Perivascular spaces: normal and giant

Giant perivascular space: a rare cause of acute neurosurgical emergency

We present a rare case of giant perivascular space in mesencephalo-thalamic region causing hydrocephalus. The patient presented insidiously over 6 months. However, the patient suddenly deteriorated in the hospital with visual symptoms, increasing headache and papilloedema, prompting urgent VP shunt and biopsy. Patient's symptoms resolved completely after decompression and he continues to remain symptom free. This patient is only the second described case of giant perivascular space with sudden deterioration of symptoms. This case report is intended to highlight this rare presentation of this cyst which can potentially suggest a more aggressive underlying lesion and prompt a biopsy which can be risky, given the proximity to perforators and normal structures, which is otherwise not necessary.

Spontaneous regression of asymptomatic tumefactive perivascular spaces in the anterior temporal lobe

Perivascular spaces are fluid-filled spaces that surround the perforating vessels of the brain and are normal findings on brain imaging. These are usually asymptomatic and are considered a manifestation of aging. Perivascular spaces occasionally undergo significant enlargement and are referred to as tumefactive perivascular spaces, which are often indistinguishable from neoplastic lesions. Spontaneous regression of tumefactive perivascular spaces during follow-up is rare. We report the imaging findings and clinical course of a patient who showed spontaneous regression of tumefactive perivascular spaces in the anterior temporal lobe, together with a literature review and discussion regarding the characteristics and pathogenesis of spontaneous regression of tumefactive perivascular spaces. Most studies in the available literature report tumefactive perivascular spaces in the anterior temporal lobe; in our view, the characteristics of anterior temporal lobe tumefactive perivascular spaces may differ from those of tumefactive perivascular spaces that occur at other locations.

Symptomatic Giant Virchow-Robin Spaces: A Rare Cause of Spastic Quadriparesis in 43-Year-old Ethiopian Patient: A Case Report

Background

Virchow-Robin Spaces (VRS) are perivascular spaces that surround small arteries and arterioles. These normal anatomical structures are thought to be involved in the drainage of interstitial fluid and also to play an immunomodulatory role by hosting macrophages. Rarely, it becomes giant and symptomatic resulting in mass effect on adjacent neuronal structures and ventricular system causing different neurological disorders.

Case Presentation

We report a 43-year-old, Ethiopian woman who presented with progressive weakness of all her extremity over the period of seven years. She had associated speech difficulty, visual blurring and pseudo-bulbar affect. Neurologic examination revealed spastic quadriparesis with increased deep tendon reflexes and up going plantar bilaterally. She had horizontal nystagmus, dysarthria and reduced bilateral visual acuity, otherwise normal cognition and cranial nerves examination. Brain MRI showed T1 hypointense, T2 hyperintense and non-enhancing multiple cystic lesions of different size, mainly in bilateral basal ganglia area with mass effect on adjacent internal capsule and lateral ventricles. Considering her clinical presentation and typical radiological features, diagnosis of symptomatic dilated Virchow-Robin spaces was made, and the patient was treated symptomatically.

Conclusion

Commonly, dilation of Virchow-Robin spaces are not symptomatic, but giant Virchow-Robin spaces, as in our patient may result in spastic quadriparesis, causing great disability on the patient. Thus, we recommend considering symptomatic Virchow-Robin spaces as a potential differential diagnosis of progressive quadriparesis, as early neurosurgical intervention may reduce the neurological complications, such as spastic quadriparesis.

Giant tumefactive perivascular spaces: A case report

Background

Perivascular spaces are interstitial fluid-filled regions located deep to the pia mater. They play roles in lymphatic drainage and the central nervous system immunological function. When they enlarge, they are referred to as giant tumefactive perivascular spaces. Often misdiagnosed as cystic neoplasms, they require a high degree of clinical suspicion and key radiological features to be accurately diagnosed. We describe an interesting case in which a man presented with worsening headache, subsequently found on neuroimaging to have this phenomenon.

Case Description

A 32-year-old man with low testosterone presented to the ER for worsening headache, blurred vision, and photophobia. Computed tomography of the brain showed hydrocephalus with follow-up magnetic resonance imaging revealing several enlarged cystic spaces within the brain, concerning for neoplasm. He ultimately left against medical advice before the further evaluation was done. He followed up with a neurosurgeon as an outpatient, where further review showed characteristic features indicative of giant tumefactive perivascular spaces, thus avoiding the need for unnecessary biopsy and potential surgery.

Conclusion

Often misdiagnosed as cystic neoplasms, giant tumefactive perivascular spaces are benign processes that can have a broad presentation with the most common finding being a headache. Key radiologic features, including smooth margins, isointensity to cerebrospinal fluid, and lack of postcontrast enhancement, are crucial to diagnosis, preventing unnecessary surgery with increased morbidity.

Dilated Virchow-Robin space and Parkinson's disease: A case report of combined MRI and diffusion tensor imaging

In this manuscript we report the case of a 69-year-old female patient, who suffers from Parkinson's disease (PD) with a dilated Virchow-Robin space (dVRS) on the left anterior perforated substance. During a magnetic resonance imaging examination, the presence of a dVRS was discovered on the left anterior perforated substance. Subsequently, the patient has been subjected to further investigation of magnetic resonance imaging and diffusion tensor imaging (DTI). The DTI data of our PD patient showed increased peak frequency of left fractional anisotropy and decreases in the distribution of Mean Diffusivity(MD) with changes in the fiber density compared to the normal contralateral tract. We hypothesize that the DTI changes are due to dVRS. In the text a review of the recent literature on the presence of dVRSs, located in mono and bilateral seat, in patients with PD is reported, explaining its possible implications on disease progression, cognitive decline, and worsening of symptoms.

Linear sign in cystic brain lesions ≥5 mm: A suggestive feature of perivascular space

OBJECTIVE

To determine the prevalence of a linear sign within enlarged perivascular space (EPVS) and chronic lacunar infarction (CLI) ≥ 5 mm on T2-weighted imaging (T2WI) and time-of-flight (TOF) magnetic resonance angiography (MRA), and to evaluate the diagnostic value of the linear signs for EPVS over CLI.

METHODS

This study included 101 patients with cystic lesions ≥ 5 mm on brain MRI including TOF MRA. After classification of cystic lesions into EPVS or CLI, two readers assessed linear signs on T2WI and TOF MRA. We compared the prevalence and the diagnostic performance of linear signs.

RESULTS

Among 46 EPVS and 51 CLI, 84 lesions (86.6%) were in basal ganglia. The prevalence of T2 and TOF linear signs was significantly higher in the EPVS than in the CLI (P < .001). For the diagnosis of EPVS, T2 and TOF linear signs showed high sensitivity (> 80%). TOF linear sign showed significantly higher specificity (100%) and accuracy (92.8% and 90.7%) than T2 linear sign (P < .001).

CONCLUSIONS

T2 and TOF linear signs were more frequently observed in EPVS than CLI. They showed high sensitivity in differentiation of them, especially for basal ganglia. TOF sign showed higher specificity and accuracy than T2 sign.

KEY POINTS

• Linear sign is a suggestive feature of EPVS. • Time-of-flight magnetic resonance angiography can reveal the lenticulostriate artery within perivascular spaces. • Linear sign helps differentiation of EPVS and CLI, especially in basal ganglia.

Spontaneous regression and recurrence of a tumefactive perivascular space

Perivascular spaces can occasionally appear mass-like (tumefactive or giant perivascular space), and can be associated with clinical symptoms. Spontaneous regression of a tumefactive perivascular space is a very rare phenomenon with only two reported cases in the English medical literature. Spontaneous regression of a tumefactive perivascular space along with resolution of clinical symptoms, followed by spontaneous recurrence associated with symptom recurrence is an extremely rare occurrence, which to the best of our knowledge, has not been reported in the medical literature. We describe a case of spontaneous regression of a tumefactive perivascular space, three years after its initial detection, followed by spontaneous recurrence after two years.

Towards the automatic computational assessment of enlarged perivascular spaces on brain magnetic resonance images: a systematic review

Enlarged perivascular spaces (EPVS), visible in brain MRI, are an important marker of small vessel disease and neuroinflammation. We systematically evaluated the literature up to June 2012 on possible methods for their computational assessment and analyzed confounds with lacunes and small white matter hyperintensities. We found six studies that assessed/identified EPVS computationally by seven different methods, and four studies that described techniques to automatically segment similar structures and are potentially suitable for EPVS segmentation. T2-weighted MRI was the only sequence that identified all EPVS, but FLAIR and T1-weighted images were useful in their differentiation. Inconsistency within the literature regarding their diameter and terminology, and overlap in shape, intensity, location, and size with lacunes, conspires against their differentiation and the accuracy and reproducibility of any computational segmentation technique. The most promising approach will need to combine various MR sequences and consider all these features for accurate EPVS determination.

Giant tumefactive perivascular spaces that expanded and became symptomatic 14 years after initial surgery

BACKGROUND

Perivascular spaces (PVSs) or Virchow-Robin spaces in the brain are pial-lined interstitial fluid (ISF)-filled structures surrounding the penetrating arteries and arterioles. These spaces appear as 1- to 2-mm in diameter, round, oval, or curvilinear smooth-walled structures on magnetic resonance imaging (MRI). Typical PVSs are asymptomatic. Occasionally, they become enlarged and cause specific clinical manifestations that depend on location and the degree of tissue compression. In this case, they are referred to as giant tumefactive PVSs. To our knowledge, there have been no reported cases in which giant PVSs increased remarkably in number and size during both the natural course and postoperative course. We describe a rare progression of giant tumefactive PVSs 14 years after initial surgery.

CASE DESCRIPTION

On first admission at age 17, endoscopic ventriculocystostomy and third ventriculostomy were performed to relieve hydrocephalus caused by cysts compressing the cerebral aqueduct. Fourteen years later, the multicystic lesion reappeared with an increase in both cyst number and size. The patient showed no hydrocephalus but presented with oculomotor and trochlear nerve palsies, which were caused by a mass effect on the midbrain. Endoscopic ventriculocystostomy was performed and symptoms improved.

CONCLUSION

This is the first case report in which giant PVSs increased significantly in number and size.

Regression of dilated perivascular spaces of the brain

PURPOSE

Perivascular, or Virchow-Robin, spaces of the brain represent interstitial fluid-filled spaces continuous with subpial spaces, and not invagination of cerebrospinal fluid-filled subarachnoid spaces. Regression of a dilated, or even giant, perivascular space occurs rarely. The purpose of this paper is to describe magnetic resonance imaging evidence of complete regression of dilated perivascular spaces (dPVSs).

METHODS

Patient 1 was a 76-year-old woman with right hemiparesis and aphasia from a left cranial vault meningioma infiltrating the superior sagittal sinus, and a left temporal lobe giant perivascular space. Patient 2 was a 70-year-old man with pituitary apoplexy, vasospasm, cerebral ischemia, and two dPVSs, one in the right temporal lobe, and one in the left anterior perforate substance. Patient 3 was a 78-year-old man with a generalized seizure, and a right temporal lobe dPVS.

RESULTS

In all the patients, temporal lobe giant or dPVSs underwent regression, following meningioma subtotal resection (patient 1) or pituitary lesion shrinkage (patient 2), or spontaneously (patient 3). In patient 2, the left anterior perforate substance dPVS was unchanged.

CONCLUSIONS

Temporal lobe giant or dPVSs may regress, eventually together with resection or regression of intracranial tumors, also distant from the PVSs. Cerebral edema does not seem the only factor influencing dilatation of PVSs.

Enhancement of Virchow-Robin Spaces

Virchow-Robin spaces are enclosed spaces filled with interstitial fluid and covered with pia that accompany arteries, arterioles, veins and venules as they perforate the brain. They are round, linear or punctuate areas depending on the image that parallel cerebrospinal fluid attenuation or signal intensity. They are classically described as isointense to cerebrospinal fluid on images obtained with all pulse sequences. They appear hypointense relative to brain on T1-weighted MR scans and present a high signal intensity on T2-weighted MR scans. They also show complete signal suppression on fluid-attenuated inversion recovery (FLAIR) scans and no enhancement after intravenous contrast administration. However, many pathologic states result in abnormal dilation with an increased number of Virchow-Robin spaces visible on MRI imaging and many pathological conditions cause the spaces to enhance. The purpose of this study is to present the major causes of Virchow-Robin enhancement.

Enhancement of robin-virchow spaces MRI evaluation

The perivascular spaces are normally microscopic. Even in normal brain some Robin-Virchow spaces are usually seen in the area of substantia innominata at the level of anterior commissure. Many pathologic states result in abnormal dilatation with an increased number of spaces visible on MRI imaging. Dilatation is most commonly associated with anterior abnormalities that arise due to aging, diabetes, hypercholesterolemia, smoking, hypertension and other vascular risk factors. The precise etiology of dilatation is currently unknown.