Spasm of the near reflex associated with metabolic encephalopathy.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M L Moster.
Explore the source record for details and available documents.
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.
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.
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.
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.
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.
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.
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.
A 70-year-old man underwent coronary artery bypass graft complicated postoperatively by visual loss. The diagnosis was nonarteritic anterior ischemic optic neuropathy. Possible predisposing factors in this patient were hypotension, anemia, a "disk at risk," and internal carotid artery stenosis. In the postoperative setting, the erythrocyte sedimentation rate may be elevated, as it was in this case and does not by itself suggest a diagnosis of giant cell arteritis.
PURPOSE: To study the function of the parvocellular (P) and the magnocellular (M) visual systems with steady-state visual evoked potentials (VEPs) in anisometropic amblyopes. METHODS: A matrix of isolated checks was superimposed on a steady background with different check sizes and temporal frequencies to form specific stimuli to preferentially activate the P or the M visual system. The amplitude of the VEP fundamental frequency was analyzed at the electrode Oz of 5 anisometropic amblyopes and 22 normal subjects. The normal subjects were tested at two visual acuity (VA) levels, 20/20 and 20/40, modified by lenses, to match with the VA levels of the fellow eyes and the amblyopic eyes of the amblyopes, respectively. RESULTS: No significant amplitude difference was found between the dominant eyes and nondominant eyes of the normal subjects for either P or M stimuli at both 20/20 and 20/40 VA levels (P>.05). No significant amplitude difference was found between the fellow eyes of the amblyopes and the dominant eyes of normals for either P or M stimuli at 20/20 VA level (P>.05). A significant amplitude difference was found between the amblyopic eyes and the nondominant eyes of the normals for P stimuli (P<.05) but not for M stimuli (P>.05) at 20/40 VA level. CONCLUSIONS: The amplitude of the VEP fundamental frequency was selectively reduced for P stimuli in anisometropic amblyopic eyes. This clinical electrophysiologic finding confirms that only the function of the P visual system is abnormal in anisometropic amblyopic eyes.