COVID-19 neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital.

Many patients with SARS-CoV-2 infection develop neurological signs and symptoms; although, to date, little evidence exists that primary infection of the brain is a significant contributing factor. We present the clinical, neuropathological and molecular findings of 41 consecutive patients with SARS-CoV-2 infections who died and underwent autopsy in our medical centre. The mean age was 74 years (38-97 years), 27 patients (66%) were male and 34 (83%) were of Hispanic/Latinx ethnicity. Twenty-four patients (59%) were admitted to the intensive care unit. Hospital-associated complications were common, including eight patients (20%) with deep vein thrombosis/pulmonary embolism, seven (17%) with acute kidney injury requiring dialysis and 10 (24%) with positive blood cultures during admission. Eight (20%) patients died within 24 h of hospital admission, while 11 (27%) died more than 4 weeks after hospital admission. Neuropathological examination of 20-30 areas from each brain revealed hypoxic/ischaemic changes in all brains, both global and focal; large and small infarcts, many of which appeared haemorrhagic; and microglial activation with microglial nodules accompanied by neuronophagia, most prominently in the brainstem. We observed sparse T lymphocyte accumulation in either perivascular regions or in the brain parenchyma. Many brains contained atherosclerosis of large arteries and arteriolosclerosis, although none showed evidence of vasculitis. Eighteen patients (44%) exhibited pathologies of neurodegenerative diseases, which was not unexpected given the age range of our patients. We examined multiple fresh frozen and fixed tissues from 28 brains for the presence of viral RNA and protein, using quantitative reverse-transcriptase PCR, RNAscope® and immunocytochemistry with primers, probes and antibodies directed against the spike and nucleocapsid regions. The PCR analysis revealed low to very low, but detectable, viral RNA levels in the majority of brains, although they were far lower than those in the nasal epithelia. RNAscope® and immunocytochemistry failed to detect viral RNA or protein in brains. Our findings indicate that the levels of detectable virus in coronavirus disease 2019 brains are very low and do not correlate with the histopathological alterations. These findings suggest that microglial activation, microglial nodules and neuronophagia, observed in the majority of brains, do not result from direct viral infection of brain parenchyma, but more likely from systemic inflammation, perhaps with synergistic contribution from hypoxia/ischaemia. Further studies are needed to define whether these pathologies, if present in patients who survive coronavirus disease 2019, might contribute to chronic neurological problems.

Gonadotroph tumours with a low SF-1 labelling index are more likely to recur and are associated with enrichment of the PI3K-AKT pathway.

AIMS: The gonadotroph tumour (GT) is the most frequently resected pituitary neuroendocrine tumour. Although many symptomatic GT are successfully resected, some recur. We sought to identify histological biomarkers that may predict recurrence and explore biological mechanisms that explain this difference in behaviour. METHODS: SF-1 immunohistochemistry of 51 GT, a subset belonging to a longitudinal prospective cohort study (n = 25), was reviewed. Four groups were defined: Group 1-recently diagnosed GT (n = 20), Group 2-non-recurrent GT with long-term follow up (n = 11), Group 3-initial resections of GT that recur (n = 7) and Group 4-recurrent GT (n = 13). The percentage of SF-1 immunolabelling in the lowest staining fields (SF-1 labelling index (SLI)) was assessed and RNA sequencing was performed on 5 GT with SLI <80% and 5 GT with SLI >80%. RESULTS: Diffuse, strong SF-1 immunolabelling was the most frequent pattern in Groups 1/2, whereas patchy SF-1 staining predominated in Groups 3/4. There was a lower median SLI in Groups 3/4 than 1/2. Overall, GT with SLI <80% recurred earlier than GT with SLI >80%. Differential expression analysis identified 89 statistically significant differentially expressed genes (FDR <0.05) including over-expression of pituitary stem cell genes (SOX2, GFRA3) and various oncogenes (e.g. BCL2, ERRB4) in patchy SF-1 GT. Gene set enrichment analysis identified significant enrichment of genes involved in the PI3K-AKT pathway. CONCLUSIONS: We speculate that patchy SF-1 labelling in GT reflects intratumoural heterogeneity and are less differentiated tumours than diffusely staining GT. SF-1 immunolabelling patterns may have prognostic significance in GT, but confirmatory studies are needed for further validation.

Prognostic value of nadir GH levels for long-term biochemical remission or recurrence in surgically treated acromegaly.

CONTEXT: Outcome of acromegaly surgery is assessed by IGF-1 and glucose-suppressed GH, but whether the latter provides additional clinically relevant information when IGF-1 is normal is unclear. The role of GH suppression testing after surgery requires clarification. METHODS: We studied 97 acromegaly patients with normal IGF-1 after surgery by measuring GH after oral glucose longitudinally, initially at ≥ 3 months after surgery and repeated one or more times ≥ 1 year later. Nadir GH was categorized as normal or abnormal relative to the 97.5th percentile of nadir GH in 100 healthy subjects, which were ≤ 0.14 µg/L (DSL IRMA) or ≤ 0.15 µg/L(IDS iSYS). Signs and symptoms scores and insulin resistance were followed longitudinally. RESULTS: Of 68 patients with initial normal GH suppression 63 (93%) remained in remission and of 29 with initial abnormal GH suppression, 9 (31%) recurred. Recurrence was more common in patients with abnormal suppression (P < 0.001). A total of 14 patients recurred, including 5 with normal GH suppression progressing to abnormal and then recurrence. Overall, serial signs and symptoms and insulin resistance assessments did not identify patients with abnormal suppression or recurrence. CONCLUSION: Risk of recurrence after surgery is increased for patients with a normal IGF-1 level, but abnormal GH suppression. We newly find, using both our and others' cut-offs, that while normal suppression predicts long-term remission in most patients, some can progress from normal to abnormal suppression and then recurrence after many years of follow up. Nadir GH levels are of prognostic value in acromegaly patients with normal IGF-1 levels after surgery.

Isoflurane Use in the Treatment of Super-Refractory Status Epilepticus is Associated with Hippocampal Changes on MRI.

BACKGROUND: Refractory status epilepticus (RSE) is associated with high morbidity and mortality. Experts recommend aggressive management with continuous intravenous infusions or inhaled anesthetics such as isoflurane. However, there is concern that MRI changes in RSE reflect isoflurane neurotoxicity. We performed a case-control study to determine whether isoflurane is neurotoxic, based on MRI signal changes. METHODS: We performed a retrospective case-control study of the incidence of MRI changes in RSE treated with and without isoflurane. Charts were reviewed for demographic and treatment information. T1, T2, and FLAIR sequences of MRIs were reviewed independently by two neuroradiologists blinded to treatment group for presence or absence of signal change or atrophy in the meninges, cortex, white matter, basal ganglia, thalamus, hippocampus, brainstem, and cerebellum. RESULTS: Eight cases of RSE receiving treatment with isoflurane were identified and double-matched with 15 controls who received only intravenous anesthetics. Baseline characteristics were similar. Hippocampal signal change was observed more frequently in cases receiving isoflurane (p = 0.026). CONCLUSIONS: Hippocampal signal changes were associated with isoflurane use in patients with RSE. They were also associated with number of seizure days prior to MRI and the use of multiple anesthetic agents. Similar changes have been seen as a result of RSE itself, and one cannot rule out the possibility these changes represent seizure-related effects. If isoflurane-related, these hippocampal signal changes may be the result of a direct neurotoxic effect of prolonged isoflurane use or failure of isoflurane to protect the hippocampus from seizure-induced injury despite achieving electrographic burst-suppression.

Ropinirole for the Treatment of Hyperprolactinemia: A Dose-Escalation Study of Efficacy and Tolerability.

CONTEXT: Treatment of hyperprolactinemia with ergoline dopamine agonists (DAs) can be complicated by intolerance and resistance. OBJECTIVE: This study examines the efficacy and tolerability of the nonergot DA ropinirole for the long-term treatment of hyperprolactinemia. METHODS: Twelve hyperprolactinemic women were treated with ropinirole in a 6-month, open-label, dose-escalation trial; 7 of the 12 continued treatment in an extension study for up to 17 months. Ropinirole doses were uptitrated to achieve normal prolactin (PRL) levels, restore menses, and eliminate galactorrhea. RESULTS: Two of the 12 participants were DA naive; 6 of 12 were ergot DA intolerant; and 1 of 12 had known ergot DA resistance. Baseline PRL levels were 126.2 ± 41.4 ng/mL (SEM). Ropinirole was uptitrated from 0.125 to 0.25 mg/h to a median total daily dose (TDD) of 2 mg/d (1-4 mg/d [interquartile range]). PRL normalization was achieved in 50% of the participants (5 with microadenomas and 1 with idiopathic hyperprolactinemia) at a median effective TDD of 1 mg/d. Of the patients achieving PRL normalization, 83% were ergot DA intolerant. A persistent partial biochemical response (PRL reduction >50% from baseline) was achieved in 17% of the participants. During treatment, menses resumed in 67% of amenorrheic patients; galactorrhea resolved in 67%. Mild adverse effects were reported in 92% of participants; however, ropinirole was not discontinued because of intolerance even among the 50% of individuals with a prior history of ergot DA intolerance and resultant medication discontinuation. CONCLUSION: These data demonstrate the efficacy and tolerability of ropinirole for the treatment of hyperprolactinemia in patients with microprolactinomas and idiopathic hyperprolactinemia and suggest ropinirole may represent a novel therapeutic alternative for treating hyperprolactinemic disorders in patients with ergot DA intolerance.

Prospective, longitudinal study of cancer predictors and rates in a New York City cohort of 598 patients with acromegaly.

PURPOSE: Long-term GH/IGF-1 excess could increase risk of cancer in acromegaly, but individual levels of these hormones do not relate to this risk. Therefore, we newly investigated longitudinally-measured IGF-1 levels as a potential predictor of cancer in a large NYC acromegaly cohort. METHODS: We conducted a prospective, longitudinal study of 598 acromegaly (309 men, 289 women) and 292 clinically nonfunctioning pituitary adenoma (CNFPA)(140 women, 152 men) patients from the same underlying population. GH and IGF-1 levels were measured longitudinally and outcomes were observed during long-term follow-up. Cumulative exposure to IGF-1 excess was tested as a predictor of cancer. We compared cancer prevalence in acromegaly and CNFPA cohorts and incidence in each to that expected from SEER data. RESULTS: Cancer prevalence by last follow up was 22.6% in acromegaly and 12.7% in CNFPAs (OR = 1.99 (95% CI, 1.34, 2.97)(P=0.0005). Overall SIR for cancer was 1.78 (1.51, 1.81) in the acromegaly and 1.26 (0.89, 1.70) in the CNFPA cohorts. Cumulative exposure to IGF-1 excess, OR=1.278 (1.060, 1.541)(P = 0.01), years from acromegaly diagnosis to cancer or last follow up, OR= 1.03 (1.004, 1.057)(P=0.024), and age at follow up, OR =1.064 (1.047, 1.082)(P<0.001), were predictors of cancer. CONCLUSIONS: Cancer risk is increased in acromegaly, but not in CNFPA patients. Cumulative exposure to IGF-1 excess is a predictor of cancer in acromegaly. Our data suggest that cancer risk in acromegaly relates to the degree and duration of IGF-1 excess and that full appreciation of this risk requires long-term follow up.

Hypothalamic obesity in patients with craniopharyngioma: treatment approaches and the emerging role of gastric bypass surgery.

Hypothalamic obesity is a potential sequela of craniopharyngioma, arising from hypothalamic damage inflicted by either the tumor and/or its treatment. The marked weight gain that characterizes this disorder appears to result from impaired sympathoadrenal activation, parasympathetic dysregulation, and other hormonal and hypothalamic disturbances that upset the balance between energy intake and expenditure. Given hypopituitarism is commonly present, careful management of hormonal deficits is important for weight control in these patients. In addition, diet, exercise, and pharmacotherapy aimed at augmenting sympathetic output, controlling hyperinsulinism, and promoting weight loss have been used to treat this disease, but these measures rarely lead to sustained weight loss. While surgical interventions have not routinely been pursued, emerging data suggests that surgical weight loss interventions including Roux-en-Y gastric bypass can be safely and effectively used for the management of hypothalamic obesity in patients with craniopharyngioma.

Intracerebral monitoring of silent infarcts after subarachnoid hemorrhage.

BACKGROUND: Silent infarction is common in poor-grade subarachnoid hemorrhage (SAH) patients and associated with poor outcome. Invasive neuromonitoring devices may detect changes in cerebral metabolism and oxygenation. METHODS: From a consecutive series of 32 poor-grade SAH patients we identified all CT-scans obtained during multimodal neuromonitoring and analyzed microdialysis parameters and brain tissue oxygen tension (PbtO2) preceding CT-scanning. RESULTS: Eighteen percent of the reviewed head-CTs (12/67) revealed new infarcts. Of the eight infarcts in the vascular territory of the neuromonitoring, seven were clinically silent. Neuromonitoring changes preceding radiological evidence of infarction included lactate-pyruvate-ratio elevation and brain glucose decreases when compared to those with distant or no ischemia (P ≤ 0.03, respectively). PbtO2 was lower, but this did not reach statistical significance. CONCLUSIONS: These data suggest that there may be distinct changes in brain metabolism and oxygenation associated with the development of silent infarction within the monitored vascular territory in poor-grade SAH patients. Larger prospective studies are needed to determine whether treatment triggered by neuromonitoring data has an impact on outcome.

Presenting Features in 269 Patients With Clinically Nonfunctioning Pituitary Adenomas Enrolled in a Prospective Study.

CONTEXT: Clinically nonfunctioning pituitary adenomas (CNFPAs) typically remain undetected until mass effect symptoms develop. However, currently, head imaging is performed commonly for many other indications, which may increase incidental discovery of CNFPAs. Since current presentation and outcome data are based on older, retrospective series, a prospective characterization of a contemporary CNFPA cohort was needed. OBJECTIVE: To determine the prevalence of incidental presentation and hypopituitarism and its predictors in a CNFPA cohort that spanned 6 to 9 mm micro- to macroadenoma included observational and surgical therapy. METHODS: At enrollment in a prospective, observational study, 269 patients with CNFPAs were studied by history, examination, blood sampling, and pituitary imaging analysis and categorized into incidental or symptoms presentation groups that were compared. RESULTS: Presentation was incidental in 48.7% of patients and due to tumor symptoms in 51.3%. In the symptoms and incidental groups, 58.7% and 27.4% of patients had hypopituitarism, respectively, and 25% of patients with microadenomas had hypopituitarism. Many had unappreciated signs and symptoms of pituitary disease. Most tumors were macroadenomas (87%) and were larger in the symptoms than incidental and hypopituitary groups than in the eupituitary groups. The patients in the incidental group were older, and males were older and had larger tumors in both the incidental and symptoms groups. CONCLUSIONS: Patients with CNFPAs commonly present incidentally and with previously unrecognized hypopituitarism and symptoms that could have prompted earlier diagnosis. Our data support screening all large micro and macro-CNFPAs for hypopituitarism. Most patients with CNFPAs still have mass effect signs at presentation, suggesting the need for more awareness of pituitary disease. Our ongoing, prospective observation of this cohort will assess outcomes of these CNFPA groups.

Magnetic resonance imaging characteristics of pilomyxoid astrocytoma.

OBJECTIVE: Pilomyxoid astrocytoma (PMA) is a recently identified pediatric low-grade neoplasm that was previously classified as pilocytic astrocytoma (PA), yet demonstrates unique histological features and more aggressive behavior. These tumors have been shown to have significantly shorter progression-free and overall survival probability than classical low-grade astrocytomas, as well as a high rate of cerebrospinal fluid (CSF) dissemination. This paper describes the radiographic features of PMA. METHODS: Magnetic resonance imaging (MRI) was obtained for ten PMAs. Radiographic characteristics of the tumor were recorded in each case. All tissue samples were independently reviewed for confirmation of pathologic diagnosis. RESULTS: All tumors appeared well-circumscribed with no evidence of peritumoral edema or parenchymal infiltration on MRI. All tumors except one originated from the midline of the neuroaxis. Specifically, five tumors (50.0%) were located in the hypothalamic region, two (20.0%) were located in the spine, two (20.0%) were located in the dorsal brainstem and one was located in the right thalamus. Five tumors (50.0%) demonstrated solid composition, with the remaining five showing some cystic components. Mass effect, hydrocephalus and central necrosis were observed in 62.5, 50.0 and 0.0% of cases, respectively. Eight tumors (80%) were hyperintense on T1-weighted MRI. Seven tumors (77.8%) were hyperintense on T2-weighted MRI. All tumors were hyperintense on fluid attenuated inversion recovery (FLAIR) sequence and hypointense on diffusion weighted imaging (DWI). Upon contrast administration, six tumors (60.0%) enhanced heterogeneously and four tumors (40.0%) enhanced homogenously. CONCLUSION: Pilomyxoid astrocytoma is a well-circumscribed pediatric neoplasm that commonly originates from the midline of the neuroaxis and lacks peritumoral edema or central necrosis. It is critical to recognize the predominantly solid and well-circumscribed nature of the neoplasm to avoid confusion with an infiltrating astrocytoma.

Chronic myelopathy due to a giant spinal arachnoid cyst: a complication of the intrathecal injection of phenol. Case report.

Acquired intradural arachnoid cystic lesions of the spine have been associated with trauma, hemorrhage, parasitic infections, and other insults that cause inflammation and subarachnoid adhesions. The authors describe the case of a previously healthy 36-year-old woman who presented with a chronic myelopathy due to the progressive development of a giant spinal arachnoid cyst that resulted after the intrathecal injection of phenol for the management of chronic upper extremity pain. Neurological examination, spinal computed tomography, and magnetic resonance imaging were used for diagnostic and follow-up purposes. Even after the initial excision of the cyst, the patient remained symptomatic with minimal functional recovery.

Intramedullary inclusion cysts of the cervicothoracic junction. Report of two cases in adults and review of the literature.

Intramedullary inclusion cysts are extremely rare within the rostral spinal cord. In this case report the authors outline the clinical features and surgical treatment of one dermoid cyst and one epidermoid cyst of the cervicothoracic junction. The authors also include a relevant literature discussion regarding the treatment and the embryological origin of these lesions.

Pitfall in the Diagnosis of Diabetes Insipidus and Pregnancy.

Diabetes insipidus (DI) during pregnancy and the perinatal period is an uncommon medical problem characterized by polyuria and excessive thirst. Diagnosis of DI may be overlooked in the setting of pregnancy, a time when increased water intake and urine output are commonly reported. We report two cases: one of transient DI in a young woman during her third trimester of twin pregnancy in association with acute fatty liver and hypertension and one of postpartum DI secondary to Sheehan syndrome from rupture of a splenic artery aneurysm. These cases illustrate the spectrum with which DI related to pregnancy and delivery can present and highlight the difficulty in making the diagnosis since the symptoms are often initially overlooked.

Long-term survival with ACTH-secreting carcinoma of the pituitary: a case report and review of the literature.

A 48-yr-old woman was evaluated 21 yr after receiving treatment for an ACTH-secreting metastatic pituitary carcinoma. She had been diagnosed with Cushing's disease 35 yr earlier at the age of 14 yr and had undergone bilateral adrenalectomy. Six years later she developed Nelson's syndrome, which was treated with resection of a pituitary adenoma followed by radiotherapy to the sella turcica. Eight years later she was found to have craniospinal metastases with three remote intracerebral lesions. Two of these lesions were surgically resected and stained positive for ACTH by immunofluorescence. She subsequently received whole-brain radiotherapy and is doing well 21 yr later with no lesions seen on magnetic resonance imaging and no evidence of recurrent metastatic disease. We present this case in detail along with a literature review of ACTH-secreting pituitary carcinoma.

Trigeminal Nerve-Blood Vessel Relationship as Revealed by High-resolution Magnetic Resonance Imaging and Its Effect on Pain Relief after Gamma Knife Radiosurgery for Trigeminal Neuralgia.

OBJECTIVE: Blood vessel (BV) compression of the trigeminal nerve (Cranial Nerve [CN] V) is a common cause of trigeminal neuralgia (TN). High-resolution magnetic resonance imaging scans obtained during gamma knife radiosurgery (GKRS) in patients with TN may be used to analyze the BV-CN V relationship. Follow-up data from a large series of patients treated with GKRS for TN were used to provide information regarding the BV-CN V relationship and pain relief. METHODS: T1-weighted, axial 1-mm-thick volume acquisition magnetic resonance imaging scans were obtained through the area of CN V at its exit from the brainstem after injection of 15 ml of gadolinium. The BV-CN V relationship on the symptomatic side that was treated with GKRS was categorized into the following groups: Group 1 (no close relationship), Group 2 (BV close to CN V but not touching it), and Groups 3 and higher (BV-CN V contact). RESULTS: A total of 181 symptomatic nerves were studied in 179 patients with TN who were treated with GKRS. In BV-CN V Groups 1, 2, and 3 and higher, respectively, were 43 sides (24%), 31 sides (17%), and 107 sides (59%). In 100 sides where there was no surgical procedure before GKRS, 50% or greater pain relief was more likely in those with BV-CN V contact (51 [88%] of 58 sides) than in those without BV-CN V (29 [69%] of 42 sides) (P = 0.024). BV-CN V contact was observed more often in men (55 [69%] of 80 sides) than in women (52 [52%] of 101 sides) (P = 0.023) and more often in patients who had unilateral TN (104 [62%] of 169 patients) rather than bilateral TN (2 [20%] of 10 patients) (P = 0.016). CONCLUSION: In patients who have not undergone previous surgery for TN, BV-CN V contact revealed by high-resolution magnetic resonance imaging may indicate a particularly favorable response to GKRS.

Pilomyxoid astrocytoma: a review.

Pilomyxoid astrocytoma (PMA) is a recently described type of brain tumor. PMA shares similar features with pilocytic astrocytoma (PA), the most common central nervous system (CNS) tumor in the pediatric population, yet displays subtle histologic differences. Previous studies have shown PMA to behave more aggressively than PA, with shorter progression-free and overall survival as well as a higher rate of recurrence and CNS dissemination. These findings suggest that PMA may be a unique and distinct neoplasm. This review summarizes the histologic, clinical, and radiographic characteristics of PMA. In addition, the current treatment options and research endeavors involving this disease are described. Increased recognition of PMA within the medical community has the potential to affect the treatment and prognosis of pediatric low-grade astrocytomas.

Clinical utility of plasma POMC and AgRP measurements in the differential diagnosis of ACTH-dependent Cushing's syndrome.

CONTEXT: Distinguishing between pituitary [Cushing's disease (CD)] and ectopic causes [ectopic ACTH syndrome (EAS)] of ACTH-dependent Cushing's syndrome can be challenging. Inferior petrosal sinus sampling (IPSS) best discriminates between CD and occult EAS but is a specialized procedure that is not widely available. Identifying adjunctive diagnostic tests may prove useful. In EAS, abnormal processing of the ACTH precursor proopiomelanocortin (POMC) and the accumulation of POMC-derived peptides might be expected and abnormal levels of other neuropeptides may be detected. OBJECTIVE: The objective of the study was to evaluate the diagnostic utility of POMC measurements for distinguishing between CD and occult EAS in patients referred for IPSS. Another objective of the study was to evaluate in parallel the diagnostic utility of another neuropeptide, agouti-related protein (AgRP), because we have observed a 10-fold elevation of AgRP in plasma in a patient with EAS from small-cell lung cancer. DESIGN AND PARTICIPANTS: Plasma POMC and AgRP were measured in 38 Cushing's syndrome patients presenting for IPSS, with either no pituitary lesion or a microadenoma on magnetic resonance imaging, and in 38 healthy controls. RESULTS: Twenty-seven of 38 patients had CD; 11 of 38 had EAS. The mean POMC was higher in EAS vs CD [54.5 ± 13.0 (SEM) vs 17.2 ± 1.5 fmol/mL; P < .05]. Mean AgRP was higher in EAS vs CD (280 ± 76 vs 120 ± 16 pg/mL; P = .01). Although there was an overlap in POMC and AgRP levels between the groups, the POMC levels greater than 36 fmol/mL (n = 7) and AgRP levels greater than 280 pg/mL (n = 3) were specific for EAS. When used together, POMC greater than 36 fmol/mL and/or AgRP greater than 280 pg/mL detected 9 of 11 cases of EAS, indicating that elevations in these peptides have a high positive predictive value for occult EAS. CONCLUSIONS: Expanding upon previous observations of high POMC in EAS, this study specifically demonstrates elevated POMC levels can identify occult ectopic tumors. Elevations in AgRP also favor the diagnosis of EAS, suggesting AgRP should be further evaluated as a potential neuroendocrine tumor marker.

Review of imaging techniques in the diagnosis and management of brain metastases.

Brain metastasis is one of the most common diagnoses encountered by neurologists, neurosurgeons, radiologists, and oncologists. The aim of this article is to review imaging modalities used in the diagnosis and follow-up of brain metastases. Through the use of various imaging techniques more accurate preoperative diagnosis and more precise intraoperative planning can be made. Post-treatment evaluation can also be refined through the use of these imaging techniques.

Relationship between brain interstitial fluid tumor necrosis factor-α and cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

Tumor necrosis factor-alpha (TNF-alpha) has a crucial role in the onset of hemolysis-induced vascular injury and cerebral vasoconstriction. We hypothesized that TNF-alpha measured from brain interstitial fluid would correlate with the severity of vasospasm following aneurysmal subarachnoid hemorrhage (aSAH). From a consecutive series of 10 aSAH patients who underwent cerebral microdialysis (MD) and evaluation of vasospasm by CT angiogram (CTA) or digital subtraction angiography (DSA), TNF-alpha levels from MD were measured at 8-hour intervals from aSAH days 4-6 using enzyme-linked immunosorbent assay. An attending neuroradiologist blinded to the study independently evaluated each CTA and DSA and assigned a vasospasm index (VI). Five patients had a VI<2 and 5 patients had a VI>2, where the median VI was 2 (range 0-13). The median log TNF-alpha area under the curve (AUC) was 1.64pg/mL *day (interquartile range 1.48-1.71) for the VI<2 group, and 2.11pg/mL *day (interquartile range 1.95-2.47) for the VI>2 group (p<0.01). Thus, in this small series of poor-grade aSAH patients, the AUC of TNF-alpha levels from aSAH days 4-6 correlates with the severity of radiographic vasospasm. Further analysis in a larger population is warranted based on our preliminary findings.