Intracranial hypotension presenting with severe encephalopathy. Case report

Spontaneous intracranial hypotension complicated by diffuse cerebral edema and episodes of severely elevated intracranial pressure: illustrative case

BACKGROUND

Spontaneous intracranial hypotension (SIH) is a well-documented condition that typically follows a defined clinical course. Previously published studies describing the pathophysiology of SIH have demonstrated extensive evidence of low intracranial pressure (ICP) driving the clinical features of the condition. Through lumbar puncture and use of intracranial monitoring devices, however, both low and normal cerebrospinal fluid (CSF) pressures have been documented. This report outlined and discussed the unique finding of elevated ICP associated with clinical features of SIH.

OBSERVATIONS

Here, the authors presented a case of a patient with spontaneous spinal CSF leak who developed tonsillar herniation, cerebral edema, and subsequent episodes of elevated ICP. Although more diverse presentations of SIH are being reported, the authors believed the case to be unique because SIH was accompanied by elevated ICP.

LESSONS

This case adds to the growing body of literature surrounding SIH by demonstrating that patients can develop elevated CSF pressures associated with acute encephalopathy.

Multilevel, ultra-large-volume epidural blood patch for the treatment of neurocognitive decline associated with spontaneous intracranial hypotension: case report

Spontaneous intracranial hypotension (SIH) is a progressive clinical syndrome characterized by orthostatic headaches, nausea, emesis, and occasionally focal neurological deficits. Rarely, SIH is associated with neurocognitive changes. An epidural blood patch (EBP) is commonly used to treat SIH when conservative measures are inadequate, although some patients require multiple EBP procedures or do not respond at all. Recently, the use of a large-volume (LV) EBP has been described to treat occult leak sites in treatment-refractory SIH. This article describes the management of a patient with profound neurocognitive decline associated with SIH, who was refractory to conservative management and multiple interventions. The authors describe the successful use of an ultra-LV-EBP of 120 ml across multiple levels, the largest volume reported in the literature, and describe the technical aspects of the procedure. This procedure has resulted in dramatic and sustained symptom resolution.

Coma

Objective

To review our experience with patients with spontaneous intracranial hypotension (SIH) and coma because, although disorders of consciousness may complicate SIH, no comprehensive study of such patients has been reported.

Methods

Using a prospectively maintained registry, we identified all patients with SIH in whom coma developed. Patients or their caregivers/families were contacted for follow-up. Patients were compared to a cohort of patients with SIH without coma.

Results

The mean age of the 12 men and 3 women with SIH was 56.2 years (range 34–72 years) at the time of onset of coma. In one-third of patients, coma developed after craniotomy for subdural hematomas or for an unrelated intracranial pathology. Imaging showed brain sagging, including bilateral temporal lobe herniation, in all 15 patients and brainstem edema in 8 patients (53%). Overall, coma was reversible in 7 of 15 patients treated with epidural blood patches, in 2 of 4 treated with percutaneous glue injections, and in 6 of 6 treated surgically. Only 1 patient had residual neurologic deficit related to coma (Glasgow Outcome Scale score 4 [moderate disability]). Compared to patients with SIH without coma (n = 568), those with coma were older, more often were male, and more often underwent surgery.

Conclusions

Coma in SIH is rare, reversible, and invariably associated with brain sagging. Coma due to SIH may be refractory to the usual percutaneous procedures, and surgical closure of the CSF leak may be required to regain consciousness.

An Objective Study of Anatomic Shifts in Intracranial Hypotension Using Four Anatomic Planes

PURPOSE

Intracranial hypotension (IH) often remains undetected using current MR diagnostic criteria. This project aims to demonstrate that central incisural herniation is highly effective in helping to make this diagnosis.

MATERIALS AND METHODS

Magnetic resonance imaging (MRI) was analyzed in 200 normal and 81 clinically known IH patients. MRI reference lines approximating the plane of the incisura, the plane of the diaphragma sella, the plane of the foramen magnum, and the plane of the visual pathway were utilized to measure the position of selected brain structures relative to these reference lines.

RESULTS

All IH patients had highly statistically significant (p < 0.0001) measurable evidence of downward central incisural herniation when compared to normal controls. The first of the important observations was a downward shift of the mammillary bodies, which shortened the midsagittal width of the interpeduncular fossa cistern. A concurrent downward shift and deformity of the tuber cinereum accompanied the mammillary body shift. The second essential observation was an abnormal clockwise rotation of the long axis of the visual pathway. A severity grading system is proposed based on the extent of these shifts as well as secondary shifts of the brain stem, splenium, and cerebellar tonsils.

CONCLUSION

This study objectively delineates the anatomic shifts of brain structures adjacent to the incisura and foramen magnum. This methodology is sufficient to recognize the features of IH and to stratify the spectrum of IH findings into a functional grading system for quantifying the results of interventional therapy.

The status of diagnosis and treatment to intracranial hypotension, including SIH

Intracranial hypotension, especially spontaneous intracranial hypotension (SIH), is a well-recognized entity associated with cerebrospinal fluid (CSF) leaks, and has being recognized better in resent years, while still woefully inadequate. An increasing number of factors including iatrogenic factors are realized to involve in development and progression of intracranial hypotension. The diagnosis remains difficult due to the various clinical manifestations, some of which are nonspecific and easily to be neglected. Multiple imaging tests are optional in CSF leakage identification while clinicians are still confronted with difficulties when making selection resulting from superiorities and disadvantages of different imaging tests. Treatments for intracranial hypotension are multifarious but evidence is anecdotal. Values of autologous epidural blood patching (EBP), the mainstay of first-line interventional treatment currently, is getting more and more regards while there are no systematic review of its efficacy and risks. Hereby, the purpose of this review was to reveal the present strategy of intracranial hypotension diagnosis and treatment by reviewing literatures, coupled with our experience in clinical work.

Epidural Anesthesia Complicated by Subdural Hygromas and a Subdural Hematoma

Inadvertent dural puncture during epidural anesthesia leads to intracranial hypotension, which if left unnoticed can cause life-threatening subdural hematomas or cerebellar tonsillar herniation. The highly variable presentation of intracranial hypotension hinders timely diagnosis and treatment. We present the case of a young laboring adult female, who developed subdural hygromas and a subdural hematoma following unintentional dural puncture during initiation of epidural anesthesia.

Intracranial hypotension: clinical presentation, imaging findings, and imaging-guided therapy

PURPOSE OF REVIEW

To illustrate clinical presentations, imaging findings, and diagnostic and therapeutic approaches associated with various conditions of intracranial hypotension.

RECENT FINDINGS

Intracranial hypotension occurs spontaneously, following (lumbar) dural puncture, accidental dural opening, or excessive surgical cerebrospinal fluid drainage. The typical clinical manifestation - orthostatic headache - may be masqueraded by atypical clinical findings, including coma, frontotemporal dementia, leptomeningeal hemosiderosis-associated symptoms, and others. MRI signs are highly specific, but the imaging strategy to search for spinal cerebrospinal fluid leaks (none, computed tomography myelography, magnetic resonance myelography with gadolinium, digital subtraction myelography) is a matter of debate. The same is true for the mode of treatment (bed rest, blind, fluoroscopy or computed tomography-guided epidural blood patching, fibrin patching, surgery).

SUMMARY

Clinical presentation as well as diagnostic and therapeutic approaches in intracranial hypotension are very heterogenous.

Reversible Coma: A Rare Presentation of Spontaneous Intracranial Hypotension

Background:

Spontaneous intracranial hypotension (SIH) is a well-recognized neurologic disorder that typically presents with orthostatic headaches, low cerebral spinal fluid pressures and distinct abnormalities on magnetic resonance imaging.

Methods:

We present a case of a rare presentation of SIH.

Results:

A 49-year-old man presented with a two week history of orthostatic headaches that rapidly progressed to encephalopathy and coma, requiring intubation. Neuroimaging revealed abnormalities typical of SIH; diffusely enhancing pachymeninges, subdural fluid collections, and descent of the brain. Treatment with an epidural blood patch reversed his coma within minutes. Following a second blood patch, the patient became asymptomatic. No cerebral spinal leak could be identified on magnetic resonance imaging or on a nuclear medicine technetium cerebral spinal fluid flow study. At six month follow-up, he remained symptom free.

Conclusion:

The mechanism of coma in SIH is presumed to be compression of the diencephalon from downward displacement of the brain. Although it is very unusual for patients with SIH to present with coma, it is important to recognize since the coma may be reversible with epidural blood patches.

Subdural hygroma accompanied by parenchymal and subarachnoid haemorrhage after epidural analgesia in an obstetric patient

BACKGROUND

Anaesthetists need to know the different causes of persistent headache or a change in level of consciousness following epidural analgesia for labour. Failure to recognise these neurological complications can lead to delayed diagnoses, with subsequent serious implications.

METHODS

We present a patient who was re-admitted for postural headache resulting from an unrecognised dural puncture during an epidural for pain relief while in labour. During the interview, the patient confirmed drug use (cocaine), so she was evaluated by a psychiatrist with possible post-partum psychosis or drug withdrawal syndrome. Afterwards, the patient deteriorated neurologically, showing impaired consciousness and seizures.

RESULTS

The cranial computed tomography showed bilateral frontoparietal subdural collections with intraparenchymal and subarachnoid haemorrhaging. She improved by burr hole drainage of subdural hygroma and a blood patch.

CONCLUSIONS

Neurological signs should alert the clinician to the possibility of subdural collection and other possible complications such as sinking of the brain in order not to delay the request for imaging tests for diagnoses and effective treatments.

Large-volume blood patch to multiple sites in the epidural space through a single-catheter access site for treatment of spontaneous intracranial hypotension

BACKGROUND AND PURPOSE

Spontaneous intracranial hypotension can be a therapeutic challenge to the treating physician. In this study, we present our experience with the administration of a large-volume blood patch to multiple sites in the epidural space through a single-catheter access site.

MATERIALS AND METHODS

A retrospective review was conducted of patients with spontaneous intracranial hypotension who underwent a large-volume blood patch to multiple sites in the epidural space through a single-catheter access site from 2010 to 2012. Patient demographic data, clinical charts, indications for treatment, radiographic images, procedure notes, and postprocedure hospital course were reviewed.

RESULTS

Overall, 9 patients were identified who underwent 20 blood patch procedures. Patients were selected to undergo the large-volume procedure either because they had a failed site-directed epidural blood patch or if imaging demonstrated multiple possible leak sites. There were 6 women and 3 men, with an average age of 33.5 years. The mean volume of blood injected per procedure was 54.1 mL (median=55 mL; range=38-70 mL). All patients had an orthostatic headache as one of their presenting symptoms; 22% also presented with neurocognitive decline and behavioral changes; 89% of patients had improvement or resolution of their symptoms; and 80% of patients who had a previously failed site-directed epidural blood or fibrin glue patch improved with a large volume catheter-directed blood patch.

CONCLUSIONS

Our experience supports the use of a large-volume blood patch to multiple sites in the epidural space through a single-catheter access site for the treatment of spontaneous intracranial hypotension. Additionally, our results indicate a role for this procedure in refractory cases of spontaneous intracranial hypotension.

Movement disorders associated with spontaneous CSF leaks: A case series

Importance and Objective

Headache is the most common symptom in spontaneous CSF leaks, frequently associated with additional manifestations. Herein, attention is drawn to movement disorder as a notable manifestation of spontaneous CSF leaks.

Design

Four women and one man (ages 51–78 years) with spontaneous CSF leaks and movement disorders were evaluated clinically and by pertinent neuroimaging studies with follow-up of one to seven years (mean 3.2 years).

Results

The movement disorder consisted of choreiform movements in two patients, torticollis in one, mixed tremor in one, and parkinsonism in one. All except the last patient had headaches (orthostatic in one, Valsalva maneuver-induced in one, both orthostatic and Valsalva-induced in two, lingering low-grade headache in one). Diffuse pachymeningeal enhancement and sinking of the brain was noted in all. CT-myelography showed definite CSF leak in three and equivocal leak in one, while no leak could be located in the fifth patient. Two patients improved over time with complete resolution of the movement disorder. One responded to epidural blood patch with complete resolution of his choreiform movements. Two patients required surgery and epidural blood patches. Results were drastic but nondurable in one, while complete recovery was achieved in the other.

Conclusion

Movement disorders are uncommon in spontaneous CSF leaks but occasionally can be one of the major components of the clinical presentation.

Management of patients with spontaneous intracranial hypotension causing altered level of consciousness: report of two cases and review of literature

BACKGROUND

Decreased level of consciousness is a rare neurological manifestation of spontaneous intracranial hypotension (SIH), which typically presents with orthostatic headache. The optimal management of this uncommon presentation remains uncertain.

METHODS

We analyzed the presentation, management and outcome of two patients in our institution and reviewed 22 patients reported in the literature with SIH and decreased level of consciousness, defined as any decrease in the patient's Glasgow Coma Scale score.

RESULTS

There were 20 male and four female patients (M:F ratio of 5:1) with an average age of 52 years (range 37 to 68 years). There was a variable time interval of up to many months between the initial presentation of SIH and changes in the level of consciousness. An epidural autologous blood patch was eventually successful in 79% of the patients, although up to three trials were necessary in seven of these patients. Intrathecal saline infusion used as a temporizing measure resulted in excellent response within hours in five out of six patients who received this treatment. Drainage of the subdural collection either did not result in any sustained improvement or resulted in clinical deterioration in 12 out of 12 patients who received this treatment.

CONCLUSIONS

In the absence of a clinical trial because of the rarity of this entity, the treatment of SIH complicated by decreased level of consciousness remained controversial in the past. However, current collective experience supports early treatment of patients with SIH and decreased level of consciousness with one or more epidural blood patches. Fibrin glue and surgical duroplasty are the next steps in the management of patients in whom epidural blood patches fail. Drainage of the subdural collections may be detrimental.

Intracranial hypotension producing reversible coma: a systematic review, including three new cases

Intracranial hypotension is a disorder of CSF hypovolemia due to iatrogenic or spontaneous spinal CSF leakage. Rarely, positional headaches may progress to coma, with frequent misdiagnosis. The authors review reported cases of verified intracranial hypotension-associated coma, including 3 previously unpublished cases, totaling 29. Most patients presented with headache prior to neurological deterioration, with positional symptoms elicited in almost half. Eight patients had recently undergone a spinal procedure such as lumbar drainage. Diagnostic workup almost always began with a head CT scan. Subdural collections were present in 86%; however, intracranial hypotension was frequently unrecognized as the underlying cause. Twelve patients underwent one or more procedures to evacuate the collections, sometimes with transiently improved mental status. However, no patient experienced lasting neurological improvement after subdural fluid evacuation alone, and some deteriorated further. Intracranial hypotension was diagnosed in most patients via MRI studies, which were often obtained due to failure to improve after subdural hematoma (SDH) evacuation. Once the diagnosis of intracranial hypotension was made, placement of epidural blood patches was curative in 85% of patients. Twenty-seven patients (93%) experienced favorable outcomes after diagnosis and treatment; 1 patient died, and 1 patient had a morbid outcome secondary to duret hemorrhages. The literature review revealed that numerous additional patients with clinical histories consistent with intracranial hypotension but no radiological confirmation developed SDH following a spinal procedure. Several such patients experienced poor outcomes, and there were multiple deaths. To facilitate recognition of this treatable but potentially life-threatening condition, the authors propose criteria that should prompt intracranial hypotension workup in the comatose patient and present a stepwise management algorithm to guide the appropriate diagnosis and treatment of these patients.

Spontaneous intracranial hypotension syndrome may mimic aseptic meningitis

BACKGROUND

Spontaneous intracranial hypotension (SIH) is recognized with increasing frequency. A throbbing headache occurring or worsening in the upright position and improving after lying down, a so-called 'orthostatic headache', low cerebrospinal fluid (CSF) pressure, and diffuse pachymeningeal enhancement on brain magnetic resonance imaging (MRI) are the major features of the classic syndrome. These patients, who are admitted with fever, headache, and CSF findings revealing lymphocytic pleocytosis, elevated protein concentration, normal glucose levels, and negative culture results, are prone to be misdiagnosed with aseptic meningitis. The aims of this single-centre retrospective study were to determine the epidemiological, clinical, laboratory, and radiological features of patients initially evaluated as having aseptic meningitis but subsequently diagnosed with SIH, and to touch upon the key points of the differential diagnosis in daily infectious diseases practice.

METHODS

Patients referred to Cerrahpasa Medical School with a presumed diagnosis of aseptic meningitis or viral meningitis between 1 January 2006 and 1 January 2011 were reviewed. Epidemiological, clinical, laboratory, radiological, and follow-up data obtained from the hospital database were processed. Patients confirmed to have SIH syndrome were included for evaluation.

RESULTS

Eleven cases of SIH syndrome were diagnosed during the study period (8 male and 3 female, median age 30 y, range 21-44 y). All had headache, hearing changes, and nausea. Vomiting (10/11) and posterior neck pain (9/11) were also frequent. Seven had fever and 5 had a stiff neck. Four cases had lymphocytic pleocytosis, 4 cases had elevated CSF protein concentrations (> 1.5 times the upper limit of normal), and 2 cases had slightly lower CSF glucose levels. Polymerase chain reaction (PCR) analyses of the CSF for Mycobacterium tuberculosis complex, herpes simplex viruses 1 and 2, and enteroviruses were negative in all cases. MRI of the 11 cases revealed signs of spontaneous CSF leaks with diffuse pachymeningeal gadolinium enhancement (11/11), sagging of the brain (9/11), enlargement of the pituitary (6/11), engorgement of the venous structures (5/11), and subdural fluid collections (2/11). CSF leaks were demonstrated by intrathecal magnetic resonance or computed tomography myelography at different levels along the thoracic spine (7/11), cervico-thoracic junction (2/11), and thoraco-lumbar junction (2/11). Autologous blood injection into the spinal epidural space ('blood patch') was performed for treatment. Strict bed rest followed, and all patients recovered fully within a week; no recurrence or complication was observed during the follow-up periods, which ranged from 6 months to 5 y.

CONCLUSIONS

Findings of fever, headache, and meningeal irritation are generally accepted as the clinical features of meningitis. When CSF findings are not characteristically compatible with bacterial meningitis and particularly when the headache is orthostatic in nature, SIH should also be included in the differential diagnosis. MRI findings are characteristic and clearly contribute to the differential diagnosis between viral meningitis and SIH.

Frontotemporal brain sagging syndrome: an SIH-like presentation mimicking FTD

BACKGROUND

Behavioral variant frontotemporal dementia (bvFTD) is a relatively well-defined clinical syndrome. It is associated with frontal and temporal lobe structural/metabolic changes and pathologic findings of a neurodegenerative disease. We have been evaluating patients with clinical and imaging features partially consistent with bvFTD but with evidence also suggestive of brain sagging, which we refer to as frontotemporal brain sagging syndrome (FBSS).

METHODS

Retrospective medical chart review to identify all patients seen at our institution between 1996 and 2010, who had a clinical diagnosis of FTD and imaging evidence of brain sag.

RESULTS

Eight patients, 7 male and 1 female, were diagnosed with FBSS. The median age at symptom onset was 53 years. All patients had insidious onset and slow progression of behavioral and cognitive dysfunction accompanied by daytime somnolence and headache. Of the 5 patients with functional imaging, all showed evidence of hypometabolism of the frontotemporal regions. On brain MRI, all patients had evidence of brain sagging with distortion of the brainstem; 3 patients had diffuse pachymeningeal enhancement. CSF opening pressure was varied and CSF protein was mildly elevated. A definite site of CSF leak was not identified by myelogram or cisternography, except in one patient with a site highly suggestive of leak who subsequently underwent surgery confirming a CSF leak. In 2 patients with a neuropathologic examination, there was no evidence of a neurodegenerative disease.

CONCLUSIONS

This case series demonstrates that FBSS may mimic typical bvFTD but should be recognized as an unusual presentation that is potentially treatable.

Postsurgical intracranial hypotension: diagnostic and prognostic imaging findings

BACKGROUND AND PURPOSE

CSF loss with consecutive intracranial hypotension has been discussed as a possible pathogenetic mechanism in poor clinical outcome after uneventful neurosurgery and appears to be correlated to specific imaging findings. The purpose of this study was to describe the clinical and imaging findings of symptomatic intracranial hypotension likely induced by wound suction drainage.

MATERIALS AND METHODS

This is a review of previously published cases of patients in whom this condition developed after uneventful intracranial surgery. We performed an analysis of 3 more cases, of which 2 occurred after spinal surgery with accidental dural opening.

RESULTS

Sixteen patients who remained unconscious or did not become fully responsive after surgery showed symmetric bilateral thalamic/basal ganglia signal intensity changes on CT and MR imaging studies. Of these 16 patients, 4 died and 2 also had brain stem signal intensity changes. All patients had rapid and distinct intraoperative and postoperative CSF loss documented on CT and/or MR imaging studies by a transient increase of the sag ratio, defined as maximal anteroposterior midbrain diameter by maximal bipeduncular diameter.

CONCLUSIONS

The clinical course and typical MR imaging findings characterize the disease entity postsurgical intracranial hypotension. These findings also underline the potential danger of wound suction drainage in the case of possible CSF loss.

Spontaneous Spinal Cerebrospinal Fluid Leaks

Spontaneous intracranial hypotension is an uncommon but not rare cause of new onset daily persistent headaches. A delay in diagnosis is the norm. Women are affected more commonly than men and most are in the fifth or sixth decade of life. The underlying cause is a spontaneous spinal cerebrospinal fluid (CSF) leak. Typically the headache is orthostatic in nature but other headache patterns occur as well. Associated symptoms are common and include neck pain, a change in hearing, diplopia, facial numbness, cognitive abnormalities and even coma. Typical imaging findings consist of subdural fluid collections, pachymeningeal enhancement, pituitary hyperaemia and brain sagging, but magnetic resonance imaging may be normal. Myelography is the study of choice to identify the CSF leak but is not always necessary to make the diagnosis. Treatment consists of bedrest, abdominal binder, epidural blood patching, percutaneous fibrin glue injection or surgical CSF leak repair. Outcomes have been poorly studied.

Emergent image-guided treatment of a large CSF leak to reverse "in-extremis" signs of intracranial hypotension

We report the use of an emergent, targeted fibrin spinal epidural blood patch with subarachnoid saline infusion to rapidly reverse "in-extremis" clinical and imaging signs of posterior-fossa coning brought about by acute-on-chronic intracranial hypotension, itself consequent to a cervicothoracic CSF leak. Treatment resulted in a dramatic recovery and eventual discharge with return to normal lifestyle and occupation. The clinical and imaging danger signs are reviewed; fibrin patch technique and potential pitfalls in postprocedure management are analyzed.

Spontaneous intracranial hypotension with deep brain swelling

Spontaneous intracranial hypotension (SIH) is caused by leakage of CSF, and characterized on MRI by brain sagging, dilatation of veins and dural sinuses, subdural fluid collections and post-contrast enhancement of the thickened dura. A few cases may present a very severe brain sagging through the tentorial notch and swelling of the diencephalic-mesencephalic structures, with absent or scarce subdural collections and post-contrast enhancement. These patients may have surprisingly few neurological signs or may become drowsy and even lapse into coma due to central herniation. We retrospectively examined the diffusion studies obtained in five patients with these MRI findings, in seven patients with SIH without brain swellings and in ten controls. Mean diffusivity was increased in SIH patients with brain swelling in areas draining into the deep venous system, collected by the vein of Galen (vG) and straight sinus (SS). In the hypothesis that central herniation might be responsible for venous stagnation because of impaired flow of the vG into the SS, the vG/SS angle was measured. The angle formed by the vG entering the SS was not altered in patients without brain swelling (group E, 67.8 degrees +/- 10.3 degrees, mean +/- SD, range 49-80 degrees) when compared to controls (group C, 73.3 degrees +/- 12.3 degrees, mean +/- SD, range 56-95 degrees). It was, however, grossly decreased in patients with brain swelling (group D, 40.7 degrees +/- 12.8 degrees, mean +/- SD, range 22-61 degrees), P < 0.001 for comparison with groups E and C. As suggested by previous studies, downward stretching of the vG and narrowing of the vG/SS angle may cause a functional stenosis at the vG-SS junction. We suggest that in the application of the Monro-Kellie doctrine to SIH, the brain volume should not be considered as always invariable.

Short- and Long-Term Outcomes of Spontaneous CSF Hypovolemia

We undertook a study to investigate the short- and long-term outcomes of spontaneous CSF hypovolemia. Fifty-three consecutive patients with spontaneous CSF hypovolemia were included. Short-term outcome was assessed 4 weeks after the treatment in all patients. Long-term outcome after a mean follow-up of 61 months (range, 13-101 months) was evaluated in 26 patients. There were 18 men and 35 women (66%) with an age range of 22-64 years (mean 37 +/- 9.5). In assessing the short-term outcome of CSF hypovolemia, we found that complete headache relief was significantly higher in 43 patients who received epidural blood patch (EBP) than in 10 patients treated with supportive measures (p < 0.05). After a mean follow-up of 61 months, 25 (96%) of the 26 patients evaluated for long-term outcome had complete headache relief. These results suggest that EBP is safe and effective, resulting in excellent short- and long-term outcomes of CSF hypovolemia.

Spectrum of subdural fluid collections in spontaneous intracranial hypotension

Object. Spontaneous intracranial hypotension is a noteworthy but commonly misdiagnosed cause of new daily persistent headaches. Subdural fluid collections are frequent radiographic findings, but they can be interpreted as primary rather than secondary pathological entities, and uncertainties exist regarding their optimal management. The authors therefore reviewed their experience with subdural fluid collections in 40 consecutive patients with spontaneous spinal cerebrospinal fluid (CSF) leaks and intracranial hypotension.

Methods. The mean age of the 26 female and 14 male patients was 43 years (range 13–72 years). Subdural fluid collections were present in 20 patients (50%); 12 of these patients (60%) had subdural hygromas alone, and eight (40%) had subacute to chronic subdural hematomas (SDHs) associated with significant mass effect. The subdural hygromas resolved within several days to weeks following treatment of the underlying CSF leak. Three patients with SDHs underwent evacuation of the hematoma prior to the establishment of the diagnosis of spontaneous intracranial hypotension, but the SDHs did not resolve until the underlying spinal CSF leak was treated. In the remaining five patients, the CSF leak was treated primarily and the SDHs resolved over a 1- to 3-month period without the need for evacuation.

Conclusions. Subdural fluid collections are common in spontaneous intracranial hypotension, varying in appearance from thin subdural hygromas to large SDHs associated with significant mass effect. These collections can be safely managed by directing treatment at the underlying CSF leak without the need for hematoma evacuation.

Spontaneous intracranial hypotension associated with transdural thoracic osteophyte reversed by primary dural repair

✓ Spontaneous intracranial hypotension (SIH) is an increasingly recognized syndrome associated with a specific set of clinical and imaging findings; however, determining the site of spinal cerebrospinal fluid (CSF) leakage in these patients is often difficult, and indications for surgical intervention need to be better defined. The authors report on a 55-year-old woman who presented with posture-related headache, disorientation, and memory impairment. Imaging features were consistent with SIH. Computerized tomography myelography demonstrated a large T2–3 anterior transdural osteophyte associated with a CSF fistula. After an unsuccessful trial of conservative therapy, the patient underwent median sternotomy, T2–3 discectomy and removal of osteophyte, which allowed adequate exposure for primary dural repair. Postoperatively, there was immediate and prolonged resolution of all of her symptoms. This case of SIH was caused by transdural penetration by an anterior osteophyte and CSF leakage in the upper thoracic spine, which was treated effectively by anterior exposure and primary dural repair. Aggressive surgical intervention may be required to treat upper thoracic CSF leaks refractory to other measures.

Spontaneous Intracranial Hypotension Presenting as Mental Deterioration

A 55-year-old woman had new onset of postural headache followed by change of mental status 3 weeks later. Magnetic resonance imaging (MRI) of the brain and whole spine showed typical spontaneous intracranial hypotension (SIH) findings, bilateral subdural hematoma, and cerebrospinal fluid leakage over the T7-T9. Her headache and mentality improved after epidural blood patches. Early recognition and correct diagnosis are crucial for successful treatment in patients with SIH presenting with mental confusion.

[Extraordinary high cerebrospinal fluid protein in two cases of intracranial hypotension syndrome]

Intracranial hypotension is a rare cause of chronic headache. Although there is still debate about the aetiology, it is believed that the syndrome is caused by low cerebrospinal fluid volumes due to dural leakage. Such leakages can occur spontaneously after lumbar puncture or surgical or traumatic opening of the dura. In magnetic resonance contrast imaging, diffuse meningeal enhancement can be seen; usually the pressure at the cerebrospinal opening is lower than normal. Sometimes a pleocytosis and, in most cases, increased protein content can be identified in the CSF. These protein levels most frequently range between 0.5 g/l and 2 g/l. Here we describe two patients with typical clinical signs and neuroradiological alterations of intracranial hypotension syndrome but with extraordinarily high CSF protein levels (8.3 g/l and 9.63 g/l). On the basis of these findings, the putative causes of elevated CSF protein contents are discussed.

Spontaneous low cerebrospinal pressure/volume headaches

The majority, if not all, of the cases of spontaneous intracranial hypotension result from spontaneous cerebrospinal fluid (CSF) leaks. The disorder has a broad clinical and imaging spectrum with substantial variability in clinical and imaging features, in CSF findings, and in response to treatment. Headache is the most common symptom and is typically orthostatic, but with chronicity the orthostatic features may blur into a chronic, lingering headache. Other clinical features include neck pain, nausea, emesis, interscapular pain, diplopia, dizziness, change in hearing, visual blurring, radicular upper extremity symptoms, and a variety of other, but much less common, manifestations. The most common imaging feature is diffuse pachymeningeal gadolinium enhancement. Other manifestations include imaging evidence of sinking of the brain, subdural fluid collections, enlargement of the pituitary, engorgement of venous sinuses, and engorgement of epidural venous plexus. CSF opening pressure is typically low and CSF analysis may be normal or show increased protein concentration and a primarily lymphocytic pleocytosis. No longer can the entity be simply equated with post-spinal puncture headaches. The pathogenetic core and the independent variable is decrease in CSF volume, whereas clinical imaging and CSF findings, including CSF opening pressures, are all variables dependent on the loss of CSF volume. Many patients respond well to treatment, but some present stubborn therapeutic challenges. A subgroup of patients with orthostatic headaches is gradually recognized who have disorders other than CSF leaks.

Low cerebrospinal fluid pressure syndromes

Only 12 years ago the first report on pachymeningeal gadolinium enhancement in low-pressure headaches appeared in the literature. In this short interval the enormous impact of MRI on so-called "spontaneous intracranial hypotension" and "low-pressure head-aches" has become obvious. A much broader clinical and imaging spectrum of the disease is now recognized and a substantially larger number of patients is diagnosed. In the past decade there has been remarkable progress in understanding this disorder and its associated cerebrospinal fluid (CSF) dynamics. Some of the older concepts or presumptions have been challenged while novel observations continue to appear in the literature. We are still in the learning phase.

Pseudohypoxic Brain Swelling: A Newly Defined Complication after Uneventful Brain Surgery, Probably Related to Suction Drainage

OBJECTIVE

This is the first description of a severe and sometimes fatal complication after uneventful intracranial surgery. The clinical presentation and imaging features mimic those of global cerebral hypoxia. Extensive investigations were performed to discover the pathogenesis.

METHODS

Seventeen cases of pseudohypoxic brain swelling (PHBS) were collected from our institution and from various other neurosurgical departments and were studied for common features. PHBS can occur in a mild, moderate, or severe degree. It is characterized by a very early postoperative onset of clinical deterioration (clouded or lost consciousness and pupillary abnormalities), in association with typical bilateral computed tomographic or magnetic resonance imaging changes (hypodensities or altered intensities in the basal ganglia and/or thalamus). The following variables were considered: age, primary pathological lesion and intracranial location, previous cranial surgery, anesthetic risk, type of anesthesia, approach and duration of surgery, intraoperative observations, technical monitoring results, and blood gas analyses. The results of postoperative computed tomography and various other imaging studies, intracranial pressure measurements, transcranial Doppler sonography, toxicological analyses, brain and muscle biopsies, and autopsies were also considered in the investigation. Several countermeasures were instituted and evaluated.

RESULTS

Anoxemic and ischemic hypoxia was excluded as a cause of PHBS. No evidence was found for inhibition of the respiratory chain, mitochondriopathy, poisoning, or adverse effects of drugs.

CONCLUSION

Indications of intracranial hypotension, induced by suction drainage, being the main pathomechanism of PHBS are discussed. A serious warning is issued regarding the use of suction drainage after intracranial surgery.

Subdural haematoma: a potentially serious consequence of spontaneous intracranial hypotension

BACKGROUND

Spontaneous intracranial hypotension (SIH) is characterised by postural headache and low opening pressure at lumbar puncture without obvious cause. Cranial magnetic resonance imaging often shows small subdural collections without mass effect, dural enhancement, venous sinus dilatation, or downward displacement of the brain. The condition is thought to be benign.

OBJECTIVES

To evaluate the incidence of subdural haematoma as a serious complication of SIH.

METHODS

A prospective survey of all cases of SIH presenting to a large neuroscience unit over a two year period.

RESULTS

Nine cases of SIH were seen. Four of these were complicated by acute clinical deterioration with reduced conscious level because of large subdural haematomas requiring urgent neurosurgical drainage.

CONCLUSIONS

SIH should not be considered a benign condition. Acute deterioration of patients' clinical status may occur secondary to large subdural haematomas, requiring urgent neurosurgical intervention.

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

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.

Multi-level Disruption of the Spinal Nerve Root Sleeves in Spontaneous Spinal Cerebrospinal Fluid Leakage. Two Case Reports

A 37-year-old male and an 18-year-old male presented with spontaneous spinal cerebrospinal fluid (CSF) leakage from multiple nerve root sleeves. Both patients suffered abrupt onset of intense headache followed by nausea, dizziness, and one patient with and one without positional headache. Radioisotope spinal cisternography of both patients revealed that the CSF leaks were not localized in a special zone but distributed to multiple spinal nerve root sleeves. Magnetic resonance (MR) myelography suggested that the spinal CSF column was fully expanded to the root sleeves. The extraspinal nerve bundles demonstrated numerous high intensity spots. Both patients were treated conservatively, and their symptoms resolved within one month. Repeat radioisotope cisternography and MR myelography confirmed the spine was normal after recovery. We suggest that spreading disruption of the arachnoid membrane occurs at the nerve root sleeves due to CSF overflow into the spinal canal.

Spontaneous intracranial hypotension associated with bilateral chronic subdural hematomas--case report

A 34-year-old female presented with spontaneous intracranial hypotension (SIH) manifesting as severe postural headache and meningism. Magnetic resonance (MR) imaging with gadolinium showed diffuse pachymeningeal enhancement. She developed bilateral chronic subdural hematomas 4 weeks after the onset of the symptoms. MR imaging showed descent of the midline structures of the brain. The bilateral chronic subdural hematomas were surgically drained, with no remarkable pressure. Postoperative MR imaging showed complete resolution of the pachymeningeal enhancement and relevation of the midline structures of the brain. SIH is an uncommon and probably unrecognized condition because of the usually benign course. However, this case emphasizes that SIH is not entirely benign. SIH should be considered if there is no identifiable risk for intracranial hemorrhage, particularly in young patients. Neurosurgical intervention for the treatment of the underlying cerebrospinal fluid leak may be required if SIH persists.