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M L Moster

Publications and source records attributed to M L Moster.

At least 19 recordsLinked to original sources
PubMed1996

The peak latency of orbital presaccadic spike potential with horizontal eye movements.

PURPOSE: To investigate the peak latency of the orbital presaccadic spike potential (SP) with horizontal eye movement in normals. METHODS: Orbital SP was recorded in 28 normal subjects from 8 electrodes around the eyes with Pz as the reference while performing 5 degrees, 10 degrees, 20 degrees, 30 degrees and 40 degrees horizontal saccades to visual targets. SP peak latency was measured from SP onset to SP peak on averaged data aligned on SP peak. RESULTS: Significant main effects on SP peak latency are found for saccade size (P < 0.01), saccade direction (P < 0.01) and electrode site (P < 0.05). No significant main effect on SP peak latency is found for eye (P > 0.05). SP peak latency increases with increasing saccade size from 5 degrees to 40 degrees. SP peak latency is longer with saccades back to center than away from center, and with abducting saccades than with adducting saccades. SP peak latency differs at the electrode sites with an order from shorter to longer as follows: inner canthus (IC); inferior orbit (IO); outer canthus (OC); superior orbit (SO). CONCLUSIONS: The effects on the peak latency of orbital SP can be explained by the saccade dynamic property, volume conduction as well as physiologic and anatomic factors of the eyes and orbits. The peak latency of orbital SP can be used to reflect the temporal characteristics of ocular motor units controlling saccadic eye movement.

Adolescent↗
PubMed1995

The effects of time point alignment on the amplitude of averaged orbital presaccadic spike potential (SP).

Effects of two time-point selection averaging techniques on orbital SP amplitude were studied on 10 normal subjects performing horizontal saccades. One technique involved averaging from the SP peak, another technique involved averaging from the saccadic onset. The time-point selection methods only affected the magnitude of SP amplitude but did not interact with experimental conditions. Repeated measures analysis of variance showed that SP amplitudes were higher in data aligned on SP peak than those aligned on saccadic onset (P < 0.01). No significant second order (saccade by degree) or third order (saccade by direction) interactions involving averaging method were found (P > 0.05).

Adolescent↗
PubMed1992

Giant cell arteritis in the ocular ischemic syndrome.

Oculomotor nerve paresis, ocular hypotony, anterior segment ischemia, and the ocular ischemic syndrome are uncommon manifestations of giant cell arteritis. Four patients with these findings had giant cell arteritis documented by temporal artery biopsy. Cerebral angiography or ultrasonography, or both, performed in three patients, excluded hemodynamically significant stenosis of the internal carotid artery as the cause of ocular ischemia and cerebral aneurysms as the cause of oculomotor nerve paresis. Corticosteroid treatment, administered to three patients, resulted in resolution of the oculomotor deficits and the clinical signs of ocular ischemia, although the visual acuity in one patient improved from 20/400 to 20/60. Giant cell arteritis should be considered in the differential diagnosis of the ocular ischemic syndrome.

Aged↗
PubMed1992

Thyroid ophthalmopathy presenting as superior oblique paresis.

Six patients with thyroid ophthalmopathy presented with what appeared to be a unilateral superior oblique paresis by the three-step test, which was eventually followed by more typical findings of thyroid disease. This early motility defect in thyroid ophthalmopathy may be caused by a restrictive process due to involvement of the inferior rectus muscle. Clues to the proper diagnosis included an increase in vertical deviation in upgaze, elevation of intraocular tension in upgaze, and the lack of excyclodeviation. These features should be assessed in patients with isolated superior oblique paresis.

Adult↗
PubMed1991

Delayed visual loss due to trauma of the internal carotid artery.

The group of six patients in this study experienced delayed visual loss following head trauma. Visual loss occurred from 1 day to 13 years after the initial injury. All patients suffered indirect trauma to the internal carotid artery resulting in formation of either an aneurysm or pseudoaneurysm or a carotid-cavernous fistula. Review of the radiologic and clinical findings was performed in six patients. The diagnosis was established by computed tomography, magnetic resonance imaging, and angiography. All patients had follow-up clinical evaluation and imaging studies. Treatment by neurosurgical or interventional neuroradiologic procedures resulted in significant visual improvement in five patients. Different pathophysiologic mechanisms could be correlated with the delayed visual loss produced by the two types of lesions. The pathologic changes associated with the aneurysms/pseudoaneurysms included direct compression of optic nerves and/or chiasm and intracranial hematoma. A carotid-cavernous fistula caused delayed visual loss by either hematoma at the orbital apex or compression of the chiasm and/or optic nerves by saccular dilatation of the cavernous sinus. The delayed onset of decreased vision following head trauma should alert the physician to the possibility of a traumatic aneurysm/pseudoaneurysm or a carotid-cavernous fistula. Different neuro-ophthalmologic symptoms can usually be correlated with the pathologic changes demonstrated by neuroimaging procedures.

Adolescent↗
PubMed1991

Radiation-induced optic neuropathy: a magnetic resonance imaging study.

Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.

Aged↗
PubMed1990

Topography of scalp potentials preceding self-initiated saccades.

We studied 3 scalp potentials recorded prior to saccades in relation to visual targets (the presaccadic negativity [PSN], presaccadic positivity [PSP], and spike potential [SP]) in normal subjects performing self-initiated saccades in darkness. There was a prominent PSN beginning at -800 msec, maximal at the vertex. This finding is consistent with activation of the supplementary eye field in the anterior mesial frontal cortex, a concept which correlates with cortical neuron recordings in monkeys and cerebral blood flow studies in humans. A widespread PSP, with greatest amplitude over the posterior scalp, suggests parieto-occipital participation even in the absence of visual targets. The sharp character of SP with focal lateralized frontal negativity, its "mirror image" scalp distribution when comparing leftward to rightward saccades, and its timing near the onset of saccades support an origin near the orbit, in either ocular motor nerves or muscles.

Adult↗
PubMed1988

Alternating skew on lateral gaze (bilateral abducting hypertropia).

We report thirty-three patients with alternating skew deviation on lateral gaze. The right eye was hypertropic in right gaze, and the left eye was hypertropic in left gaze. Most patients had associated downbeat nystagmus and ataxia and were diagnosed as having lesions of the cerebellar pathways or the cervicomedullary junction. This contrasts with a previous report in which alternating skew was seen mainly in lesions of the midbrain pretectum.

Adolescent↗
PubMed1988

Dural carotid-cavernous sinus vascular malformation with facial nerve paresis.

Facial nerve paresis is rarely seen in dural cavernous sinus arteriovenous malformations or carotid-cavernous sinus fistulae. A patient with an otherwise typical presentation of a spontaneous carotid-cavernous sinus malformation was found to have ipsilateral infranuclear facial nerve paresis. Angiography revealed a dural arteriovenous malformation with early petrosal sinus filling. Possible mechanisms for the paresis include compression of the facial nerve by increased venous pressure and "stealing" of the arterial supply by the malformation.

Aged↗
PubMed1985

Visual function in prolactinoma patients treated with bromocriptine.

Ten patients with prolactin-secreting pituitary adenomas (prolactinoma) and visual dysfunction were treated primarily with bromocriptine. Nine patients had improvement of visual field or acuity associated with computed tomography (CT) evidence of a decrease in tumor size and reduction of serum prolactin level (SPL). Visual improvement usually began within days of commencing bromocriptine therapy. One patient with initial improvement had a worsening of visual fields at 11 months despite a normal SPL and a stable CT appearance of tumor size. This patient and the single patient without visual improvement underwent trans-sphenoidal hypophysectomy (TSH), but neither patient had postoperative visual improvement. Two other patients underwent TSH for nonvisual reasons. The remaining six patients have maintained excellent visual function at last follow-up (average of 18 months on bromocriptine therapy). This study shows that bromocriptine is an effective short- and long-term therapy for most patients with visual dysfunction due to prolactinoma.

Adult↗
PubMed1984

Isolated sixth-nerve palsies in younger adults.

Acquired sixth-nerve palsies are relatively rare in younger adults. We reexamined 49 patients, aged from 15 to 50 years, with isolated sixth-nerve palsies who were seen between 1972 and 1982 at the Wills Eye Hospital in Philadelphia. In this group, the following etiologies were encountered: vasculopathy (14 patients [29%]), tumors (eight patients [16%]), multiple sclerosis (six patients [12%]), presumed inflammation (four patients [8%]), trauma (three patients [6%]), postlumbar puncture (two patients [4%]), and orbital amyloidosis (one patient [2%]). Eleven patients (22%) had no determined cause of their sixth-nerve palsy. The implications for the clinical management of isolated sixth-nerve palsies in younger adults are discussed.

Abducens Nerve↗
PubMed1983

Chronic subdural hematoma with transient neurological deficits: a review of 15 cases.

Fifteen patients with chronic subdural hematomas had transient neurological deficits. The important clinical features were aphasia in 9 patients, absence of headache in 8, and head injury in 8. Computed tomographic scan correctly identified all 15 cases of chronic subdural hematoma and should be considered mandatory before initiating anticoagulation in patients with transient ischemic attacks.

Aged↗
PubMedDate not supplied

Unilateral disk edema in a young woman.

A patient with elevated intracranial pressure from aqueductal stenosis presented with unilateral disk edema, enlarged blind spot and a vague visual disturbance. The importance of considering elevated intracranial pressure in some cases without bilateral papilledema is emphasized.

Adult↗
PubMedDate not supplied

Physiologic functional imaging in "functional" visual loss.

Neuroimaging with nuclear medicine techniques permits assessment of brain function by measurement of metabolism or blood flow. Such studies complement the anatomic information derived from computed tomography (CT) or magnetic resonance imaging (MRI). We describe two patients with occipital lesions who were initially diagnosed with functional visual loss. Neither CT scan nor MRI adequately demonstrated the source of visual dysfunction; however, single proton emission tomography (SPECT) scanning in a patient with carbon monoxide poisoning and positron emission tomography (PET) scanning in a patient with post-hypoxic delayed encephalopathy were helpful in confirming the organic substrate of their visual impairment. Functional imaging techniques such as SPECT and PET should be considered in patients with suspected cortical visual loss and normal CT or MR scans.

Adult↗