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Biomedical subjects

N R Graff-Radford

Publications and source records attributed to N R Graff-Radford.

At least 19 recordsLinked to original sources
PubMed1992

Behavioral neurology and stroke.

The role that stroke patients have played in the history of behavioral neurology was illustrated by describing some contributions made by Broca, Dejerine, Wilbrand, Liepman, and Geschwind. The recent work on the anatomic basis of recovery or lack of recovery in aphasia was discussed and the network of structures important in attention were reviewed. The study of stroke patients with amnestic syndromes (particularly those with basal forebrain and diencephalic lesions) was discussed as well. Starting with Liepman's classic contribution, and then looking at more recent studies, the left hemisphere's role in limb praxis was analyzed. The different syndromes that result when the superior and inferior visual association cortices are damaged were described and illustrated. A summary of neurobehavioral syndromes related to stroke that may present to the psychiatrist because the patient does not have an hemiparesis was given. The relationship of stroke to dementia and depression was reviewed.

Amnesia↗
PubMed1990

Diencephalic amnesia.

The anatomical basis and cognitive profile of diencephalic amnesia remain unclear. We report a two-part study. First, we studied 4 patients with bilateral medial thalamic infarctions using magnetic resonance imaging and comprehensive neuropsychological testing. All patients were followed for more than 1 year. Using a stereotactic method, we plotted the lesions in an atlas delineating the probable structure involved. Secondly, in 2 monkeys, using autoradiography, we traced the pathway from the amygdala to the dorsomedial nucleus, paying particular attention to the intrathalamic course of the amygdalothalamic projections. Our findings were (1) patients develop amnesia when infarctions are located anteriorly; (2) in patients with amnesia, the lesions can be small and strategically located, probably interfering with both hippocampal-related neural structures such as the mamillothalamic tract, and amygdala-related neural structures such as the ventroamygdalofugal pathway; and (3) a specific component of the latter is situated lateral but immediately adjacent to the mamillothalamic tract in the monkey, enabling both structures to be damaged bilaterally by small mirror image lesions. The amnesia is characterized by deficits in anterograde verbal and visual learning and in retrograde amnesia, but motor learning is preserved. We raise the possibility that bilateral diencephalic lesions may interfere particularly with temporal aspects of memory.

Adult↗
PubMed1990

Progressive aphasia in a patient with Pick's disease: a neuropsychological, radiologic, and anatomic study.

Although Pick's disease is generally considered as a dementia characterized by signs of frontal lobe dysfunction, it can present with selective language defects rather than with cognitive decline. In this study, we report prospective and serial clinical, neuropsychological, and neuroradiologic observations in a 59-year-old man whose prominent disturbance was in the retrieval and learning of names denoting concrete entities and actions. Postmortem study confirmed the diagnosis of Pick's disease and revealed that neuronal loss and gliosis were most prominent in left anterior temporal cortices. The findings are in keeping with evidence that the left anterior temporal cortices and interconnected hippocampal system are critically involved in the learning and retrieval of verbal lexical items. The evidence from this patient, along with similar evidence from the literature we reviewed, suggests that when patients present with a progressive aphasia characterized by anomia, Pick's disease should be considered as the probable diagnosis.

Aphasia↗
PubMed1989

Factors associated with hydrocephalus after subarachnoid hemorrhage. A report of the Cooperative Aneurysm Study.

Hydrocephalus is an important complication of subarachnoid hemorrhage (SAH). We analyzed several factors possibly related to hydrocephalus following SAH in 3521 patients from the International Study on the Timing of Aneurysm Surgery. Hydrocephalus was diagnosed on admission computed tomographic (CT) scans in 15% of patients and was thought to be clinically symptomatic in 13.2% of patients. There was a 5.9% overlap between these groups. Using contingency table analysis, we found the following were significantly related to clinical hydrocephalus: increasing age; preexisting hypertension; admission blood pressure measurements; postoperative hypertension; admission CT findings of intraventricular hemorrhage, a diffuse collection of subarachnoid blood, and a thick focal collection of subarachnoid blood; posterior circulation site of aneurysm; focal ischemic deficits; use of antifibrinolytic drugs preoperatively; hyponatremia; admission level of consciousness; and a low score on the Glasgow outcome scale. Using discriminate factor analysis to predict clinical hydrocephalus, the most important variables in order were the following: CT hydrocephalus, intraventricular hemorrhage, admission level of consciousness, presubarachnoid hypertension, increasing age, subarachnoid blood noted on CT scan, posterior circulation aneurysm site, and hypertension postoperatively (canonical correlation = .399). We conclude that the development of hydrocephalus after SAH is multifactorial. Factors that compromise cerebrospinal fluid circulation acutely (eg, intraventricular hemorrhage, hemorrhage from a posterior circulation site of aneurysm, and diffuse spread of subarachnoid blood) contribute to the development of acute hydrocephalus. These same factors, plus the use of antifibrinolytic drugs preoperatively, are also important in the pathogenesis of clinical hydrocephalus, perhaps by promoting subarachnoid fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Anterior choroidal artery territory infarction: a small vessel disease.

To investigate the cause(s) of infarction in the anterior choroidal artery territory, we studied 31 patients (18 men, 13 women) aged 19-82 (mean 58) years, with infarction in this territory documented by computed tomography. All patients were evaluated within 30 days after infarction and had carotid artery studies (arteriography in 17, duplex ultrasound in 14). Fifteen patients had echocardiography. Risk factors for atherosclerosis were chronic hypertension in 20 patients, smoking in 17, diabetes in 10, age greater than 69 years in eight, and elevated serum cholesterol concentration in three. The percentage of patients with extracranial carotid artery stenosis (four of 31, 13%) and the severity of stenosis (mild in two, moderate in two) were similar to that reported in neurologically asymptomatic individuals. The percentage of patients with intracranial carotid artery stenosis (one of 17, 6%) or potential cardiac sources of emboli (two of 31, 6%) was also low. Our findings suggest that infarctions in the anterior choroidal artery territory usually result from small-vessel disease. Associated carotid artery stenosis and potential sources of cardiac emboli are rare and may be coincidental.

Adult↗
PubMed1989

Symptomatic congenital hydrocephalus in the elderly simulating normal pressure hydrocephalus.

In a series of 30 older patients shunted for symptomatic hydrocephalus, we found 3 with a head circumference at or greater than the 98th percentile. In 2, we demonstrated deterioration over 6 and 12 months by serial videotaping of gait and neuropsychological testing. In the 3rd, serial lumbar punctures over a 6-month period gave temporary improvement. In each, CTs showed ventriculomegaly without transependymal flow. One patient had an Arnold-Chiari type I abnormality identified by MRI. All had systemic hypertension. CSF pressure monitoring showed CSF pressure greater than 15 mm Hg 39% of the time in 1 patient, and 100% in another. All improved with ventriculoperitoneal shunting. Patients with probable compensated congenital hydrocephalus who functioned well throughout most of their lives may become symptomatic as they age but improve with shunt surgery. The head circumference should be measured in all older hydrocephalic patients.

Aged↗
PubMed1989

Variables predicting surgical outcome in symptomatic hydrocephalus in the elderly.

We prospectively studied 30 older patients who had shunt surgery for symptomatic hydrocephalus and measured outcome using serial videotaping of gait, neuropsychological testing, and the Katz index of activities of daily living. Twenty-three patients improved and 7 did not. Using univariate analysis and the Fisher exact test, we found that the following variables were significantly related to outcome: (1) time B-waves present on 24-hour CSF pressure record; (2) anterior/posterior ratio on slice 4 of regional cerebral blood flow study; (3) duration of dementia prior to surgery; and (4) gait abnormality preceding dementia. The following variables showed a trend towards significance: (1) time CSF pressure greater than 15 mm Hg; and (2) scoring either pass or fail on the Multilingual Visual Naming Test. We conclude that several variables are significantly associated with surgical outcome in symptomatic hydrocephalus in the elderly and can be used in deciding whether to recommend surgery.

Aged↗
PubMed1988

The role of callosal connections in speech prosody.

A 39-year-old right-handed woman suffered an aneurysmal hemorrhage damaging the anterior four-fifths of the corpus callosum as shown on MRI. Computer-aided acoustical analyses of fundamental frequency (Fo) contours and durational patterns were performed on emotive and nonemotive utterances at 4 weeks, 4 months, and 1 year postsurgery. The patient read sentences in each of five tones (happy, sad, angry, neutral, questioning) or with emphasis on certain words. She showed little Fo distinction with intended mood at 4 weeks, but her performance improved over time. This improvement in speech production was accompanied by an improvement in perceptual judgments of her intended tone by six normal listeners. Fo patterns characteristic of emphatic stress and question forms were found at all test periods, but again improved with time. Durationally, the patient showed appropriate emotive and nonemotive distinctions on most sentences. These results provide acoustic evidence that interhemispheric connections via the corpus callosum are important to proper Fo programming, especially emotive distinctions. The results suggest that the right hemisphere contributes to Fo programming but, following callosal damage, such programming can later be performed by the left hemisphere.

Adult↗
PubMed1987

Normal memory after damage to medial thalamus.

We studied two patients with nonhemorrhagic infarcts of the thalamus and assessed their cognitive functions comprehensively using standardized neuropsychological probes. Neither patient had any discernible memory impairment for verbal or nonverbal material. Analysis of magnetic resonance images with a stereotaxic method revealed that one subject had a right-sided lesion involving about 15% of the dorsomedial nucleus (DM). The other had bilateral lesions that affected about 15% of the left DM and less than 5% of the right DM. The mamillothalamic tract appeared intact in both patients. Considering that medial thalamic lesions commonly cause amnesia in human beings as well as nonhuman primates, there are two possible reasons, alone or in combination, that may explain why these patients failed to have amnesia: the amount of DM damage was less than required to cause amnesia; or the amnesia related to thalamic lesions requires damage to a second structure, such as the mamillothalamic tract or the anterior nucleus.

Adult↗
PubMed1987

Regional cerebral blood flow in normal pressure hydrocephalus.

Regional cerebral blood flow (rcbf) was studied preoperatively and at 2 and 6 months postoperatively in 22 normal pressure hydrocephalus patients using xenon-133 inhalation and single photon emission computed tomography. Sixteen of the 22 patients improved (improved group) and six did not (unimproved group). The following comparisons were made: (1) preoperative rcbf in the improved group, to 14 normal elderly volunteers and to that in 59 SDAT (senile dementia of the Alzheimer type) patients; (2) preoperative rcbf in the improved and unimproved groups to determine if rcbf could predict surgical outcome; (3) pre- to postoperative rcbf in the improved group to see if increased cbf accounted for clinical improvement. The findings were: (1) preoperative rcbf in the improved group was lower than that in normal controls but was the same as that in SDAT; however, the ratios of rcbf values in anterior and posterior brain regions were significantly different between improved group and SDAT (p = 0.02); (2) an anterior/posterior ratio of 1.05 correctly classified surgical outcome in 19/22 patients; five of six in the unimproved group were above this cut off while 14/16 in the improved group were below; (3) in the improved group rcbf increased at 2 but not at 6 months after surgery without a corresponding reduction of clinical signs, supporting the notion that increase in cbf probably does not account for clinical improvement in normal pressure hydrocephalus.

Alzheimer Disease↗
PubMed1987

Neglect in a patient with multiple sclerosis.

We report a patient with multiple sclerosis (MS) who developed left-sided neglect. Although MS is commonly associated with mental status changes, we believe that this is the first reported case of hemineglect. The deficit is probably related to the location, acuteness, size, and right hemispheric predominance of lesions in this patient.

Adult↗
PubMed1987

Callosal apraxia.

A 39-year-old right-handed woman suffered a ruptured pericallosal aneurysm. Serial MRI studies showed damage to the genu and most of the body of the corpus callosum but not the splenium. Both supplementary motor areas (SMA) appeared intact. We studied the patient's praxis performance at intervals over a 4-month period with a standardized battery. The study suggests that apraxia seen in patients with callosal lesions is probably due to the callosal damage, not to the usually associated SMA lesion. Our findings support Liepmann's idea that the left hemisphere is dominant for praxis in both hands. We propose, however, that the dominance effect is related to the type of test given and varies among individuals. As regards the latter, in some individuals the left hemisphere is strongly dominant for motor tasks, while in others it is less so. As regards the type of test, the most enduring left-hand apraxia is seen in verbal, not visuomotor tests.

Adolescent↗
PubMed1987

Idiopathic normal pressure hydrocephalus and systemic hypertension.

Nineteen patients with idiopathic normal pressure hydrocephalus (NPH) were treated with intraventricular shunts. Ten of the 14 who improved and 14 of the total group had systemic hypertension. The prevalence of hypertension in both the improved and whole NPH groups was significantly greater than in a control group with dementia (N = 122) and the published prevalence of hypertension in the US population for this age group. Four possible mechanisms for this association are discussed.

Aged↗
PubMed1986

Normal-pressure hydrocephalus. Onset of gait abnormality before dementia predicts good surgical outcome.

In 1977, Fisher reported that in patients with possible normal-pressure hydrocephalus (NPH), if the gait abnormality preceded dementia, surgery usually had a favorable outcome and vice versa. We studied this finding in 21 patients shunted for possible NPH. By evaluating serial videotapes of gait, neuropsychological tests, and Katz index ratings, preoperatively and at approximately two months and six months postoperatively, we judged 16 patients improved. In the improved group, the families reported that the gait abnormality preceded the dementia in 11 patients and occurred at the same time in five. In the unimproved group, dementia was noted first in three patients, gait abnormality first in one patient, and gait abnormality and dementia at the same time in one patient. Using Fisher's exact test, we compared the improved and unimproved groups for gait abnormality or dementia onset first and found a significant difference. We conclude that the history of gait abnormality occurring before or after dementia in patients with possible NPH is an important prognostic factor for surgical outcome.

Aged↗
PubMed1986

Developmental Foix-Chavany-Marie syndrome in identical twins.

Foix, Chavany, and Marie described a syndrome of faciopharyngoglossomasticatory diplegia resulting from bilateral anterior opercular infarction. We describe identical twins who have a developmental form of the syndrome. The twins, aged 41 years, were the product of a normal pregnancy and birth, but had subsequent delayed motor milestones, seizures, poor language development, mild mental retardation, drooling, absent gag reflexes, inability to protrude the tongue, brisk jaw jerks, impaired fine finger movements, symmetrical brisk reflexes, flexor plantar responses, and mildly spastic gait. Magnetic resonance imaging showed bilateral perisylvian cortical dysplasia compatible with polymicrogyria and incomplete opercular formation.

Adult↗
PubMed1986

An unlearned foreign "accent" in a patient with aphasia.

Rarely, aphasics may develop what appears to be a foreign accent, as noted by Monrad-Kröhn whose Norwegian patient sounded German. We describe a right-handed native American who developed a foreign accent following damage to the left premotor region and white matter anterior to the head of the left caudate nucleus. Her aphasia was of the transcortical motor type. Both she and her parents were born in the USA, she never traveled outside the country and never learned a foreign language. Phonetic analysis of her voice taped prior to the stroke revealed normal speech with a midwestern accent. In contrast, analyses of her current spontaneous speech, repetition, and reading reveal shifts in vowels, e.g., /I/----/i/, /ae/----/a/; increased diphthonigization; and tense speech posture. These features, which were especially frequent in spontaneous speech, probably explain her "accent." Acoustic analysis of fundamental frequency contours of sentences read in different emotional tones revealed a restricted range and variability of the peaks and valleys.

Aphasia↗