Biomedical subjects

Michael J Ebersold

Publications and source records attributed to Michael J Ebersold.

8 recordsLinked to original sources

PubMed2006

Long-term incidence of subaxial cervical spine instability following cervical arthrodesis surgery in patients with rheumatoid arthritis.

OBJECTIVE: Cervical spine deformities are well-known complications of RA. A 5- to 20-year follow-up of 51 consecutive rheumatoid patients who underwent posterior cervical arthrodesis is presented to evaluate the recurrence of instability and need for further surgery. METHODS: We conducted a retrospective review of the clinical features of 11 men and 40 women with an established diagnosis of RA and associated cervical deformities who underwent cervical spine surgery at the Mayo Clinic (Rochester, MN) between 1979 and 1990. Their mean age was 61 +/- 10 years (SD), and their duration of RA averaged 21 +/- 8.9 years (SD). There were 22 patients who presented with myelopathy, 7 with radiculopathy, and 22 with instability/neck pain. There were 33 patients with AAS, 2 with SMO process into the foramen magnum, 8 with SAS, and 8 with combinations of these. Preoperative reduction was followed by decompression and fusion using wiring techniques and autologous bone graft. Postoperative halo orthosis was provided for at least 3 months. The mean follow-up was 8.3 +/- 6 years (SD). RESULTS: There were 31 patients (61%) who underwent atlantoaxial arthrodesis, 17 patients (33%) who underwent subaxial, and 3 patients (6%) who underwent occipitocervical arthrodesis. During follow-up, 39% (13/33) of patients with AAS developed nonsymptomatic (6) or symptomatic/unstable (7) SASs subsequent to C1-C2 fusion. The latter 7 patients (21%) subsequently required extension of their arthrodesis. Adjacent segment disease was most common at the C3-C4 interspace after atlantoaxial fusion in 62% (8/13). Among the 8 patients who underwent isolated cervical fusion for SAS, 1 patient (1/8, 12%) developed adjacent instability after a fall and required extension of the previous fusion. No secondary procedure was required for the 6 patients initially stabilized by C1-(C6-T1) fusions for combinations of AAS + SAS. None of the patients initially treated by C1-C2 arthrodesis for AAS progressed to SMO. CONCLUSIONS: The incidence of subaxial instability in patients with rheumatoid disease who underwent cervical arthrodesis may be higher than previously reported, indicating the need for continued follow-up in these patients. Adjacent segment disease may be most common at the C3-C4 level following atlantoaxial fusion. Early stabilization of the C1-C2 complex in the patients with AAS may potentially prevent progression of SMO.

Aged↗

PubMed2006

Iatrogenic cerebellar implantation of a vestibular schwannoma. Case report.

Metastatic seeding or iatrogenic implantation of numerous types of primary central nervous system tumors, typically along cerebrospinal fluid pathways, is a frequently described albeit rare phenomenon and has never been reported in association with vestibular schwannoma (VS). The authors present a case of inadvertent surgical implantation of VS into the cerebellar hemisphere during resection of a recurrent VS in the cerebellopontine angle and internal auditory canal. A 42-year-old man presented with a 2.5-cm right VS that was removed without complication via a retrosigmoid approach. Routine imaging performed 5 years later revealed a 1.5-cm recurrence of the VS that was subsequently removed by reopening the retrosigmoid craniotomy. Five years later--10 years after initial presentation--follow-up imaging revealed a 1-cm recurrence of the VS and a separate 2.2-cm tumor in the inferior cerebellar parenchyma with surrounding edema. Both tumors were removed without complication by reopening the previous retrosigmoid craniotomy. Histological evaluation of these tumors revealed features typical of VS and similar to those of the tissue obtained from the two prior resections. Given the similarities among these tumors in pathological appearance and mitotic index, the presence of the intraparenchymal cerebellar schwannoma was probably due to intraoperative iatrogenic implantation.

Adult↗

PubMed2004

Choroid plexus papillomas: a single institutional experience.

OBJECTIVE: To determine the long-term outcome of resected choroid plexus papillomas (CPPs). METHODS: Medical records and histologic specimens were reviewed for 41 patients (19 male, 22 female; median age, 36 years; range, 6 months to 74 years) with CPP seen between 1974 and 2000. Tumor locations were as follows: 76%, fourth ventricle; 17%, lateral ventricle, and 7%, third ventricle. Fifty-six percent had a gross total resection (GTR) and 44% had a subtotal resection (STR). Median follow-up was 6.5 years. RESULTS: Five-year local control, distant brain control, and overall survival were 84%, 92%, and 97%, respectively. Comparison of GTR and STR at 5 years showed a significant increase in local control (100% vs. 68%; P = 0.04) but not in overall survival (100% vs. 94%). Even after STR, only 50% of patients required a subsequent resection for recurrence. Addition of radiation therapy to initial STR did not seem to influence outcomes. At first relapse, GTR was accomplished in 1 patient, and only STR was accomplished in the others. Addition of radiation therapy to STR in our study led to disease control in half the patients treated, and STR alone led to disease control in only a quarter of the patients. Second relapses were treated palliatively with radiation therapy. CONCLUSIONS: Surgical resection is the treatment of choice for CPPs. After initial STR, reoperations for recurrence are required only half the time. Therefore, there seems to be no role for radiation therapy after initial STR. For STRs at first relapse, local control outcome is poor.

Adolescent↗

PubMed2002

Spontaneous disc space infections in adults.

BACKGROUND: Spontaneous discitis typically affects children; much less is known about the disease in adults. We examined the clinical characteristics and the role of surgery in spontaneous infectious discitis in adults. METHODS: Twenty-nine consecutive adult patients (16 men, 13 women) with spontaneous infectious discitis were treated by a single surgeon (MJE) over a 5-year period. These patients were compared to 19 consecutive patients with postoperative discitis over the same time period. Mean follow-up was 2.4 years. RESULTS: The average age of patients with spontaneous discitis was 69.0 years. Eleven of these patients (38%) were diabetic and 9 (31%) had a known concurrent infection. Infections occurred at cervical (10%), thoracic (34%), and lumbar interspaces (59%), and at multiple disc spaces in eight cases (28%). Ten patients (34%) had an elevated serum leukocyte count and 21 patients (72%) had an elevated erythrocyte sedimentation rate. While Gram-positive infection was most common, a broad spectrum of microbes was isolated. All patients were treated with i.v. antibiotics for a mean duration of 6 weeks. Four patients required surgical fusion; the rest were treated with external immobilization. At follow-up, 21 patients (72%) were symptom-free, 3 patients (10%) had ongoing disease, and 5 patients (17%) had died of unrelated causes. Compared to patients with postoperative discitis treated over the same time period, spontaneous discitis in adults affected older patients and required a broader spectrum of antibiotic coverage. Outcomes were similar between the two groups. CONCLUSIONS: While spontaneous discitis has predominantly been reported in children, the disease also affects older adults. Spontaneous discitis in adults is associated with advanced age, diabetes mellitus, and systemic infection. Elevated serum leukocyte count lacks diagnostic sensitivity. A high cure rate is achieved with antibiotics and external immobilization. Surgical treatment is rarely required.

Aged↗

PubMed2002

Measurement of cerebrospinal fluid flow at the cerebral aqueduct by use of phase-contrast magnetic resonance imaging: technique validation and utility in diagnosing idiopathic normal pressure hydrocephalus.

OBJECTIVE: We analyzed the reliability of a protocol for measuring quantitative cerebrospinal fluid (CSF) flow at the cerebral aqueduct and established the range of CSF flows in normal elderly patients, patients with Alzheimer's and other forms of dementia, and patients with idiopathic normal pressure hydrocephalus (NPH). METHODS: A constant flow phantom was used to establish the accuracy of the CSF flow measurement. The clinical variability of the measurement was estimated by calculating the standard deviations and coefficients of variation of intra- and interobserver and intertrial data sets derived from three normal volunteers. A total of 236 patients were studied, including 47 normal elderly patients, 115 patients with cognitive impairment (9 with mild cognitive impairment, 46 with Alzheimer's disease, and 60 with other cognitive impairment), 31 patients in whom NPH was suspected but ultimately excluded, and 43 patients with a final clinical diagnosis of NPH. RESULTS: The intraobserver, interobserver, and intertrial measurement variations of 6.4, 5.4, and 8.8%, respectively, were substantially smaller than the wide variation observed among subjects. There was no statistically significant difference in flow between normal elderly patients and patients with cognitive impairment (P = 0.91). When these populations were pooled, the average flow was 8.47 ml/min (standard deviation, 4.23; range, 0.9-18.5 ml/min). The average flow rate in patients with a final clinical diagnosis of NPH was 27.4 ml/min (standard deviation, 15.3; range, 3.13-62.2 ml/min). This was significantly higher than the flow rate in each of the other three groups (all, P < 0.001). CONCLUSION: CSF flow measurements of less than 18 ml/min with a sinusoidal flow pattern are normal. CSF flow of greater than 18 ml/min suggests idiopathic NPH.

Adult↗

PubMed2002

Choristoma of the optic nerve: case report.

OBJECTIVE AND IMPORTANCE: Optic nerve choristoma is a rare lesion composed of adipose tissue and smooth muscle involving the optic nerve. Few cases have been reported. CLINICAL PRESENTATION: A 20-year-old woman presented with a history of slowly progressive visual loss in the left eye. On T1-weighted magnetic resonance imaging studies, after frequency-selective fat saturation, an optic nerve mass was detected at the level of the optic canal with signal characteristics suggesting the diagnosis of optic nerve lipoma. INTERVENTION: At left frontotemporal craniotomy, the intracranial optic nerve appeared thin and atrophic proximally and was covered by abundant adipose tissue distally. Because no cleavage plane could be identified between the fatty lesion and the optic nerve, which appeared splayed within the adipose tissue, the nerve was resected after an intraoperative biopsy. The presence of two heterotopic mesodermal elements, a rim of adipose tissue admixed with bundles of mature smooth muscle, extending into the nerve septa, warranted a diagnosis of optic nerve choristoma. CONCLUSION: Optic nerve choristoma is an uncommon optic nerve lesion. Even if imaging studies are highly suggestive of the diagnosis, pathological confirmation is required because of the high adipose tissue content in the majority of cases. The lesion, most likely malformative and nonneoplastic in nature, can be the cause of progressive visual loss.

Adolescent↗

PubMed2002

Vertebra plana caused by primary Ewing sarcoma: case report and review of the literature.

A 7-year-old boy presented with vertebra plana of T11. The presumptive diagnosis suggested by clinical presentation, conventional radiographs, and computed tomographic scans was eosinophilic granuloma. Progressive neurologic symptoms required surgical excision of the lesion and decompression. Histopathologic examination of the surgical specimen confirmed the diagnosis of Ewing sarcoma.

Back Pain↗

PubMed2002

Use of cerebrospinal fluid flow rates measured by phase-contrast MR to predict outcome of ventriculoperitoneal shunting for idiopathic normal-pressure hydrocephalus.

OBJECTIVE: To determine whether favorable clinical response and magnitude of improvement are associated with increased aqueductal cerebrospinal fluid (CSF) flow rates in patients who undergo ventriculoperitoneal shunting (VPS) for idiopathic normal-pressure hydrocephalus (NPH). PATIENTS AND METHODS: Between January 1995 and June 2000, 49 patients (14 men and 35 women; mean age, 72.9 years; range, 54-88 years) underwent magnetic resonance quantification of aqueductal CSF flow followed by VPS for presumed idiopathic NPH at the Mayo Clinic, Rochester, Minn. Logistic regression models for the odds of any improvement in score as a function of aqueductal CSF flow and separate models for any improvement in gait, incontinence, cognition, and total score were constructed. RESULTS: Forty-two patients (86%) had improvement in gait at postoperative follow-up (mean, 10 months). Of the 32 patients with incontinence, 27 (69%) improved. Of the 36 patients with cognitive impairment, 16 (44%) improved. In univariate and fully adjusted models, increased CSF flow through the aqueduct was not significantly associated with improvement or the magnitude of improvement in gait, cognition, or incontinence. Thirty-six patients underwent high-volume lumbar puncture preoperatively, of whom 5 (14%) had no response. The aqueductal CSF flow rates of these 5 patients were significantly higher than those of the patients who improved after lumbar puncture. Postoperative complications occurred in 15 patients. The aqueductal CSF flow rates in these 15 patients were not significantly different from those of patients who experienced no complications. CONCLUSION: Among patients who underwent VPS for the treatment of NPH, measurement of CSF flow through the cerebral aqueduct did not reliably predict which patients would improve after shunting or the magnitude of improvement.

Aged↗