Treating Spontaneous Intracranial Hypotension with an Anesthetic Modality: The Role of the Epidural Blood Patch

Background: Spontaneous intracranial hypotension (SIH) is a rare syndrome characterized by heterogeneity of presentation and prognosis, which can occasionally result in serious complications, such as the formation of subdural hematomas (SDHs). This case series aims to emphasize that SIH remains a diagnostic and therapeutic challenge; it can present with a broad clinical spectrum of symptoms, can lead to SDH and, if conservative treatment fails, an epidural blood patch (EBP) is a viable treatment option. Although the exact etiology of SIH is not known, it is believed to be due to cerebrospinal fluid (CSF) leak or a low CSF pressure. Case Series: Three patients (two males and one female) with ages ranging between 38 and 53 years old who presented with complaints of not only an orthostatic headache, but also a variety of symptoms of SIH, including the formation of two SDHs in one of them, were included in this series. These patients did not respond to conservative management and, subsequently, given the clinical and radiological evidence of SIH, were referred to the Anesthesiology Department for an EBP. Diagnostic workup was facilitated by imaging modalities, including magnetic resonance imaging (MRI) of the brain and spinal cord, prior to the EBP. All three patients were subjected to an EBP with an 18-gauge epidural needle. A total of between 30 and 43 mL of autologous blood was collected from the patients and was injected into the epidural space under strict aseptic conditions. Two lumbar (L₁-L₂, L₂-L₃) EBPs and one thoracic (T₁₁-T₁₂) EBP were performed on the three patients, respectively. All patients reported complete resolution of symptoms following the EBPs, while MRI improved substantially. Conclusions: This report describes three cases of SIH with CSF leak originating from the cervical, the thoracic and the lumbar level. The EBP restored CSF pressure and relieved the patients' persistent symptoms. MRI helps in revealing indirect signs of a low volume of CSF, though it may not be possible to locate the actual site of the leak. In conclusion, EBP is a well-accepted and beneficial treatment modality for SIH when conventional measures fail.

Acute Enophthalmos After Lumbar Puncture in a Patient with Type 1 Neurofibromatosis Related Sphenoid Wing Dysplasia

A 19-year-old woman with type 1 neurofibromatosis related sphenoid wing dysplasia underwent a lumbar puncture (LP) after an unexplained syncopal event. The cerebrospinal fluid work-up was unremarkable. However, 30-hours post LP, she developed marked enophthalmos ipsilateral to the calvarial dysplasia. The enophthalmos gradually resolved within 72 hours. We surmise that the patient's enophthalmos was due to an LP induced decrease of intracranial pressure in conjunction with the orbital bone anomaly.

Effect of Intravenous Ketamine on Hypocranial Pressure Symptoms in Patients with Spinal Anesthetic Cesarean Sections: A Systematic Review and Meta-Analysis

Background: Pregnant women are more likely to suffer post-puncture symptoms such as headaches and nausea due to the outflow of cerebrospinal fluid after spinal anesthesia. Because ketamine has the effect of raising intracranial pressure, it may be able to improve the symptoms of perioperative hypocranial pressure and effectively prevent the occurrence of hypocranial pressure-related side effects. Method: Keywords such as ketamine, cesarean section, and spinal anesthesia were searched in databases including Medline, Embase, Web of Science, and Cochrane from 1976 to 2021. Thirteen randomized controlled trials were selected for the meta-analysis. Results: A total of 12 randomized trials involving 2099 participants fulfilled the inclusion criteria. There was no significant association between ketamine and the risk of headaches compared to the placebo (RR = 1.12; 95% CI: 0.53, 2.35; p = 0.77; I² = 62%). There was no significant association between ketamine and nausea compared to the placebo (RR = 0.66; 95% CI: 0.40, 1.09; p = 0.10; I² = 57%). No significant associations between ketamine or the placebo and vomiting were found (RR = 0.94; 95% CI: 0.53, 1.67; p = 0.83; I² = 72%). Conclusion: Intravenous ketamine does not improve the symptoms caused by low intracranial pressure after spinal anesthesia in patients undergoing cesarean section.

Neuroimaging Pearls from the MDS Congress Video Challenge. Part 2: Acquired Disorders

The MDS Video Challenge continues to be the one of most widely attended sessions at the International Congress. Although the primary focus of this event is the presentation of complex and challenging cases through videos, a number of cases over the years have also presented an unusual or important neuroimaging finding related to the case. We reviewed the previous Video Challenge cases and present here a selection of those cases which incorporated such imaging findings. We have compiled these "imaging pearls" into two anthologies. The first focuses on pearls where the underlying diagnosis was a genetic condition. This second anthology focuses on imaging pearls in cases where the underlying condition was acquired. For each case we present brief clinical details along with neuroimaging findings, the characteristic imaging findings of that disorder and, finally, the differential diagnosis for the imaging findings seen.

Intracranial hypotension as a contributor to isolated cortical vein thrombosis

BACKGROUND

Isolated cortical vein thrombosis (ICVT), a rare type of cerebral venous thrombosis (CVT), is diagnostically challenging in some cases, and intracranial hypotension (IH) is known to cause CVT.

METHODS

In this study, we reviewed the clinical and imaging characteristics of ICVT in patients with IH caused by spinal cerebrospinal fluid leakage, based on a literature review and investigation of cases from our hospital.

RESULTS

Between January 1, 2007, and November 1, 2019, 735 patients were diagnosed with IH at our hospital; three patients developed ICVT (incidence ~ 0.4%, 3/735), and the literature review yielded an additional 23 cases. Therefore, 26 patients (mean age 35.9 ± 11.4 years old) were included in this study. The most common symptoms were headache (100.0%, 26/26), focal neurological deficits (53.8%, 14/26), and seizure (34.6%, 9/26). The initial headache was orthostatic in 96.2% (25/26) of patients, and 38.5% (10/26) of patients reported a change in the headache pattern following diagnosis of ICVT. Neuroimaging findings associated with ICVT included the cord sign (61.5%, 16/26) and parenchymal brain lesions (46.2%, 12/26), such as intracerebral hemorrhage (30.8%, 8/26), hemorrhagic infarcts (11.5%, 3/26), and localized edema (11.5%, 3/26). The percentage of patients who received anticoagulation and epidural blood patch therapy was similar (69.2% [18/26] vs. 65.4% [17/26]), and most patients recovered completely (92.3%, 24/26).

CONCLUSION

IH should be considered in the differential diagnosis in patients with ICVT. Knowledge of the relevant clinical and neuroimaging features is important to facilitate early diagnosis for favorable prognosis.

Acute Subdural Hemorrhage as the Initial Presentation of Intracranial Hypotension Following Cervical Chiropractic Manipulation: A Case Report and Systematic Review

Spontaneous intracranial hypotension (SIH) still remains an underdiagnosed etiology of new-onset headache. Important risk factors include chiropractic manipulation (CM). We present a case of a 36-year-old Filipino woman who presented with severe bifrontal and postural headache associated with dizziness, vomiting, and doubling of vision. A cranial computed tomography scan was done which showed an acute subdural hematoma (SDH) at the interhemispheric area. Pain medications were given which afforded minimal relief. On history, the headaches occurred 2 weeks after cervical CM. Cranial and cervical magnetic resonance imaging revealed findings supportive of intracranial hypotension and neck trauma, respectively. The patient improved with conservative management. We found 12 articles on SIH and CM after a systematic review of literature. Eleven patients (90.9%) initially presented with orthostatic headache. Eight patients (66.7%) were initially treated conservatively but only 5 (62.5%) had complete recovery. Recovery was achieved within 14 days from start of supportive therapy. Among the 3 patients who failed conservative treatment, 2 underwent non-directed epidural blood patch and one required neurosurgical intervention. This report highlights that a thorough history is warranted in patients with new onset headache. A history of CM must be actively sought. The limited evidence from the case reports showed that patients with SIH and SDH but with normal neurologic examination and minor spinal pathology can be managed conservatively for less than 2 weeks. This review showed that conservative treatment in a closely monitored environment may be an appropriate first line treatment.

Non-Operative Management of a Pediatric Patient With Bilateral Subdural Hematomas in the Setting of Ruptured Arachnoid Cyst

Pediatric subdural hematomas (SDH) are associated with arachnoid cysts (AC), particularly in the middle cranial fossa (MCF). Operative management of these hemorrhages is a mainstay of treatment. Conservative management may be an option if there is minimal mass effect and the patient is mildly symptomatic. A 14-year-old male presented with right frontal headaches that worsened with activity. He was found to have a large right MCF AC. Scheduled routine outpatient follow-up CT of the head demonstrated bilateral SDH. There was no history of significant head trauma. He was admitted for close observation and his inpatient scans remained stable. Outpatient follow-up imaging over the course of three and a half years demonstrated resolution of SDH and decreased AC size. He denied headaches and continued doing well in school. ACs are a risk factor for the development of SDH in young male patients after minor trauma. Development of intracranial hypotension secondary to AC rupture may have contributed to the development of bilateral SDH in our patient. We demonstrate here that close clinical follow up with serial imaging may be considered a management strategy in these patients.

Absence of CSF flow within the cerebral aqueduct in spontaneous intracranial hypotension: a report of two cases

Spontaneous intracranial hypotension (SIH) is a potentially debilitating condition resulting from a low cerebrospinal fluid (CSF) volume secondary to spinal CSF leakage. Characteristic clinical and radiological imaging findings are helpful in diagnosis. Herein, we present and discuss the magnetic resonance imaging (MRI) and CSF flow study of two patients with SIH and no CSF flow within the cerebral aqueduct, which is extremely rare in the literature.

Spontaneous Intracranial Hypotension - A Dilemma

Background

Spontaneous intracranial hypotension (SIH) is a highly misdiagnosed and underdiagnosed disorder.

Objective

Update evaluation and treatment of spontaneous intracranial hypotension.

Methods and Material

Narrative review.

Results

Traditionally, SIH is diagnosed when a headache has developed spontaneously and in temporal relation to a CSF leak (evident on imaging) and/or CSF hypotension (lumbar puncture opening pressure <60 mm CSF). However, lumbar puncture is not mandatorily required to diagnose SIH. Besides headache, other symptoms such as nausea/vomiting in 50.6%, neck pain/stiffness in 33%, tinnitus in 19%, dizziness in 14%, hearing disturbances in 10.7%, followed by visual disturbances, vertigo, back pain, and cognitive symptoms may be present. In suspected cases of SIH, brain and spine should be evaluated with MRI. Dynamic computerized tomographic myelography is required to demonstrate the site of spinal CSF leak. Epidural blood patch (EBP) is a minimally invasive treatment for spontaneous intracranial hypotension (SIH) refractory to medical management and provides symptomatic relief in up to 90% of patients even in patients with bilateral subdural hematomas. The CSF-venous fistulas do not respond well to EBP, and the most definitive curative treatment is the surgical closure of the fistula.

Conclusions

The SIH is a distinct entity and requires a high index of suspicion for diagnosis. A post-contrast MRI should be included for evaluation of headaches. Spinal MRI should be done to demonstrate the site of leak. Epidural blood patch therapy is the most effective treatment of SIH. Most SDHs associated with SIH do not require treatment.

Posterior Reversible Encephalopathy Syndrome Following Intracranial Hypotension Due to Cerebrospinal Fluid (CSF) Leakage: A Report of Two Cases

Posterior reversible encephalopathy syndrome (PRES) in cases of intracranial hypotension is a life-threatening condition. Early suspicion, appropriate treatment, and tight control of possible contributing factors that may facilitate PRES in cerebrospinal fluid (CSF) leak patients may bring a more favorable outcome, lowering the morbidity and mortality rate.

Two cases of PRES with features of intracranial hypotension are presented.

We also discussed the possible pathogenesis of PRES in patients with intracranial hypotension. We emphasize the importance of the early diagnosis and treatment of ICH by repairing the leakage and further prompt attention to tight blood pressure control in those patients to avoid PRES development.

Cranial cerebrospinal fluid leak and intracranial hypotension syndrome - a case report

Spontaneous intracranial hypotension is a rare clinical entity caused in most cases by a cerebrospinal fluid leak occurring at the level of the spinal cord. Cranial dural leaks have been previously reported as a cause of orthostatic headaches but, as opposed to spinal dural leaks, were not associated with other findings characteristic of spontaneous intracranial hypotension. We present the case of a male admitted for severe orthostatic headache. The patient had a history of intermittent postural headaches, dizziness, and symptoms consistent with post-nasal drip, which appeared several years after head trauma. Brain imaging showed signs consistent with intracranial hypotension: bilateral hygromas, subarachnoid hemorrhage, superficial siderosis, diffuse contrast enhancement of the pachymeninges, and superior sagittal sinus engorgement. No spinal leak could be identified by magnetic resonance imaging, and the patient had a rapid remission of symptoms with conservative management. Further work-up identified an old temporal bone fracture which created a route of egress between the posterior fossa and the mastoid cells. Otorhinolaryngology examination showed pulsatile bloody discharge and liquorrhea at the level of the left pharyngeal opening of the Eustachian tube. The orthostatic character of the headache, as well as the brain imaging findings, were consistent with intracranial hypotension syndrome caused by a cranial dural leak. Clinical signs and imaging findings consistent with the diagnosis of apparently “spontaneous” intracranial hypotension should prompt the search for a cranial dural leak if a spinal leak is not identified.

Update on "Treatment of orthostatic headache without intracranial hypotension: A case report" - nine years later

BACKGROUND

In 2013, one of the authors described a 36-year-old female with orthostatic headache without documented intracranial hypotension or evidence of cerebrospinal fluid leak, despite extensive workup. Headache was unresponsive to conservative treatment since 2010, showed only transient benefit after repeated epidural blood patches while vitamin A supplementation resulted in progressive improvement.

CASE

Since 2013, the patient followed a relapsing and remitting course yet relapse control became difficult after a drug induced liver injury required vitamin A discontinuation in 2017, when her headache became chronic. Greater occipital nerve blocks provided pain relief as alternative but were stopped due to the pandemic and her latest severe relapse, in late 2020, required not only restarting anaesthetic blocks and aggressive medication management, but also reassessing and treating comorbidities (obstructive sleep apnoea and major depressive disorder) with modest benefit.

CONCLUSION

Orthostatic headache without intracranial hypotension is rare, with only 28 cases reported so far, all treated empirically and all treatment options revealing to be mostly ineffective. Vitamin A anecdotally appeared to be useful in our case but had to be stopped for severe side effects, so unfavourable long-term prognosis, in ours and 2/3 of the reported cases, seems to be the rule in this intriguing entity.

Spinal Epidural Venous Plexus Enlargement as a Cause of Neurologic Symptoms: Vascular Anatomy and MRI Findings

Pathology of the spinal venous system, unlike that of the spinal arterial system, is rarely considered as a possible cause of clinical symptoms. As the imaging features of the spinal venous anatomy and its diseases are not well-known, related pathologies may be overlooked or misdiagnosed. The major noninvasive technique enabling optimal visualization of spinal venous plexuses is magnetic resonance imaging (MRI). We report MRI findings from three cases of spinal venous plexus engorgement of different etiologies that resulted in neurologic symptoms, including radiculopathy and/or back pain. These cases are discussed in the context of the relevant anatomic and pathophysiologic background.

The neurologist and the hydrops

The presence of endolymphatic hydrops has been studied in many neurological disorders. The pathophysiological mechanisms may involve CSF pressure variations, transmitted to the innear ear. This hydrops could play a role in vestibular or cochlear symptoms. For the ENT specialist, the etiological diagnosis of endolymphatic hydrops is a challenge, and neurological etiologies must be known. The treatment of these neurological causes could be effective on cochleo-vestibular symptoms. The knowledge of endolymphatic hydrops could also be a target for noninvasive tests, able to estimate CSF pressure variations. For the neurologist, this could represent a useful tool for the diagnosis and follow-up, in some of these neurological disorders, related to a CSF pressure imbalance. The purpose of this paper is to summarize literature data on endolymphatic hydrops in neurological disorders. We define some neurological conditions, for which there is a particular interest in noninvasive investigations of endolymphatic hydrops.

Incidence of postural headache after lumbar puncture requiring epidural blood patch: Effects of needle caliber; 2-year experience

PURPOSE

A common complication of lumbar puncture (LP) is postural headaches. Epidural blood patches are recommended if patients fail conservative management. Owing to a perceived increase in the number of post-lumbar puncture headaches (PLPHs) requiring epidural blood patches at a regional hospital in our network, the decision was made to switch from 20 to 22 gauge needles for routine diagnostic LPs.

MATERIALS AND METHODS

Patients presenting for LP and myelography at one network regional hospital were included in the study. The patients were contacted by nursing staff 3 days post-procedure; those patients who still had postural headaches after conservative management and received epidural blood patches were considered positive cases. In total, 292 patients were included; 134 underwent LP with 20-gauge needles (53 male, 81 female, average age 57.7) and 158 underwent LP with 22-gauge needles (79 male, 79 female, average age 54.6).

RESULTS

Of 134 patients undergoing LP with 20-gauge needles, 15 (11%) had PLPH requiring epidural blood patch (11 female, 3 male, average age 38). Of 158 patients undergoing LP with 22-gauge needles, only 5 (3%) required epidural blood patches (all female, average age 43). The difference was statistically significant (p < 0.01). Risk factors for PLPH included female gender, younger age, lower body mass index, history of prior PLPH and history of headaches.

CONCLUSION

Switching from 20-gauge to 22-gauge needles significantly decreased the incidence of PLPH requiring epidural blood patch. Narrower gauge or non-cutting needles should be considered in patients with risk factors for PLPH, allowing for CSF requirements.

Evaluation and diagnosis of spontaneous intracranial hypotension with magnetic resonance imaging

Összefoglaló. A klasszikus esetben ortosztatikus fejfájást okozó, spontán intracranialis hypotensiót az esetek túlnyomó többségében a gerinccsatornában, annak nyaki-háti átmenetében, illetve a háti szakaszán található liquorszivárgás okozza. Meglévő kötőszöveti betegség, degeneratív gerincbetegségek, illetve kisebb traumák szerepet játszhatnak a szivárgás kialakulásában. Az ortosztatikus fejfájás létrejöttében szerepet játszhat a meningealis szerkezetek, érzőidegek és hídvénák vongálódása. A klasszikus pozicionális, ortosztatikus fejfájásban szenvedő betegek körében gondolni kell a spontán intracranialis hypotensio lehetőségére, és az agykoponya, illetve a gerinc kontrasztanyaggal végzett mágneses rezonanciás vizsgálata (MRI) javasolt. A kontrasztanyaggal végzett koponya-MRI-vel klasszikus esetben diffúz, nem nodularis, intenzív, vaskos pachymeningealis kontrasztanyag-halmozás, kitágult vénássinus-rendszer, subduralis effusiók és az agytörzs caudalis diszlokációja ("slumping") látható. Fontos azonban szem előtt tartani, hogy az esetek 20%-ában ezen eltérések nem detektálhatók. Jó minőségű, randomizált, kontrollált vizsgálatok nem történtek, a kezelés hagyományokon alapul. Kezdetben általában konzervatív terápiát alkalmaznak (ágynyugalom, koffein- és folyadékbevitel), ennek hatástalansága esetén epiduralis sajátvér-injekció, epiduralis fibrinragasztó-injektálás, illetve sebészi terápia jöhet szóba. Orv Hetil. 2021; 162(7): 246-251. Summary. Spontaneous intracranial hypotension, the classic feature of which is orthostatic headache, is most commonly caused by a cerebrospinal fluid leakage at the level of the spinal canal, in most cases at the thoracic level or cervicothoracic junction. Underlying connective tissue disorders, minor trauma, degenerative spinal diseases may play a role in the development of cerebrospinal fluid leaks. Traction on pain-sensitive intracranial and meningeal structures, particularly sensory nerves and bridging veins, may play a role in the development of orthostatic headache. In the case of patients with classic orthostatic headache, the possibility of spontaneous intracranial hypotension should be considered, and if suspected, brain magnetic resonance imaging (MRI) with gadolinium and additional spine MRI are recommended. Diffuse, non-nodular, intense, thick dural enhancement, subdural effusions, engorgement of cerebral venous sinuses, sagging of the brain are typical features on brain MRI, which, however, remain normal in up to 20 percent of patients with spontaneous intracranial hypotension. Unfortunately, no randomized clinical trials have evaluated the effectiveness of the various treatment strategies and no definitive treatment protocols have been established. In clinical practice, the first-line treatment of spontaneous intracranial hypotension is conservative (bed rest, caffeine and fluid intake). If conservative therapy is not effective, epidural blood patch, epidural fibrin glue, or surgical repair should be considered. Orv Hetil. 2021; 162(7): 246-251.

The importance of repeat digital subtraction myelography in the diagnosis of cryptogenic CSF-venous fistula causing spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) is a rare disorder that occurs secondary to acquired cerebrospinal fluid (CSF) leaks in the spine. Treatment involves either an epidural blood patch or surgical ligation. Essential to the selecting the optimal management strategy is classifying the type of leak and accurate localization of its level. Hitherto, this has been achieved using conventional imaging methods such as static CT or MR myelography which are adequate for the demonstration of only high flow leaks. Digital subtraction myelography (DSM) is a novel technique which provides superior temporal and spatial resolution in the localization of more challenging slow flow leaks. However, DSM may also be initially non-diagnostic. We report a case of SIH in which repeat DSM revealed a type 3 CSF-venous fistula and demonstrate a possible mechanism of transient CSF leak block resulting in the initial false negative findings based on morphological changes in the culprit nerve sheath diverticulum-pseudomeningocoele complex. The patient underwent successful surgical ligation with clinicoradiological resolution of SIH.

Unilateral chronic subdural hematoma due to spontaneous intracranial hypotension: a report of four cases

Background: Chronic subdural hematoma (CSDH) is a common neurosurgical disease. A subset of patients with CSDH may exhibit underlying spontaneous intracranial hypotension (SIH). Bilateral CSDH has a causal relationship with SIH, but there is no known causal relationship between unilateral CSDH and SIH.Case description: We encountered four cases of unilateral CSDH due to SIH. The patients' age ranged between 44 and 64 years; there were three males and one female. All patients presented with headache as their initial symptom, and then became comatose. Computed tomography demonstrated unilateral CSDH and transtentorial herniation in all patients. Treatments were emergency epidural blood patch (EBP) and evacuation of CSDH. The site of cerebrospinal fluid leak could not be identified in three patients; therefore, EBP was performed at upper and lower spine. All patients recovered from SIH; however, one patient experienced poor outcome due to Duret hemorrhage and ischemic complications of transtentorial herniation. Cranial asymmetry was present in all four patients, and unilateral CSDH was located on the side of the most curved cranial convexity.Conclusions: Unilateral CSDH, asymmetric cranial morphology, and transtentorial herniation in relatively young patients may indicate underlying SIH.

Spontaneous Intracranial Hypotension with a Reversible Splenial Lesion after Swimming

Spontaneous intracranial hypotension (SIH) is an important cause of headache mainly associated with spinal cerebrospinal fluid leakage. We herein report the case of a 51-year-old man who developed SIH after swimming. Brain magnetic resonance imaging (MRI) showed a transient high-intensity lesion in the splenium of the corpus callosum (SCC), in addition to bilateral subdural hematomas (SDH) and pseudo-subarachnoid hemorrhage on brain computed tomography. The splenial lesion disappeared and SDH improved after an epidural blood patch. This case emphasizes that transient SCC lesions could coexist with SIH and that SIH should be considered in the differential diagnosis of SCC lesions.

Cerebral Venous Thrombosis and Subdural Collection in a Comatose Patient: Do Not Forget Intracranial Hypotension. A Case Report

BACKGROUND

The typical sign of intracranial hypotension (IH) is postural headache. However, IH can be associated with a large diversity of clinical or radiological signs leading to difficult diagnosis especially in case of coma. The association of cerebral venous thrombosis (CVT) and subdural hemorrhage is rare but should suggest the diagnosis of IH.

METHODS

Case report.

CASE DESCRIPTION

We report here a case of comatose patient due to spontaneous IH complicated by CVT and subdural hemorrhage. The correct diagnosis was delayed due to many confounding factors. IH was suspected after subdural hemorrhage recurrence and confirmed by magnetic resonance imaging (MRI). After 2 epidural patches with colloid, favorable outcome was observed.

DISCUSSION

The most common presentation of IH is postural orthostatic headaches. In the present case report, the major clinical signs were worsening of consciousness and coma, which are a rare presentation. Diagnosis of IH is based on the association of clinical history, evocative symptomatology, and cerebral imaging. CVT occurs in 1-2% of IH cases and the association between IH, CVT, and subdural hemorrhage is rare. MRI is probably the key imaging examination. In the present case, epidural patch was performed after confounding factors for coma had been treated. Benefit of anticoagulation had to be balanced in this case with potential hemorrhagic complications, especially within the brain.

CONCLUSION

Association of CVT and subdural hemorrhage should lead to suspect IH. Brain imaging can help and find specific signs of IH.