Artificial intelligence-enabled ophthalmoscopy for papilledema: a systematic review protocol

Papilledema is a pathology delineated by the swelling of the optic disc secondary to raised intracranial pressure (ICP). Diagnosis by ophthalmoscopy can be useful in the timely stratification of further investigations, such as magnetic resonance imaging or computed tomography to rule out pathologies associated with raised ICP. In resource-limited settings, in particular, access to trained specialists or radiological imaging may not always be readily available, and accurate fundoscopy-based identification of papilledema could be a useful tool for triage and escalation to tertiary care centres. Artificial intelligence (AI) has seen a rise in neuro-ophthalmology research in recent years, but there are many barriers to the translation of AI to clinical practice. The objective of this systematic review is to garner and present a comprehensive overview of the existing evidence on the application of AI in ophthalmoscopy for papilledema, and to provide a valuable perspective on this emerging field that sits at the intersection of clinical medicine and computer science, highlighting possible avenues for future research in this domain.

Metabolic crisis in maple syrup urine disease: an unusual complication of a rare disease: a case report

A 19-year-old woman with known maple syrup urine disease presented to hospital with metabolic crisis in the setting of influenza type A infection and intractable vomiting, rapidly progressing to acute cerebral oedema manifesting as refractory seizures and decreased level of consciousness needing emergency intubation and mechanical ventilation, continuous veno-venous haemodiafiltration and thiopentone coma. A computed tomography scan and magnetic resonance imaging of the brain demonstrated classic signs of cerebral oedema secondary to a metabolic crisis from the metabolic disorder. Her management posed multiple challenges to all teams involved due to lack of familiarity and experience in managing this clinical scenario in the adult intensive care setting.

Optic Nerve Sheath Diameter: A Cross-Sectional Study of Ultrasonographic Measurement in Healthy Black South African Adults

Ultrasonographic optic nerve sheath diameter (ONSD) measurement is an accurate, portable, and non-invasive method of detecting raised intracranial pressure that can also reflect dynamic, real-time changes in intracranial pressure fluctuations. Various studies have shown the mean range of ONSD to vary greatly across different population groups. This study aimed to determine the mean ONSD in healthy Black South African adults. In this cross-sectional study, healthy black South African adult participants underwent optic nerve sheath ultrasound of the right eye, with the diameter being measured at 3 mm behind the retina in two different planes. The average of the two measurements was used to find the mean optic nerve sheath diameter. This measurement was compared to that found in a Canadian adult population, and the effect of age, gender, and co-morbidities on ONSD was assessed. A total of 99 participants were included in this study, of which 39 were male and 60 were female. The mean ONSD was found to be 5.1 mm (SD ± 0.33). This value was significantly higher than the mean ONSD observed in the Canadian population (p < 0.001). There was no significant difference found between the mean ONSD in males and females (p = 0.652), and both age and presence of co-morbidities were not found to significantly correlate with ONSD. (p = 0.693 and p = 0.974, respectively).

Guidelines of the International Headache Society for Controlled Clinical Trials in Idiopathic Intracranial Hypertension

The quality of clinical trials is essential to advance treatment, inform regulatory decisions and meta-analysis. With the increased incidence of idiopathic intracranial hypertension and the emergence of clinical trials for novel therapies in this condition, the International Headache Society Guidelines for Controlled Clinical Trials in Idiopathic Intracranial Hypertension aims to establish guidelines for designing state-of-the-art controlled clinical trials for idiopathic intracranial hypertension.

Modifying skin flaps for achieving very large decompressive craniectomies in malignant middle cerebral artery territory infarcts: A technical note

INTRODUCTION

Decompressive craniectomy is a well described treatment to salvage life in large middle cerebral artery (MCA) territory infarcts. The size of the craniectomy is limited by the size of the skin incision and very large craniectomies need large skin flaps that are prone to necrosis at the wound margins.

MATERIAL AND METHODS

We describe two modifications in the skin flap that we have used in 7 patients to achieve very large bony decompressions in malignant MCA infarctions without compromising on flap vascularity. One consists of a linear extension posteriorly from the question mark or reverse question mark incision while the other is an "n" shaped incision.

RESULTS

With these modifications we achieved craniectomies of size 15.6-17.8 cm in the anteroposterior and 10.7-12 cm in vertical axis of the bone flap removed in our patients. There were no additional procedural or wound related complications in a 6-month follow up.

CONCLUSIONS

Removal of a standard size bone flap may achieve suboptimal decompression in cases of large MCA territory infarctions. Imaginative tailoring of skin flaps helps to remove larger volumes of skull with no added procedural morbidity.

Intracranial hypertension after cerebral venous thrombosis-Risk factors and outcomes

BACKGROUND AND PURPOSE

Cerebral venous thrombosis (CVT) is a special cerebrovascular disease that accounts for around 0.5%-1.0% of all strokes and often occurs in younger adults. Intracranial hypertension is the most frequent symptom of acute CVT due to venous occlusion. This study aimed to ascertain the risk factors for intracranial hypertension after CVT and to investigate whether intracranial hypertension at diagnosis may affect patient outcomes.

METHODS

We performed a retrospective cohort analysis of all patients treated for acute/subacute CVT at our department between 2018 and 2021. Logistic regression analysis was performed to identify potential risk factors associated with intracranial hypertension after CVT and clinical outcomes at the 6-month follow-up.

RESULTS

A total of 293 acute/subacute CVT survivors were eligible for inclusion, with 245 patients (83.60%) experiencing concomitant intracranial hypertension at diagnosis. In the multivariable regression analysis, hereditary thrombophilia (OR 2.210, 95% CI 1.148-4.254, p = 0.018) and thrombosis location of superior sagittal sinus (SSS) and right lateral sinus (LS) (OR 4.115, 95% CI 1.880-9.010, p = 0.000) were independently associated with intracranial hypertension. 83.67% of patients with intracranial hypertension after CVT had favorable functional outcomes (mRS score, 0-2), whereas they more often had residual visual impairment (15.51% vs. 4.17%, p = 0.036) at follow-up. The risk factors for residual visual impairment were papilledema (OR 2.971, 95% CI 1.231-7.170, p = 0.015) and visual disturbances at diagnosis (OR 2.869, 95% CI 1.123-7.327, p = 0.028), thrombosis location (SSS and right LS [OR 10.811, 95% CI 4.208-27.773, p = 0.000]; SSS and left LS [OR 3.139, 95% CI 1.409-6.995, p = 0.005]), and CVT recurrence (OR 4.763, 95% CI 1.556-14.584, p = 0.006).

CONCLUSIONS

Intracranial hypertension is the most common clinical symptom of acute CVT. At follow-up, patients with intracranial hypertension after CVT were more prone to develop residual visual impairment.

Expanding the clinical spectrum of idiopathic intracranial hypertension

PURPOSE OF REVIEW

Idiopathic intracranial hypertension (IIH) is a disorder of raised intracranial pressure (ICP). Although the majority of patients with IIH present classically with headache and papilledema, some patients may have unusual presentations or manifestations. Recent advancements in neuroimaging have facilitated the identification of other presentations associated with IIH. This review provides an overview of the expanding clinical spectrum of IIH.

RECENT FINDINGS

Presentations of IIH that are considered unusual include highly asymmetric or unilateral papilledema, IIH without papilledema, and IIH associated with cranial nerve involvement. These presentations likely reflect differences in the way cerebrospinal fluid (CSF) pressure is transmitted intracranially. Radiological signs of intracranial hypertension are increasingly recognized in patients with IIH and provide further insights into the effects of raised ICP on intracranial structures. Osseous changes in the skull base leading to formation of meningoceles and encephaloceles have been identified in patients with IIH, spontaneous skull base CSF leak, and drug-resistant temporal lobe epilepsy, suggesting a possible association.

SUMMARY

Clinicians should be familiar with the expanding clinical spectrum of IIH and the implications for the management of these presentations.

Idiopathic Intracranial Hypertension - Challenges and Pearls

Idiopathic intracranial hypertension (IIH) is defined as a syndrome of raised intracranial pressure with normal imaging of the brain and cerebrospinal fluid (CSF) composition. There is a rising incidence and prevalence of this disease related to the increased prevalence of obesity. It typically affects women of working age, and headache is the predominant morbidity in over 90%. The disease is also more prevalent in young males. There are many controversies and myths that surround IIH. There are currently few treatment options for IIH, management is typically medical with those experiencing progressive visual loss undergoing surgical procedures. Weight loss and venous sinus stenting are a few therapies directed at the etiology.

Clinical effects of hypertonic saline boluses in children with severe traumatic brain injury

AIM

To quantify the effects of 3% hypertonic saline (HTS) boluses on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in children.

METHODS

A retrospective study of patients admitted to a regional neurosurgical children's intensive care unit.

RESULTS

A total of 156 HTS boluses were given to children with traumatic brain injury. ICP decreased 6 mmHg (P < 0.01) and CPP increased 4 mmHg (P = 0.003) 1-h post-bolus. Effects persisted for 3 h post-dose ICP was 5 mmHg lower) and 4 h post-bolus CPP was 3 mmHg higher. ICP change was not associated with pre-bolus serum sodium concentration.

CONCLUSIONS

Hypertonic saline 3% at 5 mL/kg is an effective osmolar therapy for reducing ICP and increasing CPP in children for up to 3 h. '53-53' is a suitable guide - 5 mL/kg of 3% HTS will on average decrease ICP by at least 5 mmHg for 3 h. Pre-bolus serum sodium concentration is not correlated with effect size.

Headache attributed to idiopathic intracranial hypertension and persistent post-idiopathic intracranial hypertension headache: A narrative review

OBJECTIVE

Headache is a near-universal sequela of idiopathic intracranial hypertension (IIH). The aim of this paper is to report current knowledge of headache in IIH and to identify therapeutic options.

BACKGROUND

Disability in IIH is predominantly driven by headache; thus, headache management is an urgent and unmet clinical need. At present, there is currently no scientific evidence for the directed use of abortive or preventative headache therapy.

METHODS

A detailed search of the scientific literature and narrative review was performed.

RESULTS

Headache in IIH is driven by raised intracranial pressure (ICP) and reduction of ICP has been reported in some studies to reduce headache. Despite resolution of papilledema and normalization of raised ICP, a majority suffer persistent post-IIH headache. The lack of evidence-based management approaches leaves many untreated. Where clinicians attempt to manage IIH headache, they use off-label therapies to target the prevailing headache phenotype. A recent prospective open-label study demonstrated the effective use of a calcitonin gene-related peptide monoclonal antibody therapy in IIH for persistent post-IIH headache.

CONCLUSIONS

There is overwhelming evidence of the headache burden in IIH. Studies are required to investigate the biological foundations of headache related to ICP and to develop treatments specifically directed to manage headache in IIH.

Fungal Burden and Raised Intracranial Pressure Are Independently Associated With Visual Loss in Human Immunodeficiency Virus-Associated Cryptococcal Meningitis

Among 472 patients with human immunodeficiency virus-associated cryptococcal meningitis, 16% had severe visual loss at presentation, and 46% of these were 4-week survivors and remained severely impaired. Baseline cerebrospinal fluid opening pressure ≥40 cmH₂O (adjusted odds ratio [aOR], 2.56; 95% confidence interval [CI], 1.36-4.83; P = .02) and fungal burden >6.0 log₁₀ colonies/mL (aOR, 3.01; 95% CI, 1.58-5.7; P = .003) were independently associated with severe visual loss.

New horizons for idiopathic intracranial hypertension: advances and challenges

INTRODUCTION

Idiopathic intracranial hypertension (IIH) is becoming a recognized condition due to the increasing incidence linked to a global obesity epidemic.

SOURCES OF DATA

All English papers on PubMed, Cochrane and Scholar between inception until 1 March 2020 were considered.

AREAS OF AGREEMENT

Studies suggest central adiposity has a pathogenic role. Recent weight gain is a risk factor and weight loss has a key role in management.

AREAS OF CONTROVERSY

Interpretation of abnormal lumbar puncture opening pressure is debated. There is an increasing recognition of obesity stigma and how this should be approached.

GROWING POINTS

Further evidence is required for the choice of surgical intervention for fulminant IIH. Education regarding IIH should be evidence based.

AREAS TIMELY FOR DEVELOPING RESEARCH

Novel research of the pathology of IIH is influencing development of therapies such as glucagon-like peptide-1 receptor agonists and targeting unique androgen signatures. The newly discovered cardiovascular risk requires further attention.

Erenumab for headaches in idiopathic intracranial hypertension: A prospective open-label evaluation

Objective

To determine the effectiveness of erenumab in treating headaches in idiopathic intracranial hypertension (IIH) in whom papilledema had resolved.

Background

Disability in IIH is predominantly driven by debilitating headaches with no evidence for the use of preventative therapies. Headache therapy in IIH is an urgent unmet need.

Methods

A prospective, open‐label study in the United Kingdom was conducted. Adult females with confirmed diagnosis of IIH now in ocular remission (papilledema resolved) with chronic headaches (≥15 days a month) and failure of ≥3 preventative medications received erenumab 4‐weekly (assessments were 3‐monthly). The primary end point was change in monthly moderate/severe headache days (MmsHD) from baseline (30‐day pretreatment period) compared to 12 months.

Results

Fifty‐five patients, mean (SD) age 35.3 (9) years and mean duration of headaches 10.4 (8.4) years with 3.7 (0.9) preventative treatment failures, were enrolled. Mean baseline MmsHD was 16.1 (4.7) and total monthly headache days (MHD) was (29) 2.3. MmsHD reduced substantially at 12 months by mean (SD) [95% CI] 10.8 (4.0) [9.5, 11.9], p < 0.001 and MHD reduced by 13.0 (9.5) [10.2, 15.7], p < 0.001. Crystal clear days (days without any head pain) increased by 13.1 (9.5) [9.6, 15.3], p < 0.001, headache severity (scale 0–10) fell by 1.3 (1.7) [0.9, 1.9], p < 0.001, and monthly analgesic days reduced by 4.3 (9.2) [1.6, 6.9], p = 0.002. All these measures had improved significantly by 3 months, with a consistent significant response to 12 months. Headache impact test‐6 score and quality of life Short Form‐36 Health Survey significantly improved at 12 months. Sensitivity analysis revealed similar results for patients with and without a prior migraine diagnosis (28/55 (52%) patients) or those with or without medication overuse (27/55 (48%) patients).

Conclusions

This study provides evidence for the effectiveness of erenumab to treat headaches in IIH patients with resolution of papilledema. It provides mechanistic insights suggesting that calcitonin gene‐related peptide is likely a modulator driving headache and a useful therapeutic target.

Simultaneous decompressive craniectomy and caesarean section

A 24-year-old primigravid woman at 29-weeks gestation presented with headache, hypertension and proteinuria. A diagnosis of pre-eclampsia was made. Later that day she developed a left hemiparesis and neuroimaging demonstrated an intracerebral haemorrhage in the right frontal lobe as well as thrombosis of the superior sagittal sinus. She was commenced on an IV heparin infusion to manage the sinus thrombosis, and nifedipine and labetalol to treat the hypertension. GCS remained 15/15. However, 12 hours later, she became progressively agitated. Her GCS decreased to 10/15 (E3V2M5). Repeat imaging demonstrated enlargement of the haematoma, causing significant mass effect and midline shift. A decision was made to perform decompressive hemicraniectomy to save the life of the mother, and caesarean section to protect the foetus as well as providing definitive treatment of pre-eclampsia. Due to further neurological deterioration of the mother it became necessary to perform the two procedures simultaneously. We present the first reported case of decompressive craniectomy and caesarean section performed simultaneously. After discussing the case, we consider why this clinical scenario is rare and why it became necessary in this patient to perform the two procedures simultaneously.

Posterior calvarial distraction for complex craniosynostosis and cerebellar tonsillar herniation

OBJECTIVE

Children with syndromic, multisuture, and lambdoid craniosynostosis undergoing calvarial surgery often have Chiari malformation type I (CM-I) (or cerebellar tonsillar herniation). The optimal management of this patient group, including the surgical techniques and timing of surgery, remains uncertain. Posterior calvarial distraction (PCD) is an effective method to increase the supratentorial cranial volume and improve raised intracranial pressure in children with complex craniosynostosis. This study investigated the efficacy of PCD in posterior fossa (PF) volume expansion and treatment of CM-I and associated syringomyelia (syrinx) in this group of children.

METHODS

This retrospective study included patients who were surgically treated between 2006 and 2015. Over 10 years, 16 patients with multisuture synostosis, lambdoid synostosis, or craniosynostosis associated with a confirmed genetic syndrome, and a concurrent CM-I, were included. The mean age at the time of surgery was 5.1 years (range 8 months-18 years). Fourteen patients had pansynostosis and 2 had lambdoid synostosis. Eight had a confirmed syndromic diagnosis (Crouzon in 8, Apert in 4, Pfeiffer in 1, and Saethre-Chotzen in 1). Ten patients had raised intracranial pressure; 4 had syringomyelia.

RESULTS

The average clinical follow-up was 50 months (range 9-116 months). Clinically, 9 patients improved, 7 remained stable, and none deteriorated. The average distraction distance was 23 mm (range 16-28 mm). The PF anterior-posterior (AP) distance/width ratio increased from 0.73 to 0.80 mm (p = 0.0004). Although an osteotomy extending inferior to the torcula (compared with superior) was associated with a larger absolute PF AP distance increase (13 vs 6 mm, p = 0.028), such a difference was not demonstrable when the PF AP distance/width ratio was calculated. Overall, the mean tonsillar herniation improved from 9.3 to 6.0 mm (p = 0.011). Syrinx dimensions also improved in the AP (from 7.9 to 3.1 mm) and superior-inferior (from 203 to 136 mm) dimensions. No patients required further foramen magnum decompression for CM. Of the 16 patients, 2 had subsequent frontoorbital advancement and remodeling, of which 1 was for volume expansion and 1 was for cosmetic purposes. Two patients required CSF shunt insertion after PCD.

CONCLUSIONS

Following PCD, PF volume increased as well as supratentorial volume. This morphometric change was observed in osteotomies both inferior and superior to the torcula. The PF volume increase resulted in improvement of cerebellar tonsillar herniation and syrinx. PCD is an efficacious first-line, single-stage treatment for concurrent pansynostosis and lambdoid craniosynostosis, CM-I, and syrinx.

Idiopathic intracranial hypertension: Update on diagnosis and management

Idiopathic intracranial hypertension is a condition of raised intracranial pressure of unknown cause. Features include new onset headache, which is frequently non-specific; papilloedema is present, visual disturbances are common; and there may be sixth nerve palsy. Diagnosis includes brain imaging with venography to exclude structural causes and venous sinus thrombosis. Lumbar puncture reveals pressure greater than 250 mmCSF with normal constituents. Treatments aim to modify the disease, prevent permanent visual loss and manage headaches. These include weight loss. For those with rapid visual decline, urgent surgical intervention is essential. For most, this is a chronic condition characterised by significantly disabling headaches.

Posterior Globe Flattening without Papilledema in Idiopathic Intracranial Hypertension

A 64-year-old woman had a one-year history of transient visual obscurations in the left eye and was found to have left optic disc oedema with preserved visual function. She was diagnosed with unilateral papilloedema related to idiopathic intracranial hypertension. Magnetic resonance imaging of the orbits showed flattening of the globe in the right eye, which did not have disc oedema. Flattening of the posterior globe without papilloedema suggests that the barrier to transmission of cerebrospinal fluid pressure to optic nerve head is at the level of the lamina cribrosa and may be due to connective tissue changes in this area.

Formulating a Stable Mannitol Infusion while Maintaining Hyperosmolarity

Mannitol infusion is commonly used in the treatment of intracranial hypertension following traumatic brain injury. It has long been known to have stability issues, specifically, mannitol recrystallises from solutions greater than 10% w/v in ambient conditions. This can happen at any time, whether on the pharmacy shelf or during a medical procedure. This study describes the stability limits of 20% w/v mannitol infusion (the most common strength used clinically) and proposes a number of safer, stable and tuneable hyperosmotic formulations of mannitol in combination with clinically acceptable osmotic agents (NaCl, sorbitol and glycerol).

Exploring The Current Management Idiopathic Intracranial Hypertension, And Understanding The Role Of Dural Venous Sinus Stenting

Idiopathic Intracranial Hypertension (IIH) is a debilitating disorder characterised by raised intracranial pressure (ICP), papilloedema with the potential risk of permanent visual loss, and headaches that are profoundly disabling and reduce the quality of life. The first consensus guidelines have been published on investigation and management of adult IIH and one key area of uncertainty is the utility of dural venous sinus stenting for the management of headache and visual loss. There are an increasing number of series published and to help understand the successes and complications. During a patient physician priority setting, the understanding of the best type of intervention to treat IIH was assigned to the top 10 of most desired research questions for the disease. Ultimately randomised clinical trials (RCTs) in neurovascular stenting for IIH would be instructive, as the literature to date may suffer from publication bias. Due to the increasing incidence of IIH, there is no better time to systematically investigate interventions that may reverse the disease process and achieve remission. In this review we discuss the pathophysiology of IIH in relation to venous sinus stenosis, the role of venous sinus stenting with a review of the relevant literature, the advantages and disadvantages of stenting compared with other surgical interventions, and the future of stenting in the treatment of IIH.

Novel advances in monitoring and therapeutic approaches in idiopathic intracranial hypertension

PURPOSE OF REVIEW

The current article appraises the recent developments in idiopathic intracranial hypertension (IIH), with particular attention to novel therapeutic avenues and advanced clinical assessment and monitoring with optical coherence tomography and telemetric intracranial pressure devices.

RECENT FINDINGS

The incidence of IIH is increasing. The first consensus guidelines for IIH have been published detailing investigation and management algorithms for adult IIH. Improved understanding, clinical assessment and monitoring are emerging with the use of optical coherence tomography. Intracranial pressure telemetry is providing unique insights into the physiology of raised intracranial pressure in IIH. There are now an increasing number of ongoing clinical trials evaluating weight loss methods and novel targeted therapies, such as 11ß-HSD1 inhibition and Glucagon-like peptide 1 (GLP-1) receptor agonists.

SUMMARY

Several studies are evaluating new therapies for IIH. Monitoring techniques are advancing, aiding diagnosis and allowing the clinician to accurately evaluate changes in papilloedema and intracranial pressure.

Case series of six patients diagnosed and managed for idiopathic intracranial hypertension at a tertiary institution eye centre

Background

Idiopathic Intracranial Hypertension (IIH) occurs secondary to raised intracranial pressure (ICP) of unknown etiology and is diagnosed when all other causes of raised ICP have been excluded. It can leave devastating sequelae such as permanent visual loss, hence the need for timely diagnosis and treatment. Anecdotally, one or two cases of idiopathic intracranial hypertension (IIH) previously presented at the Eye Centre, KBTH yearly. However, six cases were seen within a 6-month period, prompting the need to study the clinical features of IIH in this population.

Objective

We aim to evaluate the clinical features of patients presenting with IIH at KBTH.

Methodology

This is a retrospective case series with contemporaneous collection of data of six patients who presented to the Eye Centre (KBTH) between October 2016 and March 2017 with clinical features suggestive of IIH. The patients were evaluated and diagnosed based on clinical judgement as well as using the modified Dandy criteria.

Results

All six patients were female and all except one were obese. The age range was 8 to 40 years with median 22.5 years. Symptoms in the 8-year-old were preceded by oral doxycycline for acne treatment. One patient had a history of using oral contraceptive pills prescribed for irregular menses. Clinical features of blurred vision, headache, and papilloedema were relieved with oral acetazolamide.

Conclusion

The upsurge of IIH may be due to the increased incidence of obesity in Ghana. Timely diagnosis and treatment is needed to avoid irreversible blindness.

Funding

None

Advances in the understanding of headache in idiopathic intracranial hypertension

PURPOSE OF REVIEW

To review the most relevant developments in the understanding of headache in idiopathic intracranial hypertension (IIH).

RECENT FINDINGS

The phenotype of the typical IIH headache is diverging from the historical thinking of a raised intracranial pressure headache, with the majority being classified as having migraine. A larger proportion of those with IIH have a past medical history of migraine, compared with the general population, highlighting the importance of re-examining those who have a change or escalation in their headache. The mechanisms underlying headache in IIH are not understood. Additionally, factors which confer a poor headache prognosis are not established. It is clear, however, that headache has a detrimental effect on all aspects of the patient's quality of life and is currently ranked highly as a research priority by IIH patients to better understand the pathophysiology of headache in IIH and identification of potential headache specific therapeutic agents.

SUMMARY

Headache remains the predominate morbidity in the majority of those with IIH. Headache management is an unmet need in IIH and future studies are required to investigate the probable complex mechanisms, as well as effective management.

Endoscopic Management of a Fourth Ventricular Cyst

We report a case of a 12-year-old boy with previously shunted congenital hydrocephalus, presenting with a progressive headache, nausea, vomiting, and lethargy. In the brain magnetic resonance imaging, a large cyst was seen in the superior recess of the fourth ventricle extending through the cerebral aqueduct toward the third ventricle. Endoscopic dual fenestration of the cyst was performed successfully using the posterior suboccipital approach through the foramen of Magendie, which resulted in the relief of symptoms without any complications, and the patient was symptom-free in the subsequent follow-up visits for 4 years.

Raised intracranial pressure in Crouzon syndrome: incidence, causes, and management

OBJECT Patients with Crouzon syndrome (CS) are at risk for developing raised intracranial pressure (ICP), which has the potential to impair both vision and neurocognitive development. For this reason, some experts recommend early prophylactic cranial vault expansion on the basis that if ICP is not currently raised, it is likely to become so. The aim of this study was to examine the justification for such a policy. This was done by analyzing the incidence, causes, and subsequent risk of recurrence in a series of patients with CS, in whom raised ICP was treated only after it had been diagnosed. METHODS This study was a retrospective review of the medical records and imaging data of patients with a clinical diagnosis of CS. RESULTS There were 49 patients in the study, of whom 30 (61.2%) developed at least 1 episode of raised ICP. First episodes occurred at an average age of 1.42 years and were attributable to craniocerebral disproportion/venous hypertension (19 patients), hydrocephalus (8 patients), and airway obstruction (3 patients). They were managed, respectively, by vault expansion, ventriculoperitoneal shunt insertion, and airway improvement. Fourteen of the 30 patients developed a second episode of raised ICP an average of 1.42 years after treatment for their initial episode, and 3 patients developed a third episode an average of 3.15 years after that. Causes of subsequent episodes of raised ICP often differed from previous episodes and required different management. Patients who were < 1 year old when the first episode was diagnosed were at increased risk of recurrence. CONCLUSIONS Although the incidence of raised ICP in CS is high, it did not occur in nearly 40% of children during the course of this study. The several possible causes of CS require different management and may vary from episode to episode. The authors recommend an expectant policy toward these children with careful clinical, ophthalmological, respiratory, and radiological monitoring for raised ICP, reserving intervention for when it has been detected and the appropriate treatment can be initiated.

Optic nerve sonography: A noninvasive means of detecting raised intracranial pressure in a resource-limited setting

Objective:

The aim was to assess the use of optic nerve sonography (ONS) as a quick, noninvasive diagnostic test tool for detecting raised the intracranial pressure (ICP).

Materials and Methods:

A prospective blinded observational study was conducted at Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Nigeria. The study population consisted of 160 adult patients referred to the radiology department for cranial computed tomography (CT) scan. There were 80 subjects and 80 controls. Optic nerve sheath diameter (ONSD) was measured by a radiologist using a 7.5 Megahertz ultrasound probe while cranial CT was reviewed by other radiologists blinded to the ONSD.

Results:

Sixty-nine subjects (86.3%) had intracranial space occupying lesions (SOL) with cranial CT confirmed features of increased ICP, mean binocular ONSD of 5.7 ± 0.59 mm while 11 (13.7%) had intracranial SOL without any cranial CT evidence of increased ICP, mean binocular ONSD of 4.8 ± 0.39 mm. The difference of mean ONSD of the two groups was statistically significant (P = 0.0001). The controls had a mean binocular ONSD of 4.5 ± 0.22 mm and the difference in mean binocular ONSD for subjects with raised ICP and the controls were also statistically significant (P = 0.0001). A cut-off value of 5.2 mm (sensitivity 81.2% [95% confidence interval (CI): 69.9–89.6], specificity 100% [95% CI: 71.5–100]) was obtained from the receiver operator characteristics curve as the mean binocular ONSD that best predicts raised ICP confirmed by at least a sign on cranial CT.

Conclusions:

Optic nerve sonography can differentiate between normal and elevated ICP and may serve as a useful screening tool in resource-limited practice.

James Hill of Dumfries: First modern neurosurgical procedures

James Hill (1703-1776) was a surgeon from Dumfries in Scotland who can lay claim to being the first to treat head injury patients in a thoroughly modern manner. He was highly regarded in his lifetime and for a century afterwards but has subsequently been forgotten. He had the lowest surgical mortality for trepanation of any surgeon of his time. He uniquely presented his results after a lengthy follow-up of many years. His management of cranial fractures was advanced. He did not use the trepan for fissures as others did and his conservative management of depressed fractures was based on biological rather than mechanical notions. He had an instinct for the management of raised intracranial pressure (ICP) unique in his day even though he could not have understood it in modern terms. He operated on head injuries only if there was a disturbance of consciousness. He was aware of the importance of cerebral pulsation and was alone in recording it in a majority of operated patients. He was ready to open the dura when necessary and did so six times. He introduced non-compressive bandaging over skull defects after surgery. In three cases he shaved off brain hernias which resulted in marked clinical improvement. He not only understood that an injury or disease on one side caused a deficit on the other side but uniquely encompassed this knowledge in his treatment planning. In view of these many insights and achievements, he deserves to be considered as the first surgeon whose neurosurgical management is recognisably close to modern practice.

Correlation of measurement of optic nerve sheath diameter using ultrasound with magnetic resonance imaging

Background and Aims:

Analysis to correlate the measurements of optic nerve sheath diameter (ONSD) obtained by using ultrasound to magnetic resonance imaging (MRI) techniques in order to establish the accuracy of ocular sonography as a noninvasive modality for detecting raised intracranial pressure (ICP).

Materials and Methods:

A prospective, observational study was performed in 100 cases of adult meningoencephalitis patients admitted to Intensive Care Unit in whom MRI was performed for neurodiagnosis. ONSD was measured in such patients, 3 mm behind the globe in each eye. A mean binocular ONSD >4.6 mm in female and 4.8 mm in male was taken as cut-off values for diagnosing raised ICP. This was compared with ONSD measured on T2-weighted MRI image measured 3 mm behind the globe. The reading obtained from both the methods were compared with Bland–Altman analysis for correlation and the findings were tabulated.

Results:

The mean ONSD values measured with ultrasonography (USG) and MRI for female were 5.48 ± 0.43 mm and 5.68 ± 0.44 mm and for male were 5.40 ± 0.37 mm and 5.56 ± 0.38 mm, respectively. The mean age of the female and male was 53.90 ± 17.84 and 56.06 ± 15.67 years, respectively. On comparing ultrasound with MRI-derived ONSD values, we found acceptable agreement between both methods for measurements at a depth of 3 mm (r = 0.02, P < 0.001).

Conclusion:

In our study, we have found a good correlation between ocular USG and MRI of ONSD. The study has shown agreement with the fact that ocular sonography can be used as a noninvasive tool for detecting raised ICP with accuracy.

Enlarged Optic Nerve Sheath in Aneurysmal Subarachnoid Hemorrhage despite Normal Intracranial Pressure

INTRODUCTION

This study investigates the diagnostic value of optic nerve sheath diameter (ONSD) assessed by transorbital sonography for estimation of intracranial pressure (ICP) in patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS

Simultaneous measurements of the ONSD and ICP in 27 patients suffering from SAH and acute hydrocephalus after placement of an extraventricular drain.

RESULTS

Despite normal mean ICP values ONSD was significantly higher in patients with SAH compared with healthy volunteers and no relevant decline of ONSD over time could be identified. In addition, no correlation between ONSD and ICP was observed.

CONCLUSIONS

In patients with SAH and acute hydrocephalus after aneurysm rupture, the ONSD remains expanded after normalization of ICP. This is most likely due to an impaired retraction capability of the optic nerve sheath. This finding should be considered when using transorbital sonography in the neuromonitoring of aneurysmal SAH.

Noninvasive intracranial pressure monitoring via optic nerve sheath diameter for robotic surgery in steep Trendelenburg position

Background:

Recent reports of increased intracranial pressure (ICP) due to steep Trendelenburg (ST) position causing neurological deterioration, decreased regional cerebral oxygen saturation and postoperative visual loss after robotic urological and gynecological surgeries led us to consider a simple technique of ICP monitoring. Ours is one of the first instances reported of quantitative noninvasive measurement of increase in ICP with ST position by serial measurement of binocular optic nerve sheath diameter (ONSD) in patients undergoing robot assisted urological and gynecological oncosurgery. We tested whether ONSD values rose to above the upper limits of normal and for what length of time they remained elevated.

Materials and Methods:

Prospective, randomized, interventional, parallel group, active control study conducted on 252 American Society of Anesthesiologists I and II patients. ONSD was measured using 7.5 MHz linear ultrasound probe in supine and Trendelenburg positions.

Statistics:

Student's t-test to compare the inter-group mean ONSD and the repetitive t-test for intra-group analysis.

Result:

Comparison of the mean ONSD values of both groups yielded a 2-tailed significance P <0.01 at all compared time points intra- and post-operatively. In Group-O (open surgery; supine position), the baseline mean bilateral ONSD was 4.36 mm, which did not show any statistically significant change throughout open surgery and postoperative period. On de-docking the robot, 6.2 mm was the mean ONSD value in Group-R (robotic group) while 4.3 mm was the corresponding value in control Group-O.

Conclusion:

ONSD evaluation is a simple, quick, safe, readily available, reliable, cost effective, noninvasive, potential standard of care for screening and monitoring of patients undergoing robotic surgery in ST position.

Transorbital Ultrasonographic Measurement of Optic Nerve Sheath Diameter in Brain Death

BACKGROUND

Ultrasonographic measurement of optic nerve sheath diameter (ONSD) can successfully be used to estimate intracranial pressure (ICP) elevation. Its utility in corroboration of brain death (BD) was herein studied.

METHODS

ONSD was measured in 29 subjects with BD; in 19 comatose patients (with raised ICP in 11), 20 patients with various neurological diseases, and 40 healthy control subjects. The distance between the inner and outer edges of the echolucent lines around hyperechoic area surrounding the optic nerve (ON) was identified as ONSD external (ONSDe) and ONSD internal (ONSDi).

RESULTS

Compared to patients with neurological diseases (5.75 ± .79 mm) or healthy controls (5.98 ± .63 mm), ONSDe was significantly higher in comatose patients (7.61 ± .97 and 6.71 ± 1.07 mm in those with and without raised ICP) and BD subjects (8.34 ± .66 mm). ONSDi showed similar trends across the groups: 6.09 ± .71 mm in BD; 5.89 ± .37 mm in comatose control with elevated ICP; 5.16 ± .49 mm in comatose control with normal ICP; 4.36 ± .68 mm in neurological control; 4.69 ± .67 mm in healthy control. The accuracy of ONSDe measurements in differentiating patients with ICP elevation (n = 40) was .965 as determined by area under the curve (AUC) of receiver-operator characteristics curves. Similarly, accuracy in discrimination of BD was .952. However, ONSDe showed limited yield to identify BD cases among comatose patients with Glasgow coma scale score of 3, where accuracy was .803 (95% CI: .709-.816) and decreased further to .722 (95% CI: .610-.816) when analyses were restricted to comatose patients with ICP elevation. AUC values for ONSDi was similar or lower.

CONCLUSION

ONSD is significantly greater in subjects with BD. However, quantification of ONSD cannot discriminate BD subjects from comatose ones with raised ICP with 100% certainty.

Optic nerve sheath diameter as a marker for evaluation and prognostication of intracranial pressure in Indian patients: An observational study

BACKGROUND AND AIMS

The aim was to evaluate efficacy of optic nerve sheath diameter (ONSD) by ultrasound as a noninvasive method for detecting raised intracranial pressure (ICP) in intensive care unit, to compare with computed tomography/magnetic resonance imaging (MRI) findings of raised ICP and to prognosticate ONSD value with treatment.

MATERIALS AND METHODS

We conducted a prospective, observational study on 101 adults by including 41 healthy individuals in group A as control and 60 patients in group B admitted with fever, headache, vomiting, and altered sensorium. We examined them in supine position using 10 MHz linear array probe on closed eyelid. ONSD was measured 3 mm behind the globe in each eye. A mean binocular ONSD > 4.6 mm in female and 4.8 mm in male was considered abnormal. Midline shift, edema, effacement or ONSD > 5.0 mm on T2 MRI suggestive of elevated ICP was used to evaluate ONSD accuracy.

RESULTS

Group A mean ONSD was 4.6 mm in females and 4.8 mm in males. Group B mean ONSD for 17 females was 5.103 ± 0.6221 mm (P = 0.002) and for 43 males 5.081 ± 0.5799 mm (P = 0.032). Radiological sign of raised ICP was confirmed in 35 patients (females = 11 and males = 24) with high ONSD value. Sensitivity of detecting raised ICP by ONSD was 84.6% in females and 75% in males while specificity was 100% in both genders. Out of 25 patients without radiological signs of raised ICP 10 patients showed high ONSD (females = 4.735 mm and males = 4.907 mm). ONSD was well prognosticated with treatment modalities.

CONCLUSION

Bedside ocular ultrasonography for measuring ONSD can be used an early test for diagnosing raised ICP as it is a noninvasive, cost effective bedside test, which can be repeated for re-evaluation.

The role of inhaled nitric oxide beyond ARDS

Patients with traumatic brain injury complicated by acute respiratory distress syndrome (ARDS) are not uncommon in intensive care unit (ICU). The ventilatory management of patients combined with both of these catastrophic conditions is not straightforward. Evidence-based permissive hypercapnia strategy for ARDS could be fatal in patients with intracranial hypertension. Adjunctive use of inhaled nitric oxide (INO) is well-defined as a rescue therapy in severe ARDS, but its specific role in intracranial hypertension is somewhat uncertain. We report a case, which following traumatic brain injury developed both intracranial hypertension and ARDS. INO was given for ARDS, but coincidentally it also improved the raised intracranial pressure (ICP) and patient's neurological outcome. The case report will be followed by literature review on the role of INO in raised ICP.

A 6-year-old girl with fever, rash, and increased intracranial pressure

BACKGROUND

Rocky Mountain spotted fever (RMSF) is a well-described, potentially lethal, tick-borne zoonotic infection and has very effective therapy. However, the diagnosis might not be made early enough, often leading to worse outcomes.

OBJECTIVE

Our aim was to discuss the diagnostic dilemmas facing the physician when evaluating patients with suspected RMSF.

METHODS

We report a case of RMSF in a 6-year-old girl who presented to our hospital with a 7-day history of fever, headache, and a petechial rash. After blood cultures were obtained, the patient was treated empirically with doxycycline, vancomycin, and ceftriaxone. During the next 24 h, her clinical status worsened, with acute onset of altered mental status, posturing, and fixed and dilated pupils. A computed tomography scan of the brain demonstrated diffuse cerebral edema with evidence of tonsillar herniation. She died 24 h after admission. A serum specimen tested positive for immunoglobulin G to Rickettsia rickettsii at a titer of 128 dilutions, confirming recent infection.

CONCLUSIONS

We present this case to raise awareness of RMSF in patients who present with a nonspecific febrile illness in tick-endemic areas in the United States. Early diagnosis and treatment with doxycycline before day 5 of illness is essential and can prevent morbidity and mortality.

Neuroimaging and other investigations in patients presenting with headache

Headache is very common. In the United Kingdom, it accounts for 4.4% of primary care consultations, 30% of referrals to neurology services and 0.5-0.8% of alert patients presenting to emergency departments. Primary headache disorders account for the majority of patients and most patients do not require investigation. Warning features (red flags) in the history and on examination help target those who need investigation and what investigations are required. This article summarizes the typical presentations of the common secondary headaches and what neuroimaging and other investigations are appropriate for each headache type.

Role of hypertonic saline and mannitol in the management of raised intracranial pressure in children: A randomized comparative study

OBJECTIVE

To compare the efficacy and side effects of 3% hypertonic saline and mannitol in the management of raised intracranial pressure in children.

DESIGN

Prospective randomized study.

SETTING

Pediatric intensive care unit (PICU) in a tertiary care hospital.

SUBJECT

200 patients with raised intracranial pressure.

MATERIALS AND METHODS

Patients were randomized into two statistically comparable groups; Group A (n = 98) was treated with mannitol while Group B (n = 100) was treated with 3% hypertonic saline. Group C (n = 2) included those members of Group A in whom serum osmolality ≥320 mosmol/kg and were then treated with 3% hypertonic saline. Both Drugs were given at a loading dose of 5 ml/kg stat followed by 2 ml/kg in every 6 h(both have same osmolarity) for two days in their respective groups. Besides monitoring, blood pressure (NIBP), mean arterial pressure (pre and post 30 min of drug), serum sodium, chloride and osmolality were measured. Intracranial pressure was assessed indirectly by measuring mean arterial ressure "MAP". Student paired 't' test was applied.

RESULTS

Decrease in MAP was highly significant (P<0.001) at 0 h in males 0,6 h in females, and moderately significant at 12,36 h in females and significant(P<0.05) at 6,24,42 h in males of Group B. Decrease in coma hours was a highly significant finding (P<0.001) in Group B. In Group B, serum sodium and chloride increased significantly but remained within acceptable limits. There was no difference in osmolality and mortality (fisher Z).

CONCLUSION

Mannitol has several side effects, 3% hypertonic saline is a safe and effective alternative in managing cerebral edema.