance imaging (MRI) is the preferred diagnostic method. Although MRI reveals characteristic findings, head computed tomography (CT) is usually the first diagnostic step, but identifying features of SIH on CT is often difficult. This study was specifically designed to evaluate the utility of head CT in detecting upper cervical epidural venous engorgement as a sign of SIH. OBSERVATIONS: Of 24 patients with SIH diagnosed between March 2011 and May 2023, 10 did not undergo upper cervical CT. In the remaining 14 patients, engorgement of the upper cervical epidural venous plexus was observed. CT detection rates were consistent with MRI for spinal fluid accumulation or dural thickening. After treatment, in 92.9% of patients, the thickness of the epidural venous plexus decreased statistically significantly from 4.8 ± 1.3 mm to 3.6 ± 1.2 mm. LESSONS: This study suggests that upper cervical spine CT focused on epidural venous engorgement may be helpful in the initial diagnosis of SIH and may complement conventional MRI evaluation. Extending CT imaging to the upper cervical spine will improve the diagnostic accuracy of patients with positional headaches suspected to be SIH.

Enlarging neurenteric cyst at the craniocervical junction with a fluid-fluid level on magnetic resonance imaging: illustrative case.

BACKGROUND: Neurenteric cysts are relatively rare benign congenital intracranial cystic lesions that enlarge rarely and very slowly. The authors present a case of an enlarging neurenteric cyst at the craniocervical junction with a fluid-fluid level on magnetic resonance imaging (MRI). OBSERVATIONS: A 34-year-old man with no significant medical history underwent head MRI to investigate mild headaches. An incidental cystic lesion, approximately 8 mm in diameter, was revealed at the craniocervical junction. Serial follow-up MRI showed cyst enlargement with a fluid-fluid level. Four years later, the cyst reached a size of 15 mm and was surgically removed. The cyst contained cloudy fluid with a high protein concentration, without any bleeding or tissue fragments. Pathological examination confirmed the diagnosis of a neurenteric cyst. The patient recovered well, was discharged home, and has remained recurrence free for 2 years. LESSONS: The growth dynamics of the relatively rapidly expanding neurenteric cyst at the craniocervical junction were monitored over time using MRI. This cyst exhibited the distinctive feature of a fluid-fluid level as it enlarged. Investigating the mechanisms underlying fluid-fluid level formation may offer novel insights into the pathogenesis of cyst enlargement. https://thejns.org/doi/10.3171/CASE24180.

Brainstem hemorrhage associated with venous hypertensive myelopathy without dural arteriovenous fistula: illustrative case.

BACKGROUND: Venous hypertensive myelopathy (VHM), formerly known as "Foix-Alajouanine syndrome," is a spinal cord dysfunction caused by impaired perfusion of the spinal cord. Most cases are attributed to spinal dural arteriovenous fistulas (dAVFs), but there are scattered reports of VHM without concomitant dAVF. Furthermore, no cases of VHM associated with intracranial hemorrhage exist. OBSERVATIONS: A 68-year-old man with a history of hypertension presented with a sudden headache, proximal paresis of the left upper extremity, impaired pain and temperature sensation in the right upper extremity, dysphagia, and dysarthria. Computed tomography scans showed intraparenchymal hemorrhage in the left medulla oblongata and a linear, continuous high-density area extending from the medulla oblongata to the cervical spinal cord. Magnetic resonance images showed cervical spondylosis at the C5-6 and C6-7 levels, with high signal intensity changes from the medulla oblongata to the lower cervical cord on T2-weighted images. Cerebral angiography showed no abnormal vessels. Conservative treatment gradually improved symptoms and the high signal intensity areas. LESSONS: This case highlights intracranial hemorrhage occurring from extracranial causes and the possibility of VHM due to cervical spondylosis. When hemorrhagic lesions of the craniovertebral junction or spinal parenchymal lesions are encountered, the underlying pathology should be investigated thoroughly and systematically. https://thejns.org/doi/10.3171/CASE24441.

Symptomatic Cerebellar Cyst Formation after Foramen Magnum Meningioma Removal: A Case Report.

Background Symptomatic cerebellar cyst formation after surgery is rare and the mechanism remains unknown. We describe a cerebellar cyst that gradually expanded, becoming symptomatic, after the removal of a foramen magnum meningioma and discuss the mechanism of cyst formation. Case Description A 76-year-old woman with a tumor at the foramen magnum was treated by posterior fossa craniotomy and C1 hemilaminectomy. The patient suddenly developed cerebellar symptoms and consciousness disturbance approximately 1 week into an otherwise good postoperative course. Imaging showed a subcutaneous pseudomeningocele in the occipital region and cerebellar cyst formation. After resolution by fenestration of the cerebellar cyst and duraplasty, the patient's symptoms gradually improved. No tumor or cerebellar cyst recurrence has been detected in over 5 years since the surgery. Conclusion Postoperative pseudomeningocele appeared crucial for cerebellar cyst formation. Postoperative development of symptomatic cerebellar cysts is rare but should be recognized as a serious, sometimes life-threatening, postoperative complication of posterior fossa surgery.

Spontaneous asymptomatic common carotid artery dissection resembling a carotid web: illustrative case.

BACKGROUND: Carotid artery dissection is a common cause of ischemic stroke, predominantly affecting the internal carotid artery, with rare involvement of the common carotid artery (CCA). The limited literature makes diagnosis and management challenging, particularly in asymptomatic patients. In this report, the authors present a unique case of spontaneous, asymptomatic CCA dissection that resembled a carotid web, shedding light on its clinical spectrum and management. OBSERVATIONS: A 70-year-old man was diagnosed with an intimal flap in the left CCA. Although the findings resembled those of a carotid web, cerebral angiography confirmed the presence of an intimal flap and arterial wall irregularities indicative of vascular dissection. Endarterectomy successfully prevented the stroke, and the postoperative recovery was uneventful. Pathological examination confirmed the diagnosis of CCA dissection. LESSONS: Spontaneous CCA dissection, though rare, presents significant diagnostic and therapeutic challenges. Because of morphological similarities, differentiating the diagnosis from a carotid web can be difficult. Available treatment strategies include antiplatelet therapy and surgical intervention. In this case, endarterectomy was chosen to avoid antithrombic treatment in anticipation of further invasive treatments for other conditions. The successful outcome highlights the potential as a treatment option, emphasizing the need for an individualized approach to each patient. https://thejns.org/doi/10.3171/CASE24344.

Midbrain hemorrhage presenting with isolated downward gaze palsy: A case report.

Background: Diseases presenting with only downward gaze palsy are extremely rare particular in cerebral hemorrhage. Case Description: A 63-year-old man with no medical history developed a downward-dominant vertical gaze paralysis with a convergence disorder. Computed tomography and magnetic resonance imaging showed a small hemorrhage of 13 mm in diameter in the right midbrain tegmental area. The patient was conservatively treated. His symptoms showed a gradual improvement from upward gaze paralysis and convergence disorder followed by downward gaze paralysis. All symptoms disappeared in 3 weeks after the onset. The center of vertical eye movement was thought to be the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF) and posterior commissure (PC). Conclusion: In this case, bilateral riMLF and PC were impaired, resulting in bilateral vertical ocular motility disorder with upward gaze paralysis. Brainstem hemorrhage rarely presents with vertical gaze palsy. Most are cerebral infarctions, and few are due to cerebral hemorrhage. This case was important for better understanding the pathophysiology of an ocular motility disorder. We also summarized the characteristics of isolated vertical gaze palsy caused by cerebral hemorrhage.

Spontaneous resorption of a convexity arachnoid cyst associated with intracystic hemorrhage and subdural hematoma: A case report.

Background: Intracranial arachnoid cysts (ACs) are developmental anomalies usually filled with cerebrospinal fluid (CSF), rarely resolving throughout life. Here, we present a case of an AC with intracystic hemorrhage and subdural hematoma (SDH) that developed after a minor head injury before gradually disappearing. Neuroimaging demonstrated specific changes from hematoma formation to AC disappearance over time. The mechanisms of this condition are discussed based on imaging data. Case Description: An 18-year-old man was admitted to our hospital with a head injury caused by a traffic accident. On arrival, he was conscious with a mild headache. Computed tomography (CT) revealed no intracranial hemorrhages or skull fractures but an AC was seen in the left convexity. One month later, follow-up CT scans showed an intracystic hemorrhage. Subsequently, an SDH appeared then both the intracystic hemorrhage and SDH gradually shrank, with the AC disappearing spontaneously. The AC was considered to have disappeared, along with the spontaneous SDH resorption. Conclusion: We present a rare case where neuroimaging demonstrated spontaneous resorption of an AC combined with intracystic hemorrhage and SDH over time, which may provide new insights into the nature of adult ACs.

De novo formation of twig-like middle cerebral artery: An illustrative case.

Background: Twig-like middle cerebral artery (T-MCA) is a rare vascular abnormality characterized by the replacement of the M1 segment of the middle cerebral artery (MCA) with a plexiform arterial network of small vessels. T-MCA is generally regarded as an embryological persistence. Conversely, T-MCA may also be a secondary sequela but no reports of cases of de novo formation exist. Here, we report the first case describing possible de novo T-MCA formation. Case Description: A 41-year-old woman was referred to our hospital from a nearby clinic because of transient left hemiparesis. Magnetic resonance (MR) imaging revealed mild stenosis of the bilateral MCAs. The patient then underwent MR imaging follow-ups once a year. MR imaging at the age of 53 showed a right M1 occlusion. Cerebral angiography revealed a right M1 occlusion and formation of a plexiform network consistent with the occlusion site, leading to the diagnosis of de novo T-MCA. Conclusion: This is the first case report describing possible de novo T-MCA formation. Although a detailed laboratory examination did not confirm the etiology, autoimmune disease was suspected to have precipitated this vascular lesion.

Continuous Epidural Saline Infusion for the Treatment of Spontaneous Intracranial Hypotension.

OBJECTIVE: Spontaneous intracranial hypotension (SIH) is an increasingly recognized cause of orthostatic headache, but treatment strategies remain controversial. The epidural blood patch is a well-known and widely used treatment in patients with conservative treatment-resistant SIH, but symptoms may not improve even after multiple epidural blood patches, and resistant patients suffer from a lack of appropriate treatment options. Therefore, this study assessed the safety and efficacy of continuous epidural saline infusion (CESI) for SIH treatment. METHODS: CESI was performed in 11 consecutive patients affected by conservative treatment-resistant SIH. Patient characteristics were obtained by reviewing medical records retrospectively. Headache intensity was assessed using the numerical rating scale (NRS), and changes in NRS before and after treatment were recorded. RESULTS: The average treatment period for CESI was 21.3 ± 9.6 days, and the average follow-up period was 35.0 ± 30.2 months. CESI was without major complications or mortality, and no infections occurred, even without prophylactic antibiotics. The median NRS score before treatment was 10 points, improving to 5 points 1 day after infusion (P < 0.05), 2 points 1 week after infusion (P < 0.05), and 0 points at 3 months after infusion and the final follow-up. No patients have since experienced recurrence of orthostatic headaches. CONCLUSIONS: CESI appears to be a safe and well-tolerated procedure for SIH. Further experience may demonstrate this technique to be a viable treatment option for SIH.

Fenestrated Anterior Communicating Artery Complex Mimicking an Unruptured Aneurysm: Diagnostic Pitfall.

Anatomical variations often occur in the anterior communicating artery (AComA) complex, and a careful preoperative evaluation is required before repair of this lesion. We report a case of a fenestrated AComA complex mimicking an unruptured cerebral aneurysm. A 49-year-old woman was referred to our hospital under suspicion of unruptured aneurysms of the AComA and the left middle cerebral artery on magnetic resonance angiography (MRA). Additional three-dimensional computed tomographic angiography (CTA) showed the lesion arising from the AComA complex with a maximum diameter of 4.2 mm. Intraoperative findings showed that the putative aneurysm was actually a fenestrated AComA complex as the blood vessels that formed the AComA complex were dilated and meandering. After the operation, MRA and CTA three-dimensional images were reviewed again but we could still not diagnose the lesion as a fenestrated AComA complex rather than an aneurysm. However, in the MRA source image, a secant line in the lesion was the only finding suggestive of a fenestration. The AComA complex is often associated with various vascular malformations, and it is essential to consider this association in the preoperative evaluation. The interpretation of source images may be helpful for accurate diagnosis and surgical planning.

Significance of perilesional T1 hyperintense areas in the differential diagnosis of primary adult-type diffuse glioma: A case report.

Perilesional T1 hyperintensity on magnetic resonance imaging (MRI) of intra-axial brain masses is an unusual feature of the perilesional area, characteristic of cavernous malformations (CMs) and metastatic brain tumors (METs). Here, we report a case of primary diffuse glioma with a perilesional T1 hyperintense area (HIA) on MRI. A 61-year-old woman with transient aphasia visited our hospital. Radiological examination revealed an intra-axial mass with acute/subacute hemorrhaging and calcification in the left frontal lobe. It was presumed to be a CM because of the perilesional T1 HIA. Gross total resection of the tumor was performed, and the pathological diagnosis was anaplastic oligodendroglioma, not otherwise specified by World Health Organization 2016 classification. Histopathological findings in the perilesional T1 HIA indicated hemorrhage involvement in the surrounding white matter. No recurrence appeared after radio-chemotherapy. Perilesional T1 HIAs, characteristic of CMs and METs, are also seen in primary diffuse gliomas. Therefore, caution should be taken when using this sign for the differential diagnosis of intracranial masses.

Nonaneurysmal subarachnoid hemorrhage associated with COVID-19 infection: A case report.

Background: Most coronavirus disease 2019 (COVID-19)-related cerebrovascular disorders are ischemic while hemorrhagic disorders are rarely reported. Among these, subarachnoid hemorrhage (SAH) is very rarely reported and nonaneurysmal SAH has been reported in only about a dozen cases. Here, we report a case of nonaneurysmal SAH as the only clinical manifestation of COVID-19 infection. In addition, we reviewed and analyzed the literature data on cases of nonaneurysmal SAH caused by COVID-19 infection. Case Description: A 50-year-old woman presented to an emergency department with a sudden headache, right hemiparesis, and consciousness disturbance. At that time, no fever or respiratory failure was observed. Laboratory data were within normal values but the rapid antigen test for COVID-19 on admission was positive, resulting in a diagnosis of COVID-19 infection. Computed tomograms (CTs) showed bilateral convexal SAH with a hematoma but three-dimensional CT angiograms showed no obvious sources, such as a cerebral aneurysm. Therefore, the patient was diagnosed with nonaneurysmal SAH associated with COVID-19 infection. With conservative treatment, consciousness level and hemiparesis both improved gradually until transfer for continued rehabilitation. Approximately 12 weeks after onset, the patient was discharged with only mild cognitive impairment. During the entire course of the disease, the headache, hemiparesis, and mild cognitive impairment due to nonaneurysmal SAH with small hematoma were the only abnormalities experienced. Conclusion: Since COVID-19 infection can cause nonaneurysmal hemorrhaging, it should be considered (even in the absence of characteristic infectious or respiratory symptoms of COVID-19) when atypical hemorrhage distribution is seen as in our case.

Idiopathic focal calvarial thinning: A case report.

Background: Calvarial bone thinning is a rare clinical entity, with only several cases reported (including Gorham-Stout disease), but the cause is often unknown. Here, we report such a case of unilateral calvarial thinning with an unknown cause. Case Description: A 77-year-old woman undergoing imaging examination for unruptured cerebral aneurysms for the past several years noticed a progressive cranial deformity. Computed tomography revealed progressive thinning of the right parietal bone and cranial deformity but laboratory tests showed no causative findings. A cranioplasty was performed to protect the brain and confirm the pathology. Grossly, pigmentation and deformity were observed on the outer plate of the bone but the inner plate was intact. Pathological examination revealed preserved bone cells and no necrosis. In addition, there were no findings of vascular hyperplasia or malignancy. It appeared that localized osteoporosis had occurred, mainly in the outer plate of the bone, but the cause was unclear. Conclusion: Progressive focal calvarial thinning is rarely reported and the mechanism in this case was unknown. It is important to determine the cause of the bone thinning to evaluate the need for surgical intervention from the viewpoint of brain protection and prevention of cerebrospinal fluid leakage.

Aplastic or twiglike middle cerebral artery with contralateral middle cerebral artery stenosis showing transient ischemic attack: illustrative case.

BACKGROUND: Aplastic or twiglike middle cerebral artery (Ap/T-MCA) is a rare anomaly characterized by a unilateral MCA occlusion with plexiform vessels that causes hemorrhagic and (less commonly) ischemic strokes. The reasons for this are rarely discussed, and thus optimal treatment for ischemic Ap/T-MCA remains controversial. Here, the authors report a case of Ap/T-MCA with transient ischemic attacks treated by bypass surgery and discuss the mechanism of ischemic development and treatment methods. OBSERVATIONS: A 62-year-old hypertensive man with transient, recurrent left hemiparesis visited the authors' hospital. Magnetic resonance angiography showed proximal occlusion of the right MCA and stenosis in the left MCA. Digital subtraction angiography revealed occlusion of the right MCA and abnormal vascular networks, leading to a diagnosis of Ap/T-MCA with contralateral MCA stenosis. Antiplatelet therapy with aspirin was insufficient, and a superficial temporal artery-MCA bypass was performed. There were no ischemic or hemorrhagic events postoperatively. LESSONS: Atherosclerosis seems to have a significant impact on the development of ischemic stroke in patients with Ap/T-MCA, and the presence of coexisting atherosclerotic stenotic vascular lesions outside the Ap/T-MCA site is substantial in its development. Bypass surgery is a promising treatment option for ischemic Ap/T-MCA.

Spontaneous regression of a posterior fossa meningioma: A case report.

Background: Since most incidentally discovered meningiomas grow or remain unchanged, spontaneous regression is extremely rare. Here, we report a case of posterior fossa meningioma showing spontaneous regression. Case Description: A 55-year-old female was referred to our hospital because she was diagnosed with a left posterior fossa meningioma (diameter: 1.6 cm) during a brain check-up. The patient was followed up on periodic magnetic resonance imaging studies. Tumor size remained almost unchanged for 2 years but then began to regress. Twelve years after the initial examination, the tumor diameter idiopathically decreased from 1.6 cm to 1.1 cm while the tumor volume decreased from 2.3 cm3 to 0.5 cm3 (about 1/4th the original size). Postmenopausal hormonal imbalances may have been associated with the observed spontaneous regression. Conclusion: Understanding the natural history of meningiomas is essential for a better selection of treatment approaches or appropriate follow-up. This case may provide new insights into the progression of meningiomas.

Intracranial varix of the transverse-sigmoid dural arteriovenous fistula mimicking a ruptured middle cerebral artery aneurysm: A case report.

Background: Hemorrhagic stroke is caused by various vascular abnormalities, such as aneurysms, arteriovenous malformations, and dural arteriovenous fistulas (DAVF). Magnetic resonance angiography (MRA) and three-dimensional computed tomography angiography (3DCTA) are used as efficient initial diagnostic modalities in assessing the etiology of hemorrhagic stroke. We describe the unusual case of a false-positive aneurysm on MRA and 3DCTA. Case Description: A 65-year-old nonhypertensive woman was brought to our hospital with a sudden onset of headache and left hemiparesis. She also had chemosis in the right eye. CT and magnetic resonance imaging showed an intracerebral hemorrhage in the right temporal lobe. MRA and 3DCTA showed a rounded mass suggestive of an aneurysm arising from the bifurcation of the middle cerebral artery (MCA) and also demonstrated an abnormal tortuous vessel contacting with a rounded mass. Digital subtraction angiography showed a transversesigmoid sinus DAVF with a varix in contact with the MCA bifurcation. Hematoma evacuation and venous drainage disconnection through the right frontotemporal craniotomy were performed. Conclusion: This case is very instructive and clinicians should keep in mind that detailed neurological and radiological examinations are essential in obtaining an accurate diagnosis, especially if the bleeding source is similar in shape and location to common lesions (such as a cerebral aneurysm).

Simultaneous intracerebral and subarachnoid hemorrhages caused by multiple infectious intracranial aneurysms treated endovascularly and by microsurgical clipping: illustrative case.

BACKGROUND: Infected intracranial aneurysms are relatively rare but tend to occur in multiple locations. Establishing an optimal treatment strategy for multiple ruptured aneurysms is often challenging, especially when simultaneous ruptures occur in different locations. We report a case of simultaneous intracerebral and subarachnoid hemorrhages caused by the rupture of multiple infected intracranial aneurysms. OBSERVATIONS: A 23-year-old male with a 2-week history of chronic fever presented with sudden onset of severe headache and visual disturbance. Computed tomography showed intracerebral hemorrhage in the right occipital lobe and subarachnoid hemorrhage in the area of the left Sylvian fissure. Further investigation documented Staphylococcus bacteremia, verrucae on the mitral valve, and aneurysms arising from the right posterior cerebral artery (PCA) and the left middle cerebral artery (MCA). A larger aneurysm arising from the PCA was successfully occluded endovascularly, but subsequent endovascular occlusion of the MCA aneurysm was unsuccessful because some important branches were observed extending from the aneurysm. The left MCA aneurysm was then obliterated by angioplastic clipping via left pterional craniotomy. The patient showed a favorable neurological recovery after treatment. LESSONS: In such complex cases of infectious aneurysms, the method and timing of treatment need to be carefully determined based on the medical condition.

Prevotella brain abscess in a healthy patient with a patent foramen ovale: Case report.

BACKGROUND: Brain abscesses are relatively rare life-threatening infectious lesions often concomitant with a direct spillover of inflammation in the head or neck, hematogenous infections, and immunocompromised conditions. They rarely occur in adults without such predisposing factors. Prevotella is a well-known dental pathogen that very rarely causes brain abscesses. CASE DESCRIPTION: We report such an abscess in a 51-year-old man who was innately healthy and had no oral lesions. A comprehensive computed tomography examination of the chest, abdomen, and pelvis, was inconclusive but a transesophageal echocardiogram bubble study revealed a mild patent foramen ovale (PFO) that matched Grade 1 criteria. We deduced that the right-left shunt due to the PFO could have contributed to the brain infection and treated the patient successfully via surgical abscess aspiration and antibiotics. CONCLUSION: In case of a brain abscess occurring in healthy adults, it is essential to investigate the source of infection and the existence of an arterio-venous shunt, such as PFO.