INTRACRANIAL HYPOTENSION SECONDARY TO LUMBAR NERVE SLEEVE TEAR

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.

Spontaneous intracranial hypotension secondary to congenital spinal dural ectasia and genetic mosaicism for tetrasomy 10p: illustrative case

BACKGROUND

Spontaneous intracranial hypotension has historically been a poorly understood pathology that is often unrecognized and undertreated. Even more rarely has it been described in pediatric patients with an otherwise benign past medical history.

OBSERVATIONS

Herein the authors describe one of the youngest patients ever reported, a 2-year-old girl who developed severe headaches, nausea, and vomiting and experienced headache relief after lying down. Imaging revealed tonsillar herniation 14 mm below the foramen magnum, presumed to be a Chiari malformation, along with extensive dural cysts starting from thoracic level T2 down to the sacrum. She was found to have streaky skin pigmentary variation starting from the trunk down to her feet. Genetic analysis of skin biopsies revealed mosaicism for an isodicentric marker chromosome (10p15.3–10q11.2 tetrasomy) in 27%–50% of cells. After undergoing a suboccipital and cervical decompression at an outside institution, she continued to be symptomatic. She was referred to the authors’ hospital, where she was diagnosed with spontaneous intracranial hypotension.

LESSONS

After receiving a series of epidural blood patches, the patient experienced almost complete relief of her symptoms. To the authors’ knowledge, this is the first time this chromosomal anomaly has ever been reported in a living child, and this may represent a new genetic association with dural ectasia.

Symptomatic intraspinal lumbosacral pseudomeningocele, a late consequence of root avulsion injury secondary to a gunshot wound

Background

Traumatic pseudomeningocele are usually a late consequence of cervical root avulsion injury and its occurrence in lumbosacral region is rare. This pathology is mostly due to violent blunt traumatic events and usually develops outside of the spinal canal. Occasionally, a pseudomeningocele may grow inside of the spinal canal causing delayed neurological deficit due to compromise of the adjacent neural structures.

Case description

Evaluation of a delayed left lower extremity weakness in a young man with a history of a gunshot wound injury revealed an extradural pseudomeningocele arising from an S1 root avulsion injury with compressive effect on the adjacent L5 root

Outcome

Excision of the cyst wall and reinstitution of the nerve root sheath resulted in an uneventful recovery

Conclusion

To the best of our knowledge, the presented case with traumatic pseudomeningocele is the first example secondary to high velocity bullet injury. Furthermore, management of traumatic intraspinal pseudomeningocele subsequent to root avulsion injury has not been paid sufficient attention. In this paper, the surgical strategy will be discussed in detail.

Spontaneous intracranial hypotension: two steroid-responsive cases

Purpose

Spontaneous intracranial hypotension (SIH) is characterised by orthostatic headache, low cerebrospinal fluid pressure and diffuse pachymeningeal enhancement after intravenous gadolinium contrast administration. Magnetic resonance imaging (MRI) often plays a crucial role for correct diagnosis.

Case description

We described two similar cases of SIH, whose clinical and imaging features are typical for this pathology. At MRI brain scan, both patients showed diffuse and intense pachymeningeal enhancement and moderate venous distension and epidural vein engorgement. The two patients were treated with bed rest and oral steroid therapy, with complete and long-lasting symptomatic relief.

Conclusions

Orthostatic nature of headache is the most indicative clinical feature suggesting SIH; contrast-enhanced MRI provides definite imaging diagnostic findings. Conservative treatment coupled to steroid therapy is often sufficient to obtain complete disappearance of symptoms.

Impaired cerebrospinal fluid pressure

Abnormalities of cerebrospinal fluid (CSF) pressure are relatively common and may lead to a variety of symptoms, with headache usually being the most prominent one. The clinical presentation of alterations in CSF pressure may vary significantly and show a striking similitude to several primary headache syndromes. While an increase in CSF pressure may be of primary or secondary origin, a pathologic decrease of CSF pressure is usually the result of a meningeal rupture with a resulting leakage of CSF. The pathophysiologic mechanisms of idiopathic intracranial hypertension (IIH) remain largely unknown. However recent evidence indicates that an abnormality in CSF outflow and absorption is likely to play a significant role. Treatment usually consists of a combination of weight loss and a pharmacologic approach using carbonic anhydrase inhibitors. Recent results of the first randomized, double-blind, placebo-controlled trial (RCT) with acetazolamide proved its efficacy in reducing headache and visual disturbances. Clinical evidence suggests efficacy for topiramate and furosemide but no RCT has been conducted to date to confirm these results. In contrast to IIH, spontaneous intracranial hypotension frequently remits spontaneously without specific treatment. If necessary, treatment options range from conservative methods to epidural blood or fibrin sealant patches and surgical interventions.

Chiari-like displacement due to spontaneous intracranial hypotension in an adolescent: Successful treatment by epidural blood patch

BACKGROUND

Spontaneous intracranial hypotension is a rarely diagnosed cause of headache, especially in children and adolescents. It is due to cerebrospinal fluid (CSF) leakage via spinal fistulae occurring without major trauma.

CASE PRESENTATION

An adolescent patient presented with a 3-month history of strictly postural headache. Cranial magnetic resonance imaging (MRI) showed pronounced Chiari-like prolapse of the cerebellar tonsils, narrow ventricles and enlarged cerebral veins. On spinal MRI, myelographic sequences revealed a large collection of CSF around the first sacral roots. CT myelography proved extensive spinal CSF leakage. Hence, we applied epidural patches at multiple levels. Afterwards, symptoms and radiologic findings, including Chiari-like displacement, completely resolved.

CONCLUSION

A Chiari-like descent of the cerebellar tonsils alone does not secure the diagnosis of a Chiari I malformation. Especially if other findings indicate spinal CSF leakage, a systematic work-up should be initiated. In most cases, interventional techniques seal the leak successfully, resulting in a favorable outcome.

Spontaneous cerebrospinal fluid leak from an anomalous thoracic nerve root: case report

The authors report the case of a 28-year-old woman with a spontaneous cerebrospinal fluid leak from the sleeve of a redundant thoracic nerve root. She presented with postural headaches and orthostatic symptoms indicative of intracranial hypotension. CT myelography revealed that the lesion was located at the T-11 nerve root. After failure of conservative management, including blood patches and thrombin glue injections, the patient was successfully treated with surgical decompression and ligation of the duplicate nerve, resulting in full resolution of her orthostatic symptoms.

Extended Pneumocephalus after Drainage of Chronic Subdural Hematoma Associated with Intracranial Hypotension : Case Report with Pathophysiologic Consideration

Chronic subdural hematoma (SDH) is a well-known disease entity and is traditionally managed with surgery. However, when associated with spontaneous intracranial hypotension (SIH), the treatment strategy ought to be modified, as classical treatment could lead to unwanted consequences. A 59-year-old man presented with a case of SIH that manifested as a bilateral chronic SDH. He developed fatal extensive pneumocephalus and SDH re-accumulation as a complication of burr-hole drainage. Despite application of an epidural blood patch, the spinal cerebrospinal fluid leak continued, which required open spinal surgery. Chronic SDH management should not be overlooked, especially if the exact cause has not been determined. When chronic SDH assumed to be associated with SIH, the neurosurgeon should determine the exact cause of SIH in order to effectively correct the cause.

Cervical epidural blood patch--A literature review

OBJECTIVE

Epidural blood patches (EBP) are rarely performed at the cervical levels, primarily due to fear of neurological complications such as spinal cord compression. We reviewed the literature to provide an evidence-based review of performance of cervical EBPs, with a specific focus on indication, technique, safety, and efficacy.

DESIGN

A comprehensive electronic literature search was done to include studies that reported on performance of cervical EBPs in patients with CSF leak at the cervical level. Data regarding indication, level of CSF leak, level of cervical EBP, volume of blood used, efficacy, and complications were collected.

RESULTS

A total of 15 studies, reporting on 19 patients were included. All patients presented with a headache that increased in the standing position, and improved in the supine position. All patients were identified to have a CSF leak at the cervical level. Eight patients first underwent a lumbar EBP, without complete, long-term relief. All these patients, along with 11 patients who did not undergo a lumbar EPB prior to cervical EBP, reported complete, long-term pain relief. EBPs were mostly done in the prone position, using imaging guidance. An average of 5-8 mL of autologous blood was injected in the epidural space. No major neurological complications were reported in any patient.

CONCLUSION

The review suggests that cervical EBP can be performed for cervical CSF leaks associated with positional headache without a significant risk of serious adverse events.

CLASSIFICATION OF EVIDENCE

Our review provides Class II level of evidence that cervical EBPs are safe and effective in reliving positional headache due to CSF leak.

Posterior thoracic laminoplasty with dorsal, intradural identification of ventral defect and transdural discectomy for a spontaneous cerebrospinal fluid leak: case report

Spontaneous intracranial hypotension (SIH) has been increasingly reported in the literature concomitant with the improved sensitivity of imaging modalities. Although typically associated with meningeal weakening, a handful of cases of SIH secondary to thoracic disc osteophytes have been reported. Five of 7 reported cases were treated with epidural blood patch (EBP) alone while 2 required surgical management. There is no standard operative approach; both anterior and posterolateral approaches can be cumbersome and associated with morbidity, particularly in young, healthy patients. The authors report a case of SIH in which a ventral dural tear secondary to a calcified thoracic disc was repaired via posterior thoracic laminoplasty with dorsal durotomy and intradural exposure of the ventral defect with transdural discectomy followed by primary closure.

A 34-year-old man presented with low-pressure headaches following axial load injury from a ski accident 5 years earlier. The patient's symptoms were refractory to a trial of conservative treatment and EBP, and he developed bilateral upper-extremity paresthesias. MRI of the spine demonstrated an extrathecal collection spanning the thoracic spine, and dynamic CT myelography identified contrast extravasation adjacent to a calcified paramedian disc at T9–10. The patient underwent posterior laminoplasty with neuromonitoring. A ventral dural defect was visualized via a dorsal durotomy, the penetrating disc osteophyte was removed transdurally, and the ventral and dorsal dura maters were closed primarily. Both somatosensory and motor evoked potentials were unchanged during surgery. The patient has remained asymptomatic more than 10 months postoperatively and he has resumed work as a surgeon.

Cases of SIH secondary to a calcified thoracic disc are rare with little precedent as to optimal surgical intervention. This case illustrates the potential usefulness of posterior laminectomy in nonmyelopathic patients in whom there is no evidence of canal compromise and for whom neuromonitoring is available. Additionally, surgeon experience and patient preference may guide surgical planning.

The surgical treatment of three young chronic subdural hematoma patients with different causes

Chronic subdural hematoma (CSDH), which rarely happens in the young, is thought to be a disease of the elderly. Whereas unspecific symptoms and insidious onset in juveniles and young adults, as a result of its relative low morbidity, CSDH is usually neglected even undertreated in the young. Through the three cases and review of the current literature on this subject, we tried to illustrate the clinical and etiopathological characteristics of this entity and find out the most appropriate treatment strategy. We report three young CSDH patients with different but similar symptoms. The present histories, tests and examinations revealed different predisposing factors accounting for the genesis of CSDH. Their preoperative symptoms were all resolved with burr hole and drainage operation. Juveniles and young adults suffering from CSDH differ from that of their elderly counterparts in their clinical and etiopathological characteristics. Although trauma is the most important risk factor in young and old CSDH patients, some other predisposing factors may exist. Burr hole and drainage surgery could resolve the problem most of the time. But further tests and examinations even specific management should be made in some cases.

Update on intracranial hypertension and hypotension

PURPOSE OF REVIEW

The aim of this article is to review recent findings on the pathophysiology of idiopathic changes in intracranial pressure. The review will focus on idiopathic intracranial hypertension (IIH) and spontaneous intracranial hypotension (SIH).

RECENT FINDINGS

Substantial evidence indicates that IIH is associated with delayed absorption of cerebrospinal fluid (CSF). Stenoses of the transverse sinus are common in IIH, but their clinical significance has not been entirely clarified. Despite the observed efficacy of endovascular treatment in some IIH patients, a correlation between the extent of observed stenoses and the clinical course of the disease could not be demonstrated. The underlying cause of SIH is a spontaneous CSF leakage into the epidural space. Conservative treatment and the epidural blood patch remain the treatment of choice for this rare syndrome.

SUMMARY

Recent clinical evidence indicates that IIH is probably a result of CSF outflow abnormality rather than of CSF production. Further research is needed to elucidate the causes of elevated intracranial pressure and the mechanism leading to visual loss. Prospective randomized clinical trials are needed to clarify a possible therapeutic potential of endovascular treatment. Research efforts on SIH should focus further on associated connective tissue disorders predisposing to CSF leaks.

Anterior sacral pseudomeningocele following minimal trauma

Sacral fractures are rare and seldom result in formation of a sacral pseudomeningocele. Treatment of these pseudomeningoceles usually consists of conservative management with flat bedrest or open operative management. The authors describe the case of a 55-year-old woman with an anterior sacral pseudomeningocele that was successfully treated using a lumbar drain for temporary continuous CSF drainage. The patient first presented to an outside institution several days after sacral trauma from an ice skating fall. Initial symptoms included throbbing headaches relieved by lying flat. Head and cervical spine CT demonstrated no abnormality. As symptoms worsened, she presented to another institution where MRI of the lumbar spine indicated sacral fracture with pseudomeningocele. The patient subsequently transferred to the authors' facility, where symptoms included headaches and occasional mild sacral pain. Given her headaches and the authors' concern for CSF leak, another head CT scan was performed. This revealed no subdural hematoma or other abnormality. A subsequent CT myelogram revealed an anterior sacral pseudomeningocele at S3–4 with an anterior irregular linear filling defect, likely representing torn dura. Treatment included placement of a lumbar drain (10 ml/hr) and flat bedrest. Resolution of the CSF leak occurred on postprocedure Day 9. At the 4-week follow-up visit, the patient had no clinical symptoms of CSF leak and no neurological complaints. To our knowledge, this is the first description of temporary continuous CSF drainage used to treat a posttraumatic sacral pseudomeningocele. This technique may reduce the need for potentially complicated surgical repair of sacral fractures associated with CSF leak in select patients.

Clinical experiences with spontaneous intracranial hypotension: a proposal of a diagnostic approach and treatment

OBJECTIVE

We analyzed our clinical experience with patients with intracranial hypotension and developed a strategic model for the diagnosis mainly using Radioisotope (RI) cisternography and treatment of spontaneous intracranial hypotension (SIH).

METHODS AND MATERIALS

We retrospectively analyzed our clinical experiences with 30 cases of SIH from January 2000 through December 2006. All patients had confirmed by magnetic resonance image (MRI). RI cisternography or computed-tomography (CT) myelography was done for disclosing a cerebrospinal fluid leakage point. Initially patients were treated with medication. When patients complained of persistent headache, we performed epidural blood patch (EBP) administration. We performed subdural hematoma evacuation when it grew or worsened neurological status.

RESULTS

Twenty-one women (70%) and 9 men (30%) were enrolled. The mean age was 40 years (range: 30-58 years). After initial diagnosis with MRI, RI cisternography and CT myelography were helpful in pinpointing the exact leakage site. Four patients were treated only with the medication and 24 patients were treated with the epidural blood patch (EBP). Half of them achieved dramatic relief of symptoms after the initial EBP. A blind EBP was performed in 15 patients. Six patients experienced recurrence of symptoms. Hematoma evacuation was performed in 8 patients. None of diagnostic tools or treatment methods showed distinct superiority in predicting a favorable clinical outcome.

CONCLUSION

Clinicians should be systematic in their approach to plan a treatment regimen for patients with SIH. We suggest the use of a flow diagram when determining how to best approach and treat patients with SIH.

Spontaneous intracranial hypotension without intracranial hypotension

A 52-year-old man with a family history of multiple aneurysms presented with the gradual onset of generalized headaches and bilateral sixth nerve palsies. Following intravenous contrast, MRI revealed diffuse pachymeningeal enhancement consistent with spontaneous intracranial hypotension (SIH). Lack of any postural component to the headaches and repeatedly normal opening pressures on lumbar puncture delayed the diagnosis. A cerebrospinal fluid (CSF) leak was not found, but an epidural blood patch led to resolution of symptoms. Although the atypical features of nonorthostatic headache and normal CSF opening pressure have been documented in SIH, and failure to find the site of the leak is not unusual, this case illustrates a confluence of all these findings. An underlying disorder of connective tissue has been linked to SIH, and we propose that decreased meningeal compliance could account for a symptomatic low-volume state of CSF without a low opening pressure.

Spontaneous dural tear leading to intracranial hypotension and tonsillar herniation in Marfan syndrome: a case report

BACKGROUND

We describe the case of a 38 year old male with Marfan syndrome who presented with orthostatic headaches and seizures.

CASE PRESENTATION

The patient was diagnosed with Spontaneous Intracranial Hypotension secondary to CSF leaks, objectively demonstrated by MR myelogram with intrathecal contrast. Epidural autologous blood patch was administered at the leakage site leading to significant improvement.

CONCLUSION

Our literature search shows that this is the second reported case of a Marfan patient presenting with symptomatic spontaneous CSF leaks along with tonsillar herniation.

Traumatic lumbosacral pseudomeningocele associated with spinal fracture

BACKGROUND CONTEXT

Traumatic pseudomeningocele and avulsion of lumbosacral nerve roots are rare in the absence of fractures of the pelvic ring or hip dislocation. Clear prognoses for the root avulsion or pseudomeningocele do not exist.

PURPOSE

To present a patient who developed a posttraumatic pseudomeningocele after lumbosacral injury.

STUDY DESIGN

Case report and review of the literature.

METHODS

A patient who sustained traumatic pseudomeningocele of the lumbar spine was treated nonsurgically and followed over a 2-year period.

RESULTS

Nerve root deficit largely recovered, although an asymptomatic pseudomeningocele persisted.

CONCLUSIONS

The radiographic diagnosis of lumbar root avulsion is not predictive, and recovery may be expected in some patients without operative intervention. Management of patients with lumbar nerve root avulsion and posttraumatic pseudomeningocele should be based on the size and clinical significance of the pseudomeningocele.

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.

Recurrent subdural hematoma caused by cerebrospinal fluid leakage. Case report

The authors report a case of a recurrent subdural hematoma (SDH) that was caused by a persistent cerebrospinal fluid (CSF) leak from an L1-2 fistula. A 34-year-old man experienced severe headaches due to SDH, and he underwent aspiration of subdural fluid four times due to recurrent collections. Further evaluation with computerized tomography (CT) myelography demonstrated extradural extravasation of contrast through an L1-2 fistula. The patient underwent an L1-2 laminectomy; a small dural defect with CSF leakage at the left nerve root sleeve was found and was repaired. Following the repair, the patient had no further recurrence of SDH. Recurrent SDH, caused by spontaneous CSF leakage through a lumbar CSF fistula, is extremely rare. In cases of recurrent SDH, radiographic workup with spinal CT myelography should be considered.

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.

Intracranial hypotension syndrome: a comprehensive review

Intracranial hypotension may have variable clinical presentations, but has a rather uniform component of postural headache among its symptomatology. Its symptoms are explainable given the effects of the hypotension and attempts within the craniospinal axis to maintain volume homeostasis in the face of cerebrospinal fluid leakage (Monro–Kellie hypothesis). The imaging corollaries of the consequences of intracranial hypotension are especially well depicted on magnetic resonance imaging studies.

Orthostatic headache syndrome with CSF leak secondary to bony pathology of the cervical spine

The syndrome of orthostatic (low pressure) headaches is well described and most commonly occurs following deliberate violation of the dura (e.g. lumbar puncture). This syndrome can also occur spontaneously and results from the leakage of CSF. We describe three patients who suffered from spontaneous CSF leaks secondary to bony pathology of the cervical spine, and propose that this may be a more common aetiology than originally thought. Often these patients are difficult to manage medically, and surgery may be necessary for symptomatic relief.

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.

Surgical treatment of spontaneous spinal cerebrospinal fluid leaks

Spontaneous spinal cerebrospinal fluid (CSF) leaks are an increasingly recognized cause of intracranial hypotension. In this report the authors review the indications for surgery, surgical techniques, and surgery-related outcomes for these lesions. The major presenting symptoms include postural headaches, nausea, vomiting, and diplopia. Often, there is no history of traumatic injury. The most common cranial magnetic resonance (MR) imaging features include pachymeningeal gadolinium enhancement and sagging of the brain. On spinal MR images, diverticula are frequently noted. In cases in which symptoms are severe and refractory to less invasive measures, surgical intervention is indicated. Tears in the dura or leaking diverticula that are identified as the sources of the CSF leak often can be ligated or repaired. When a source of CSF egress is not found intraoperatively, packing the epidural space with blood-soaked Gelfoam or muscle at the appropriate level can lead to relief of symptoms. Occasionally the dural defect is large, irregular, or has attenuated borders that may not be possible to repair with sutures. These may be repaired by packing the defect with muscle or blood-soaked Gelfoam. Indications for and outcomes of surgery in patients with this condition will become more defined as surgeons gain experience with these procedures.

Spontaneous spinal cerebrospinal fluid leaks: a review

Spontaneous intracranial hypotension has become a well-recognized clinical entity, but it remains an uncommonly, and probably underdiagnosed, cause of headache; its estimated prevalence is only one in 50,000 individuals. The clinical spectrum of spontaneous intracranial hypotension is quite variable and includes headache, neck stiffness, cranial nerve dysfunction, radicular arm pain, and symptoms of diencephalic or hindbrain herniation. Leakage of the spinal cerebrospinal fluid (CSF) is the most common cause of spontaneous intracranial hypotension. A combination of an underlying weakness of the spinal meninges and a more or less trivial traumatic event is often found to cause this event in these patients. Typical magnetic resonance imaging findings include diffuse pachymeningeal enhancement, sub-dural fluid collections, and downward displacement of the brain, sometimes mimicking a Chiari I malformation. Opening pressure is often, but not always, low, and examination of CSF may reveal pleocytosis, an elevated protein count, and xanthochromia. The use of myelography computerized tomography scanning is the most reliable method for the accurate localization of the CSF leak. Most CSF leaks are found at the cervicothoracic junction or in the thoracic spine. The initial treatment of choice is a lumbar epidural blood patch, regardless of the location of the CSF leak. If the epidural blood patch fails, the blood patch procedure can be repeated at the lumbar level, or a blood patch can be directed at the exact site of the leak. Surgical repair of the CSF leak is safe and generally successful, although a distinct structural cause of the leak often is not found.

The syndrome of spontaneous intracranial hypotension

The authors report four cases of headache and other symptomatology related to the syndrome of intracranial hypotension. They were seen in a routine clinical practice over the past 3 years. The clinical features, magnetic resonance imaging (MRI) findings, and follow-up of these patients are described. Review of the prior literature on the topic is also included. All four patients presented with orthostatic headache syndrome. Three of the four demonstrated diffuse leptomeningeal thickening and enhancement on MRI studies. One subsequently developed a subdural effusion. One patient demonstrated downward displacement of the posterior fossa initially, which resolved on follow-up MRI scanning. Possible pathophysiologies of the syndrome are discussed.

Intracranial hypotension presenting with severe encephalopathy. Case report

A patient with severe and protracted symptoms from intracranial hypotension is described. The patient's presentation was marked by diffuse encephalopathy and profound depression of consciousness. This case report expands the presently known clinical spectrum of this uncommon and generally benign illness. The clinical and laboratory findings typically observed in the syndrome of intracranial hypotension are outlined. The pathophysiological mechanisms of the phenomenon are briefly discussed. Intracranial hypotension is a potentially severe illness with specific treatments that are distinct from the treatment of most neurological diseases. Three cardinal features--postural headache, pachymeningitis, and descent of midline cerebral structures--should prompt the diagnosis.

Spinal dural enhancement on magnetic resonance imaging associated with spontaneous intracranial hypotension. Report of three cases and review of the literature

This report offers a description of typical changes seen on gadolinium-enhanced magnetic resonance (MR) imaging of the entire spine that indicate spontaneous intracranial hypotension (SIH). To the authors' knowledge, this is the first report of its kind. They describe three cases of SIH that were accompanied by dural enhancement throughout the neuraxis on imaging, with the evolution of associated subdural and epidural fluid collections in the spine. Recognition of this disorder is important to be able to distinguish it from an infectious or neoplastic process in which surgical intervention might be warranted. Evaluation using gadolinium-enhanced cranial and spinal MR imaging in patients with postural headaches and an (111)In-labeled cerebrospinal fluid leak study are discussed. Treatment with an epidural blood patch is shown to be particularly effective, with resolution of the radiological and clinical findings.

Acquired Chiari I malformation secondary to spontaneous spinal cerebrospinal fluid leakage and chronic intracranial hypotension syndrome in seven cases

OBJECT

Spontaneous spinal cerebrospinal fluid (CSF) leakage with development of the intracranial hypotension syndrome and acquired Chiari I malformation due to lumbar spinal CSF diversion procedures have both been well described. However, concomitant presentation of both syndromes has rarely been reported. The object of this paper is to present data in seven cases in which both syndromes were present. Three illustrative cases are reported in detail.

METHODS

The authors describe seven symptomatic cases of spontaneous spinal CSF leakage with chronic intracranial hypotension syndrome in which magnetic resonance (MR) images depicted dural enhancement, brain sagging, loss of CSF cisterns, and acquired Chiari I malformation.

CONCLUSIONS

This subtype of intracranial hypotension syndrome probably results from chronic spinal drainage of CSF or high-flow CSF shunting and subsequent loss of brain buoyancy that results in brain settling and herniation of hindbrain structures through the foramen magnum. Of 35 cases of spontaneous spinal CSF leakage identified in the authors' practice over the last decade, MR imaging evidence of acquired Chiari I malformation has been shown in seven. Not to be confused with idiopathic Chiari I malformation, ideal therapy requires recognition of the syndrome and treatment directed to the site of the spinal CSF leak.

Lumbosacral nerve root avulsion

Lumbosacral nerve root avulsion is a rare clinical entity. Since the first description in 1955, only 35 cases have been reported. It is often associated with pelvic fractures and may be missed in the initial clinical examination as these patients usually present with multiple injuries. We present three such cases with clinical and radiological findings. These patients were involved in road traffic accidents. Two had fractures of the sacroiliac joint with diastasis of the symphysis pubis (Tile type C 1.2) and one had fractures of the public rami (Tile type B 2.1). All three had various degrees of sensory and motor deficit of the lower limbs. Lumbar myelogram shows characteristic pseudomeningoceles in the affected lumboscral region. Magnetic resonance (MR) imaging provides an additional non-invasive modality to diagnose this condition.

Syndrome of orthostatic headaches and diffuse pachymeningeal gadolinium enhancement

OBJECTIVE

To characterize clinical and imaging features, biopsy findings, etiologic factors, and outcome in the syndrome of intracranial hypotension, headaches, and diffuse pachymeningeal gadolinium enhancement on magnetic resonance imaging (MRI).

MATERIAL AND METHODS

We describe our experience with 26 consecutive patients with orthostatic headaches and diffuse pachymeningeal gadolinium enhancement, for all of whom clinical, imaging, and follow-up data were available. For 10 patients who had undergone meningeal biopsy, slide material was also reviewed.

RESULTS

The 15 men and 11 women ranged from 24 to 76 years of age. All 26 patients had postural headaches; in 22 patients, the headaches were completely alleviated by recumbency. Nausea or emesis, neck pain, horizontal diplopia, changes in hearing, photophobia, upper limb pains or paresthesias, visual blurring, or dysgeusia was noted in some of the patients. Cardinal MRI features were diffuse pachymeningeal gadolinium enhancement (100%), subdural collections of fluid (69%), and evidence of descent of the brain (62%) that sometimes resembled type I Chiari malformation. Cerebrospinal fluid (CSF) opening pressures were 40 mm or less in only 46%. In three patients, CSF pressures were consistently no less than 90 and as high as 130 mm of water. A variable pleocytosis of 5 or more cells/mm3 was noted in 15 patients (more than 40 cells/mm3 in 4 patients). A variable increase in CSF protein was noted in at least one spinal tap in 23 patients. Six patients had overdraining CSF shunts; CSF leak was documented in another 11 patients. Shunt revision or ligation and surgical correction of the leak led to a resolution of the clinical and MRI abnormalities in all cases thus treated. Improvement occurred with epidural blood patch in four patients. Three of the 12 patients treated supportively have remained symptomatic. Histologically, a thin subdural zone of fibroblasts and thin-walled vessels was noted in an amorphous matrix. Two patients with prolonged symptoms had a more pronounced proliferative reaction.

CONCLUSION

The syndrome of low-pressure headaches and pachymeningeal gadolinium enhancement is being recognized with increasing frequency. The source of the CSF leak can be demonstrated in many patients. Meningeal abnormalities are likely attributable to decreased CSF volume and hydrostatic CSF pressure changes. The prognosis is typically good.

Recurrence of spontaneous intracranial hypotension with subdural hematomas

A 59-year-old man developed postural headache associated with a low CSF pressure. A CT scan revealed no abnormal findings and the orthostatic symptoms resolved without treatment 6 weeks after onset. He was diagnosed as having spontaneous intracranial hypotension (SIH) and remained symptom-free until he experienced recurrence of postural headache 9 months later. A lumbar puncture demonstrated low CSF pressure, and a CT scan revealed slit-like ventricles with narrowing of the sulci, Sylvian fissures, and infratentorial cisterns, in addition to bilateral subdural masses. After draining the hematomas, his symptoms resolved completely, and a follow-up CT scan was normal. We hypothesize that recurrent SIH in this case was due to small recurrent tears of a root sleeve. This case emphasizes the importance of follow-up of SIH for at least 9 months after resolution of symptoms.

Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension

Spinal cerebrospinal fluid (CSF) leaks are often implicated as the cause of the syndrome of spontaneous intracranial hypotension, but they have rarely been demonstrated radiographically or surgically. The authors reviewed their experience with documented cases of spinal CSF leaks of spontaneous onset in 11 patients including their surgical observations in four of the patients. The mean age of the six women and five men included in the study was 38 years (range 22-51 years). All patients presented with a postural headache; however, most had additional symptoms, including nausea, emesis, sixth cranial-nerve paresis, or local back pain at the level of the CSF leak. All patients underwent indium-111 radionucleotide cisternography or computerized tomographic (CT) myelography. The location of the spontaneous CSF leak was in the cervical spine in two patients, the cervicothoracic junction in three patients, the thoracic spine in five patients, and the lumbar spine in one patient. The false negative rate for radionucleotide cisternography was high (30%). Subdural fluid collections, meningeal enhancement, and downward displacement of the cerebellum, resembling a Chiari I malformation, were commonly found on cranial imaging studies. In most patients, the symptoms resolved in response to supportive measures or an epidural blood patch. Leaking meningeal diverticula were found to be the cause of the CSF leak in four patients who underwent surgery. In three patients these diverticula could be ligated with good result but in one patient an extensive complex of meningeal diverticula was found to be inoperable. Two patients had an unusual body habitus and joint hypermobility, and two other patients had suffered a spontaneous retinal detachment at a young age. In conclusion, spontaneous spinal CSF leaks are uncommon, but they are increasingly recognized as a cause of spontaneous intracranial hypotension. Most spinal CSF leaks are located at the cervicothoracic junction or in the thoracic spine, and they may be associated with meningeal diverticula. The radiographic study of choice is CT myelography. The disease is usually self-limiting, but in selected cases our experience with surgical ligation of leaking meningeal diverticula has been satisfactory. An underlying connective tissue disorder may be present in some patients with a spontaneous spinal CSF leak.

Spontaneous intracranial hypotension from a CSF leak in a patient with Marfan's syndrome

A patient with Marfan's syndrome had spontaneous intracranial hypotension secondary to a proved CSF leak. It is postulated that the leak was caused by minor, unrecognised trauma rupturing spinal arachnoid diverticula. The diverticula were probably pre-existing abnormalities complicating the Marfan's syndrome. It is concluded that patients with spinal meningeal defects may be at increased risk of developing CSF leaks, possibly secondary to unrecognised trauma.

Surgical treatment of spontaneous intracranial hypotension associated with a spinal arachnoid diverticulum. Case report

The authors present the case of a 22-year-old woman who developed spontaneous intracranial hypotension as a result of a cerebrospinal fluid leak from a thoracic extradural arachnoid diverticulum. The patient was successfully treated by ligation of the diverticulum. The entity of spontaneous intracranial hypotension and its relevance to neurosurgery are discussed.

Neurovisual findings in the syndrome of spontaneous intracranial hypotension from dural cerebrospinal fluid leak

BACKGROUND

Spontaneous intracranial hypotension has been considered a rare clinical entity, with less than 75 cases reported in the medical literature. With the advent of magnetic resonance imaging (MRI), spontaneous intracranial hypotension currently is being recognized more frequently. The authors report the neurovisual manifestations of this disorder in a consecutive series of three patients.

METHODS

Each patient underwent clinical examination, computerized visual field testing, and MRI. After treatment, each patient was re-examined, and MRI was repeated.

RESULTS

Two patients had transient visual obscurations and unusual binasal visual field defects on automated perimetry. A third patient had diplopia from an abducens nerve paresis. After treatment of spontaneous intracranial hypotension, these findings improved or resolved.

CONCLUSIONS

This case series, and a review of previously reported cases, indicates that neurovisual problems are common in patients with spontaneous intracranial hypotension. Findings may include diplopia from sixth nerve paresis, transient visual obscurations, blurred vision, visual field defects, photophobia, and nystagmus.

The effect of intracranial hypotension on cerebral blood flow in a feline model

Intracranial hypotension is a known clinical entity but its pathophysiology has been meagerly studied. Any setting with cerebrospinal fluid leakage or drainage can cause intracranial hypotension. A feline model of kaolin induced chronic hydrocephalus with controlled cerebrospinal fluid drainage from a lateral ventricle yields reproducible intracranial hypotension of up to -15 torr for several hours to -80 torr of about 10 minutes. The magnitude of this hypotension is significantly greater than can be attained by cisterna magna drainage. This new model allows multiple cerebral parameters to be studied during intracranial hypotension. In 11 cats with stable blood pressure and intracranial hypotension of at least -15 torr, regional blood flow utilizing the hydrogen clearance method in the cerebral cortex and subcortical nuclei was unchanged relative to the baseline. These results imply that: 1) cerebral vascular autoregulation is maintained during significantly increased perfusion pressure due to negative intracranial pressure, 2) the symptomatology of clinical intracranial hypotension is not due to decreased cerebral perfusion.

Meningeal enhancement and low CSF pressure headache. An MRI study

A 34-year-old woman developed severe and incapacitating positional headaches two weeks following a minor head trauma. Lumbar punctures demonstrated unmeasurable or very low CSF pressures. Gadolinium-enhanced cranial MRI showed diffuse enhancement of thickened meninges, suggesting inflammation. One year later, MRI was normal.

Primary intracranial hypotension and abnormal radionuclide cisternography. Report of a case and review of the literature

We report a case of spontaneous posture-dependent headache associated with primary intracranial hypotension (PIH). The spinal fluid pressure was 0 cm H2O. Radioisotope cisternography showed that the cerebrospinal fluid flow was normal at the level of the spinal cord, but was suggestive for a hyperabsorption or leakage of CSF below the craniocervical junction.

Treatment of spontaneous cerebrospinal fluid leak with epidural blood patch. Case report

A case of spontaneous cerebrospinal fluid (CSF) leak from a sacral nerve root sleeve is reported. The leak resulted in CSF hypotension, which failed to resolve with prolonged bed rest. An epidural blood patch using autologous blood placed percutaneously via the caudal canal was successful in treating the problem.

Conus medullaris nerve root avulsions

The association of avulsive lesions and pain has been well established in avulsions of the brachial plexus from the cervical spinal cord, but avulsive lesions of the conus medullaris have not previously been recognized or documented by direct observation. Six patients with intractable lower-extremity pain due to avulsion of nerve roots from the conus medullaris were treated by thoracolumbar laminectomy and dorsal root entry zone (DREZ) lesions. Patients with avulsion of lumbosacral roots from the conus medullaris have a characteristic clinical presentation. They are usually young men who, as a result of a motorcycle accident, have suffered multiple pelvic or long-bone fractures or traumatic amputation of part of the lower extremity. Early in their course there is pain not directly attributable to the injured part. The pain is described as intense and burning, with episodic radiation and electric shock-like sensations in the injured or phantom limb. If the leg is intact, there is usually a dermatomal pattern to the distribution of the pain and neurological deficit. A myelogram often reveals a traumatic pseudomeningocele similar to those seen in the cervical region after avulsion of the brachial plexus. Surgical exploration of the conus medullaris usually reveals the extent of nerve root avulsion, and an appropriate DREZ operation can be performed.