Detection of CSF leaks with magnetic resonance imaging in intracranial hypotension syndrome

Intracranial hypotension syndrome (IHS) is a rare disorder characterized by postural headache, low cerebrospinal fluid (CSF) pressure, dural thickening and pachymeningeal contrast enhancement as a consequence of decreased CSF volume. The present report is a case of spontaneous IHS due to dural leak at the level of T12–L1. The site of CSF leakage was not detectable on either conventional magnetic resonance imaging (MRI) or T2-weighted MR myelography. However, it was evident on contrast-enhanced MR myelography (CE-MRM). The present report discusses the efficacy of CE-MRM in the detection of CSF leaks according to the literature so far.     

Magnetic resonance imaging findings of intracranial hypotension

Neurological Sciences - This study aims to evaluate the differences in the sizes and configurations of various structures on brain MRIs of patients with intracranial hypotension (ICH) compared to...     

Spontaneous intracranial hypotension

Since the introduction of magnetic resonance imaging (MRI), spontaneous intracranial hypotension has been diagnosed much more frequently. The aim of this review is to discuss the symptoms and signs of the condition, in particular the characteristics of the associated headache, with sudden onset after sitting or standing, so that it can be included under the rubric of 'thunderclap headache'. This type of headache, like post lumbar puncture headaches, may be caused by cerebral vasodilatation and exacerbated by lowered pressure of the cerebrospinal fluid (CSF). Other symptoms include neck stiffness, nausea, vomiting, vertigo, tinnitus, deafness, and cognitive abnormalities. The clinical picture can sometimes mimic frontotemporal dementia, and the behaviour of some patients can sometimes be described as hypoactive–hypoalert, with somnolence, impaired attention, and stereotyped motor activity. Sagging of the brain, caused by leakeage of the CSF, can cause lesions in the brainstem with stupor, gaze palsies, and cranial nerve palsies. The condition can be a risk factor for cerebral venous thrombosis because of slowing of the blood flow and distortion of the blood vessels. The clinical picture may well suggest the diagnosis, but the headache may possibly indicate a subarachnoid haemorrhage. However, MRI will help to confirm the diagnosis and to localize the site of the CSF leak. MRI myelograms are of particular value, but if they are equivocal a computed tomography myelogram should be performed. The leakage of CSF is due to a tear in the dura, most frequently where the spinal roots leave the subarachnoid space. If this does not heal with bedrest, an epidural blood patch or a percutaneous injection of fibrin glue may be needed. More information is required on long-term follow-up.     

Spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) is typically manifested by orthostatic headaches that may be associated with one or more of several other symptoms, including pain or stiffness of the neck, nausea, emesis, horizontal diplopia, dizziness, change in hearing, visual blurring or visual field cuts, photophobia, interscapular pain, and occasionally face numbness or weakness or radicular upper-limb symptoms. Cerebrospinal fluid (CSF) pressures, by definition, are quite low. SIH almost invariably results from a spontaneous CSF leak. Only very infrequently is this leak at the skull base (cribriform plate). In the overwhelming majority of patients, the leak is at the level of the spine, particularly the thoracic spine and cervicothoracic junction. Sometimes, documented leaks and typical clinical and imaging findings of SIH are associated with CSF pressures that are consistently within limits of normal. Magnetic resonance imaging of the head typically shows diffuse pachymeningeal gadolinium enhancement, often with imaging evidence of sinking of the brain, and less frequently with subdural fluid collections, engorged cerebral venous sinuses, enlarged pituitary gland, or decreased size of the ventricles. Radioisotope cisternography typically shows absence of activity over the cerebral convexities, even at 24 or 48 hours, and early appearance of activity in the kidneys and urinary bladder, and may sometimes reveal the level of the leak. Although various treatment modalities have been implemented, epidural blood patch is probably the treatment of choice in patients who have failed an initial trial of conservative management. When adequate trials of epidural blood patches fail, surgery can offer encouraging results in selected cases in which the site of the leak has been identified. Some of the spontaneous CSF leaks are related to weakness of the meningeal sac, likely in connection with a connective tissue abnormality.     

Spontaneous intracranial hypotension.

The clinical features and radiological appearances of spontaneous intracranial hypotension are described in three patients and the medical literature is reviewed. Awareness of this condition and its differentiation from more sinister meningitic processes is important to avoid unnecessary invasive investigations and to allow prompt diagnosis and effective treatment.     

自发性低颅压综合征和肥厚性硬脑膜炎的临床及影像特征比较

目的比较自发性低颅压综合征(SIH)和肥厚性硬脑膜炎(HP)的临床及影像特征,为二者鉴别提供参考。方法收集作者医院收治的8例SIH患者和6例HP患者临床特征及影像学资料并进行对比分析。结果 (1)SIH:亚急性起病5例,急性起病3例;所有患者均以体位性头痛为核心表现。6例脑脊液压力低于60mmH H_2O,余2例分别为70和90 mmHH_2O;脑脊液红细胞计数轻度增高1例,蛋白轻度增高2例(分别为0.71和0.84 g/L),余5例脑脊液常规、生化均正常。头颅MRI结果示弥漫均匀硬脑膜增厚强化。(2)HP:急性起病2例,缓慢起病4例;所有患者均以头痛为核心表现并伴有其他神经系统受累的症状体征,其中表现为慢性每日头痛5例,发作性头痛1例。脑脊液压力在正常范围(90～1 50 mmH_2O)5例,另1例压力为75 mmH_2O;5例白细胞数轻度增高[(8～1 2)×10~6/L],4例蛋白增高(1.1～2.7 g/L)。4例红细胞沉降率增高(26～62 mm/h),3例C反应蛋白增高(13.4～36.1 μg/mL),2例类风湿因子增高。头颅MRI结果示硬脑膜局限性增厚强化3例,硬脑膜弥漫增厚强化3例。结论 SIH和HP虽为不同性质的两种疾病,但临床表现、影像改变存在很多相似之处。早期进行影像学检查,收集详尽的临床资料进行对比分析,必要时行纵向随访追踪,将有助于二者的鉴别。     

Spontaneous intracranial hypotension: correlation of imaging findings with clinical features

BACKGROUND: Spontaneous intracranial hypotension (SIH) is increasingly recognized as a clinically variable and likely underdiagnosed syndrome caused by non-traumatic CSF leaks. The aim of this study was to correlate the findings of imaging studies - magnetic resonance imaging (MRI), radionuclide cisternography - with clinical features and CSF pressure in SIH in order to improve the diagnostic yield and management in patients with SIH. METHODS: Clinical case study of 10 consecutive cases of SIH, MRI, radio-isotope cisternography. RESULTS: 5 out of 10 patients had unusual clinical symptoms of SIH(2 subdural haematomas, 1 gait ataxia, 1 tinnitus, 1 haemodialysis-associated headache). In 7 patients pachymeningeal gadolinium enhancement was detected in MRI accompanied by a reduced CSF opening pressure. In contrast, the 3 patients with normal MRI also had a normal CSF pressure. Radio-isotope cisternography was abnormal in all patients tested. There was no correlation between the severity of clinical symptoms and MRI or radionuclide cisternography findings. CONCLUSIONS: The spectrum of clinical symptoms and imaging findings in SIH is highly variable. There- fore the diagnosis of SIH is often delayed. Radio-isotope cisternography is an important additional diagnostic method to detect CSF leaks or pathological kinetics of radio-isotope movement particularly in cases with normal MRI findings.     

Brain magnetic resonance imaging abnormalities in neuromyelitis optica

Objective – Brain abnormalities in neuromyelitis optica (NMO) attracted much attention. Our study was to identify the brain magnetic resonance imaging (MRI) abnormalities in Chinese NMO patients. Methods – Patients who fulfilled the latest diagnostic criteria of NMO proposed by Wingerchuk et al. [Neurology 66 (2006) 1485] and whose brain MRI did not meet the multiple sclerosis (MS) criteria of McDonald et al. [Ann Neurol 50 (2001) 121] were selected to perform MRI scanning of the brain, spinal cord and optic nerves. Results – Twenty‐eight of 33 patients (84.8%) had abnormal MRI findings. Twenty‐two patients (66.7%) presented with well‐defined brain parenchymal lesions and the other six patients (18.2%) with macroscopic symmetrical diffuse hyperintensities in deep white matter. Fifteen of 22 patients had more than one lesion (≥2 lesions) and the other seven patients had single lesion. In the supratentorium, most lesions were punctate or small round dot and non‐specific in juxtacortical, subcortical and deep white matter regions, a few were patchy atypical confluent lesions. Brainstem was easily involved (14/33, 42.4%) especially in medulla (7/33, 21.2%). Conclusions – This study demonstrates the characteristics of brain MRI abnormalities in Chinese NMO patients, which are helpful to the revision of diagnostic criteria for NMO.     

Functional magnetic resonance imaging of human absence seizures

We studied a patient with idiopathic generalized epilepsy and frequent absences, using electroencephalogram-correlated functional magnetic resonance imaging. Four prolonged runs of generalized spike-wave discharge occurred during a 35-minute experiment. Time-locked activation was observed bilaterally within the thalami in conjunction with widespread but symmetrical cortical deactivation with a frontal maximum. We demonstrate the reciprocal participation of focal thalamic and widespread cortical networks during human absence seizures and suggest reductions in cortical blood flow, in response to synchronized electroencephalogram activity.     

视神经脊髓炎患者头颅磁共振成像特点

目的 分析视神经脊髓炎(neuromyelitis optica,NMO)患者头颅MRI特点.方法 对27例NMO患者的头颅MRI进行回顾性分析.结果 22例(81.5%)NMO患者存在不同类型的头部病灶,并可分为非特异性(7例)、非典型性(1例)、多发性硬化样(MS-like,3例)及脑室-导水管-中央管周围型(11例),但以脑室-导水管-中央管周围型最为常见(40.7%),且NMO患者颅内的病灶数与最后一次MRI检查的时间呈正相关(r=0.475,P=0.025).结论 NMO患者脑内病灶类型多样,但以脑室-导水管-中央管周围型最为常见,可能存在不同机制.对疑似病例早期进行头颅MRI检查相当必要.     

Spontaneous intracranial hypotension with slit ventricles

A case of spontaneous intracranial hypotension syndrome is described. Computed tomography showed slit ventricles with tight basal cisterns. Prompt improvement of symptoms was achieved by intramuscular dexamethasone treatment. A follow-up CT scan demonstrated re-expansion of ventricles and basal cisterns.     

Spontaneous intracranial hypotension: case report

Spontaneous intracranial hypotension is a rare syndrome associated with postural cephalalgia and low pressure of the cerebrospinal fluid. We report the case of a 45 years-old man with spontaneous intracranial hypotension with MRI diffuse meningeal enhancement.     

伴脑膜肥厚的原发性低颅压综合征与肥厚性硬膜炎的临床对比分析

目的探讨伴脑膜肥厚的原发性低颅压综合征(SIH)与肥厚性硬膜炎(HP)的临床特点及鉴别诊断,以提高对低颅压综合征的诊治水平。方法回顾性分析有脑膜肥厚的10例原发性低颅压综合征与10例肥厚性硬膜炎的临床、实验室资料,影像学检查及治疗和转归等。结果两组病人的临床表现、CSF改变及影像学改变有相似之处,但SIH的头痛与体位变化有关,CSF压力明显低于正常,影像学上可有硬膜下积液,治疗主要以补液为主,与HP有区别。结论低颅压综合征与肥厚性硬膜炎虽有相似之处,但两者病因、发病机制和治疗上仍有区别,应注意鉴别,以防误诊。