Biomedical subjects

S Lessell

Publications and source records attributed to S Lessell.

At least 109 records · Page 6Linked to original sources

PubMed1986

Periodic alternating nystagmus associated with albinism.

We examined a 73-year-old woman with the rare association of albinism and (presumably) congenital periodic alternating nystagmus. The mechanism of the nystagmus in this case is uncertain. Anomalous retinogeniculate pathways have been documented in albino animals. Periodic alternating nystagmus might occur in some patients with albinism if there are also anomalies in the pathways conveying visual information to the cerebellum and brainstem.

Aged↗

PubMed1986

Retrograde horseradish peroxidase transport after oculomotor nerve injury.

We studied the distribution of somatic motor neurons innervating the cat superior rectus 3-6 months after oculomotor nerve injury using intramuscular horseradish peroxidase (HRP). In normal cats, 98% or more of the labelled superior rectus motoneurons were in the contralateral oculomotor subnucleus. Two experimental cats who exhibited little or no evidence of recovery showed few labelled cells (4% of controls) which were distributed in both the ipsilateral and contralateral oculomotor nucleus. The other three experimental cats demonstrated definite signs of recovery, and HRP injections labelled more cells (20% of controls) also distributed in the ipsilateral and contralateral oculomotor subnuclei. This study shows that, after sectioning, the oculomotor nerve regenerates and anomalous connections develop between the somatic motoneurons of the ipsilateral oculomotor nucleus and the superior rectus. These findings support the hypothesis that acquired oculomotor synkinesis developing after third nerve injury results from misdirection of regenerating axons.

Animals↗

PubMed1985

Brightness-sense and optic nerve disease.

We describe a simple device used to compare the sense of brightness in the two eyes. An investigation of brightness-sense with this device in normal persons and patients with optic nerve disease, maculopathies, cataract, and factitious visual impairment shows that brightness testing can provide useful information supplementary and complementary to conventional clinical and laboratory investigations. Impairment of brightness-sense was a consistent finding among patients with optic neuropathies and, in some cases, brightness testing appeared to be more sensitive than other techniques in establishing the presence of disease. Brightness-sense was also used to monitor the course of the patient's illness. Abnormalities were also found among some patients with unilateral maculopathies, but significant intereye differences in brightness-sense were not encountered among normal persons or patients with cataracts. Patients with factitious visual loss gave variable responses, and the nature of their disorder could be identified by the inconsistency of their responses.

Adolescent↗

PubMed1985

Intrapapillary refractile bodies in optic nerve sheath meningioma.

Intrapapillary refractile bodies were observed in seven of 13 patients with chronic optic disc edema secondary to optic nerve sheath meningioma. The observation of refractile bodies preceded or coincided with decline in vision and disappeared as optic atrophy supervened. Intrapapillary refractile bodies appear to be a nonspecific sign of chronic optic disc edema.

Adult↗

PubMed1985

Cup-disc ratio and ischemic optic neuropathy.

Cup-disc ratios in the fellow eyes of 26 patients with unilateral, nonarteritic, anterior ischemic optic neuropathy were compared with the ratios in fellow eyes of 29 patients with unilateral idiopathic or demyelinative optic neuritis. The ratios in both groups were also compared with the ratios of a large group of normal subjects evaluated in a population survey. Observers measured the cup-disc ratio by viewing color stereophotographs. The cup-disc ratios of the fellow eyes of patients with anterior ischemic optic neuropathy were significantly smaller on average than were those of the fellow eyes of patients with optic neuritis and the normal subjects. Eyes with small cup-disc ratios may be more vulnerable to infarction than are eyes with large cup-disc ratios.

Adult↗

PubMed1985

Long-term follow-up after single toxic exposure to trichloroethylene.

In an earlier report [Feldman and Lessell, 1967], neurologic findings following acute intoxication to trichloroethylene were presented. Facial anesthesia, asymmetric pupillary responses, and electrical evidence of sensorimotor neuropathy accompanied neuropsychological deficits, manifested by difficulty in solving sequential problems and poor memory affecting the acquisition of new information. Twelve years after the initial exposure, patches of hypalgesia over the malar eminences persisted and corneal reflexes remained absent, although sensation in the snout region was totally normal. Neuropsychological test results continued to demonstrate impaired attention and short-term memory as well as diminished visuospatial organization and sequencing, 16 years after exposure. In addition, MMPI profile and interview suggested continued depressive symptomatology. Eighteen years after exposure, findings included paresthesia and hypalgesia in the malar area of the face as well as myokymia of the facial muscles. Facial nerve latency studies were normal as were pattern shift visual evoked responses. The patient continued to have large pupils that reacted asymmetrically to light. In the right eye, contraction was synchronous in all segments of the sphincter. In the left eye, there was segmental contraction, suggestive of a tonic pupil. This report offers evidence of long-term residual oculomotor and ciliary reflex dysfunction as well as impaired neuropsychological performance as a result of acute TCE intoxication.

Affective Symptoms↗

PubMed1984

A syndrome of arterial-occlusive retinopathy and encephalopathy.

An analysis of two new cases and four previously reported cases produced evidence for a syndrome of arterial-occlusive retinopathy and encephalopathy. All six patients were women; they ranged in age from 21 to 40 years. The clinical features of this condition include multiple branch retinal arterial occlusions and encephalopathy in which behavioral and memory disturbances predominate early. Hearing loss is frequent. Except for cerebrospinal fluid pleocytosis and an increased cerebrospinal fluid protein level, there are few laboratory or radiographic abnormalities. The disease may be responsive to corticosteroid therapy. There are some similarities between this syndrome and systemic lupus erythematosus but it appears to be a distinct disease entity. A comparison of the retinal findings with those described in experimental allergic encephalitis suggests that this may be a virally induced immune-mediated disease. Although only four clearly documented examples of this syndrome have been reported, we suspect that cases may have been overlooked because of failure to recognize arterial branch occlusions in the peripheral retina.

Adult↗

PubMed1984

Transient oculomotor synkinesis in temporal arteritis.

In a patient with temporal arteritis, ophthalmoplegia developed associated with a transient oculomotor synkinesis or aberrant regeneration. The synkinesis suggests that the ophthalmoplegia was neurogenic rather than myogenic. Based on published experiments, it appears that transient synkinesis is compatible with the hypothesis that aberrant regeneration of axons in the third nerve is the cause of oculomotor synkinesis.

Eye Movements↗

PubMed1984

Diffuse disseminated atheroembolism. Three cases with neuro-ophthalmic manifestation.

Neuro-ophthalmic manifestations led to the diagnosis of diffuse disseminated atheroembolism (DDA) in three men whose systemic symptoms had remained unexplained for years. The cholesterol emboli that cause DDA originate from friable plaques in the aorta and great vessels. Ophthalmologists should be alert to the diagnosis of DDA in patients with elevated ESRs, stroke, transient amaurosis, or cholesterol emboli in the fundi. Early diagnosis is important because arteriography, endarterectomy, and anticoagulation seem to increase the risk of serious, even fatal, embolization in these patients.

Aged↗

PubMed1984

Transient visual obscurations with elevated optic discs.

The pathogenesis of the transient obscurations of vision that occur with papilledema is a subject of speculation and debate. We present four examples of transient obscurations of vision that were clinically indistinguishable from those of papilledema; they occurred in patients with elevated optic discs from causes not related to increased intracranial pressure. The underlying mechanism for visual obscurations in all of these patients appear to be transient ischemia of the optic nerve head consequent to increased tissue pressure. Axonal swelling, intraneural masses, and increased influx of interstitial fluid may all contribute to increases in tissue pressure in the optic nerve head. The consequent reduction in perfusion pressure renders the small, low-pressure vessels that supply the optic nerve head vulnerable to compromise. Brief fluctuations in intracranial or systemic blood pressure may then result in transient loss of function in the eyes. We postulate that such mechanisms may apply in all cases of optic disc elevation, including papilledema.

Adult↗

PubMed1984

Neuro-ophthalmology of sphenoid sinus carcinoma.

Three cases of sphenoid sinus carcinoma observed personally and 39 identified in the English language publications are reviewed. Sphenoid carcinoma constitutes only 0.3 per cent of sinus cancer. Its symptoms and signs are nonspecific until the sinus wall is penetrated. Once breached, specific neuro-ophthalmological symptoms and signs ensue, resulting from involvement of anatomically contiguous structures. These are characterized most commonly by the sphenocavernous syndrome and less frequently by isolated sixth nerve palsies and visual loss. Identified best by plain radiography, polytomography and computerized tomography, diagnosis of sphenoid carcinoma requires direct biopsy. Treatment, principally with radiotherapy supplemented by chemotherapy, has been disappointing with most patients dead by three years. The authors believe that in rapidly evolving neuro-ophthalmological syndromes of basal origin, accompanied by intractable headache, sphenoid sinus cancer must be considered.

Blepharoptosis↗

PubMed1984

Tonic pupil with giant cell arteritis.

A patient with giant cell arteritis and ischaemic optic neuropathy developed bilateral tonic pupils. This pupillary abnormality may result from ischaemia of the ciliary ganglia. Despite the propensity for patients with giant cell arteritis to develop vascular occlusions in the eye and orbit, tonic pupils have rarely been described, and several reasons for this are proposed. The arteries supplying the ciliary ganglia are frequently involved in giant cell arteritis, but their anastomotic pattern may confer protection from ischaemia. Tonic pupils may also be overlooked amidst the more dramatic manifestations of giant cell arteritis.

Adie Syndrome↗

PubMed1984

Ischemic optic neuropathy associated with optic disc drusen.

Ischemic optic neuropathy developed in five eyes of four patients with optic nerve drusen. Two of the patients were in their 20s, a decade when idiopathic ischemic optic neuropathy is rare. This argues against a chance concurrence of drusen and idiopathic ischemic optic neuropathy. Infarction of the distal portion of the optic nerve in patients with drusen may result from mechanical distortion of blood vessels in the laminar and prelaminar regions.

Adult↗

PubMed1983

Bilateral optic neuropathy with remission in young men. Variation on a theme by Leber?

Five young men had painless, progressive, bilateral loss of central vision with late optic atrophy. One had a family history of Leber's optic neuropathy. After being functionally blind for four to 21 months, spontaneous improvement began leading to remarkable recovery of vision in all patients. We propose that these are cases of Leber's optic neuropathy in which an unusual capacity for recovery may have been related to a lack of microvascular abnormalities in the fundi.

Adult↗

PubMed1983

Chronic isolated abducens paresis from tumors at the base of the brain.

A chronic sixth-nerve paresis, even if isolated, may be neither benign nor idiopathic. We describe five patients with tumors in the basisphenoid region manifested clinically by isolated, unilateral abducens paresis for five to 20 years. There were three meningiomas (one confirmed by biopsy, two presumed), a neurilemmoma, and a chondrosarcoma. Isolated abducens paresis may persist for years in both children and adults with tumors or aneurysms. All patients with chronic sixth-nerve paresis should undergo vigorous neuroradiologic investigations to rule out a petrous apex-cavernous sinus mass lesion.

Abducens Nerve↗

PubMed1983

Downbeat nystagmus. Long-term therapy with moderate-dose lithium carbonate.

Downbeat nystagmus developed in a 67-year-old hypomagnesemic woman while she was receiving lithium carbonate for depression. This nystagmus abated each time lithium carbonate therapy was withdrawn, and no alternative causes of nystagmus were demonstrated. However, this nystagmus occurred despite serum lithium carbonate levels in the nontoxic range. Total-body magnesium deficiency may have enhanced the toxic effect of lithium carbonate on cerebellomedullary connections.

Aged↗

PubMed1983

Ocular motility testing in the evaluation of visual hallucinations.

Distinguishing organic visual hallucinations from those caused by hysteria or malingering is important but difficult. We found that ocular motility testing is helpful in making the distinction in some patients who allege that their hallucinations move. A 9-year-old girl thought to have organic hallucinations, possibly caused by an occipital lobe neoplasm, was unable to generate smooth pursuit movements when she attempted to follow the movements of the hallucinations. Instead, she executed a series of small downward saccades. Her hallucinations were presumably stress-induced. Conversely, a 62-year-old man with hypertension, arteriosclerotic heart disease, and depression, whose hallucinations were thought to be hysterical, was able to execute smooth pursuit movements when he attempted to follow the hallucinations. Detection of a previously unrecognized visual field defect helped to establish that the hallucinations were organic. Thus, patients with moving organic hallucinations may produce smooth pursuit movements when attempting to follow the hallucinations, but patients with feigned or hysterical hallucinations, who lack a fixation target, are likely to execute a series of saccades.

Brain Ischemia↗

PubMed1983

Dorsal midbrain syndrome from giant aneurysm of the posterior fossa: report of two cases.

Two patients with giant posterior fossa aneurysms compressing the upper ventral brainstem presented principally with findings referable to the dorsal midbrain (upgaze paralysis and lid retraction). We hypothesize that the signs were produced by kinking of the upper brainstem, thus compressing the dorsal midbrain against the free edge of the tentorium of the cerebellum.

Aged↗