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Biomedical subjects

A H Ropper

Publications and source records attributed to A H Ropper.

At least 73 records · Page 4Linked to original sources
PubMed1991

Atrial natriuretic factor and salt wasting after aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The causes of volume depletion and hyponatremia after subarachnoid hemorrhage are not fully understood but may be in part due to natriuresis or "cerebral salt wasting." Because previous studies using infrequent hormone sampling have given inconsistent results, we determined if elevations in atrial natriuretic factor concentrations preceded negative sodium and fluid balances. METHODS: We measured diurnal atrial natriuretic factor and vasopressin concentrations and sodium balance for 5 days in 14 consecutive patients after aneurysmal subarachnoid hemorrhage. RESULTS: Plasma concentrations of atrial natriuretic factor on admission were elevated in subarachnoid hemorrhage patients (mean +/- SD 106 +/- 59 pg/ml) compared with acutely ill controls (39 +/- 30 pg/ml). In eight patients, high peak concentrations of atrial natriuretic factor, greater than 300 pg/ml or a twofold increase above baseline, were followed by natriuresis and a negative sodium balance. Three patients, two of whom became hyponatremic, developed cerebral infarcts after natriuresis. Vasopressin concentrations were slightly elevated just after hemorrhage but subsequently declined to normal values. CONCLUSIONS: A markedly increased atrial natriuretic factor concentration precedes natriuresis in some patients and, with other abnormalities of water handling possibly including a relatively diminished vasopressin concentration, may cause volume depletion. Patients with natriuresis appear to be at increased risk for delayed cerebral infarction after subarachnoid hemorrhage.

Adult↗
PubMed1991

Sarcoid peripheral neuropathy.

We studied 10 patients with sarcoidosis and peripheral neuropathy. Six had a subacute or chronic axonal sensorimotor neuropathy without cranial neuropathy, beginning months to years after established systemic sarcoidosis. One patient had severe enough diaphragmatic weakness to require mechanical ventilation. Four patients had atypical neuropathies: acute Guillain-Barré syndrome, mononeuritis multiplex, unilateral lumbosacral plexopathy, and a purely sensory neuropathy, all before systemic sarcoidosis became evident, and all except one had cranial nerve abnormalities. Autopsy in one patient with sensorimotor neuropathy showed only scattered foci of lymphocytes in spinal roots and ganglia with nerve fiber loss.

Adult↗
PubMed1990

Acute relapsing Guillain-Barré syndrome after long asymptomatic intervals.

Five patients who recovered from an initial episode of Guillain-Barré syndrome had acute relapses 4, 10, 15, 17, and 36 years later, respectively. Two patients had multiple subsequent relapses. The antecedent illnesses, distribution of weakness, and clinical courses of each relapse were similar for each patient, except that relapses in three patients were briefer than the initial episode. One patient had asymptomatic sarcoidosis. Pharyngeal, oculomotor, and diaphragmatic weakness requiring a ventilator were common. Complete recovery or mild residual deficits, return of reflexes, normal cerebrospinal fluid protein at the onset of recurrent episodes, and normal or virtually normal nerve conduction velocities at various times distinguished these patients from those with more typical chronic relapsing inflammatory polyneuropathy.

Acute Disease↗
PubMed1990

Blood pressure fluctuations in the dysautonomia of Guillain-Barré syndrome.

A 76-year-old man with severe Guillain-Barré syndrome had extremes of hypotension alternating with hypertension. His blood pressure paralleled both systemic vascular resistance and cardiac output. Heart rate, rather than stroke volume, was the major determinant of cardiac output over a wide range of blood pressures. It was at times invariant for several hours and was unresponsive to carotid massage or respiratory cycles, but slowed slightly with each episode of hypotension. Trend monitoring indicated that hypotension preceded reductions in pulmonary artery diastolic pressure. These findings suggest that hypotension resulted from a vasodepressor response with a vagotomized heart and that hypertension was the result of increased sympathetic activity. Both extremes were caused by parallel changes in vascular resistance and heart rate. Dysfunction of baroreflex buffering may have accounted for the rapid swings in pressure.

Aged↗
PubMed1990

Electrodiagnostic abnormalities in 113 consecutive patients with Guillain-Barré syndrome.

We performed electrodiagnostic tests on 113 consecutive patients with acute Guillain-Barré syndrome (103 within 3 weeks of onset). The most common motor conduction abnormalities were proximal conduction block alone (27%), proximal block associated with a distal lesion (27%), and generalized slowing (22%). Other combinations of abnormalities each occurred in fewer than 10% of patients. Thirty-seven percent of patients initially had normal sensory nerve conduction study results, most often in association with proximal conduction block. The characteristic early electrodiagnostic changes in Guillain-Barré syndrome were often present when cerebrospinal fluid protein concentration was still normal. Extensive early fibrillations occurred in 10 patients, 6 of whom recovered well. Patients with early generalized slowing of motor nerve conduction velocity, combined abnormalities, or low muscle action potential amplitudes in ulnar, median, and peroneal nerves generally, but not always, had poorer outcomes than patients with conduction block in one nerve segment. There was no consistent relationship between results of electrophysiologic studies and overall clinical grade or limb power, except that none of the patients with an isolated proximal block had virtual or complete paralysis in the same limb.

Adolescent↗
PubMed1990

The opposite pupil in herniation.

I serially examined the pupil opposite the one already enlarged from transtentorial herniation in 13 patients. The main abnormalities, stereotyped in most patients, were an initially diminished light reaction with a 2.5- to 4-mm-diameter pupil, followed by slight reduction in size, and then reenlargement to greater than original size, all with preserved roundness. Subsequent deterioration varied among patients, but a transitional oval shape was infrequent and oculomotor function was preserved until both pupils were enlarged and fixed. Once the pupil on the side of a mass enlarges, heralding herniation, subsequent deterioration can be appreciated through changes in reactivity and size of the opposite pupil.

Encephalocele↗
PubMed1989

A preliminary MRI study of the geometry of brain displacement and level of consciousness with acute intracranial masses.

We determined the horizontal and vertical components of brain displacement on coronal MRIs in 10 patients with acute supratentorial masses. The vertical distances from the superior sagittal sinus to the pontomesencephalic junction (PMJ) and from the vertical midline of the brain to the PMJ did not differ from measurements in 30 patients without masses. Horizontal displacement of the 3rd ventricle (mean, 5.2 mm) exceeded vertical displacement of the PMJ (mean, 1.2 mm) in all but 1 patient. Total brain displacement near the incisura increased from 3 mm in awake patients to 6 to 13 mm in stuporous and comatose patients and remained predominantly horizontal. Uncal herniation, seen only in a patient who was imaged a day after the onset of coma, did not appear to be the immediate cause of brainstem compression but was accompanied by prominent lateral distortion above the tentorium. This preliminary study suggests that most patients with acute unilateral masses have upper brainstem distortion due predominantly to horizontal shift at or above the tentorium.

Acute Disease↗
PubMed1988

Campylobacter diarrhea and Guillain-Barré syndrome.

Four of 106 consecutive patients with acute Guillain-Barré syndrome had preceding bacterial enteritis caused by Campylobacter jejuni. One had a severe illness with axonal damage and poor outcome; three had typical courses with good recovery. Preceding illnesses in the other 102 patients were the following: diarrhea in nine (with negative stool cultures in five), upper respiratory tract infections in 46, hepatitis in six, other infectious illnesses in eight, and none in 33. Eight patients previously reported with Campylobacter associated with Guillain-Barré syndrome, and the serologic and clinical diagnosis of Campylobacter enteritis in this context, are reviewed.

Adult↗
PubMed1988

Three patients with Fisher's syndrome and normal MRI.

Three patients with Fisher's syndrome had normal MRI scans of the brainstem 6 days, 7 days, and 5 weeks, respectively, after the onset of illness. This further supports a peripheral origin for the ataxia and ophthalmoplegia in this illness and distinguishes it from brainstem encephalitis.

Aged↗
PubMed1988

Physiological support and monitoring of critically ill patients during magnetic resonance imaging.

Magnetic resonance (MR) imaging has been largely restricted to patients who are neurologically and hemodynamically stable. The strong magnetic field and radiofrequency transmissions involved in acquiring images are potential sources of interference with monitoring equipment. A method of support and physiological monitoring of critically ill neurosurgical and neurological patients during MR imaging using a 0.6-tesla MR system is reported. This technique has not caused degradation of the MR image due to electrical interference. Adequate preparation and precautions allow many critically ill neurosurgical and neurological patients to safely undergo MR imaging.

Brain↗
PubMed1988

Intracranial pressure and outcome in adult encephalitis.

The relationship between intracranial pressure (ICP) and outcome was studied in 10 adults with encephalitis. Eight had biopsy-proven herpes simplex encephalitis, one had acute hemorrhagic leukoencephalitis, and in one case the cause of encephalitis was unknown. Monitoring of ICP was instituted because of clinical deterioration or computerized tomography evidence of brain swelling, and was begun a mean of 7 days after the onset of symptoms and continued for a mean of 9 days. All five survivors, but only one of the five fatalities, had an initial ICP of less than 12 mm Hg (p less than 0.05). Four patients with a mean daily ICP of less than 20 mm Hg survived, whereas five of six patients with higher ICP's died (p less than 0.05). Peak ICP did not occur until the 12th day of illness on average. The Glasgow Coma Scale score at the time the ICP monitor was inserted did not correlate with outcome. Intracranial pressure monitoring in severe encephalitis may be a useful adjunct for therapy and an indicator of prognosis.

Adult↗
PubMed1987

Transcranial Doppler in brain death.

Transcranial Doppler examinations (TCD) of 24 brain-dead adult patients demonstrated persistent movement of blood within the middle cerebral arteries in 21. The characteristic pattern of Doppler shift frequencies, seen in 14, was a sharply contoured, brief anterograde systolic envelope with reversed diastolic flow. Five others had variants of this pattern, and two had anterograde flow throughout the cardiac cycle, except at the end of diastole. This suggests that the internal carotid and proximal middle cerebral artery circulation remains patent, but distal resistance to flow in the brain is very high in the majority of brain-dead patients. Three other patients with absent brainstem reflexes but persistent EEG activity had normal TCD patterns. The characteristic pattern on TCD may be a useful ancillary finding in the diagnosis of brain death, and normal TCD patterns probably exclude the diagnosis.

Brain↗
PubMed1987

Artery-to-artery embolism causing stroke in the posterior circulation.

The features of strokes caused by embolism from the vertebral artery (VA) to the posterior cerebral artery (PCA) are reported in 12 patients ("local" or "artery-to-artery embolism"). Occipital infarction occurred with prominent, fluctuating brainstem ischemic symptoms in six; with minor, transient brainstem symptoms in five; and with basilar artery occlusion in one. Visual field abnormalities were found on initial examination in eight and several days after the onset of brainstem symptoms in four. Radiographic studies in 11 identified extracranial (5 patients) or intracranial (3 patients) VA disease, or occlusion of both segments (3 patients) as sources of emboli to the PCA. Mural thrombus in the VA or embolic occlusion of distal branches of the PCA was visualized in five.

Adult↗
PubMed1987

Severe dysarthria with right hemisphere stroke.

Ten patients are presented with severe dysarthria from a right hemisphere stroke, 4 with autopsies, emphasizing that this lesion alone is compatible with severely slurred speech. Most had oropharyngeal weakness; the accompanying hemiparesis was of variable severity. Superficial or deep infarctions were responsible, the smallest involving the right frontal operculum.

Cerebral Infarction↗
PubMed1986

Lateral displacement of the brain and level of consciousness in patients with an acute hemispheral mass.

Brain-tissue shifts associated with drowsiness, stupor, and coma were studied by clinical examination and CT scanning in 24 patients with acute unilateral cerebral masses. Studies were performed soon after the appearance of the mass to detect the earliest CT changes associated with depression of consciousness. Contrary to traditional concepts, early depression of the level of alertness corresponded to distortion of the brain by horizontal displacement rather than transtentorial herniation with brain-stem compression. Horizontal displacement of the pineal body of 0 to 3 mm from the midline was associated with alertness, 3 to 4 mm with drowsiness, 6 to 8.5 mm with stupor, and 8 to 13 mm with coma. Moreover, drowsy or stuporous patients and some comatose patients had widened cisterns between the tentorial edge and the midbrain on the side of the mass, suggesting that the space was not filled by herniated medial temporal lobe. Downward displacement of the pineal body, indicating central transtentorial herniation, did not occur. Compression of one hemisphere by the other anteriorly (transfalcial herniation) was inconsistently related to alertness, though very large anterior displacements may have caused stupor in some patients. Current concepts of the pathoanatomical nature of depressed consciousness, based on pathological material obtained well after clinical examinations, may require revision, because they do not reflect early brain-tissue distortions.

Brain↗
PubMed1986

Self-audible venous bruits and high jugular bulb.

The association between self-audible bruits and ipsilateral high jugular bulbs was demonstrated in five patients, emphasizing the benign nature of the condition. Symptoms included a unilateral pulsatile "whooshing" that was eliminated by gentle pressure on the neck or extreme head rotation to the symptomatic side and was enhanced by conditions that increased cardiac output. The bruits were not audible to examiners. On the basis of one patient with an intracranial tumor, it is proposed that raised intracranial pressure alone, in the absence of a jugular bulb abnormality, is an insufficient explanation for a venous self-audible bruit.

Adolescent↗