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Biomedical subjects

Neil R Miller

Publications and source records attributed to Neil R Miller.

At least 19 recordsLinked to original sources
PubMed2006

Rosai-Dorfman disease presenting with widespread intracranial and spinal cord involvement.

Rosai-Dorfman disease is associated with a histiocytic infiltration of lymphoid tissue, but may also involve the orbit, nasopharynx, respiratory pathways, gastrointestinal tract, endocrine glands (particularly the thyroid), bone, and skin. Neurologic manifestations are rare, occurring in 4% of one series, and the diagnosis is often not made until pathology is available. Using data from two cases, we present the clinical manifestations, pathology, and treatment, and review the literature regarding the ocular and neurologic manifestations. Finally, we discuss the optimum management of this disorder.

Adult↗
PubMed2006

Prevalence of a normal C-reactive protein with an elevated erythrocyte sedimentation rate in biopsy-proven giant cell arteritis.

OBJECTIVE: The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are laboratory tests that have been said to have a strong correlation with a positive temporal artery biopsy in patients with suspected giant cell arteritis (GCA). Published reports suggest that the CRP is a more sensitive diagnostic indicator of GCA and can be elevated when the ESR is normal. It is also clear that the CRP and ESR can both be normal or both be elevated in patients with biopsy-proven GCA and that the CRP can be elevated when the ESR is normal. The purpose of this study was to ascertain if the CRP can be normal when the ESR is elevated in biopsy-proven GCA. DESIGN: Retrospective, longitudinal, comparative study. PARTICIPANTS: One hundred nineteen patients from 6 major tertiary-care university-affiliated medical centers. METHODS: The charts from 119 patients with temporal artery biopsies positive for GCA were reviewed for age, gender, pretreatment ESR, and pretreatment CRP. MAIN OUTCOME MEASURES: The ESR in millimeters per hour Westergren was graded as normal or abnormal based on 2 validated formulas. The CRP was graded as normal or abnormal based on established criteria set forth in the literature as well as at The Johns Hopkins Hematology laboratory. RESULTS: In this study, the ESR had a sensitivity of 76% to 86%, depending on which of 2 formulas were used, whereas an elevated CRP had a sensitivity of 97.5%. The sensitivity of the ESR and CRP together was 99%. Only 1 of the 119 patients (0.8%) presented with a normal ESR and normal CRP (double false negative); 2 patients (1.7%) had a normal CRP despite an elevated ESR according to both formulas. CONCLUSION: Although most patients with GCA have both an elevated ESR and CRP, there can be nonconcordance of the 2 blood tests. Although such nonconcordance is most often a normal ESR but an elevated CRP, the finding of an elevated ESR and a normal CRP also is consistent with GCA. The use of both tests provides a slightly greater sensitivity for the diagnosis of GCA than the use of either test alone.

Aged↗
PubMed2006

Supramaximal doses of botulinum toxin for refractory blepharospasm.

PURPOSE: To investigate the response to supramaximal doses of botulinum toxin in patients with refractory blepharospasm. DESIGN: Prospective, nonrandomized, open-label interventional case series. PARTICIPANTS: Eight consecutive patients with blepharospasm requiring injections every 2 months despite receiving 100 U of botulinum toxin per session. INTERVENTION: Increasing the dose of botulinum toxin per session above the conventional maximum. MAIN OUTCOME MEASURES: Duration of treatment effect and patients' subjective response to treatment. RESULTS: Supramaximal dosages were well tolerated. Seven of 8 patients had a prolonged interval between injections relative to that associated with their previous dosing regimen. Four of the patients elected to continue with the new dosage. CONCLUSION: In select patients with essential blepharospasm who are refractory to standard treatment regimens, increasing the dosage of botulinum toxin above 100 U per session may decrease the interval between injections, improve the patient's quality of life, or both.

Aged↗
PubMed2006

Prevalence of Chiari I malformation and cerebellar ectopia in patients with pseudotumor cerebri.

BACKGROUND: Chiari I malformation (CM) may be present pre-surgically in pseudotumor cerebri (PTC) patients. Whether inferior tonsillar displacement (ITD) is coincidental or linked to increased intracranial pressure is unclear. This study aimed to identify the prevalence of both CM and cerebellar ectopia (CE) (ITD below the foramen magnum > or = 5 mm and 2-4 mm, respectively) in PTC patients. METHODS: Retrospective review combined with prospective assessment of 68 PTC patients with available brain magnetic resonance imaging (MRI) scans and reports. Data collected included patient demographics, height, weight, co-morbid conditions, and medications. MRIs were analyzed for cerebellar tonsillar position, and results were compared with original reports. RESULTS: Of 68 PTC patients, 60 (88%) had normal position of the cerebellar tonsils and 8 (12%) had ITD by report. Of the latter group, 4 were identified as CM and 4 as CE. On review of MRIs, however, 16 patients (24%) had ITD, 7 having CM and 9 having CE. All patients with ITD were female, most were overweight or obese, and most had presumed idiopathic intracranial hypertension (IIH). CONCLUSION: ITD exists pre-surgically in a significant percentage of PTC patients. ITD is most common in obese or overweight women with presumed IIH. In fact, this subset of patients may actually represent a secondary form of PTC and may benefit from correction of ITD to restore normal intracranial pressure.

Adolescent↗
PubMed2006

Origin of the relative afferent pupillary defect in optic tract lesions.

OBJECTIVE: To determine the percent decussation of pupil input fibers in humans and to explain the size and range of the log unit relative afferent pupillary defect (RAPD) in patients with optic tract lesions. DESIGN: Experimental study. PARTICIPANTS AND CONTROLS: Five patients with a unilateral optic tract lesion. METHODS: The pupil response from light stimulation of the nasal hemifield, temporal hemifield, and full field of each eye of 5 patients with a unilateral optic tract lesion was recorded using computerized binocular infrared pupillography. Six stimulus light intensities, separated by 0.5-log unit steps, were used; 12 stimulus repetitions were given for each stimulus condition. MAIN OUTCOME MEASURES: For each stimulus condition, the pupil response of each eye was characterized by plotting the mean pupil contraction amplitude as a function of stimulus light intensity. The percentage of decussating afferent pupillomotor input fibers was calculated from the ratio of the maximal pupil contractions elicited from each eye. The RAPD was determined pupillographically from full-field stimulation to each eye. RESULTS: In all patients, the pupil response from the functioning temporal hemifield ipsilateral to the tract lesion was greater than that from the functioning contralateral nasal hemifield. This temporal-nasal asymmetry increased with increasing stimulus intensity and was similar in hemifield and full-field stimuli, eventually saturating at maximal light intensity. The log unit RAPD did not correlate with the estimated percentage of decussating pupil fibers, which ranged from 54% to 67%. CONCLUSIONS: In patients with a unilateral optic tract lesion, the pupillary responses from full-field stimulation to each eye are the same as comparing the functioning temporal field with the functioning nasal field. The percentage of decussating fibers is reflected in the ratio of the maximal pupil contraction amplitudes resulting from stimulus input between the two eyes. The RAPD that occurs in this setting reflects the difference in light sensitivity between the intact temporal and nasal hemifields. Its magnitude does not correlate with the difference in the number of crossed and uncrossed axons, but its sidedness contralateral to the side of the optic tract lesion is consistent with the greater percentage of decussating pupillomotor input.

Adolescent↗
PubMed2006

Neuro-ophthalmologic manifestations of psychogenic disease.

From a neuro-ophthalmologic standpoint, five areas may be affected by psychogenic disease: (1) vision, including visual acuity and visual field; (2) ocular motility and alignment; (3) pupillary size and reactivity; (4) eyelid position and function; and (5) corneal and facial sensation. The physician faced with a patient complaining of decreased vision or some other disturbance related to the afferent or efferent visual systems for which there is no apparent biologic explanation has three responsibilities. First, the physician must ascertain that an organic disorder is not present. Second, the physician should induce the patient to see or do something that would not be possible if the condition were organic in nature. Finally, the physician should attempt to determine whether the patient has an underlying psychiatric disease or is experiencing psychosocial stress. In this article, manifestations of psychogenic disease as they pertain to vision are considered, and, where appropriate, the various methods used to diagnose and treat these phenomena are discussed.

Accommodation, Ocular↗
PubMed2006

New concepts in the diagnosis and management of optic nerve sheath meningioma.

Optic nerve sheath meningiomas are by far the most common tumors of the optic nerve sheath. The diagnosis can be suspected in most cases from clinical findings and supported by the results of neuroimaging, obviating tissue biopsy in the majority of cases. Observation may be appropriate in patients with mild or no visual deficit or in whom visual loss is not progressing, whereas stereotactic fractionated radiation therapy has been demonstrated to improve or stabilize vision in progressive or advanced cases. Attempts at surgical excision, and even biopsy, of optic nerve sheath meningiomas are associated with a high risk of blindness and should be reserved for the rare case of an anteriorly located, primarily exophytic tumor with focal involvement of the dural sheath.

Humans↗
PubMed2006

Tilted optic discs visualized by magnetic resonance imaging.

A young woman with headaches displayed ophthalmoscopic features suggestive of papilledema. MRI showed no intracranial abnormalities but demonstrated oblique insertion of the optic nerve into the left globe and posterior nasal flattening of the left globe, features consistent with congenitally tilted optic discs. This is the second report to show that orbital MRI can demonstrate this phenomenon.

Adult↗
PubMed2006

Hyperbaric oxygen therapy for radiation-induced optic neuropathy.

INTRODUCTION: Radiation-induced optic neuropathy (RON) is an infrequent but devastating consequence of radiation exposure to the visual pathways, usually following months to years after the treatment of paranasal or intracranial tumours. Hyperbaric oxygen (HBO) therapy is one of several therapies that have been tried for this condition. The purpose of this review is to describe the clinical characteristics of RON, the rationale for the use of HBO in this condition, and the available clinical data on its safety and efficacy. METHODS: MEDLINE searches were performed on radiation optic neuropathy, hyperbaric oxygen therapy, and similar terms, and selected references were reviewed. The results were combined with the experience at our own institution. RESULTS: RON typically follows a fulminant course with characteristic symptoms, examination findings, and imaging. The threshold for prior radiation exposure depends upon the delivery system used and patient characteristics. Therapy with anticoagulants or steroids has been unsuccessful. While there are case reports in the literature of successful treatment with HBO, therapy with HBO has to be initiated soon after the onset of vision loss, and even then yields variable results at best. CONCLUSIONS: There is still no consistently successful treatment for RON. HBO may be attempted in selected cases, but the prognosis for preservation of vision remains grim.

Humans↗
PubMed2006

New concepts in the management of optic nerve sheath meningiomas.

INTRODUCTION: Primary optic nerve sheath meningiomas (ONSMs) are the most common primary tumours of the optic nerve sheath. The diagnosis and management of ONSMs have changed dramatically in the last decade. In this review article, we discuss the latest information regarding these issues. MATERIALS AND METHODS: References for this manuscript were obtained by searching the database PubMed using the phrase "optic nerve sheath meningioma". Approximately 150 articles were identified and reviewed. These articles served as reference sources for other articles, books and chapters on the subject. The results were combined with our personal experience, which includes over 100 cases of ONSMs that have been observed or treated with one or more of the modalities described below. RESULTS: The diagnosis of ONSM can be suspected in most cases from clinical findings and supported by the results of neuroimaging, obviating tissue biopsy in the majority of cases. Management depends on several factors. Observation may be appropriate in patients with mild or no visual deficit or in whom visual loss is not progressing, whereas stereotactic fractionated radiation therapy has been documented to improve or stabilise vision in progressive or advanced cases. Attempts at excision of ONSMs are associated with a high risk of blindness and should be reserved for the rare case of an anteriorly located, primarily exophytic tumour with focal involvement of the dural sheath. Rare patients with acute visual deterioration may benefit from optic nerve sheath fenestration. CONCLUSION: The majority of ONSMs can be suspected on clinical grounds and diagnosed with readily available non-invasive neuroimaging. Stereotactic fractionated radiotherapy is currently the treatment of choice for ONSMs that require therapy.

Humans↗
PubMed2005

The incidence of vision loss due to perioperative ischemic optic neuropathy associated with spine surgery: the Johns Hopkins Hospital Experience.

STUDY DESIGN: Twenty-year retrospective review of 14,102 spine surgeries. OBJECTIVE: To determine the incidence of perioperative ischemic optic neuropathy (POION) in spine surgery at our institution. SUMMARY OF BACKGROUND DATA: In recent years, perioperative vision loss in patients undergoing spine surgery has become an issue of increasing concern to physicians, patients, and medicolegal experts. The incidence of POION in spine surgery has been addressed in two separate studies that found incidences of 0% and 0.12%. METHODS: We performed a 20-year database search for all patients who underwent spine surgery and had a concurrent ICD-9 discharge diagnosis pertaining to vision loss. Patient charts were reviewed in detail to confirm the diagnosis of POION. RESULTS: Of 14,102 cases of spine surgery during the study time frame, we identified 4 cases of POION, for an incidence of 0.028%. In 3 of the 4 cases, surgery was performed with the patient in the prone position; the fourth patient was placed in the lateral decubitus position. All affected patients had experienced intraoperative anemia, hypotension, or both. The average time of surgery was 420 minutes. CONCLUSIONS: POION is a rare but potentially devastating and untreatable complication of spine surgery, particularly that performed with the patient in the prone position. Anemia, hypotension, long duration of surgery, and significant intraoperative hydration may all be risk factors for this condition. All patients undergoing spine surgery should be informed about the low but definite risk of this condition, and every attempt should be made during surgery to maintain stable hemoglobin and mean arterial pressure and to avoid overhydration.

Academic Medical Centers↗
PubMed2005

Periocular petrolatum.

PURPOSE: This report describes the clinical and histopathologic features and discusses the diagnostic difficulties and management of periocular deposition of petrolatum-based materials. METHODS: Excision of orbital and eyelid tissue, tissue processing, and histopathologic examination was performed in patients with deposition of petroleum-based products. Transmission electron microscopy was performed in 3 cases. RESULTS: Between 1983 and 2003, 11 patients were diagnosed with periocular petrolatum deposition, based on clinical history and the characteristic histopathologic features of polymorphic dropout spaces, and varied from a noninflammatory lesion (paraffinoma) to those with an associated granulomatous inflammatory reaction. CONCLUSIONS: The diagnosis of petrolatum deposition can be challenging due to the range of symptoms and variable delay in presentation. Petrolatum products should be avoided during surgery and used judiciously in the postoperative period. To avoid confusion with nonspecific cases of lipogranulomatous inflammation, the terms "ointment granuloma" or "orbital paraffinoma" should be used to refer to patients presenting with orbital/eyelid lesions caused by ointment use.

Adolescent↗
PubMed2005

Oligodendrocyte dysfunction after induction of experimental anterior optic nerve ischemia.

PURPOSE: The early response and survival of oligodendrocytes after axonal stroke and their potential contribution to neuronal survival in vivo have not been adequately addressed. The purpose of this study was to investigate the changes occurring in the retina and optic nerve (ON) in anterior ischemic optic neuropathy (AION), using a c-fos transgenic mouse model. METHODS: A new mouse model of AION (rodent AION) was developed to evaluate the in vivo stress response of oligodendrocytes and retinal ganglion cells (RGCs) in a transgenic mouse strain, using the immediate early stress-response gene c-fos, RT-QPCR technology, immunohistochemistry, and electron microscopy. Confocal microscopy was used with cell-specific antibodies to characterize the timing of cells responding to rAION. The TUNEL assay detected cells undergoing apoptosis. Ultrastructural changes were analyzed by electron microscopy. RESULTS: In rAION, oligodendrocytes rapidly respond in vivo to ischemic ON damage, with c-fos activation as an early detectable event. Early evidence of progressive oligodendrocyte stress, is followed by demyelination, wallerian degeneration of the ON, and oligodendrocyte and RGC death far from the primary lesion. CONCLUSIONS: After rAION induction oligodendrocytes, as well as RGCs, undergo progressive stress, with dysfunction and apoptosis. The findings lead to a proposal that progressive retrograde oligodendrocyte stress, away from the primary lesion, is an important factor after ischemic optic neuropathy. Postinduction demyelination must be addressed for effective neuroprotection of ischemic and hypoxic white matter.

Animals↗
PubMed2004

Neurologic impairment 10 years after optic neuritis.

BACKGROUND: Participants enrolled in the Optic Neuritis Treatment Trial have been observed for more than a decade to assess the relationship between optic neuritis and the development of clinically definite multiple sclerosis. OBJECTIVE: To assess neurologic disability 10 to 12 years after an initial episode of optic neuritis. DESIGN: Longitudinal follow-up of a clinical trial. SETTING: Fourteen Optic Neuritis Treatment Trial clinical centers performed standardized neurologic examinations, including an assessment of neurologic disability. PARTICIPANTS: One hundred twenty-seven patients who had developed clinically definite multiple sclerosis. MAIN OUTCOME MEASURES: Functional Systems Scale and Expanded Disability Status Scale. RESULTS: The disability of most patients was mild, with 65% of patients having an Expanded Disability Status Scale score lower than 3.0. The degree of disability appeared to be unrelated to whether the baseline magnetic resonance imaging scan was lesion-free or showed lesions (P =.51). Among patients with baseline lesions, the degree of disability was unrelated to the number of lesions that were present on the scan (P =.14). Two patients died owing to severe multiple sclerosis, one of whom had no lesions revealed on the baseline scan. CONCLUSION: Most patients who develop clinically definite multiple sclerosis following an initial episode of optic neuritis will have a relatively benign course for at least 10 years.

Adult↗