Faculty Bibliography

Background Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (LITT) is a minimally invasive treatment modality that has been gaining traction in neuro-oncology. Laser ablation is a particularly appealing treatment option when eloquent neurologic function at the tumor location precludes conventional surgical excision. Although typically performed under general anesthesia, LITT in awake patients may help monitor and preserve critical neurologic functions. Objective To describe intraoperative workflow and clinical outcomes in patients undergoing awake laser ablation of brain tumors. Methods We present a cohort of six patients with tumors located in eloquent brain areas that were treated with awake LITT and report three different workflow paradigms involving diagnostic or intraoperative MRI. In all cases, we used NeuroBlate® (Monteris Medical, Plymouth, MN) fiberoptic laser probes for stereotactic laser ablation of tumors. The neurologic status of patients was intermittently assessed every few minutes during the ablation. Results The mean preoperative tumor volume that was targeted was 12.09 ± 3.20 cm³, and the estimated ablation volume was 12.06 ± 2.75 cm³. Performing the procedure in awake patients allowed us close monitoring of neurologic function intraoperatively. There were no surgical complications. The length of stay was one day for all patients except one. Three patients experienced acute or delayed worsening of pre-existing neurologic deficits that responded to corticosteroids. Conclusion We propose that awake LITT is a safe approach when tumors in eloquent brain areas are considered for laser ablation.

BACKGROUND:Eye-hand coordination (EHC) is a sophisticated act that requires interconnected processes governing synchronization of ocular and manual motor systems. Precise, timely and skillful movements such as reaching for and grasping small objects depend on the acquisition of high-quality visual information about the environment and simultaneous eye and hand control. Multiple areas in the brainstem and cerebellum, as well as some frontal and parietal structures, have critical roles in the control of eye movements and their coordination with the head. Although both cortex and cerebellum contribute critical elements to normal eye-hand function, differences in these contributions suggest that there may be separable deficits following injury. METHOD/METHODS:As a preliminary assessment for this perspective, we compared eye and hand-movement control in a patient with cortical stroke relative to a patient with cerebellar stroke. RESULT/RESULTS:We found the onset of eye and hand movements to be temporally decoupled, with significant decoupling variance in the patient with cerebellar stroke. In contrast, the patient with cortical stroke displayed increased hand spatial errors and less significant temporal decoupling variance. Increased decoupling variance in the patient with cerebellar stroke was primarily due to unstable timing of rapid eye movements, saccades. CONCLUSION/CONCLUSIONS:These findings highlight a perspective in which facets of eye-hand dyscoordination are dependent on lesion location and may or may not cooperate to varying degrees. Broadly speaking, the results corroborate the general notion that the cerebellum is instrumental to the process of temporal prediction for eye and hand movements, while the cortex is instrumental to the process of spatial prediction, both of which are critical aspects of functional movement control.

OBJECTIVE:Investigations have found associations of homonymous thinning of the macular ganglion cell/ inner-plexiform layer (GCIPL) with demyelinating lesions in the post-chiasmal visual pathway among patients with multiple sclerosis (MS). Retinal thinning may also occur through retrograde trans-synaptic degeneration, a process by which lesions in post-geniculate visual pathway structures lead to thinning of the GCIPL across thalamic synapses. The purpose of our study was to determine the frequency of homonymous hemimacular thinning that occurs in association with post-chiasmal visual pathway demyelinating lesions in patients with MS and other demyelinating diseases. METHODS:Adult patients with demyelinating diseases (MS, neuromyelitis optica spectrum disorder [NMOSD], myelin oligodendrocyte glycoprotein antibody disease (anti-MOG)) who were participants in an ongoing observational study of visual pathway structure and function were analyzed for the presence of hemimacular GCIPL thinning on OCT scans. Brain MRI scans were examined for the presence of post-geniculate visual pathway demyelinating lesions. RESULTS:Among 135 participants in the visual pathway study, 5 patients (3.7%) had homonymous hemimacular GCIPL thinning. Eleven patients (8.1%) had a whole+half pattern of GCIPL thinning, characterized by hemimacular thinning in one eye and circumferential macular thinning in the contralateral eye. All but one patient with homonymous hemimacular thinning had demyelinating lesions in the post-geniculate visual pathway; however, these lesions were located in both cerebral hemispheres. CONCLUSION/CONCLUSIONS:Homonymous hemimacular thinning in the GCIPL by OCT is associated with post-chiasmal visual pathway demyelinating lesions but it appears to be a relatively uncommon contributor to GCIPL loss. Patients with this pattern of GCIPL often fail to complain of hemifield visual loss. Future studies with prospective and detailed MR imaging may be able to more closely associate demyelinating lesions in anatomically appropriate regions of the post-chiasmal visual pathways with homonymous hemimacular thinning.

The cavernous sinus is a complex structure susceptible to a wide variety of vascular, neoplastic and inflammatory pathologies. Vascular pathologies include ICA aneurysms, carotid-cavernous fistulas, cavernous sinus thrombosis, and cavernous hemangioma. Neoplasms that involve the cavernous sinus include pituitary adenoma, meningioma, schwannoma, lymphoma, perineural tumor spread, metastases, and direct tumor invasion. Infectious and inflammatory diseases include Tolosa-Hunt syndrome, sarcoidosis, granulomatosis with polyangiitis, IgG-4 related disease and invasive fungal infections. In this article, we review the clinical and imaging findings of a number of pathologies involving the cavernous sinus, focusing on key features that can narrow the differential diagnosis and, in some cases, support a particular diagnosis.

Coronavirus disease 2019 (COVID-19) has been reported in association with a variety of brain imaging findings such as ischemic infarct, hemorrhage, and acute hemorrhagic necrotizing encephalopathy. Here, we report brain imaging features in 11 critically ill COVID-19 patients with persistently depressed mental status who underwent MRI between April 5-25, 2020 at our institution. These features include, 1) Confluent T2 hyperintensity and mild restricted diffusion in bilateral supratentorial deep and subcortical white matter (in 10 of 11 patients), and 2) multiple punctate microhemorrhages in juxtacortical and callosal white matter (in 7 of 11 patients). We also discuss potential pathogeneses.

The transsphenoidal corridor for pituitary adenoma surgery was established as early as 1906 by Schloffer and was subsequently refined by Cushing throughout the early 20thcentury [1]. The use of intraoperative magnetic resonance imaging (iMRI) in endoscopic endonasal transsphenoidal resections, however, is a relatively contemporary addition to the surgical treatment of pituitary tumors. The morbidity of these cases has decreased over the years in light of advances in intraoperative navigation as well as improvements in endoscope dynamics and surgical instruments. Despite such improvements, a substantial number of patients require repeat surgeries or subsequent radiotherapy for residual and/or recurrent disease. This can be largely attributed to cavernous sinus invasion or suprasellar extension, which pose technical challenges to achieving gross total resections (GTRs). The rate of GTR for pituitary tumors cited in the literature varies from 59-88%.[2-3] The advantage of iMRI is that it provides the surgeon with immediate feedback regarding their progress and ability to safely achieve GTR which, in pituitary surgery, is critical for long term cure. Additionally, although there is concern for increased risk of postoperative endocrine dysfunction, Zhibin et al prove that this is not necessarily the case. In their series, 133 patients who underwent iMRI had higher rates of GTR and did not have a significant difference in postoperative hypopituitarism. [4] This study includes a combined retrospective and prospective comparative analysis of 238 patients who underwent transsphenoidal resection of a pituitary tumor from January 2013 until May 2019. All patients were operated on by one of four experienced neurosurgeons and one of three experienced otolaryngologists. There were 203 patients who did not undergo iMRI and 25 patients who did. A 3 tesla MRI magnet was used in all cases. All intraoperative images were read and interpreted by a senior neuroradiologist at our institution. Amongst the two groups, there was no statistically significant difference in patient age (p = 0.488), tumor size (microadenoma versus macroadenoma, p = 0.878), and primary versus recurrent tumor (p = 0.837). The use of iMRI did not yield a decrease in the length of stay (4.84 days in the no iMRI group and 5 in the iMRI group, p = 0.777). There were zero cases of a return to the OR for residual tumor in the intraoperative MRI group versus the non-MRI group. However, this did not reach statistical significance. This study did not yield a statistically significant difference in GTR (p = 0.75), near total resection (NTR, p = 0.167), or subtotal resection (p = 0.083). This is likely secondary to a low sample size and therefore power in the iMRI group. Finally, there was no significant difference in the number of patients requiring postoperative DDAVP (p = 0.099) or hydrocortisone (p = 0.873) after discharge. Preliminary results reveal a potential benefit of iMRI use to assess for residual disease which can be addressed immediately during the initial operation, thus decreasing the need for re-operations. Furthermore, the ability to correlate intraoperative findings with an intraoperative structure may lead to more precise identification and preservation of normal gland, which can possibly decrease the incidence of postoperative endocrine dysfunction

BACKGROUND:Spinal epidural lipomatosis (SEL) is a rare condition defined as pathological overgrowth of the normally present epidural fat within the spinal canal. SEL is associated with Cushing disease, obesity and chronic corticosteroid therapy. Diabetes mellitus type 1 (DM1) has not known to be a risk factor for SEL. The neurological symptoms of SEL are attributed mainly to mechanical compression on the spinal cord and the cauda equina. METHODS:A retrospective chart review of patients evaluated at NYU Multiple Sclerosis Care Center identified three diabetic patients with progressive myelopathy associated with SEL. We report the clinical course, diagnostic workup and outcomes in these three patients with SEL-associated myelopathy. RESULTS:Three patients (2 females and 1 male) had long-standing DM1 and developed progressive myelopathy in their early 40's. All were found to have thoracic SEL (extensive extradural T1, T2 hyperintense signal; biopsy confirmed in one case) with associated extensive abnormal cord signal in lower cervical/upper thoracic spinal cord. A comprehensive evaluation for metabolic, infectious, autoimmune and vascular causes of myelopathy that included serologies, cerebrospinal fluid analyses, and spinal angiography did not reveal an alternative cause for myelopathy. One of the patients underwent a surgical decompression of SEL with subsequent clinical and radiologic improvement. CONCLUSIONS:Our case series suggest that patients with DM1 and myelopathy of unknown cause should be evaluated for SEL. Timely diagnosis and appropriate intervention may forestall progression of neurological disability and even result in neurologic improvement. SEL should be considered on the short list of diagnoses that cause potentially reversible progressive myelopathy.