Pseudotumoral Encephalic Schistosomiasis: A Literature Review

Pseudotumoral encephalic schistosomiasis (PES) is the chronic form of cerebral neuroschistosomiasis, and is rarely encountered in clinical practice. Clinically, PES closely resembles other intracranial space-occupying lesions including brain tumors. Laboratory investigations are usually inconclusive, and neuroradiologic findings are frequently reported as non-specific. Such diagnostic difficulties may result in delayed diagnosis and treatment. Across the literature, there is a paucity of information about and controversy over many aspects of the disease. Particularly, inconsistent magnetic resonance imaging (MRI) findings, a wide variation of medical treatment protocols, lacking consensus regarding the indications of surgery, and undetermined information regarding the impact of the extent of resection on prognosis. We herein review the pertinent literature with the aim of providing focused information regarding the pathogenesis of PES, its currently identified more distinctive neuroimaging features, and the indications and extent of surgery in light of the state-of-the-art operative neurosurgical practice. A distinctive multinodular arborizing pattern of PES lesions can often be observed on MRI in patients with PES. Praziquantel is considered by many authors to be the drug of choice in all cases, and seems to be effective at variable dose regimens. Although lesion excision utilizing current technology is generally safe, the indications and extent of surgery are still undetermined and should be decided on a case-by-case basis. Multicenter collaborative research is further needed to fill the existing gaps in the current knowledge on PES.

Endoscopic Endonasal Surgery for Uncommon Pathologies of the Sellar and Parasellar Regions

Endoscopic skull base surgery has become an integral part of the present neurosurgical armamentarium. The pioneering efforts in which the purely endoscopic transsphenoidal approach was introduced have triggered a growing tide of using the endoscopic endonasal procedures for a large variety of skull base lesions. Because of their anatomical peculiarities, lesions of the sellar and parasellar regions lend themselves very well to the endoscopic endonasal approaches. Apart from the common pathological entities, many other less frequent pathologies are encountered in the sellar and parasellar area. In this chapter, we review the surgical technique of the endoscopic endonasal transsphenoidal approach and its extensions applied to a variety of rare and uncommon pathological entities involving the sella turcica and clivus. An overview of these pathological entities is also presented and exemplified.

Coronavirus disease 2019 infection and pituitary apoplexy: A causal relation or just a coincidence? A case report and review of the literature

Background:

Pituitary tumor apoplexy (PA) is an emergency condition caused by hemorrhage or infarction of the preexisting adenoma. Many factors are currently well-known to predispose to PA. However, during the period of coronavirus disease 2019 (COVID-19) pandemic, case reports of PA associated with COVID-19 infection have been sequentially published. To the best of our knowledge, four cases have been reported so far in the English literature. We herein report the fifth case of this association and review the pertinent literature.

Case Description:

A 55-year-old male patient with confirmed COVID-19 infection presented by progressive decrease in visual acuity and oculomotor nerve palsy. His medical history is notable for diabetes mellitus, hypertension, and pituitary macroadenoma resection 11 years ago. He was on hormonal replacement therapy for panhypopituitarism that complicated the surgery. Previous magnetic resonance (MR) imaging studies were consistent with enlarging residual pituitary adenoma. During the current hospitalization, computed tomography revealed hyperdensity of the sellar and suprasellar areas. MR imaging revealed PA in a recurrent large adenoma. Endoscopic endonasal transsphenoidal resection was uneventfully undertaken with near total excision of the adenoma and partial improvement of visual loss and oculomotor palsy. Histopathological examination demonstrated classic features of PA. However, his chest condition progressed and he had to be transferred to COVID-19 intensive care unit in the referring hospital where he was intubated and put on mechanical ventilation. One week later, the patient unfortunately passed away due to complications of severe COVID-19 pneumonia.

Conclusion:

We report the fifth case of PA associated with COVID-19 infection. Based on our patient’s clinical findings, review of the other reported cases, as well as the available literature, we put forth a multitude of pathophysiological mechanisms induced by COVID-19 that can possibly lead to the development of PA. In our opinion, the association between both conditions is not just a mere coincidence. Although the histopathological features of PA associated with COVID-19 are similar to PA induced by other etiologies, future research may disclose unique pathological fingerprints of COVID-19 virus that explains its capability of inducing PA.

Effect of Sphenoid Sinus Pneumatization on the Surgical Windows for Extended Endoscopic Endonasal Transsphenoidal Surgery

BACKGROUND

Little is known on the impact of the pattern and extent of pneumatization of the sphenoid sinus (SS) on the dimensions of the surgical windows used in extended endoscopic endonasal transsphenoidal approaches. We therefore investigated whether the distances between the 2 optic canals and between the paired paraclival carotid arteries are influenced by the pattern and extent of pneumatization of the SS.

METHODS

One hundred high-resolution computed tomography scans from 47 adult female and 53 adult male patients were analyzed. The pattern of SS pneumatization was classified into conchal, presellar, and sellar types. Sellar-type sinuses were then classified according to a newer detailed classification system. Maximal anteroposterior (AP), transverse (TR), and craniocaudal diameters of the SS, interoptic distance at the limbus sphenoidale (IODL) and at the entrance of the optic canal (IODE) and the intercarotid distance between the paraclival carotids (ICD) were measured. A 2-tailed Mann-Whitney U test and Pearson correlation coefficient (R) were used for statistical analysis. A P value <0.05 was considered statistically significant.

RESULTS

Positive correlation was found between IODL and both AP and TR diameters of the SS; between IODE and both AP and TR diameters of the SS; and between ICD and all diameters of the SS. The highest correlation for each of the IODL, IODE, and ICD was noted with the TR diameter of the SS.

CONCLUSIONS

During the development of the SS, pneumatization progress likely exerts quantitative and direction-specific forces, which gradually increase the interoptic and intercarotid distances.

Endoscopic Endonasal Excision of Large and Giant Pituitary Adenomas: Radiological and Intraoperative Correlates of the Extent of Resection

BACKGROUND

Despite the superb visualization offered by the endoscopic endonasal transsphenoidal approach, the resection rates of large and giant pituitary adenomas have remained much lower than those of smaller macroadenomas. Various tumor characteristics can influence the extent of resection (EOR) and have been variably reported. Additional understanding of these factors is mandatory to improve the results. We analyzed the radiological and intraoperative tumor characteristics influencing the EOR in a cohort of patients with large and giant pituitary macroadenomas undergoing endoscopic endonasal transsphenoidal excision under our care.

METHODS

Twenty-eight patients were included. Magnetic resonance images were retrospectively analyzed for pre- and postoperative tumor volumetric analysis; preoperative tumor volume calculation using the formula (A × B × C/2); preoperative radioanatomical characteristics, including tumor shape, radiological structure, contrast enhancement, and extension; and the EOR. Intraoperative data were retrieved and included.

RESULTS

The preoperative calculated tumor volume was 38.14 ± 23.02 cm³ and the preoperative measured tumor volume was 50.345 ± 17.36 cm³. A statistically significant difference was found between the calculated and measured tumor volumes for the whole cohort and for tumors with a maximum diameter >3.9 cm. A statistically significant difference in the EOR was found at a volume threshold of 26.2 cm³. Large cysts, heterogeneous enhancement, Knosp grade ≤2, soft tumor consistency, and tumor hemorrhage were significantly associated with gross total resection.

CONCLUSIONS

Volumetric analysis should replace 2-dimensional methods in determining the size of large and giant pituitary adenomas. Specific tumor characteristics were associated with the EOR and could help in predicting the EOR for these tumors.

Endoscopic treatment of middle fossa arachnoid cysts

BACKGROUND

Endoscopic treatment of middle fossa arachnoid cysts is an alternative option to microsurgical fenestration and shunting procedures. The procedure is minimally invasive and obviates the morbidity of craniotomy and shunting.

METHODS

Operative charts and videos of patients undergoing endoscopic fenestration of middle fossa arachnoid cysts were retrieved from the senior author's database of endoscopic procedures and reviewed. Description of the surgical techniques was then formulated.

CONCLUSIONS

Endoscopic fenestration of middle fossa arachnoid cysts entails communicating the cyst cavity to the basal cisterns via multiple fenestrations that should be made as large as possible with care to avoid injury of the juxtaposed neurovascular structures.

Endoscopic treatment of adult idiopathic obstruction of the foramen of Monro

BACKGROUND

Adult idiopathic membranous obstruction of the foramen of Monro is an extremely rare condition that can be effectively treated with endoscopic foraminoplasty. A unilateral or bilateral foraminoplasty is performed if one or both of the foramina of Monro are obstructed, respectively. Endoscopic septum pellucidotomy is usually used in combination with the foraminoplasty.

METHODS

The operative chart and video of one of our patients undergoing endoscopic treatment for adult idiopathic membranous obstruction of the foramen of Monro were retrieved from our database and reviewed. A description of the surgical technique was then formulated.

CONCLUSIONS

The surgical technique of endoscopic foraminoplasty plus septum pellucidotomy for adult idiopathic membranous obstruction of the foramen of Monro is described.

Neuroendoscopy in Kuwait: Evolution, Current Status, and Future Directions

An overview of the development of neuroendoscopy at the neurosurgery department, Ibn Sina Hospital in Kuwait, is presented with an outline of difficulties and obstacles faced by the field until it reached its current status. The factors and solutions that helped us overcome these problems are also elaborated on. After a modest beginning few years ago, endoscopic skull base procedures, intraventricular neuroendoscopy, and spinal endoscopy are regularly performed in the department. Although neuroendoscopy is not per se a neurosurgical subspecialty, it is an area that requires special training. Achieving an appropriate level of care necessitates these highly trained neurosurgeons to collaborate together and with other specialties to create teamsgeared towards offering such treatment options topatients. Importantly, a multitude of essential facilities should be available to make such a pattern of practice possible. In our experience, this was made possible through continued efforts that have finally paid off and gradually led to a complete shift of the face of neuroendoscopic practice in our department. Our future endeavors aim at further development of neuroendoscopy in the department to create a center of excellence.

Ventricular volume and neurocognitive outcome after endoscopic third ventriculostomy: is shunting a better option? A review

BACKGROUND

Shunts are generally associated with a smaller post-treatment ventricular size in comparison to endoscopic third ventriculostomy (ETV).

METHODS

To determine whether such a difference in ventricular size has neurocognitive implications, we reviewed the current literature pertaining to the (1) neurocognitive sequelae of hydrocephalus, (2) neurocognitive outcome after ETV, (3) extent of reversal of neurocognitive changes associated with hydrocephalus after shunting, and (4) data on correlation between post-treatment ventricular volume and neurocognitive outcome after ETV.

RESULTS

Collectively, the results of the available studies should call into question the correlation between the residual postoperative ventricular volume and neurocognitive outcome.

CONCLUSION

The available literature is so far in support of ETV as a valid and effective treatment modality in hydrocephalic patients. No sufficient evidence is available to justify resorting to shunting on the premise that it is associated with a better neurocognitive outcome.

Infundibular Recess Angle Reduction After Endoscopic Third Ventriculostomy: Does It Reflect Clinical Success?

BACKGROUND

Although the ventricular size is significantly reduced after endoscopic third ventriculostomy (ETV) in most successfully treated patients, ventricular size reduction is not always seen after a successful ETV. Practical and reliable radiologic parameters are still needed to assess the clinical success of an ETV.

METHODS

We retrieved the clinical and radiologic data of patients who underwent an ETV. Patients with the following criteria were included: (1) preoperative magnetic resonance imaging studies available, (2) postoperative magnetic resonance imaging studies done within the first 2 postoperative weeks, and (3) the infundibular recess clearly visible on preoperative and postoperative sagittal magnetic resonance imaging. Preoperative and postoperative measurements of the angle of the infundibular recess of the third ventricle were performed on midsagittal T1-weighted, T2-weighted, fast imaging employing steady-state acquisition, or constructive interference in steady state images.

RESULTS

The extent of reduction of the infundibular recess angle predicted the clinical outcome of ETV during the early postoperative period with a high degree of accuracy. The average reduction was about 48% in successful procedures versus only 15% in failed procedures.

CONCLUSIONS

The degree of reduction of the angle of the infundibular recess of the third ventricle correlated with the amount of third ventricular decompression after ETV. Most importantly, such a reduction was noted to occur during the early postoperative period when radiologic changes are less pronounced. Assessment of change in infundibular recess angle measurement is easy to perform and may prove helpful in cases with no clear-cut clinical evidence of success of ETV.

Endoscopic biopsy of brain tumors: Does the technique matter?

Background:

Endoscopic biopsy of brain tumors is an important part of the armamentarium of management of intra- and periventricular tumors that is generally considered an acceptable and, in some situations, a preferred method for tissue sampling. The diagnostic yield of the procedure has been variably reported. Technical aspects of the procedure should undoubtedly reflect on its success rate and accuracy. Such impact on diagnostic yield of endoscopic brain biopsy is infrequently discussed in the literature.

Methods:

A search of the medical literature was conducted for publications on endoscopic brain biopsy. These reports were analyzed regarding the various technical aspects.

Results:

In the 43 publications analyzed, lenscopes were exclusively used in 22 reports and a tissue diagnosis was possible in 362 out of 387 endoscopic biopsies with a diagnostic yield of 93.54%. Only fiberscopes were used in 8 reports and a tissue diagnosis was possible in 100 out of 132 endoscopic biopsies with a diagnostic yield of 75.76%. The diagnostic yield in the mixed and unspecified groups was 88.95 and 88.04%, respectively. Very few details on the histopathological methods and tumor molecular genetics could be found.

Conclusion:

Endoscopic biopsy of brain tumors has a higher diagnostic yield when lenscopes are used. Neuronavigation seems to add to the diagnostic accuracy of the procedure. Studies detailing molecular genetic features of biopsied tumors are necessary in the future.

Blake's pouch cyst and Werdnig-Hoffmann disease: Report of a new association and review of the literature

Background:

We report a case of a neonate with proximal spinal muscular atrophy (SMA) type 1 (also known as Werdnig-Hoffmann disease or severe infantile acute SMA) associated with a Blake's pouch cyst; a malformation that is currently classified within the spectrum of Dandy-Walker complex. The association of the two conditions has not been previously reported in the English literature. A comprehensive review of the pertinent literature is presented.

Case Description:

A male neonate was noted to have paucity of movement of the four limbs with difficulty of breathing and poor feeding soon after birth. Respiratory distress with tachypnea, necessitated endotracheal intubation and mechanical ventilation. Pregnancy was uneventful except for decreased fetal movements reported by the mother during the third trimester. Neurological examination revealed generalized hypotonia with decreased muscle power of all limbs, nonelicitable deep tendon jerks, and occasional tongue fasciculations. Molecular genetic evaluation revealed a homozygous deletion of both exons 7 and 8 of the survival motor neuron 1 (SMN1) gene, and exon 5 of the neuronal apoptosis inhibitory protein (NAIP) gene on the long arm of chromosome 5 consistent with Werdnig-Hoffmann disease (SMA type 1). At the age of 5 months, a full anterior fontanelle and abnormal increase of the occipito-frontal circumference were noted. Computed tomographic (CT) scan and magnetic resonance imaging (MRI) of the brain revealed a tetraventricular hydrocephalus and features of Blake's pouch cyst of the fourth ventricle.

Conclusions:

This case represents a previously unreported association of Blake's pouch cyst and SMA type 1.

Johannes Vermeer of Delft [1632-1675] and vision in neuroendoscopy

Background:

Johannes Vermeer of Delft [1632-1675] was one of the greatest Masters of the Dutch Golden Age who was intensely preoccupied with the behavior of light and other optical effects and was entitled “The Master of Light”. He fastidiously attended to the subtleties of visual expression through geometry, composition, and precise mastery of the rules of perspective. It has been our impression that some visual similarity does exist between neuroendoscopic images and some of Vermeer's paintings. Such a relation could be explained by the fact that optical devices are utilized in producing both types of display.

Methods:

We reviewed the pertinent medical and art literature, observed some video clips of our endoscopy cases, and inspected digital high resolution images of Vermeer's paintings in order to elaborate on shared optical phenomena between neuroendoscopic views and Vermeer's paintings.

Results:

Specific optical phenomena are indeed shared by Johannes Vermeer's works and neuroendoscopic vision, namely light and color effects as well as the rules of perspective.

Conclusion:

From the physical point of view, the possibility that a camera obscura inspired Vermeer's artistic creation makes the existence of a visual link between his paintings and the endoscopic views of the intracranial cavity comprehensible.

Colloid cysts posterior and anterior to the foramen of Monro: Anatomical features and implications for endoscopic excision

Background:

Colloid cysts are usually located at the rostral part of the third ventricle in proximity to the foramina of Monro. Some third ventricular colloid cysts, however, attain large sizes, reach a very high distance above the roof of the third ventricle, and pose some challenges during endoscopic excision. These features led to the speculation that for such a pattern of growth to take place, the points of origin of these cysts should be at areas away from the foramina of Monro at which some anatomical “windows” exist that are devoid of compact, closely apposed forniceal structures.

Methods:

A review of the literature on anatomical variations of the structures in the vicinity of the roof of the third ventricle and on reported cases with similar features was conducted.

Results:

Colloid cysts may grow vertically up past the roof of the third ventricle through anatomical windows devoid of the mechanical restraint of the forniceal structures.

Conclusion:

Some anatomical variations of the forniceal structures may allow unusually large sizes and superior vector of growth of a retro- or post-foraminal colloid cyst. Careful preoperative planning and knowledge of the pertinent pathoanatomy of these cysts before endoscopic excision is very important to avoid complications.

Blake's pouch cyst

BACKGROUND

In 1900, Joseph Blake described a transient posterior evagination of the tela choroidea of the fourth ventricle in the normal 130-day old human embryo. He was the first to recognize and fully elucidate on the real nature of the foramen of Magendie as an aperture, which develops within a saccular expansion of the embryonic fourth ventricular cavity. The persistence of this temporary fourth ventricular outpouching into the postnatal period and its significance either as separate entity or as an entity within the Dandy-Walker continuum has over the years been one of the most controversial topics in both neurosurgical and neuroradiological literature.

METHODS

A search of the medical literature was conducted for publications addressing the historical, embryological, and neuororadiological features as well as the clinical presentation and management of persistent Blake's pouch.

RESULTS

The literature on the various features of Blake's pouch cyst has limited areas of consensus between various authors.

CONCLUSION

Blake's pouch cyst is a rare entity that is thought to belong to the Dandy-Walker continuum. It has a variable clinical presentation and when symptomatic can be treated with an endoscopic third ventriculostomy or shunting.

John Edwin Scarff (1898-1978) and endoscopic choroid plexus coagulation: A historical vignette

John Edwin Scarff (1898-1978) was one of the pioneers of neuroendoscopy and the head of the Department of Neurological Surgery at Columbia University in New York from 1947 to 1949. In this article, we highlight the pioneering and longstanding efforts of John E. Scarff in support of endoscopic choroid plexus coagulation. These efforts represent an important part of the rich history of neuroendoscopy and a legacy to which the current procedure owes a great credit.

Computed tomographic evaluation of C5 root exit foramen in patients with cervical spondylotic myelopathy

BACKGROUND

Narrowing of the intervertebral foramen for C5 root and a larger superior articular process in myelopathic patients with postlaminoplasty motor dominant C5 radiculopathy has been reported. We investigated whether the C4-5 foraminal dimensions and surface area in patients with cervical spondylotic myelopathy are universally smaller than the intervertebral foramina at other cervical levels.

METHODS

The study population consisted of 44 consecutive patients (sex: 24 males and 20 females), averaging 55.7 years of age (range 42-84) years who presented with clinical features suggestive of cervical spondylotic myelopathy. Using computed tomography (CT) imaging, we prospectively compared height, transverse diameter, and surface area of the C4-5 foramen to those of C3-4, C5-6 and C6-7 foramina of the same side in the whole study population as well as in male and female patients.

RESULTS

In the whole study population at C4-5 intervertebral foramen the mean foraminal height was 8.37 ± 1.3 mm on the right and 8.85 ± 1.16 mm on the left; and the mean foraminal transverse diameter on the right was 4.97 ± 1.35 mm and 5.14 ± 1.16 mm on the left. No statistically significant difference was found between the measurements in the whole study population at various levels, between or within male and female patient groups.

CONCLUSION

C4-5 intervertebral foramen is not uniformly smaller in patients with cervical spondylotic myelopathy.

An overview of the current surgical options for pineal region tumors

BACKGROUND

The list of pineal region tumors comprises an extensive array of pathological entities originating within one of the most complex areas of the intracranial cavity. With the exception of germ cell tumors, microsurgical excision is still nowadays the mainstay of management for most pineal region tumors.

METHODS

A search of the medical literature was conducted for publications addressing surgical options for management of pineal region tumors.

RESULTS

The infratentorial supracerebellar and the occipital transtentorial approaches are currently the most frequently used approaches for pineal region tumors. Endoscopic tumor biopsy with simultaneous endoscopic third ventriculostomy has emerged as a minimally invasive and highly effective strategy for initial management since it addresses the issue of tissue diagnosis and offers a solution for the associated hydrocephalus frequently encountered in these patients. Endoscope-assisted microsurgery and purely endoscopic excision have been reported in few reports and are likely to be more utilized in the future.

CONCLUSION

Preoperative planning is very crucial and should most importantly be individualized according to the anatomical features of the lesion and structures encountered during the procedure.