Supratentorial lymphocytic inflammation with parenchymal perivascular enhancement responsive to steroids: A case report and literature review.

BACKGROUND: Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids is a rare disorder that presents with subacute brainstem symptoms such as ataxia, facial paresthesias, and episodic diplopia, thought to be due to a T-cell medicated perivascular inflammatory process. A supratentorial variant, Supratentorial Lymphocytic Inflammation with Parenchymal Perivascular Enhancement Responsive to Steroids (SLIPPERS), has been described in only three patients. CASE DESCRIPTION: A 71-year-old male presented with word-finding difficulties, confusion, and left leg weakness. Radiographic workup demonstrated multiple supratentorial ring-enhancing lesions. PET/CT demonstrated hypermetabolism and susceptibility-weighted imaging demonstrated a hemorrhagic component. Frozen pathology revealed a predominately T-cell and monocyte inflammatory infiltrate. He demonstrated interval improvement to dexamethasone therapy, but then demonstrated worsening of his symptoms following discontinuation. CONCLUSION: Given his dramatic response to corticosteroids, he was diagnosed with SLIPPERS. SLIPPERS is an underrecognized diagnostic entity to consider in patients with ring-enhancing lesions and can present with hypermetabolic lesions on PET/CT.

Facing a Feared Situation: Endoscopic Endonasal Approach for Petroclival Lesions With Internal Carotid Artery Encasement: 2-Dimensional Operative Video.

A 33-yr-old woman presented with diplopia due to partial III and VI cranial nerve palsies, and an magnetic resonance imaging (MRI) showed a left petroclival lesion with cavernous sinus invasion. The ipsilateral internal carotid artery (ICA) was displaced and encased by the tumor. Chondroid tumors such as this are known to be high risk for ICA injury1; however, given the patient's young age a radical resection was desirable,2 depending on the risk of such a strategy. Therefore, a preoperative balloon test occlusion (BTO) was performed to estimate the risk of stroke in case of ICA sacrifice.3 Clinical and single-photon emission computed tomography testing predicted low risk of stroke, allowing for aggressive resection. A preoperative ICA occlusion was not performed as intraoperative control was believed to be adequate and preservation is always preferable when possible due to rare inaccuracies in BTO and long term risks of occlusion. An endoscopic endonasal and right contralateral transmaxillary approach with intraoperative neurophysiology were performed to remove this lesion.4,5 During surgery, the ICA proved dehiscent, and was therefore clip sacrificed.6 An immediate postoperative digital subtraction angiography showed minimally delayed, but adequate, blood flow to the left cerebral hemisphere. Postoperative MRI showed complete removal and no significant infarct. The patient was discharged in stable neurological condition, with only a slightly worsened CN III palsy. Experience with management of ICA injury is of uttermost importance in endoscopic endonasal surgery,1,2 and requires adequate training and an experienced 2-surgeon team.7 The patient provided consent to the submission and publication of the related surgical video.

Endoscopic Nasopharyngectomy Combined with a Nerve-sparing Transpterygoid Approach.

OBJECTIVES/HYPOTHESIS: Surgical management of nasopharyngeal tumors has evolved in the endoscopic era. Lateral exposure remains difficult especially near the petrous internal carotid artery and bony Eustachian tube (ET). Our study examines the need to sacrifice the vidian and greater palatine nerves in order to successfully perform en bloc endoscopic nasopharyngectomy. METHODS: Four cadaveric specimens (eight sides) were dissected bilaterally using a binarial, extended, endoscopic endonasal approach (EEA). Nasopharyngectomy was completed including an extended transptyergoid approach for resection of the cartilaginous ET at its junction with the bony ET. Dissection was attempted without sacrifice of the vidian or palatine nerves. RESULTS: Successful en bloc nasopharyngectomy combined with a nerve-sparing transpterygoid approach was achieved in all specimens with successful preservation of the palatine and vidian nerves. The approach provided exposure of foramen lacerum, the petrous carotid, foramen spinosum, and foramen ovale as well as all segments of the cartilaginous Eustachian tube, Meckel's cave and the parapharyngeal carotid. There was no inadvertent exposure or injury of the internal carotid artery. CONCLUSION: Endoscopic nasopharyngectomy combined with a nerve-sparing transpterygoid approach allows for en bloc resection of the cartilaginous Eustachian tube and nasopharyngeal contents with broad skull base exposure and preservation of the internal carotid artery, vidian and palatine nerves. LEVEL OF EVIDENCE: VI Laryngoscope, 130:2343-2348, 2020.

Evaluation of Intranasal Flap Perfusion by Intraoperative Indocyanine Green Fluorescence Angiography.

BACKGROUND: Vascularized intranasal flaps are the primary reconstructive option for endoscopic skull base defects. Flap vascularity may be compromised by injury to the pedicle or prior endonasal surgery. There is currently no validated technique for intraoperative evaluation of intranasal flap viability. OBJECTIVE: To evaluate the efficacy of indocyanine green (ICG) near-infrared angiography in predicting the viability of pedicled intranasal flaps during endoscopic skull base surgery through a pilot study. METHODS: ICG near-infrared fluorescence endoscopy was performed during endoscopic endonasal surgery for skull base tumors. Intraoperative and postoperative data were collected regarding enhancement of the flap body and pedicle. Fluorescence was rated qualitatively. Postoperatively, flap perfusion was evaluated via MRI-contrast enhancement in addition to clinical outcomes (cerebrospinal fluid leak and endoscopic flap appearance). RESULTS: Thirty-eight patients underwent ICG fluorescence angiography. Both the body and pedicle enhanced in 20 patients (53%), while the pedicle only enhanced for 12 patients (32%), the body only for 3 (8%), and neither for 3 (8%). When both the pedicle and body enhanced with ICG, the rate of postoperative MRI contrast enhancement was 100% and the rate of flap necrosis was 0%. The sensitivity and specificity of flap pedicle ICG enhancement for predicting postoperative flap MRI enhancement were 97% and 67%, respectively. Two of 3 patients without enhancement developed flap necrosis. CONCLUSION: ICG fluorescence angiography of intraoperative flap perfusion is feasible and correlates well with outcomes of postoperative MRI flap enhancement and flap necrosis. Additional study is needed to further refine the imaging technique and optimally characterize the clinical utility.

Dural prostate adenocarcinoma metastasis with subdural hematoma mimicking the appearance of an epidural hematoma.

Prostatic adenocarcinoma presenting as metastatic disease to the nervous system is a rare pathologic entity and has infrequently been reported over the last several years. Furthermore, although its presentation as chronic subdural hematomas has been repeatedly reported previously in the literature, to our knowledge there is no report of its appearance mimicking an epidural hematoma on noncontrast head CT. Here we describe the clinical presentation, evaluation and surgical intervention of a patient with a dural prostate carcinoma metastasis with chronic subdural hematoma mimicking an epidural hematoma.