Interhemispheric contralateral approach: the falx as a retractor.

The contralateral transfalcine approach is a valuable option to access lesions around the mesial surface of the brain hemispheres. Despite a favourable perspective, surgical manoeuvres within the interhemispheric fissure carry a risk of inadvertent injury to the healthy cortex on the craniotomy side. To overcome this drawback, a new method of brain retraction was developed. After dissecting the interhemispheric fissure, the falx was incised in an upside-down U-shaped manner and hinged inferiorly, taking care not to violate the inferior sagittal sinus. The falcine flap was reflected laterally and fixed to the lateral edge of the craniotomy, providing homogeneous retraction of the ipsilateral mesial cortex. Surgery proceeded with the brain surface hidden from the surgeon's view and protected by the flap. The absence of retractor devices hindering the surgeon's movements further simplified the procedure.

Mini-craniotomy for intra-axial brain tumors: a comparison with conventional craniotomy in 306 patients harboring non-dural based lesions.

The use of a mini-craniotomy approach involving linear skin incision and a bone flap of about 3 cm has been reported for several neurosurgical diseases, such as aneurysms or cranial base tumors. More superficial lesions, including intra-axial tumors, may occasionally raise concerns due to insufficient control of the tumor boundaries. The convenience of a minimally invasive approach to intrinsic brain tumors was evaluated by comparing 161 patients who underwent mini-craniotomy (MC) for intra-axial brain tumors with a group of 145 patients operated on by the same surgical team through a conventional craniotomy (CC). Groups were propensity-matched for age, preoperative condition, size and location of the tumor, and pathological diagnosis. Results were analyzed focusing on operative time, the extent of resection, clinical outcome, hospitalization time, and time to start adjuvant therapy. Mini-craniotomy was equally effective in terms of extent of resection (GTR: 70.9% in the MC group vs 70.5% in the CC group) but had shorter operative time (average: 165 min in the MC group vs 205 min in the CC group p < 0.001) and lower rate of postoperative complications both superficial (1.03% vs 6.5% in the CC group p = 0.009) and deep (4% in the MC group vs 5.5% in the CC group p = 0,47). No relationship was found between the size or location of the tumor and resection rate. The MC group had reduced hospitalization time (average: 5.8 days vs 7.6 in CC group p < 0.001) and faster access to adjuvant therapies. 92.5% of the MC patients, which were scheduled for treatment, started radiotherapy within 8 weeks after surgery as opposed to 84.1% in the CC group (p = 0.04). These findings support the increasing use of mini-craniotomy for intra-axial brain tumors.

Balloon-Assisted Corpus Callosotomy. Reducing the Impact of Transcallosal Approaches.

BACKGROUND: The interhemispheric transcallosal approach is widely used to remove intraventricular lesions. Corpus callosotomy gives immediate access to the ventricular chambers but is invasive in nature. Loss of callosal fibers, although normally tolerate, may cause disturbances ranging from a classical disconnection syndrome up to minor neuropsychological changes. OBJECTIVE: To open an operative window in the corpus callosum through separation rather than disconnection of the white matter fibers. METHODS: In 7 patients undergoing the interhemispheric transcallosal approach for intraventricular lesions, lying around or below the foramen of Monro, a stoma was created within the corpus callosum by using a 4F Fogarty catheter. The series included 3 colloid of the third ventricle, 2 thalamic cavernomas, 1 subependymoma, and 1 ependymoma of the foramen of Monro. We illustrate the technique and the clinico-radiological outcome, focusing on the size of callosotomy as seen on postoperative MRI. RESULTS: The balloon-assisted corpus callosotomy provided a circular, smooth-walled access to the ventricular chambers, which allowed uncomplicated removal of the lesions. On postoperative MRI, the size of the callosotomy shrinked compared with surgery (2.8-6.4 mm at follow-up vs 6-9 mm as measured intraoperatively). No signs of disconnection syndrome or new permanent deficits were observed in this series. CONCLUSION: The balloon-assisted technique produces a small callosotomy, without clinical consequences, showing a self-closing trend on postoperative MRI. This technique is a rewarding tool to reduce the impact of callosotomy while keeping the advantages of microsurgical interhemispheric approaches.

Hydrocephalus As Possible Prodromal Manifestation of COVID-19: A Report of Two Cases.

Although the etiopathology of normal pressure hydrocephalus (NPH) is still not completely defined, several studies in recent years have highlighted the role of neuro-inflammation mediators in its development. During COVID-19, the infected host develops a multifaceted inflammatory syndrome, that may lead to an uncontrolled immune system response also localized in the host nervous system. In fact, the target of the viral Spike protein, the angiotensin-converting enzyme 2 (ACE2) receptors, is widely expressed in different areas of CNS such as the olfactory epithelium, and the choroid plexus. As for idiopathic NPH, the massive release of inflammatory mediators may result in altered CSF dynamics and consequent sudden clinical decompensation. We report the cases of two patients with a known iNPH condition, in which neurological symptoms suddenly worsened, requiring hospitalization, without any evident precipitating cause. Both patients tested positive for the COVID-19 virus shortly after the neurological impairment, which had occurred, therefore, during the incubation period of the infection. On the basis of our experience we advise, in cases of NPH patients with sudden neurological worsening, to perform a molecular COVID-19 swab at the moment of clinical impairment. We, therefore, recommend considering SARS-CoV-2 infection in the differential diagnosis of a sudden and otherwise unexplainable impairment of hydrocephalic patients. Furthermore, we believe clinicians should invite NPH patients to adopt adequate preventive measures to protect them from SARS-CoV-2 infection.

Factor XI deficiency and delayed hemorrhages after resection of choroid plexus papilloma: illustrative case.

BACKGROUND: Factor XI deficiency, also known as hemophilia C, is a rare inherited bleeding disorder that may leave routine coagulation parameters within normal range. Depending on the mutation subtype, prolonged activated partial thromboplastin time may occasionally be found. The disease has an autosomal transmission, with an estimated prevalence in the general population of approximately 1 in 1 million. Heterozygosis accounts for partial deficits, but the tendency to bleed is unrelated to the measured activity of factor XI. Diagnosis usually follows unexpected hemorrhages occurring spontaneously or after trauma or surgical procedures. OBSERVATIONS: Few cases have been reported in the neurosurgical literature, all occurring spontaneously or after head trauma. Owing to its subtle features, the true incidence of the disease is probably underestimated. The authors report a case of a patient with previously undiagnosed factor XI deficiency who underwent uncomplicated resection of a fourth-ventricle papilloma and experienced delayed, severe hemorrhagic complications. LESSONS: The known association between choroid plexus tumors and intracranial bleeding raised differential diagnosis issues. This report may serve to help to investigate delayed hemorrhages after cranial surgery.

Degenerative Cervical Myelopathy: How to Identify the Best Responders to Surgery?

Surgery is the only definitive treatment for degenerative cervical myelopathy (DCM), however, the degree of neurological recovery is often unpredictable. Here, we assess the utility of a multidimensional diagnostic approach, consisting of clinical, neurophysiological, and radiological parameters, to identify patients likely to benefit most from surgery. Thirty-six consecutive patients were prospectively analyzed using the modified Japanese Orthopedic Association (mJOA) score, MEPs/SSEPs and advance and conventional MRI parameters, at baseline, and 3- and 12-month postoperatively. Patients were subdivided into "normal" and "best" responders (<50%, ≥50% improvement in mJOA), and correlation between Diffusion Tensor Imaging (DTI) parameters, mJOA, and MEP/SSEP latencies were examined. Twenty patients were "best" responders and 16 were "normal responders", but there were no statistical differences in age, T2 hyperintensity, and midsagittal diameter between them. There was a significant inverse correlation between the MEPs central conduction time and mJOA in the preoperative period (p = 0.0004), and a positive correlation between fractional anisotropy (FA) and mJOA during all the phases of the study, and statistically significant at 1-year (r = 0.66, p = 0.0005). FA was significantly higher amongst "best responders" compared to "normal responders" preoperatively and at 1-year (p = 0.02 and p = 0.009). A preoperative FA > 0.55 was predictor of a better postoperative outcome. Overall, these results support the concept of a multidisciplinary approach in the assessment and management of DCM.

Indocyanine Green Videoangiography in the Surgical Treatment of Spinal Dural Arterovenous Fistula: A Useful Application.

BACKGROUND: Indocyanine green videoangiography (ICG-V) is used with increasing frequency in neurovascular surgery. ICG-V use in spinal dural arteriovenous fistulas (DAVFs) allows visualization of the hemodynamics of the fistula and to confirm its exclusion after ligation of the feeder. Here, we illustrate how ICG-V is useful for centering the surgical exposure during mini-invasive approaches to spinal DAVFs. METHODS: An overweight 66-year-old woman with progressive paraparesis and sphincter disturbances underwent treatment for a spinal DAVF fed by the left T6 radicular artery. After intraoperative fluoroscopy, T6 hemilaminectomy was performed. Because of slight misplacement of the bone opening, the feeder was not visible at the dural opening. We placed a temporary clip on a perimedullary arterialized vein and performed ICG-V while removing the clip. RESULTS: Reviewing the video clip and analyzing the direction of ICG flow inside the perimedullary venous plexus allowed us to locate the fistula with respect to the bone window and to extend the laminectomy in the correct direction. CONCLUSIONS: IGC-V can be helpful in mini-invasive approaches to spinal DAVFs to recalibrate the bone opening after misplacement of the initial hemilaminectomy.

Fronto-orbital mucocele with intracranial extension: a case report.

Frontal sinus mucoceles are benign, pseudocystic lesion deriving from the obliteration of the sinus ostium, resulting in a continuous mucous accumulation. The growing process of a mucocele leads to a progressive enlargement of the sinus cavity, thickening and eroding its bony walls up to invading the surrounding tissues. The surgical procedure through an endoscopic endonasal approach is the current treatment option for such conditions, but in cases with an extensive bone erosion and intracranial or intraorbital extension, a transcranial approach should be preferred. We report a case of a frontal sinus mucocele with unusual intraorbital and intracranial extension, causing exophthalmos and ophthalmoplegia, removed through a transcranial frontal approach and the subsequent obliteration of the sinus.

Surgery or not? A case of ventriculus terminalis in an adult patient.

The ventriculus terminalis (VT) is an intramedullary cavity containing cerebrospinal fluid (CSF), usually located at the conus, and represents an unsuccessful regression of a normal embryological phase of the development of the neural tube. Symptoms are not univocal and may vary from aspecific signs to sphincter dysfunctions and focal neurological deficits. The correct management of this condition is still an object of debate due to its rarity and its unpredictable behaviour in adult patients. Two different studies have proposed a distinction for patients with cystic dilatation of VT based on their symptoms, suggesting that only those patients with neurological deficits clearly related to the terminal ventricle could benefit from surgery. We describe a case of an adult patient with a progressive dilatation of a diagnosed VT that we treated surgically. A management flowchart for this condition is also proposed based on our experience and a review of the literature.

Cervical intramedullary spinal cord lipoma.

BACKGROUND: Intramedullary, nondysraphic, spinal cord lipomas are rare and account for less than 1% of all spinal cord lesions. Symptoms typically consist of a progressive myelopathy associated with increasing degrees of paralysis (e.g., quadriparesis/plegia, paraparesis/plegia). CASE DESCRIPTION: A 39-year-old male, without a history of spinal dysraphism, presented with a progressive spastic quadriparesis. This was attributed to magnetic resonance-documented large intramedullary cervical lipoma. Following partial intramedullary surgical debulking of the lesion, the patient neurologically improved. CONCLUSION: Partial debulking of a cervical intramedullary lipoma in a patient who originally presented with a severe quadriparesis resulted in significant neurological improvement. Notably, utilization of intraoperative ultrasonography, CO2 laser, and both motor evoked and somatosensory evoked potentials can be helpful during the removal of such lipomas.

Reasons why a second radiological opinion is advisable: a case report of a misreported crural synovial cell sarcoma.

Synovial sarcoma (SS) is a rare condition that accounts for 5-10% of all soft-tissue sarcomas (STS). SS locates most frequently near the joints, in particular at the lower extremities, but it can also occur in other locations. We report a case of a 42-year-old male complaining of a slow-growth mass on his right thigh, reported as a femoral nerve shwannoma on the basis of the preoperative radiological investigations, which revealed to be a monophasic SS on the histological examination. During the surgical procedure, the assistance of vascular surgeons was required to reconstruct the wall of the femoral vein underlying the tumor, that was pathologically thickened, and communicated with the tumoral capsule. Although extremely rare, SS should be considered in the differential diagnosis of peripheral nerve sheath tumors, in particular if next to a large vein at the lower extremities.

Sudden post-traumatic sciatica caused by a thoracic spinal meningioma.

Spinal meningiomas usually present with slowly progressive symptoms of cord and root compression, while a sudden clinical onset is very rare. A 35-year-old previously symptom-free woman presented sudden right sciatica and weakness of her right leg following a fall with impact to her left foot. A neurological examination showed paresis of the right quadriceps, tibial and sural muscles, increased bilateral knee and ankle reflexes and positive Babinski sign. Magnetic resonance imaging (MRI) revealed the presence of a spinal T11 meningioma in the left postero-lateral compartment of the spinal canal; at this level, the spinal cord was displaced to the contralateral side with the conus in the normal position. At surgery, a meningioma with dural attachment of the left postero-lateral dural surface was removed. The intervention resulted in rapid remission of both pain and neurological deficits. Spinal meningiomas may exceptionally present with sudden pain and neurological deficits as result of tumour bleeding or post-traumatic injury of the already compressed nervous structures, both in normal patients and in those with conus displacement or tethered cord. In this case, the traumatic impact of the left foot was transmitted to the spine, resulting in stretching of the already compressed cord and of the contralateral lombosacral roots. This case suggests that low thoracic cord compression should be suspected in patients with post-traumatic radicular leg pain with normal lumbar spine MRI.