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Neurosurg Focus ; 49(2): E11, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32738792


OBJECTIVE: Opportunistic Hounsfield unit (HU) determination from CT imaging has been increasingly used to estimate bone mineral density (BMD) in conjunction with assessments from dual energy x-ray absorptiometry (DXA). The authors sought to compare the effect of teriparatide on HUs across different regions in the pelvis, sacrum, and lumbar spine, as a surrogate measure for the effects of teriparatide on lumbosacropelvic instrumentation. METHODS: A single-institution retrospective review of patients who had been treated with at least 6 months of teriparatide was performed. All patients had at least baseline DXA as well as pre- and post-teriparatide CT imaging. HUs were measured in the pedicle, lamina, and vertebral body of the lumbar spine, in the sciatic notch, and at the S1 and S2 levels at three different points (ilium, sacral body, and sacral ala). RESULTS: Forty patients with an average age of 67 years underwent a mean of 20 months of teriparatide therapy. Mean HUs of the lumbar lamina, pedicles, and vertebral body were significantly different from each other before teriparatide treatment: 343 ± 114, 219 ± 89.2, and 111 ± 48.1, respectively (p < 0.001). Mean HUs at the S1 level for the ilium, sacral ala, and sacral body were also significantly different from each other: 124 ± 90.1, -10.7 ± 61.9, and 99.1 ± 72.1, respectively (p < 0.001). The mean HUs at the S2 level for the ilium and sacral body were not significantly different from each other, although the mean HU at the sacral ala (-11.9 ± 52.6) was significantly lower than those at the ilium and sacral body (p = 0.003 and 0.006, respectively). HU improvement occurred in most regions following teriparatide treatment. In the lumbar spine, the mean lamina HU increased from 343 to 400 (p < 0.001), the mean pedicle HU increased from 219 to 242 (p = 0.04), and the mean vertebral body HU increased from 111 to 134 (p < 0.001). There were also significant increases in the S1 sacral body (99.1 to 130, p < 0.05), S1 ilium (124 vs 165, p = 0.01), S1 sacral ala (-10.7 vs 3.68, p = 0.04), and S2 sacral body (168 vs 189, p < 0.05). CONCLUSIONS: There was significant regional variation in lumbar and sacropelvic HUs, with most regions significantly increasing following teriparatide treatment. The sacropelvic area had lower HU values than the lumbar spine, more regional variation, and a higher degree of correlation with BMD as measured on DXA. While teriparatide treatment resulted in HUs > 110 in the majority of the lumbosacral spine, the HUs in the sacral ala remained suggestive of severe osteoporosis, which may limit the effectiveness of fixation in this region.

Otolaryngol Head Neck Surg ; 162(5): 666-673, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32178578


OBJECTIVE: Although granulomatosis with polyangiitis (GPA; Wegener's granulomatosis) is classically characterized by systemic disease involving the kidneys and airway, approximately 10% of patients who have it present with isolated central nervous system disease. When involving the skull base, GPA frequently mimics more common pathology, resulting in diagnostic challenges and delay. The primary objective of this study is to characterize the cranial base manifestations of GPA, highlighting aspects most relevant to the skull base surgeon. STUDY DESIGN: Retrospective review. SETTING: Tertiary academic referral center. SUBJECTS AND METHODS: Retrospective analysis of all patients with skull base GPA treated at a tertiary referral center from January 1, 1996, to May 1, 2018. RESULTS: Twenty-nine patients met inclusion criteria. Twenty-one (72%) initially presented with skull base symptomatology as their cardinal manifestation of GPA. Twenty-four (82%) presented with cranial neuropathy at some point in their disease course. The trigeminal nerve was most commonly involved (12 of 24, 50%), followed by the facial (11 of 24, 46%) and optic (8 of 24, 33%) nerves. Eighteen patients reported hearing loss attributed to the GPA disease process, presenting as conductive, sensorineural, or mixed. The most common locations for GPA-derived inflammatory skull base disease on imaging included the cavernous sinus (12 of 29, 41%) and the orbit (7 of 29, 24%). CONCLUSION: Establishing the diagnosis of skull base GPA remains challenging. Cranial neuropathy is diverse in presentation and often mimics more common conditions. Imaging findings are also unpredictable and frequently nonspecific. Careful review of patient history, clinical presentation, serology and biopsy results, and imaging can reveal important clues toward the diagnosis.

Laryngoscope ; 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31841234


OBJECTIVE: IgG4-related disease (IgG4-RD) is a recently recognized disease characterized by fibroinflammatory infiltrates rich in IgG4+ plasma cells that can present as isolated tumor-like lesions of the head and neck. The objective of the current study was to describe the cranial base manifestations of IgG4-RD. METHODS: Review of all cases at three tertiary-referral centers since disease description in 2003. RESULTS: Eleven patients were identified at a median age at presentation of 58 years (IQR, 38-65; 55% male). Ten (91%) patients had isolated skull base masses without systemic disease. Cranial neuropathies were commonly observed in the abducens (45%), trigeminal (18%), and facial nerves (18%). Lesions frequently involved the cavernous sinus (55%; 6/11) with extension to the petroclival junction in 50% (3/6). Infiltration of the internal auditory canal was present in 27% (3/11) with one case demonstrating erosion of the bony labyrinth. Preliminary clinical diagnoses commonly included nasopharyngeal cancer, pituitary macroadenoma, cholesteatoma, and meningioma / multiple meningioma syndrome. Local biopsy demonstrated >30 IgG4-positive plasma cells per high-powered field or an IgG4:IgG ratio greater than 40% in all cases. Rapid and durable clinical improvement was seen in 91% following corticosteroid and rituximab therapy. CONCLUSIONS: IgG4-RD nonspecifically presents as a rare cause of the skull base mass. Often presenting without concomitant systemic disease, local diagnostic biopsies are required. Obtaining adequate tissue specimen is complicated by densely fibrotic cranial base lesions that are frequently in close proximity to critical neurovascular structures. Primary medical therapy with corticosteroids and rituximab is effective in most patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 2019.

Neurosurgery ; 85(4): E693-E701, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30828728


BACKGROUND: Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis. Up to 50% of patients develop central nervous system involvement, and a subset of these patients can present with isolated tumor-like masses. OBJECTIVE: To describe the skull base manifestations of ECD with an emphasis on aspects most pertinent to surgeons who may be referred such patients for primary evaluation. METHODS: Scopus, Web of Science, and PubMed were searched from database inception to May 1, 2018 for articles reporting skull base ECD. An institutional retrospective analysis of all patients treated at the authors' institution since January 1, 1996 was also performed to supplement these data. RESULTS: Of 465 retrieved articles, 18 studies totaling 20 patients met inclusion criteria. Institutional review identified an additional 7 patients. Collectively, the median age at diagnosis was 49 yr (interquartile range, 42-58) with a 4:1 male-to-female ratio. Patients frequently presented with diplopia (48%), headache (30%), dysarthria (22%), and vertigo or imbalance (22%), though trigeminal hypesthesia (11%), facial nerve paresis (7%), hearing loss (7%), and trigeminal neuralgia (7%) were also observed. ECD commonly mimicked meningioma (33%), trigeminal schwannoma (8%), neurosarcoidosis (8%), and skull base lymphoma (8%). CONCLUSION: Discrete skull base lesions frequently mimic more common pathology such as meningioma or cranial nerve schwannomas. Medical therapy comprises the initial treatment for symptomatic skull base disease. Surgical resection is not curative and the utility of surgical intervention is largely limited to biopsy to establish diagnosis and/or surgical debulking to relieve mass effect.

Doença de Erdheim-Chester/diagnóstico por imagem , Doença de Erdheim-Chester/terapia , Base do Crânio/diagnóstico por imagem , Corticosteroides/administração & dosagem , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiocirurgia/métodos , Radiocirurgia/tendências , Estudos Retrospectivos
World Neurosurg ; 2018 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-30597282


BACKGROUND: Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft tissue sarcomas, with approximately 50% occurring in patients diagnosed with neurofibromatosis type 1 (NF-1). NF-1 occurs in approximately 1/3000 individuals, and given that the lifetime prevalence of MPNST is estimated at 8%-13%, synchronous development of separate MPNSTs is plausible. We sought to report the incidence of synchronous MPNST in a cohort of pathology-proven cases since 1994. METHODS: Records since 1994 were queried and identified 192 patients with pathology-proven MPNST. Medical records of these patients were reviewed to search for patients with synchronous MPNSTs. RESULTS: Retrospective review of 192 patients treated for MPNST at our institution (including 71 patients with NF-1) revealed only 1 patient with synchronous MPNSTs. A 48-year-old woman with NF-1 presented with progressive right upper and lower extremity pain and radicular symptoms. Biopsies of right sciatic and median nerve lesions revealed high-grade MPNST, and she underwent radiotherapy and complete resection of both masses. Due to initial nonspecific biopsy results and patient preference, treatment of the median nerve lesion was delayed by 8 months. She did not have recurrence of her disease at the 18-month follow-up. CONCLUSIONS: Synchronous development of MPNST is unusual, with an incidence of 1.4% in our cohort of NF-1 patients with MPNSTs. Given the reported incidence of synchronous MPNST, the rate of malignant transformation in NF-1 may be overestimated. However, heightened suspicion for malignant transformation should continue in patients harboring a diagnosis of MPNST.

Brain ; 136(Pt 8): 2444-56, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23803305


Eleven patients being evaluated with intracranial electroencephalography for medically resistant temporal lobe epilepsy participated in a visual recognition memory task. Interictal epileptiform spikes were manually marked and their rate of occurrence compared between baseline and three 2 s periods spanning a 6 s viewing period. During successful, but not unsuccessful, encoding of the images there was a significant reduction in interictal epileptiform spike rate in the amygdala, hippocampus, and temporal cortex. During the earliest encoding period (0-2000 ms after image presentation) in these trials there was a widespread decrease in the power of theta, alpha and beta band local field potential oscillations that coincided with emergent focal gamma frequency activity. Interictal epileptiform spike rate correlated with spectral band power changes and broadband (4-150 Hz) desynchronization, which predicted significant reduction in interictal epileptiform spike rate. Spike-triggered averaging of the field potential power spectrum detected a burst of low frequency synchronization 200 ms before the interictal epileptiform spikes that arose during this period of encoding. We conclude that interictal epileptiform spikes are modulated by the patterns of network oscillatory activity that accompany human memory offering a new mechanistic insight into the interplay of cognitive processing, local field potential dynamics and interictal epileptiform spike generation.

Tonsila do Cerebelo/fisiopatologia , Epilepsia do Lobo Temporal/fisiopatologia , Hipocampo/fisiopatologia , Memória/fisiologia , Rede Nervosa/fisiopatologia , Lobo Temporal/fisiopatologia , Adulto , Mapeamento Encefálico , Eletroencefalografia , Humanos , Testes Neuropsicológicos , Reconhecimento Psicológico/fisiologia