Biomedical subjects
Publications and source records attributed to S L Galetta.
A 52 year old man developed a supranuclear gaze palsy and opsoclonus after Diazinon poisoning. The diagnosis was confirmed by low plasma and red blood cell cholinesterase activity and urine mass spectroscopy. Saccadic control may be mediated in part by acetylcholine. Opsoclonus in the setting of organophosphate intoxication may occur as a result of cholinergic excess which overactivates the fastigial nuclei.
We report a case of a patient who developed a left posterior cerebral artery aneurysm 5 years after balloon occlusion of the right internal carotid artery for a giant cavernous aneurysm. The location of the new aneurysm was outside of the primary collateral pathways to the contralateral, proximally occluded, anterior circulation, illustrating the complexity of hemodynamic factors contributing to the development of intracranial saccular aneurysms. The appearance of an aneurysm in this setting supports the hypothesis that degenerative factors and hemodynamic stresses are important in the etiology of intracranial aneurysms.
A 33-year-old man developed a complete third nerve palsy in the setting of acute bacterial endocarditis. MRI revealed an ischemic stroke in the cerebral peduncle involving the third nerve fascicle. Subsequently, he was observed to have paradoxic elevation of the eyelid on adduction and downgaze. To the authors' knowledge, this is the first demonstration of oculomotor synkinesis after an acquired, ischemic CNS lesion.
The authors report three patients with acute, chronic, and recurrent neuropathy associated with varicella zoster virus (VZV) infection but without zoster rash. CSF of all three patients contained VZV immunoglobulin G antibody, but not herpes simplex virus. In two patients, serum/CSF ratios of VZV immunoglobulin G were reduced compared to normal ratios for immunoglobulin G and albumin, and one patient also had VZV immunoglobulin M in CSF. All three patients received antiviral therapy and improved. The diagnosis of nervous system infection by VZV may be confirmed by the presence of antibody to VZV in CSF even without detectable VZV DNA.
PURPOSE: To examine the potential for visual acuity loss, and its relation to extent and location of optic pathway gliomas in a cohort of children with neurofibromatosis type 1 studied with magnetic resonance imaging. METHODS: We reviewed the neuro-ophthalmologic records and brain/orbital magnetic resonance imaging scans for 43 consecutive pediatric patients with neurofibromatosis type 1 and optic pathway gliomas who were followed at the Children's Hospital of Philadelphia. The presence of visual loss, defined as abnormal visual acuity for age in one or both eyes, was determined. Optic pathway gliomas were classified by tumor extent and location according to involvement of the optic nerves, chiasm, and postchiasmal structures by magnetic resonance imaging. RESULTS: Involvement of the optic tracts and other postchiasmal structures at tumor diagnosis was associated with a significantly higher probability of visual acuity loss (P =.048, chi-square test). Visual loss was noted in 20 of 43 patients (47%) at a median age of 4 years; however, three patients developed visual acuity loss for the first time during adolescence. CONCLUSIONS: In pediatric patients with neurofibromatosis type 1 and optic pathway gliomas, the likelihood of visual loss is dependent on the extent and location of the tumor by magnetic resonance imaging and is particularly associated with involvement of postchiasmal structures. Furthermore, older age during childhood (adolescence) does not preclude the occurrence of visual loss. Close follow-up beyond the early childhood years, particularly for those with postchiasmal tumor, is recommended.
The clinical characteristics, differential diagnosis, and treatment options are presented for five different categories of neuro-ophthalmic disease. Nystagmus, optic neuritis, diplopia, pseudotumor cerebri, and temporal arteritis, are frequently encountered in neuro-ophthalmic practice. This article focuses on current therapies for these neuro-ophthalmic disorders. Potential differences in approach to pediatric versus adult patients are emphasized.
We report two patients who developed isolated visual symptoms and signs as initial manifestations of Creutzfeldt-Jakob disease (CJD). Both patients had normal conventional T1- and T2-weighted brain magnetic resonance (MR) images; in one patient, early cortical abnormalities were detected by diffusion-weighted and fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI). Results from the cerebrospinal fluid assay for the 14-3-3 brain protein were also negative in one patient, despite pathologic confirmation of CJD at autopsy. The Heidenhain variant of CJD should be considered in all patients who present with isolated visual manifestations, including homonymous hemianopsia and normal conventional brain MRI. Diffusion-weighted and FLAIR MRI may demonstrate early cortical abnormalities in patients with CJD. The CSF assay for the 14-3-3 protein may be normal, even in pathologically confirmed cases.
The Controlled High Risk Avonex Multiple Sclerosis Study (CHAMPS) tested whether interferon beta la (Avonex) treatment would benefit patients who had experienced a first acute demyelinating event involving the optic nerve, brain stem/cerebellum, or spinal cord, and who displayed MRI brain signal abnormalities that have previously predicted a high likelihood of future MS-like events. The study randomized 383 patients into an Avonex-treated and a placebo-treated group; both groups received intravenous methylprednisolone 1 gm/d followed by prednisone 1 mg/kg for 11 days. The Avonex-treated group demonstrated a 44% reduction in the 3-year cumulative probability of developing clinically definite multiple sclerosis (rate ratio 0.56, 95% confidence interval 0.38 to 0.8; P = 0.002). At 18 months, treatment with Avonex was associated with a significant reduction of new T2 lesions, gadolinium enhanced lesions and T2 lesion volume. Among placebo-treated patients, 82% had developed a new subclinical MRI signal abnormality by the eighteenth month after study entry. Treatment benefit was observed irrespective of the qualifying event. The findings of this study support the efficacy of Avonex therapy in significantly reducing the 3-year likelihood of future neurologic events and worsening of the brain MRI in patients with a first acute CNS demyelinating event.
Ophthalmologic practice requires a solid foundation in the principles and interpretation of the neuro-ophthalmologic examination. This article reviews the techniques used in the neuro-ophthalmologic examination to assess visual acuity, ocular motility, visual fields, the pupils, the eyelids, and the fundus. The neuro-ophthalmological examination in comatose patients is also reviewed. Neuro-ophthalmic techniques are paramount in the assessment of comatose patients, especially with regard to brainstem localization and diagnosis.
BACKGROUND: Ross syndrome is an uncommon disorder characterized by the triad of segmental anhidrosis, hyporeflexia, and tonic pupils. METHODS: The authors describe the clinical findings of five patients with Ross syndrome and detail the results of their pharmacologic and autonomic testing. RESULTS: In four patients, the classic findings of Ross syndrome were accompanied by Horner's syndrome. Other symptoms of dysautonomia were also common. CONCLUSIONS: These findings suggest that Ross syndrome is a dysautonomic condition of varying expression resulting from a generalized injury to ganglion cells or their projections.
Bickerstaff's brainstem encephalitis (BBE) is an immune disorder of unknown etiology. Previous reports of successful treatment of BBE involved steroids or plasma exchange. We describe a patient with BBE who demonstrated rapid clinical recovery after treatment with intravenous immune globulin. Our findings suggest that IVIg is an alternative treatment in BBE, especially when plasma exchange is difficult or contraindicated. Our patient also demonstrated pseudoretraction and pseudoptosis during clinical recovery, an observation which supports a differential immune attack on components of the third nerve or supranuclear regions, and expands our understanding of the pathophysiology of BBE.
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A patient presented with symptoms of limbic and brainstem encephalitis, motor and sensory neuronopathy, cerebellar dysfunction, and highly positive anti-Hu antibodies. He also harbored P/Q-type calcium channel antibodies and manifested the Lambert-Eaton myasthenic syndrome (LEMS). Small-cell lung cancer was found, and he received both antineoplastic therapy and intravenous immunoglobulin (IVIg). Remission of the malignancy was achieved. Although the anti-Hu-related manifestations improved after therapy, LEMS has persisted, leading to IVIg dependency.
OBJECTIVE: To investigate the ability of a portable, personal computer-driven, pupillometer to record the pupillary response curve during the swinging flashlight test. Also, to determine whether these response curves can be used to identify and quantify relative asymmetry in the pupillary light reflex between eyes in healthy volunteers with simulated afferent pupil defects (APDs) and patients with optic neuropathies. DESIGN: Comparative, observational case series and instrument validation. PARTICIPANTS: Healthy volunteers with no known ocular disease and patients (n = 20) with various optic neuropathies noted to have relative APDs on examination. METHODS: Pupillary response curves of the right eye were recorded with a portable, electronic, infrared pupillometer from healthy volunteers (with and without simulated APDs) and patients with APDs while the light stimulus alternated between eyes, simulating the swinging flashlight test. Simulated APDs in healthy volunteers were created with increasingly dense neutral density filters in front of the left eye. MAIN OUTCOME MEASURES: Differences in constriction amplitude, latency, and constriction velocity of the pupillary response with right eye stimulation versus left eye stimulation in both groups of subjects. RESULTS: A significant correlation between neutral density filter strength and intereye differences was seen for all measurement parameters in volunteers with simulated APDs. Depending on the measurement parameter and stimulus intensity, simulated APDs of 0.6 log units or more could be distinguished from normal responses. Clinically graded true APDs had intereye differences similar to simulated APDs of the same density. Those with real and simulated APDs of 0.9 log units or more could be distinguished from healthy volunteers with 80% sensitivity and 92% specificity. Responses from those with real and simulated small APDs of 0.3 to 0.6 log units could not be distinguished reliably. CONCLUSIONS: Portable, personal-computer driven, electronic, infrared pupillography can record the swinging flashlight test accurately and identify large afferent pupillary defects. An affordable, portable, reliable device for identifying relative APDs would be useful in the identification and follow-up of patients with neurogenic vision loss.
OBJECTIVE: To describe the neuro-ophthalmic findings in patients with orbital drainage from cerebral arteriovenous malformations (AVMs). METHODS: We reviewed the records of 100 consecutive adult patients with cerebral AVMs who presented to our institution during a 4-year period. All patients with orbital drainage were identified, and their neuro-ophthalmic evaluations were reviewed. RESULTS: Three patients (3%) were identified with orbital drainage from a cerebral AVM. The first patient presented with typical chiasmal syndrome (reduced visual acuity, bitemporal hemianopia, and optic atrophy). Magnetic resonance imaging demonstrated a large left temporal and parietal lobe AVM with compression of the chiasm between a large pituitary gland and a markedly enlarged carotid artery. The second patient presented with headaches and postural monocular transient visual obscurations. Examination revealed normal visual function with minimal orbital congestion and asymmetrical disc edema, which was worse in the left eye. Magnetic resonance imaging revealed a large right parietal and occipital lobe AVM without mass effect or hemorrhage and an enlarged left superior ophthalmic vein. The third patient had no visual symptoms and a normal neuro-ophthalmic examination; a right parietal lobe AVM was discovered during an examination for the cause of headaches. CONCLUSION: Orbital drainage from cerebral AVMs is rare. Manifestations may include anterior visual pathway compression, dilated conjunctival veins, orbital congestion, and asymmetrical disc swelling.