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Biomedical subjects

M A Naeser

Publications and source records attributed to M A Naeser.

At least 19 recordsLinked to original sources
PubMed1992

Neuropsychological and neuroanatomical dimensions of ideomotor apraxia.

Fifty-five right-handed men with left hemisphere stroke were systematically investigated for ideomotor apraxia of various body parts. Standardized aphasia and apraxia examinations in all cases, and appropriately timed CT in 28 cases, were used for analysis of psychological and anatomical properties of ideomotor apraxia. It is not possible to ignore the modality of eliciting the movement (command or imitation) and the body part being moved (buccofacial, limb or whole body) from any comprehensive theory about ideomotor apraxia. Different levels of performance are seen with different body parts to different modalities in different aphasic groups. Some subtypes of ideomotor apraxia (buccofacial) have highly specified anatomical basis. Some (limb) have apparently distributed anatomies, and others (whole body) have as yet unknown bases.

Adult↗
PubMed1990

Late recovery of auditory comprehension in global aphasia. Improved recovery observed with subcortical temporal isthmus lesion vs Wernicke's cortical area lesion.

This study examined the relationship between recovery of auditory comprehension in global aphasia patients after 1 year post onset, and temporal lobe lesion in Wernicke's cortical area vs temporal lobe lesion in the subcortical temporal isthmus area. Computed tomographic scans and language behavior were examined in 14 right-handed globally aphasic stroke patients with lesion in the left hemisphere. Nine patients had large cortical/subcortical frontal, parietal, and temporal lobe lesion that included more than half of Wernicke's cortical area (FPT cases). Five patients had large cortical/subcortical frontal and parietal lobe lesion, but only subcortical temporal lobe lesion, including the temporal isthmus (FPTi cases). All patients were tested acutely at 1 to 4 months post onset and again at 1 to 2 years post onset. There was a significantly greater increase in the amount of recovery that had taken place after 1 to 2 years post onset for the FPTi group vs the FPT group in the overall Boston Diagnostic Aphasia Examination (BDAE) Auditory Comprehension Z score. In four of the five FPTi cases, the late BDAE Auditory Comprehension Z scores were above -0.5 (mild-to-moderate comprehension deficits). Most recovery was in single-word comprehension. In eight of the nine FPT cases, the late BDAE Auditory Comprehension Z-scores were below -0.5 (moderate-to-severe comprehension deficits). There was no significant difference between the two groups in recovery of spontaneous speech, repetition, or naming, where severe deficits remained in most cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Temporal dimensions of consonant and vowel production: an acoustic and CT scan analysis of aphasic speech.

This study explored a number of temporal (durational) parameters of consonant and vowel production in order to determine whether the speech production impairments of aphasics are the result of the same or different underlying mechanisms and in particular whether they implicate deficits that are primarily phonetic or phonological in nature. Detailed analyses of CT scan lesion data were also conducted to explore whether more specific neuroanatomical correlations could be made with speech production deficits. A series of acoustic analyses were conducted including voice-onset time, intrinsic and contrastive fricative duration, and intrinsic and contrastive vowel duration as produced by Broca's aphasics with anterior lesions (A patients), nonfluent aphasics with anterior and posterior lesions (AP patients), and fluent aphasics with posterior lesions (P patients). The constellation of impairments for the anterior aphasics including both the A and AP patients suggests that their disorder primarily reflects an inability to implement particular types of articulatory gestures or articulatory parameters rather than an inability to implement particular phonetic features. They display impairments in the implementation of laryngeal gestures for both consonant and vowel production. These patterns seem to relate to particular anatomical sites involving Broca's area, the anterior limb of the internal capsule, and the lowest motor cortex areas for larynx and tongue. The posterior patients also show evidence of subtle phonetic impairments suggesting that the neural instantiation of speech may require more extensive involvement, including the perisylvian area, than previously suggested.

Aged↗
PubMed1990

Broca's area aphasias: aphasia after lesions including the frontal operculum.

We report 9 cases of aphasia following lesions in the region of the left frontal operculum. It is not possible to capture their variety of clinical manifestations with the simple labels of "Broca's area aphasia." or "Broca's area aphasia." Analysis of the breakdown of various components of speech and language in these cases suggests that the operculum, lower motor cortex, and subjacent subcortical and periventricular white matter contain critical parts of different language systems. These systems can be independently impaired. There are several common language syndromes that follow damage that includes the left frontal operculum. These syndromes reflect the effects of the direction and extent of the lesion in the various language systems.

Adult↗
PubMed1989

Severe nonfluency in aphasia. Role of the medial subcallosal fasciculus and other white matter pathways in recovery of spontaneous speech.

The relationship between location and extent of lesion on CT scan and limitation in spontaneous speech was examined. The severity of spontaneous speech ranged from cases with no speech or only verbal stereotypies (first major group) to those with reduced, hesitant, poorly articulated, agrammatic speech (nonfluent Broca's aphasia, second major group). CT scan analysis revealed no single neuroanatomical area that contained an extensive lesion which could be used to discriminate the most severe cases from the least severe. The two groups were separable, however, on the basis of the CT scan when the extent of the lesion in two subcortical white matter areas were combined: (1) the most medial and rostral portion of the subcallosal fasciculus plus (2) the periventricular white matter near the body of the lateral ventricle, deep to the lower motor/sensory cortex area for the mouth. The most rostral portion of the medial subcallosal fasciculus, located in the lateral angle of the frontal horn (extremely deep to Broca's area), contains projections from the cingulate gyrus (area 24) and the supplementary motor area, to the caudate nucleus. We suggest that one explanation for the more severe limitation in spontaneous speech in the first group is the extensive white matter lesion in these two subcortical pathways had interrupted a large number of connections for (1) initiation and preparation of speech movements, and limbic aspects of speech (lesions in the medial subcallosal fasciculus), and (2) motor execution and sensory feedback for spontaneous speech (lesions in periventricular white matter deep to the motor/sensory cortex area for the mouth). Extensive lesion in only one of these two white matter pathway areas, alone was not sufficient to produce long-lasting severe limitation in spontaneous speech and could not be used to discriminate the two groups on the basis of the CT scans. The patients with less severe limitation in spontaneous speech (nonfluent Broca's aphasia) had less extensive lesion within these two white matter areas combined, and had interrupted a smaller number of these subcortical connections. The sites of the lesions in subcortical white matter in CT scans in Broca's original case who could only produce a verbal stereotypy are similar to those in our first group with the most severe limitation in spontaneous speech. The presence or absence of hemiplegia was not related to severity or recovery of spontaneous speech. Careful examination of lesion extent in these two areas of subcortical white matter on CT scanning appears to be relevant in predicting potential for recovery of spontaneous speech in some stroke patients.

Adult↗
PubMed1988

Age-related differences in computed tomographic scan measurements.

Seventy-nine healthy men ranging in age from 31 to 87 years underwent a computed tomographic (CT) scan and were administered a neuropsychologic test battery. Midventricular, high ventricular, and supraventricular CT slices were analyzed for each individual. Computerized techniques calculated the percent of fluid volume and the mean CT density for each slice. The mean CT density of a standard tissue sample was also evaluated. The results suggest that fluid volume at the level of the ventricles is fairly stable until individuals are in their 60s, when a dramatic increase occurs. The percent of fluid volume above the level of the ventricles appears to increase slightly the ventricles appears to increase slightly in the 50s and then level off. Whole slice mean CT density numbers decreased in a linear fashion with increasing age, but the mean CT density of a standard tissue sample did not. A discriminant function derived from the CT measures was significantly correlated with a discriminant function derived from the neuropsychologic test battery. Findings based on subjects whose health status has been less carefully screened may differ from those in the present study.

Adult↗
PubMed1987

Relationship between lesion extent in 'Wernicke's area' on computed tomographic scan and predicting recovery of comprehension in Wernicke's aphasia.

This study investigated the relationship between severity of auditory comprehension in Wernicke's aphasia and amount of temporal lobe damage within Wernicke's area (posterior two thirds of superior temporal gyrus region) as well as the total temporoparietal lesion size. There was a highly significant correlation between comprehension and the amount of temporal lobe lesion in Wernicke's area. There was no significant correlation between comprehension and the total temporoparietal lesion size. Patients with damage in only half or less than half of Wernicke's area had good comprehension at six months after the onset of stroke. Patients with damage in more than half of Wernicke's area had poor comprehension even one year after the onset of stroke. Additional anterior-inferior temporal lobe lesion extension into the middle temporal gyrus area was associated with particularly poor recovery.

Aged↗
PubMed1987

Anomalous dominance in sibling stutterers: evidence from CT scan asymmetries, dichotic listening, neuropsychological testing, and handedness.

Two left-handed siblings with developmental stuttering are comprehensively described. The methods of study included speech and language evaluation, neurological and neuropsychological examinations, dichotic listening, auditory evoked responses, electroencephalogram, and CT scan asymmetry measurements. The data from each sibling showed evidence of anomalous cerebral dominance on many of the variables investigated. The CT scan measurements showed atypical asymmetries, especially in the occipital regions. These findings support the theory that stuttering may be related to anomalous cerebral dominance, both on functional as well as structural bases. Implications of anomalous dominance and the resultant effect of hemispheric rivalry on speech fluency are discussed.

Adolescent↗
PubMed1987

Generators of middle- and long-latency auditory evoked potentials: implications from studies of patients with bitemporal lesions.

We recorded middle- and long-latency auditory evoked potentials (AEPs) in 5 patients (ages 39-72 years) with bilateral lesions of the superior temporal plane. Reconstructions of CT sections revealed that primary auditory cortex had been damaged bilaterally in four of the patients, while in the fifth an extensive left hemisphere lesion included primary auditory cortex while a right hemisphere lesion had damaged anterior auditory association areas but spared primary auditory cortex. Normal middle-latency AEPs (MAEPs) were recorded at the vertex electrode in all of the patients. In 3 of the 5 patients, MAEPs also showed normal coronal scalp distributions and were comparable in amplitude following stimulation of either ear. Two patients showed abnormalities. In one case, Na (latency 17 msec)-Pa (latency 30 msec) amplitudes were reduced over both hemispheres following stimulation of the ear contralateral to the more extensive lesion. In another, with both subcortical and cortical involvement, the Pa was abolished over the hemisphere with the more extensive lesion. Long-latency AEPs were normal in 2 patients whose lesions were largely confined to the superior temporal plane. In 2 patients with lesions extending into the inferior parietal lobe, N1s were abolished bilaterally. In the fifth patient, the N1 showed a slight reduction over the hemisphere with the more extensive lesion. Middle- and long-latency AEPs were differentially affected by some lesions. For example, patients with absent N1s could produce normal Pas. A review of these results and those of previous studies of bitemporal patients suggests that abnormalities in middle- and long-latency AEPs do not necessarily reflect damage to primary auditory cortex per se, but rather the degree of damage to adjacent areas. Abnormalities in MAEPs are associated with subcortical lesions, or cortical lesions extensive enough to denervate thalamic projection nuclei. Abnormalities in the long-latency N1 reflect lesion extension into the multi-modal areas of the inferior parietal lobule. This area appears to exert a critical modulatory influence over N1 generators outside of the superior temporal plane.

Adult↗
PubMed1987

Auditory syntactic comprehension in nine aphasia groups (with CT scans) and children: differences in degree but not order of difficulty observed.

Auditory syntactic comprehension was examined in nine groups of aphasics (60 stroke cases) and 3 and 6 year old children. Ten syntactic contrast pairs were studied. Differences in degree but not order of difficulty were observed. The 5 easier pairs were Gender; On/Under; Negative/Affirmative; Object-number; Subject-number; the 5 more difficult pairs were Past/Present; Subject/Object Reversible; Is/Are; Relative Clause; and Future/Present. The "marked" half-pair was significantly more difficult--i.e., Negative vs. Affirmative; Plural vs. Singular Subject; Future or Past vs. Present. Performance on the test was significantly correlated with the BDAE Auditory Comprehension z-score and Token Test. The 3 year old children most closely resembled the Severe Wernicke's (but were better than the Globals), and the 6 year old children were similar to aphasia cases with mild comprehension deficits and frontal or parietal perisylvian lesions which spared most of Wernicke's area. Wernicke's area (posterior two-thirds superior temporal gyrus area) appears to be the area most sensitive to auditory syntactic comprehension. However, the surrounding perisylvian areas including frontal and parietal lobes are also areas sensitive to syntactic comprehension.

Adult↗
PubMed1987

Correlations of subcortical CT lesion sites and aphasia profiles.

We have analysed the aphasia profiles of 19 cases with subcortical infarction or haemorrhage. Several components of the aphasic syndromes, especially sentence length and grammatical form (together compromising fluency), ease of speech initiation, articulation, voice volume, and auditory comprehension, were individually isolated for correlation with CT lesion site. Each component had a specific lesion site correlation, and lesions in various deep periventricular white matter regions were the critical ones for all components of aphasia. Simple tabulation of lesions as cortical or subcortical, and restricting analysis to lesions of basal ganglia would both have proved inadequate to account for clinical findings. A review of 61 subcortical cases in the neurological literature for which CT and aphasia data were available supports these conclusions.

Aphasia↗
PubMed1986

Computed tomographic scan hemispheric asymmetries in right- and left-handed male and female subjects.

Patterns of computed tomographic scan asymmetries in the frontal and occipital regions of the brain were examined in 172 right- and left-handed male and female subjects; these patterns were compared with those published previously to determine which asymmetries were reliable across studies. The patterns observed appeared to be unrelated to handedness or sex and suggested that, especially in the posterior region of the brain, the majority of individuals have left hemispheres longer and wider than their right hemispheres. If anatomic asymmetries are indeed substrates for functional asymmetries, it appears more likely that they are related to at least some aspects of language dominance than to cerebral dominance for handedness.

Adolescent↗
PubMed1986

Aphasia in left-handers: lesion site, lesion side, and hemispheric asymmetries on CT.

Language in left-handed aphasics with left (n = 27) or right (n = 4) hemisphere lesion was examined. Left occipital CT asymmetry was the most common asymmetry and could not be used to predict handedness or which hemisphere, if damaged, would produce aphasia. When left hemisphere lesion sites were matched between eight left-handed and eight right-handed aphasics, there were no significant group differences on language measures. Two nonfluent cases with good comprehension and large right frontal, parietal, and temporal lesions appeared to have "Broca's area" in the right hemisphere, but "Wernicke's area" in the left. Results suggest separate hemispheric loci for handedness, speech output, and/or comprehension dominance in some left-handers.

Aphasia↗
PubMed1986

Sentence level auditory comprehension treatment program for aphasic adults.

The purpose of this study was to investigate whether a newly developed sentence level auditory comprehension (SLAC) treatment program could be used to improve language comprehension test scores in adults with chronic aphasia. Results indicate that the SLAC treatment program can be used with chronic patients; performance on a standardized test (the Token Test) was improved after treatment; and improved performance could not be predicted from either anatomic CT scan lesion sites or pretreatment test scores. One advantage to the SLAC treatment program is that the patient can practice listening independently with a tape recorder device (Language Master) and earphones either in the hospital or at home.

Aphasia↗
PubMed1985

CT scan lesion localization and response to melodic intonation therapy with nonfluent aphasia cases.

The purpose of this retrospective study was to investigate the relationship between CT scan lesion localization and good or poor response to Melodic Intonation Therapy (MIT) as measured by pre- and post-MIT treatment scores. The four good response (GR) cases improved in speech characteristics ratings for Phrase Length and Grammatical Form on the Boston Diagnostic Aphasia Examination; the four poor response (PR) cases showed no improvement. The GR cases had lesions which involved Broca's area and/or white matter deep to it plus large superior lesion extension into periventricular white matter deep to the lower motor cortex area for face. These GR cases had no large lesion in Wernicke's area and no lesion in the temporal isthmus or the right hemisphere. The PR cases, however, had bi-lateral lesions or lesion including Wernicke's area or the temporal isthmus.

Adult↗
PubMed1979

The resolving stroke and aphasia. A case study with computerized tomography.

A 39-year-old man suffered an intracerebral hemorrhage in the region of the left internal capsule deep to Wernicke's area. The location of the lesion was confirmed by computerized tomography (CT) performed two days postictally. Two weeks after admission, the Boston Diagnostic Aphasia Examination (BDAE) diclosed Wernicke's aphasia. We hypothesize that the hematoma exerted pressure on Wernicke's cortical area, thus causing the resulting Wernicke's aphasia at that time. A CT scan three months later showed absorption of the hematoma, with a residual low-density lesion deep to Wernicke's area, in the region of the arcuate fasciculus. At that time, BDAE testing disclosed a mild conduction aphasia. Serial CT scanning combined with discriminating clinical evaluation of aphasia provides a valuable opportunity for study of the processes underlying stroke resolution and aphasia.

Adult↗
PubMed1979

Effects of three syllable durations using the melodic intonation therapy technique.

Five nonfluent aphasics were presented English phrases with three syllable durations; a regular speech, non-intoned duration less than 1 sec per syllable, and two modified Melodic Intonation Therapy (MIT) intoned durations of 1.5 sec per syllable and 2.0 sec per syllable. All subjects had the greatest number of correct phrase productions at the longest MIT duration (p less than 0.001) and the greatest number of failures at the regular non-intoned duration. Therefore, syllable duration is an important acoustic parameter to consider when using an MIT technique with severe nonfluent aphasics.

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