Real-life study of the use of oto-acoustic emissions in the diagnosis of intracranial hypotension.

BACKGROUND: The diagnosis of spontaneous or post-traumatic intracranial hypotension (IH) mainly relies on clinical features and neuro-imaging. However, the results of brain and spine magnetic resonance imaging are not always contributive. There is an interest for other non-invasive procedures, able to confirm or refute the diagnosis. The use of oto-acoustic emissions (OAE) was previously reported on isolated cases of IH associated with endolymphatic hydrops (ELH). The aim of this study was to assess the real-life utilization of this electrophysiological method in a larger population of suspected IH. METHODS: A retro-prospective cohort study was conducted from November 2013 to July 2022 in patients with a suspected or doubtful diagnosis of IH. They were assessed for ELH by recording bilateral distortion product of oto-acoustic emissions (DPOAE) in sitting then in supine position. RESULTS: Among the 32 patients assessed, the diagnostic of IH was confirmed in 18 patients. An ELH was shown in 15 of them (83%), but also in seven other patients. They had several differential diagnoses: chronic migraine, Chiari malformation, rebound intracranial hypertension and perilymph fistula. CONCLUSIONS: This procedure seems to be insufficient to exclude differential diagnosis when intracranial hypotension is suspected.

Why can spontaneous intracranial hypotension cause behavioral changes? A case report and multimodality neuroimaging comparison with frontotemporal dementia.

Frontotemporal Brain Sagging Syndrome (FBSS) is a rare condition characterized by the presence of spontaneous intracranial hypotension associated with behavioural disturbances mimicking the behavioural variant of Frontotemporal dementia (bvFTD). It has been suggested that behavioural symptoms are caused by damage to the connectivity of the frontal lobes due to the brain sagging. However, no studies have directly explored brain connectivity in patients with FBSS. Here, we report a new case of FBSS with persistent behavioural disturbances, whom we compared to 20 patients with bvFTD and to 13 cognitively healthy controls using Magnetic Resonance Imaging (MRI). We explored differences related to grey matter (GM) volume with voxel-based morphometry, functional connectivity with seed-based analysis, and white matter (WM) microstructural integrity with tract-based spatial statistics. We found that the FBSS patient, like the controls, had greater GM volume relative to the bvFTD patients. Moreover, the FBSS patient had greater functional connectivity from a left inferior frontal gyrus seed than both the bvFTD patients and healthy controls groups in dorsolateral frontal areas. Like the bvFTD group the FBSS patient had decreased WM integrity relative to the controls, especially in the posterior part of the corpus callosum, and the magnitude of these abnormalities correlated with measures of apathy across the FBSS and bvFTD patients. Our results suggest that behavioural changes associated with SIH are mainly due to altered WM connectivity.

Ectasia dural e hipotensión endocraneal en síndrome de Marfán / Dural ectasia and intracranial hypotension in Marfan syndrome

INTRODUCCIÓN: El síndrome de Marfán es un trastorno multisistémico del tejido conectivo de herencia autosómica dominante, de expresión variable. La ectasia dural es un compromiso frecuente, pero poco conocido, que puede asociarse a síndrome de hipotensión endocraneana (SHE). OBJETIVO: Pre sentar un caso de cefalea invalidante secundario a SHE, para advertir de esta rara complicación, que debe tenerse presente en niños portadores de conectivopatías, en especial síndrome de Marfán. CASO CLÍNICO: Adolescente femenina de 13 años, portadora de sindrome de Marfán, de diagnóstico clínico según criterios de Ghent 2010, que consultó por cefalea ortostatica invalidante de 6 meses de evolución. La Resonancia Magnetica (RM) de cerebro mostró múltiples signos de hipotensión endocraneana, mientras que la RM de columna total mostró una ectasia dural que determinó la dilatación del saco tecal y remodelación posterior de los cuerpos vertebrales, especialmente a nivel del sacro. Se realizó tratamiento con parche sanguíneo autólogo epidural con buena respuesta clínica. CONCLUSIONES: La ectasia dural, frecuente en el sindrome de Marfán, es una causa predisponente a fuga de líquido cefaloraquideo (LCR), que podría causar cefalea ortostática segundaria al SHE.

INTRODUCTION: Marfan syndrome is an autosomal dominant, multi-systemic connective tissue di sorder of different presentations. Dural ectasia is a common, but little known complication that can be associated with intracranial hypotension syndrome (IHS). OBJECTIVE: To present a case of severe headache secondary to IHS in order to warn about this rare complication, which must be considered in children carriers of connective tissue diseases, especially Marfan syndrome. CLINICAL CASE: 13-year- old female carrier of Marfan syndrome, clinically diagnosed according to the 2010 Ghent criteria, who consulted due to a 6-months history of severe orthostatic headache. Head magnetic resonance imaging (MRI) showed multiple signs of intracranial hypotension, while whole-spine MRI showed dural ectasia that caused the thecal sac dilation and subsequent remodeling of vertebral bodies, es pecially the sacral ones. Treatment with an autologous epidural blood patch was administered with good clinical response. CONCLUSIONS: Dural ectasia, frequent in Marfan syndrome, is a predisposing cause of cerebrospinal fluid (CSF) leakage, which could cause orthostatic headache secondary to IHS.

Epidural blood patch for spontaneous intracranial hypotension (SIH): a report of two cases.

One of the latest diagnoses that need to be considered when evaluating patients with persistent headache is spontaneous (postural) intracranial hypotension (SIH). The diagnosis can be clinched by magnetic resonance imaging (MRI) findings of subdural collections, meningeal enhancement and tonsillar descent. Cerebrospinal fluid leak has been postulated as the cause, and both medical and surgical treatment options have been documented. The treatment of choice is, however, an epidural blood patch. Here we discuss two cases of SIH treated successfully with epidural blood patch.

Headache and Dural Enhancement: Two Case Studies of Different Treatable Pathologies.

BACKGROUND: Hypertrophic pachymeningitis (HP) and spontaneous intracranial hypotension are different treatable diseases, which should promptly be recognized and treated to prevent neurologic sequelae. Headache and dural enhancement are the main features of both diseases, thus differentiating between these 2 conditions can be difficult. CASES DESCRIPTION: We present 2 cases with headache and dural enhancement, in which the differential diagnosis was challenging at presentation because, in both cases, clear positional pain modification was not reported. Each patient was referred to us with the suspicion of a diagnosis actually affecting the other one. Based on further findings, which supported diagnosis of spontaneous intracranial hypotension in the first case and of HP in the second one, we briefly review clinical, radiologic, and laboratory features, which can help in the differential diagnosis. CONCLUSIONS: An accurate diagnostic workup is mandatory to distinguish among HP and intracranial hypotension.

Dural ectasia and intracranial hypotension in Marfan syndrome. / Ectasia dural e hipotensión endocraneal en síndrome de Marfán.

INTRODUCTION: Marfan syndrome is an autosomal dominant, multi-systemic connective tissue di sorder of different presentations. Dural ectasia is a common, but little known complication that can be associated with intracranial hypotension syndrome (IHS). OBJECTIVE: To present a case of severe headache secondary to IHS in order to warn about this rare complication, which must be considered in children carriers of connective tissue diseases, especially Marfan syndrome. CLINICAL CASE: 13-year- old female carrier of Marfan syndrome, clinically diagnosed according to the 2010 Ghent criteria, who consulted due to a 6-months history of severe orthostatic headache. Head magnetic resonance imaging (MRI) showed multiple signs of intracranial hypotension, while whole-spine MRI showed dural ectasia that caused the thecal sac dilation and subsequent remodeling of vertebral bodies, es pecially the sacral ones. Treatment with an autologous epidural blood patch was administered with good clinical response. CONCLUSIONS: Dural ectasia, frequent in Marfan syndrome, is a predisposing cause of cerebrospinal fluid (CSF) leakage, which could cause orthostatic headache secondary to IHS.

Spontaneous Intracranial Hypotension: Pathogenesis, Diagnosis, and Treatment.

Spontaneous intracranial hypotension (SIH) is a clinical syndrome that is increasingly recognized as an important and treatable secondary cause of headaches. Insight into the condition has evolved significantly over the past decade, resulting in a greater understanding of the underlying pathophysiology, development of new diagnostic imaging tools, and a broadening array of targeted treatment options. This article reviews the clinical presentation and pathogenesis of SIH, discusses the important role of imaging in diagnosis, and describes how imaging guides treatment.

Brainstem evoked potentials and magnetic resonance imaging abnormalities in differential diagnosis of intracranial hypotension.

OBJECTIVE: To compare brainstem acoustic evoked potentials (BAEP) and magnetic resonance imaging (MRI) in the differential diagnosis of intracranial hypotension (IH), Chiari malformation (CM) and sensorineural hearing loss (SNHL). METHODS: BAEP were recorded in 18 IH, 18 CM, 20 SNHL patients and 52 controls. MRI were acquired in all IH and CM patients. RESULTS: Abnormal BAEP were observed in 94% of IH patients, in 33% of CM and 70% of SNHL patients. After recovery from IH, BAEP abnormalities disappeared. Internal auditory canal (IAC) MRI abnormalities were described in 88% of IH patients. MRI signs of IH were observed in 33-78% in IH patients, but the most frequent MRI sign was 8th nerve T2 hyperintensity, with contrast enhancement in T1 sequences. This finding, combined with wave I latency, yielded highest specificity and sensitivity for IH diagnosis. CONCLUSIONS: Our study points out how IH can be effectively distinguished from CM and SNHL through the contribution of neurophysiology and MRI; in particular, evaluation of the 8th nerve achieves a high sensitivity and specificity in patients with IH. Further studies are required to examine the combined use of BAEP recordings ad MRI in diagnosis and monitoring of patients affected by IH.

Spontaneous Intracranial Hypotension Presenting As Cervicogenic Headache: Case Report and Review of Literature.

BACKGROUND: Spontaneous intracranial hypotension is uncommon. There is a lack of understanding of its exact pathophysiology along with significant variability in its clinical management. CASE DESCRIPTION: The authors report the case of a previously well man with cervicogenic headache associated with magnetic resonance imaging features of intracranial hypotension. The salient features of this case include the details of various treatments prescribed for his condition and the therapeutic difficulties encountered. CONCLUSION: Owing to the infrequency of the diagnosis, the challenges of clinical management for this patient are discussed in relationship to current literature. Next, the highlights of this unusual case in an individual add to the growing body of literature reports for better understanding of this disease.

Ventral longitudinal intraspinal fluid collection: Rare presentation as brachial amyotrophy and intracranial hypotension.

CONTEXT: Ventral longitudinal intraspinal fluid collection (VLISFC) presenting as hand amyotrophy has been described only in a few cases and there are no reports on associated intracranial CSF hypovolemia (ICH). We describe the clinical and imaging findings of a case with combined brachial amyotrophy and ICH secondary to VLISFC. FINDINGS: A 31 year old man presented with severe positional neck discomfort, radiating pain, progressive asymmetrical wasting and weakness of distal upper limbs. Contrast Magnetic Resonance Imaging (MRI) of the spine demonstrated a ventral extradural intraspinal fluid collection extending from upper border of C6 to lower border of T3 vertebra with pockets of dorsal collection. Three-dimensional constructive interference in steady state (CISS 3D) used in spinal imaging for identification of CSF leak corroborated with the extent seen on T2 sagittal sections; however, the site of the leak was not identified. After a year he developed disturbing postural headache which was relieved in recumbent position. Follow up MRI of brain was normal while spine demonstrated significant cervical cord atrophy and bilateral cord white matter hyperintensities. Conclusion / Clinical Relevance: We report this unusual case where local compression by VLISFC located at the cervical and upper thoracic level not only caused distal bi-brachial amyotrophy mimicking Hirayama disease but also led to secondary intracranial hypotension. An early identification and intervention could possibly have prevented the onset of ICH.

Study of lamina cribrosa depth and optic nerve in patients with spontaneous intracranial hypotension.

PURPOSE: The aim of this study is to analyze the lamina cribrosa depth and to study the optic nerve in patients with spontaneous intracranial hypotension. METHODS: A total of 10 eyes of the patients with spontaneous intracranial hypotension with unknown etiology (study group) and 10 eyes of healthy patients without any ophthalmological or neurological pathologies (control group) were included. The subjects were submitted to ophthalmological examination with the evaluation of visual acuity, spherical equivalent, applanation tonometry, pachymetry, axial length, retinography, computerized static perimetry (Humphrey 30-2 SITA-Standard), and OCT Spectralis with enhanced depth image, to calculate the depth of the anterior surface of the lamina cribrosa and to measure the nerve fiber layer thickness of the optic nerve. All of these parameters were compared between the two groups. RESULTS: Mean anterior surface of the lamina cribrosa depth was 447.96 ± 118.51 (313.30-632.0) µm for the spontaneous intracranial hypotension group and 292.56 ± 40.71 (247-387) µm for the control group, with a statistically significant difference between them (p = 0.001). The thickness of the nerve fiber layer did not differ significantly in the temporal (p = 0.94), nasal (p = 0.173), superior (p = 0.41), central (p = 0.36) or inferior (p = 0.5) sectors. Four eyes of patients with spontaneous intracranial hypotension showed a marked reduction in the temporal nerve fiber layer. Pachymetry (p = 0.16), axial length (p = 0.71), and intraocular pressure (p = 0.6) did not differ significantly between groups, whereas spherical equivalent (p = 0.03) was significantly different. Visual fields were normal in both groups. CONCLUSION: The translaminar gradient is determinant in the structure of the lamina cribrosa. Low intracranial pressure associated with a high translaminar gradient leads to an increased lamina cribrosa depth similar to that observed in glaucoma patients.

Correlations among brain and spinal MRI findings in spontaneous intracranial hypotension.

OBJECTIVES: Several brain and spinal magnetic resonance imaging signs have been described in spontaneous intracranial hypotension. Their correlations are not fully studied. This study aimed to explore potential mechanisms underlying cerebral neuroimaging findings and to examine associations among spinal and brain magnetic resonance imaging signs. METHODS: We conducted a retrospective review of magnetic resonance myelography and brain magnetic resonance imaging records of patients with spontaneous intracranial hypotension. Categorical principal component analysis was employed to cluster brain neuroimaging findings. Spearman correlation was employed to analyze associations among different brain neuroimaging findings and between brain and spinal neuroimaging findings. RESULTS: In patients with spontaneous intracranial hypotension (n = 148), categorical principal component analysis of brain neuroimaging signs revealed two clusters: Cerebral venous dilation and brain descent. Among all brain magnetic resonance imaging signs examined, only midbrain-pons angle associated with anterior epidural cerebrospinal fluid collection length (surrogate spinal cerebrospinal fluid leak severity) (n = 148, Spearman's ρ = -0.38, p < .001). Subgroup analyses showed that the association between midbrain-pons angle (within brain descent cluster) and spinal cerebrospinal fluid leak severity was presented in patients with convex margins of the transverse sinuses (n = 122, Spearman's ρ = -0.43, p < .001), but not in patients without convex margins (n = 26, Spearman's ρ = -0.19, p = .348). The association between severity of transverse sinus distension and spinal cerebrospinal fluid leak severity was only presented in patients without convex margins (n = 26, Spearman's ρ = 0.52, p = .006). CONCLUSION: This study indicates that there are two factors behind the brain neuroimaging findings in spontaneous intracranial hypotension: Cerebral venous dilation and brain descent. Certain brain neuroimaging signs correlate with spinal cerebrospinal fluid leakage severity, depending on different circumstances.

Intracranial structural alteration predicts treatment outcome in patients with spontaneous intracranial hypotension.

Background Intracranial structural dislocation in spontaneous intracranial hypotension (SIH) can be measured by various intracranial angles and distances. We aimed to identify the clinical significance of structural dislocation in relation to treatment outcome in patients with SIH. Methods In this retrospective analysis, we identified patients with SIH who received an epidural blood patch (EBP) at Samsung Medical Center from January 2005 to March 2015. Structural dislocation in pretreatment MRIs of SIH patients was assessed by measuring tonsillar herniation, mamillopontine distance, the angle between the vein of Galen and straight sinus (vG/SS angle), the pontomesencephalic angle, and the lateral ventricular angle. After the first EBP, poor response was defined as the persistence of symptoms that prompted a repeat EBP. Results Out of the 95 patients included, 31 (32.6%) showed poor response. Among the radiological markers of structural dislocation, the vG/SS angle was associated with poor response (49.82 ± 16.40° vs 66.58 ± 26.08°, p = 0.002). Among clinical variables, premorbid migraine ( p = 0.036) was related to poor response. In multivariate analysis, reduced vG/SS angle was independently associated with poor response (OR 1.04 [95% CI 1.01 - 1.07] per 1° decrease, p = 0.006). In 23 patients who underwent MRI after successful treatment, the vG/SS angle significantly increased after the EBP ( p < 0.001, by paired t-test), while two patients with aggravation or recurrence showed a further reduction of their vG/SS angles. Conclusions Intracranial structural dislocation, measured by the vG/SS angle, is associated with poor response to the first EBP in patients with SIH. Successful treatment can reverse the structural dislocation.

Comparison of the sagittal sinus cross-sectional area between patients with multiple sclerosis, hydrocephalus, intracranial hypertension and spontaneous intracranial hypotension: a surrogate marker of venous transmural pressure?

There is evidence that patients with multiple sclerosis (MS) and hydrocephalus share some common pathophysiological mechanisms. Alterations in CSF pressure are known to affect cerebral venous sinus geometry. To further explore these mechanisms, we measured the superior sagittal sinus (SSS) cross-sectional area 3 cm above the torcular using T2 images in 20 MS, 10 spontaneous intracranial hypotension (SIH), 21 hydrocephalus and 20 idiopathic intracranial hypertension (IIH) patients and compared with 20 matched controls. The SSS area was reduced by 25% in hydrocephalus (p = 0.0008), increased by 22% (p = 0.037) in SIH and unchanged in IIH compared to matched controls. In MS there was a 16% increase in SSS area (p = 0.01).The findings suggest that changes in SSS cross-sectional are common between MS and SIH patients, while in hydrocephalus and IIH these are different.

Hypoactive-hypoalert behaviour and thalamic hypometabolism due to intracranial hypotension.

A 47-year-old man presented with a 9-year history of a hypoalert hypoactive behaviour syndrome, caused by the deep brain swelling variant of spontaneous intracranial hypotension. Along with apathy with retained cognition, he had stable ataxia, impaired upgaze and episodes of central apnoea. MRI brain showed a sagging brainstem, pointed ventricles and reduced angle between the vein of Galen and the straight sinus, but no meningeal enhancement or subdural collections. A dopamine transporter scan showed preganglionic dopamine receptor deficiency; a fluorodeoxy glucose positron emission tomography scan showed bilateral hypothalamic hypometabolism. This variant of spontaneous intracranial hypotension may alter deep brain functioning within the basal ganglia and thalamus, causing the hypoactive-hypoalert behaviour phenotype.

Time-Dependent Changes in Dural Enhancement Associated With Spontaneous Intracranial Hypotension.

OBJECTIVE: The objective of our study was to determine whether the presence of individual imaging signs of spontaneous intracranial hypotension (SIH) is correlated with increasing duration of headache symptoms. Of particular interest is the relationship of symptom duration to dural enhancement because it is the most commonly identified imaging sign in patients with SIH. MATERIALS AND METHODS: Eighty-nine patients with SIH who underwent pretreatment brain MRI and total-spine CT myelography and whose medical record included data on the duration of clinical symptoms were included in this cross-sectional retrospective study. Brain imaging was reviewed for the presence of dural enhancement, brain sagging, and the "venous distention" sign. CT myelograms were assessed for CSF leak. If present, a leak was subcategorized as a high-flow or low-flow leak. Differences in headache duration between subjects with and those without individual imaging signs were compared. RESULTS: Subjects without dural enhancement on brain MRI had a longer average duration of symptoms than those with dural enhancement present (average symptom duration: 45.3 ± 59.0 [SD] vs 15.1 ± 33.0 weeks, respectively; p = 0.002). No difference in symptom duration was observed between subjects whose MRI studies showed and those whose MRI studies did not show brain sagging (p = 0.10) or the venous distention sign (p = 0.21). The presence of a CSF leak on CT myelography was not associated with symptom duration (p = 0.56) except in the subgroup of patients with low-flow leaks. CONCLUSION: Increasing symptom duration in SIH is associated with decreased prevalence of abnormal dural enhancement on brain MRI. Because dural enhancement is considered a hallmark imaging feature of this condition, its absence may exacerbate the problem of underdiagnosis in chronic cases of SIH.

Atypical Presentations of Intracranial Hypotension: Comparison with Classic Spontaneous Intracranial Hypotension.

BACKGROUND AND PURPOSE: Atypical clinical presentations of spontaneous intracranial hypotension include obtundation, memory deficits, dementia with frontotemporal features, parkinsonism, and ataxia. The purpose of this study was to compare clinical and imaging features of spontaneous intracranial hypotension with typical-versus-atypical presentations. MATERIALS AND METHODS: Clinical records and neuroimaging of patients with spontaneous intracranial hypotension from September 2005 to August 2014 were retrospectively evaluated. Patients with classic spontaneous intracranial hypotension (n = 33; mean age, 41.7 ± 14.3 years) were compared with those with intracranial hypotension with atypical clinical presentation (n = 8; mean age, 55.9 ± 14.1 years) and 36 controls (mean age, 41.4 ± 11.2 years). RESULTS: Patients with atypical spontaneous intracranial hypotension were older than those with classic spontaneous intracranial hypotension (55.9 ± 14.1 years versus 41.7 ± 14.3 years; P = .018). Symptom duration was shorter in classic compared with atypical spontaneous intracranial hypotension (3.78 ± 7.18 months versus 21.93 ± 18.43 months; P = .015). There was no significant difference in dural enhancement, subdural hematomas, or cerebellar tonsil herniation. Patients with atypical spontaneous intracranial hypotension had significantly more elongated anteroposterior midbrain diameter compared with those with classic spontaneous intracranial hypotension (33.6 ± 2.9 mm versus 27.3 ± 2.9 mm; P < .001) and shortened pontomammillary distance (2.8 ± 1 mm versus 5.15 ± 1.5 mm; P < .001). Patients with atypical spontaneous intracranial hypotension were less likely to become symptom-free, regardless of treatment, compared with those with classic spontaneous intracranial hypotension (χ(2) = 13.99, P < .001). CONCLUSIONS: In this sample of 8 patients, atypical spontaneous intracranial hypotension was a more chronic syndrome compared with classic spontaneous intracranial hypotension, with more severe brain sagging, lower rates of clinical response, and frequent relapses. Awareness of atypical presentations of spontaneous intracranial hypotension is paramount.

Dural Thickening of the Internal Auditory Canal in Patients With Spontaneous Intracranial Hypotension Syndrome.

OBJECTIVE: This study aimed to assess the utility of dural thickening of the internal auditory canal (IAC) in patients with spontaneous intracranial hypotension (SIH) syndrome and determined the sensitivity and specificity of this image finding. METHODS: Magnetic resonance images were evaluated for 22 cases of definite SIH and 16 cases of unlikely SIH. On contrast-enhanced magnetic resonance imaging, pachymeningeal enhancement and dural thickening of the IAC were assessed. RESULTS: Pachymeningeal enhancement was observed in 21 of 22 patients in the definite SIH group and 1 of 16 patients in the unlikely SIH group (sensitivity, 95.5%; specificity, 93.8%). Dural thickening of the IAC was observed in 15 of 22 patients in the definite SIH group and 0 of 16 patients in the unlikely SIH group (sensitivity, 68.2%; specificity, 100%). CONCLUSIONS: Dural thickening of the IAC showed 100% specificity for SIH syndrome and can increase the accuracy of diagnosis of SIH syndrome.