Biomedical subjects
C M Fisher
Publications and source records attributed to C M Fisher.
The combination of liquid crystal thermography and duplex scanning in the diagnosis of deep vein thrombosis.
One hundred patients with clinically suspected deep vein thrombosis (DVT) were studied by liquid crystal thermography (LCT), duplex scanning and venography. Liquid crystal thermography was found to have a negative predictive value of 97% if performed within 1 week of the onset of symptoms. Duplex scanning had a sensitivity of 93% and specificity of 91% for all thrombi (proximal and calf). On the basis of these results a plan of investigation has been formulated that would avoid duplex scanning and venography in 39 of the 100 patients. Duplex scanning alone would be appropriate in 56 of the remaining 61 patients. Only six patients would be unsuitable for duplex scanning because of a very tense tender leg and require venography. The plan would miss one calf thrombus and result in treating three patients unnecessarily. This policy would be not only effective but also cost-effective.
Amnestic syndrome associated with propranolol toxicity: a case report.
An elderly woman developed an Alzheimer-like subacute dementia as a result of propranolol toxicity. Analysis of the manifestations showed that severe impairment of memory accounted for virtually all of the abnormalities. There is evidence that cerebral reactions to drug toxicity can exhibit patterns that suggest highly selective involvement of functional subdivisions of the brain.
Concerning the mechanism of recovery in stroke hemiplegia.
Two patients with pure motor hemiplegia were regaining strength in the affected limbs when a pure motor stroke developed on the opposite side. At the same time as the new hemiplegia appeared, the recovering side became re-paralyzed, suggesting that activity in the contralateral corticospinal tract had participated in the recovery process. Pathological studies were confirmatory. The literature pertaining to contralateral motor compensation is reviewed.
Visual hallucinations and racing thoughts on eye closure after minor surgery.
Two hours after minor surgery under local anesthesia, a 67-year-old man developed vivid visual hallucinations that were present only when he closed his eyes. After lasting 4 hours, the hallucinations were succeeded by racing thoughts, lasting 2 hours, and then by illusionary movements of his body. The reaction was attributed to the effect of lidocaine. The case resembles one previously reported.
Visual hallucinations on eye closure associated with atropine toxicity. A neurological analysis and comparison with other visual hallucinations.
Visual hallucinations of remarkable intensity began shortly after intravenous atropine and persisted for 11 days. They were present only when the eyes were closed and were associated with heightened dreaming and disturbed sleep. The patient remained lucid and described his experiences to his attendants. Our patient's hallucinations bore some resemblance to hypnagogic hallucinations and this became the basis for the hypothesis that the hallucinations originated in the sleep-dream system of the brain stem. It is speculated that a similar site--a metabolic locus minoris resistentiae may play a part in other types of visual hallucinations and in delirium.
Brain death--a review of the concept.
The early origins of the concept of brain death have been retraced. Using practical examples from clinical experience it has been demonstrated that conventionally, cardiac death is always accompanied by brain death. Cardiac death implies brain death. The two are inseparably linked or coupled. Death on a ventilator uncouples the two, revealing death of the brain as the true determinant of the cessation of a person's life and the heartbeat as a false measure.
Binswanger's encephalopathy: a review.
Binswanger's encephalopathy is reviewed in respect to history, computed tomography, magnetic resonance imaging, epidemiology, pathology, clinical picture, laboratory findings, differential diagnosis, and treatment. The various viewpoints on the pathogenesis of the process are discussed, in particular the role of ischemia, vascular disease, high blood pressure, lacunar infarction, hypoxia, edema, and hydrocephalus. The white matter hypomyelination of congophilic angiopathy and Alzheimer's disease should provide clues. A unifying hypothesis has not been attained.
Capsular infarcts: the underlying vascular lesions.
In ten patients, 11 infarcts involving mainly the internal capsule have been examined pathologically. Serial sections of the involved basal ganglia were studied in ten infarcts and only a gross dissection was made in the other. The implicated penetrating arteries were traced throughout their length and obstructive vascular lesions were found in nine instances. In two of the nine there was an atheromatous plaque with a superimposed thrombus, in four an atheromatous plaque had caused severe stenosis, in one a destructive arterial process lipohyalinosis had occurred, in one case the nature of the obstruction remained "uncertained," and in one the penetrating arteries were obstructed at their orifices by an atheroma in the superior division of the middle cerebral artery. In two cases the vessels were patent, suggesting embolism. The atheromas consisted almost exclusively of a conglomerate of fat-filled macrophages. The clinical correlate was a pure motor hemiplegia or hemiparesis involving the face, arm, and leg without sensory deficit, homonymous hemianopia, receptive aphasia, or apractognosia. Confusion was prominent in one patient.
Clinical and radiologic remission in reticulum cell sarcoma of the brain.
Two patients with cerebral reticulum cell sarcoma (CRCS) are reported in whom neurologic abnormalities and radiologic (computerized tomographic [CT] scan) evidence of tumor remitted. In one patient, remission followed craniectomy and corticosteroid therapy and lasted for eight months. In the other patient, at least four remissions occurred over a span of seven years, each in conjunction with the administration of corticosteroids. Corticosteroids may favorably alter the biologic activity of tumor tissue in some cases of CRCS, predisposing to clinical remission and disappearance of tumor on CT scan.
Symptomatic middle cerebral artery stenosis.
The clinical course of 16 consecutive patients with stenosis of the middle cerebral artery angiographically diagnosed between 1970 and 1977 was reviewed. All were managed nonsurgically with medical treatment including anticoagulation. Prior to therapy, transient ischemic attacks had occurred in 15 and cerebral infarction in 11. Initially, none exhibited more than a minor neurological deficit. Follow-up from one month to six years showed a benign course in 14 patients: 13 experienced no subsequent transient attacks or new stroke; 1 had repeated transient attacks for two years but not in the following four years. Two of the 16 developed a severe stroke early in the course, before medical therapy was started. No distinctive clinical or radiographic features were identified that permitted prediction of the outcome. This small series supports the need for a randomized study of bypass efficacy in these patients.
Syncope of obscure nature.
One hundred and eleven cases of syncope or loss of consciousness are analyzed. Most are of obscure nature while some illustrate features of syncope that deserve further scrutiny. The cases are divided into six groups: Resembling cardiac syncope (30 cases); vasovagal syncope (22 cases); features of both cardiac and vasovagal syncope (12 cases); orthostatic hypotensive (29 cases); akinetic seizure? (12 cases); and miscellaneous (5 cases). Some groups are subdivided according to the circumstances surrounding the spells, for example, seated eating, nocturnal, associated with bowel movement, response to anticonvulsant therapy, etc. The following conclusions seem warranted: The evidence favors the existence of a type of akinetic seizure resembling cardiac syncope; loss of consciousness while seated eating (prandial syncope) may comprise a syndrome; syncope related to bowel movement or abdominal pain is a striking association; sporadic nocturnal syncope due to temporary hyporeactivity of baroreceptors is not sufficiently recognized; alcohol ingestion may precipitate orthostatic hyporeactivity of baroreceptors is not sufficiently recognized; alcohol ingestion may precipitate orthostatic hypotension. Familial syncope, syncope proneness and cold drink syncope are illustrated.
Pyramidal infarction in the medulla: a cause of pure motor hemiplegia sparing the face.
We present a case with an infarct limited to the right pyramidal tract in the medulla. The lesion lay approximately 1 cm below the pontomedullary junction. On the basis of this case and three previously reported cases of medullary pyramidal infarction, there is defined a syndrome of severe hemiplegia with relative sparing of the face, tongue and articulation, minimal sensory loss, and good recovery. The hemiplegia is initially flaccid and later spastic. Transient symptoms, referable to the tegmentum of the medulla, occur at the onset, and reflect ischemia in the deeper territory of a paramedian penetrating vessel.
Reducing risks of cerebral embolism.
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Ataxic hemiparesis. A pathologic study.
Three stroke patients showed weakness and pyramidal signs on one side combined with a cerebellar-like ataxia on the same side. Pathologic study in each case showed an old infarct cavity in the basis pontis at the level of the junction of the upper one third and lower two thirds on the side opposite the neurologic deficit. The basilar artery was patent and the infarcts were probably the result of occlusion of penetrating arteries. This study demonstrates that a lesion of the basis pontis may be associated with a contralateral ataxia that is cerebellar in character. The designation ataxic hemiparesis is suggested for the syndrome.
Transient paralytic attacks of obscure nature: the question of non-convulsive seizure paralysis.
Eleven patients with transient paralytic attacks of obscure nature are described. Paralysis could involve face or leg alone, face and hand, or face, arm and leg. The duration varied from two minutes to one day. Four patients had brain tumors, six probably had brain infarcts, and one a degenerative process. The differential diagnosis included TIAs, migraine accompaniments, and seizures. In the absence of good evidence for the first two, the cases are discussed from the standpoint of possibly representing nonconvulsive seizure paralysis (ictal paralysis, inhibitory seizure paralysis or somatic inhibitory seizure). Because of the difficulty in defining seizures as well as TIAs and migraine in their atypical variations, a firm conclusion concerning the mechanisms of the spells was not attained. Two cases of the hypertensive amaurosis-seizure syndrome have been added as further examples of ictal deficits.