Aphasia type, age and cerebral infarct localisation

Stroke patients with nonfluent aphasia tend to be younger than fluent aphasics. We investigated whether this difference was due to an age-related change in the anatomicofunctional organisation of language areas or to an age-dependent variation on the distribution of infarct localisation. From a hospital prospective stroke database we selected those patients who suffered an ischaemic stroke with at least one non-lacunar infarct demonstrated by computed tomography (n = 423 patients). We retrieved information on language disturbance in the acute phase (no aphasia, non-fluent aphasia, fluent aphasia) and on infarct localisation by CT. Non-fluent aphasia predominated in young (aged < 51 years) patients while in elderly patients (aged > 70 years) the opposite was found (chi 2 = 8.03; P = 0.005). Posterior infarcts were also more frequent in elderly patients (chi 2 = 9.9; P = 0.002). There were 27 atypical cases (patients with lesions on language areas without aphasia) and 14 aphasics with atypical infarct localisation (9 fluent aphasics with anterior lesions and 5 non-fluent aphasics with posterior lesions). The proportions of atypical cases, their infarct location or fluency type were not influenced by age. It was concluded that the predominance of fluent aphasia in older patients was related to the higher proportion of posterior infarcts in these patients. The hypothesis of age-related changes in the anatomico-functional organisation of language areas was not supported by the present data.

The significance of body part as tool errors in limb apraxia

When pantomiming to command, individuals with left hemisphere brain damage (LBD) often produce errors in which they use a body part as if it were the tool (BPT). Some clinicians question the significance of this type of error because subjects without brain damage at times also make BPT responses. We analyzed BPT errors in LBD and normal subjects who were reinstructed to modify the inappropriate BPT responses when they occurred. We also analyzed errors in normal subjects who were never reinstructed if a BPT occurred. Whereas LBD subjects who were reinstructed produced significantly more BPT errors than normals who were also reinstructed, LBD subjects were not different from normals who were not reinstructed. When reinstructed, normal control subjects correctly modified virtually all BPT errors, whereas LBD subjects did not modify BPT errors. These findings underscore the need for reinstruction when a BPT error occurs to determine whether it represents a true BPT error, a sign of limb apraxia.

Improvement of hemispatial neglect with cold-water calorics: an electrophysiological test of the arousal hypothesis of neglect

Introducing ice-water into the left ear of right-brain-damaged patients attenuates unilateral neglect symptoms. By examining EEG changes over each hemisphere during this procedure, we were able to test a hypothesis concerning the mechanism of cold-water calorics and the attention-arousal hypothesis of hemispatial neglect. We present a case study of an 83-year-old woman with a massive right-hemisphere CVA exhibiting severe hemispatial neglect. Caloric stimulation produced a leftward eye deviation to central position, and a temporary partial remission of neglect symptoms. Significant changes in EEG activation indicated a central mechanism associated with the regularization of eye gaze. Caloric stimulation also produced a significant interaction between EEG frequency band and hemisphere, indicating that while both hemispheres increased in cortical activation, the right hemisphere increase was significantly greater. This supports the activation-arousal hypothesis of neglect over the mutual inhibition model.

Severe pathological crying after left anterior choroidal artery infarct. Reversibility with paroxetine treatment

BACKGROUND

There is increasing evidence that serotonergic neurotransmission may be damaged in poststroke pathological crying. A correlation between the clinical severity of pathological crying and the size of stroke-induced serotonergic pathway lesions is commonly accepted. We present a case of severe pathological crying after a limited left anterior choroidal artery territory infarction.

CASE DESCRIPTION

A right-handed 55-year-old man who was a heavy smoker was admitted to the hospital after a right hemiplegia of sudden onset. Clinical examination revealed a right global hemiplegia including the face and a right hemihypoesthesia. Cerebral CT scan and MRI showed an infarct in the retrolenticular part of the posterior limb of the left internal capsule extending upward into the posterior paraventricular corona radiata region. Transesophageal echocardiography revealed an atrial septal aneurysm of 15-mm excursion without associated patent foramen ovale. From the first day of admission, the patient exhibited very frequent and intense fits of pathological crying. Their persistence led to initiation of treatment with the selective serotonin reuptake inhibitor paroxetine on day 30. Complete and immediate resolution of pathological crying occurred 24 hours after onset of therapy. Follow-up examination at day 90 confirmed the absence of relapse of pathological crying.

CONCLUSIONS

We conclude that poststroke pathological crying in our patient may have been due to unilateral disruption of the capsular ascending projections of the serotonergic brain stem raphe nuclei. A small left-sided capsular lesion may have led to severe pathological crying. This disabling condition may be reversible with selective serotonin reuptake inhibitor therapy.

Psychosocial stressors in patients with major depression and silent cerebral infarction

BACKGROUND AND PURPOSE

We previously found that silent cerebral infarction (SCI) was present in most of the patients older than 50 years with major depression who were examined. The present study was designed to clarify the relationship between psychosocial stressors and SCI in patients with major depression.

METHODS

Forty-two patients with unipolar depression underwent MRI and were classified as SCI-negative (n = 19) or SCI-positive (n = 23). The SCI-positive group was subclassified into those with moderate SCI (n = 16) and those with severe SCI (n = 7). The relationship between the patients' DSM-III-R axis IV scores and SCI was evaluated.

RESULTS

The axis IV score was significantly lower in the SCI-positive group than in the SCI-negative group (P < .05). Within the SCI-positive group, the mean axis IV score was significantly lower in those with severe SCI than in those with moderate SCI (P < .05).

CONCLUSIONS

Our findings suggest that depression in patients with SCI involves more neurological factors than psychosocial stressors.

The novelty effect in recovered hemineglect

Left neglect patients, patients who had recovered from left neglect and control subjects performed a task of simple motor reaction times (RTs) to lateralised visual stimuli. Neglect and recovered patients were slower than controls on left-sided targets. To explore the time course of the allocation of attention across space, an analysis of responses as a function of the serial order of the trials was performed. While neglect patients' performance did not substantially change over time, recovered patients showed a stereotyped 'novelty effect', consisting of larger left/right RT differences at the beginning of the task than at the end of it. To explain this practice-related change, a trade-off is hypothesised between the process of learning the motor task and the mechanisms involved in recovery from neglect, such as the reorienting of attention toward the contralesional side following the initial ipsilesional orienting. A possible role is proposed for the prefrontal cortex as the crucial neural structure that mediates both processes.

Alien hand syndrome: influence of neglect on the clinical presentation of frontal and callosal variants

Three patients with mesial frontal and extensive callosal lesions due to anterior cerebral artery infarction manifested an alien hand syndrome (AHS) with varied features. Patient 1 with left hemispheric lesion showed right hand's impulsive reaching and grasping and left hand's antagonistic movements to the right (intermanual conflict; IMC). Patients 2 and 3 with right hemispheric lesion manifested a left hemihypokinesia which was thought to have suppressed the frequency and amplitude or even the occurrence of left hand's reaching and grasping. IMC and other left hand's non-antagonistic, irrelevant movements to the right remained. Because the term "IMC" is often misused and not strictly defined, its association with right hand's reaching and grasping is quite uncommon, its significance as a sign of callosal disconnection is not well validated, and because left hand's reaching and grasping tend to be suppressed by motor neglect, a trend may then develop for the right hand to be the sole focus of pathological behaviour in patients with the so-called frontal AHS (Feinberg, Schindler, Flanagan et al., 1992).

The relationship between retrograde and anterograde amnesia in patients with typical global amnesia

An extensive battery of tests of anterograde amnesia and remote memory was given to ten amnesics with lesions either to the medial temporal lobes of the diencephalon. These showed that the patients had anterograde amnesia with deficits in verbal and non-verbal recall and recognition, but preservation of word stem completion and intelligence. Mild impairments on executive tests and digit span performance were largely caused by the poor performance of the Korsakoff patients. The amnesics also showed remote memory deficits for personal and public domain information, and temporal gradients were observed for some of the tests. These deficits probably arose because the patients' anterograde amnesia was more severe than their retrograde amnesia even for the recent pre-morbid past. They were more impaired in the recall of details about famous names in their ability to recognize such names. There was also a suggestion that performance on anterograde tests did not relate strongly to that on tests of retrograde amnesia of the remote pre-morbid past. However, this effect was less apparent with memory for personal information when the format and the information tapped were matched on pre- and post-morbid tests.

[Neuropsychological analysis in 2 cases of infarction in the left precentral gyrus--with special reference to apraxia of speech and agraphia]

It remains controversial whether agraphia can coexist in a case with apraxia of speech, and whether an apraxia of speech can be classified into a category of aphasia. We examined the presence of agraphia in 2 right-handed patients of apraxia of speech. Case 1 of mild agraphia showed an infarcted lesion in the left precentral gyrus extending to the neighboring white matter, which involving the arcuate fasciculus on MRI. Positron emission tomography (PET) indicated decrease of cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) in the infarcted lesion, but no decrease of CBF and CMRO2 in the Broca's area. In this case, agraphia was more conspicuous in "kanji" than in "kana" and severity of the agraphia was not correlated to that of speech disturbance on naming test. Case 2 without agraphia showed a small infarcted lesion in the left precentral gyrus, which did not extend to the deep white matter on MRI. Agraphia can coexist with apraxia of speech in a case with the lesion in the left precentral gyrus, in which the cortical lesion is relatively widespread or extends to the deep white matter. However, lack of etiological connection between the agraphia and the apraxia of speech was suggested. We could not confirm the location in the left precentral gyrus which is responsible for the agraphia.

Differential impairments in recalling people's names: a case study in search of neuroanatomical correlates

The case of a patient with selective left hemispheric medial and lateral temporal lobe damage is described. The patient was of slightly supra-average intelligence and had no problems in normal memory functions, but was severely anomic with respect to people's names. One month post-onset, this deficit held for names of colleagues and friends she had gotten to know during the last 10 years prior to the infarct and for all names confronted with post-infarct. On the other hand, learning of face-name associations was preserved and was independent of the ability to generate context-specific information for the subjects whose names were requested. The results support the existence of category-specific naming impairments, and, moreover, indicate a deficit that has to be differentiated with regard to memory systems. A time-limited, but prolonged engagement of interconnected left medial and adjacent lateral temporal lobe structures in ecphory is stressed for context-restricted information such as proper names.

The grammatical properties of mass nouns: an aphasia case study

A patient (F.A.) is described who, as a consequence of brain damage, shows an isolated deficit concerning the use, across a series of tasks, of the grammatical properties of mass/non-countable nouns. Her use of grammar is otherwise perfect. This behaviour dissociates from that of other patients who have severe grammatical difficulties, but do not show any impairment in the mass nouns tasks that F.A. fails. This case is thought to demonstrate how specific grammatical rules, that are said to be stored at the lemma level of lexical retrieval, are indeed independently represented and accessible.

Visual extinction and prior entry: impaired perception of temporal order with intact motion perception after unilateral parietal damage

Two patients with left-sided visual extinction after right parietal damage were each given two 'prior entry' tasks that have recently been used to study attentional biases in normals. The first task presented two unconnected bars, one in each visual field, with the patients asked to judge which appeared sooner. Both patients reported that the right bar preceded the left unless the latter led by over 200 msec, suggesting a severe bias to the right affecting the time-course of visual awareness. The second task presented one continuous line in a scrolling format across the same spatial extent, with the patients asked to judge which direction the line moved in. The patients now performed normally. Thus, the perception of temporal order for separate events was impaired by the lesions, but without disrupting motion perception within single events. The implications are discussed for theories of normal and pathological attention, visual awareness, and motion perception.

Blood pressure and intellectual function in elderly subjects

OBJECTIVE

to assess the relationship between hypertension and cognitive function in elderly subjects.

METHODS

17 subjects with uncomplicated hypertension (nine male, eight female) and 27 control subjects with similar educational level and age (18 male, nine female) were studied. These individuals were recruited, according to strict selection criteria, from a random sample of 120 elderly subjects living in the community, who had a normal Mini Mental State score. An extensive neuropsychological test battery, sensitive to mild cognitive impairment, was administered in standard conditions to measure attention, concentration and judgement, psychomotor speed, memory and learning. Affective disorders were also evaluated. In all patients a computed tomography scan was performed.

RESULTS

subjects with high blood pressure had lower mean levels of performance in attentional measures; tapping test (inhibition of incorrect answers), three words-three shapes test (attempts; incidental memory) and reaction time to multiple stimuli. They also scored worse in clusters 1 and 2 of the Hamilton rating scale for depression. Confluent white matter lesions were found in nine hypertensive subjects (52.9%) and five controls (18.5%; P = 0.0170). Lacunes were demonstrated in 11 hypertensive (64.7%) and four normotensive people (14.8%; P = 0.0007). In a multivariate analysis (logistic regression), three cognitive variables (tapping, Hamilton cluster 2 and Hamilton total score) remained significantly associated with hypertension, independently of the presence of cerebral lesions.

CONCLUSIONS

in elderly otherwise normal hypertensive subjects, an attentional impairment may occur, which appears to be functional and possibly reversible rather than structural and progressive.

Acute confusional migraine and migrainous infarction in childhood

We report two children with acute confusional migraine (ACM) and another with migrainous infarction (MI), aged 7-12 years. There was a family history of migraine in all patients. The patients, who were all right-handed, all manifested sudden onset of consciousness disturbance and other neurological deficits as the first aura in their life. The symptoms in all cases almost completely resolved spontaneously within 24 h, but transient occipital slowing on EEG with laterality corresponding to the side of migrainous origin lasted more than 24 h. In the cases of ACM in the critical phase, although MRI and MR angiography showed no abnormal findings, IMP-SPECT performed within 48 h of migraine attacks revealed a regional change in cerebral blood flow, which is one particular case demonstrated hypoperfusion in the left posterior cerebral artery (PCA) territory. Therefore, although ACM was diagnosed clinically by exclusion, SPECT was thought helpful for the diagnosis of ACM. We speculated that transient hypoperfusion affecting the dominant-sided PCA territory involving the medial temporal structures was responsible for the confusion with amnesia in ACM, in contrast to the lack of confusion or amnesia in the case of MI showing cystic encephalomalacia in the right thalamic and hippocampal regions.

The effectiveness of DRL in the management and treatment of severe behaviour disorders following brain injury

Effective management of behaviour disorders following brain injury is essential if individuals are to achieve their rehabilitation potential. Best practice dictates that the intrusiveness of any operant approach used be minimal, remain in operation for the shortest time possible, and emphasize skill building. Ideally, treatment gains should maintain following its withdrawal. Reinforcement methods fulfil these criteria in that they are less intrusive, concerned with the establishment of pro-social behaviours, and encourage positive staff-patient interaction. While their efficacy has been well documented with other clinical populations, less is known regarding treatment of behaviour disorders in survivors of brain injury. Some existing studies are characterized by methodological weakness that limit understanding of any contribution made to observed improvement, and little is known regarding maintenance of treatment effects. In this paper the effectiveness of a variant of differential reinforcement, DRL, will be examined. Three cases will be presented which demonstrate increased behavioural control in response to the use of DRL. A strength of this paper is that the use of appropriate single-case design methodology, and follow-up data up to 18 months after treatment, permits more robust conclusions regarding the efficacy of DRL to be made. These are discussed, together with practical points regarding programme design.

Lexical-semantic deficits in two patients with dominant thalamic infarction

Two patients with dominant thalamic infarction, one in the tuberothalamic artery territory, the other in the paramedian artery territory, demonstrated language impairment limited to word retrieval difficulties in spontaneous language and structured naming tasks. Using a cognitive neuropsychological model of lexical processing developed in the study of patients with cortical lesions. We carried out a detailed investigation of their lexical abilities. Both patients demonstrated impairment restricted to oral and written picture naming and oral naming to definition and spared performance on tasks of lexical comprehension, oral word reading, and writing to dictation, as well as syntactic comprehension and production. Naming impairment disproportionately affected lower frequency words, and word substitutions often corresponded to objects that were semantically-related to target words. We propose that our patients' word retrieval impairments reflect a failure of thalamic input to effectively engage the cortical networks subserving lexical semantic processing, leading to degraded levels of activation as the semantic system interfaces with subsequent stages of lexical processing.

Diaschisis and neuropsychological performance after cerebellar stroke

The cerebellum has been implicated in higher-order behavior. Blood flow studies (SPECT) have shown that cerebral diaschisis can appear after cerebellar lesions and this phenomenon could serve as a basis for a potential neuropsychological derangement after cerebellar insults. Our objectives in this study were to delineate the neuropsychological profile after cerebellar stroke, to evaluate cerebral diaschisis as measured by SPECT and to correlate the findings. We prospectively studied 26 patients with cerebellar stroke and 16 subjects matched for age, sex and educational level as a control group. A neuropsychological battery test, MRI and cerebral SPECT were performed in both groups. We found that cerebellar stroke results in motor control impairment and mild naming deficit, whereas no dysfunction in declarative memory, language, visuospatial or executive abilities is evident. The anatomical distribution of the lesion does not seem relevant in terms of neuropsychological impairment or diaschisis. Both ipsilateral and contralateral diaschisis as a result of a cerebellar stroke are found, but this phenomenon does not seem to result in overt neuropsychological derangement.

Reading speed in pure alexia

This study investigated possible causes of differences in reading speed between two alexic patients who read words letter by letter. As both patients appeared to rely on serial left-to-right processing of letters within words, the difference in reading speed did not seem to be related to any differences in the extent to which the patients could recognize letters in words in parallel or 'ends-in'. Differences in reading speed also seemed to be unrelated to the patients ability to identify individual letters since their letter recognition accuracy was very similar. Furthermore, although patient PD was significantly slower at reading words aloud than patient DC, PD was in fact significantly quicker than DC on a test that has previously been used to assess letter recognition skills in letter-by-letter readers. It is therefore concluded that PD reads words more slowly because of an additional impairment at the level of the word form system. The results therefore reinforce the distinction between Type 1 and Type 2 letter-by-letter readers that was first drawn by Patterson and Kay.

Effect of head-centered and body-centered hemispace in unilateral neglect

The aim of this study was to evaluate the effects of head-centered and body-centered hemispace on a line bisection task in patients with left unilateral neglect. Five patients with left unilateral neglect were given a line bisection task under four different conditions. The results clearly demonstrate that both head-centered and body-centered hemispace had a statistically significant effect on the line bisection task. The results are discussed with respect to a reference frame of space and the validity of dividing unilateral neglect into two components (i.e., spatial neglect and object neglect) is proposed.

Atypical cerebral dominance: predictions and tests of the right shift theory

Alexander and Annett (Brain and Language, in press) described new cases of atypical cerebral specialization, and suggested that these observations and others in the literature could be explained by the right shift (RS) theory. The theory generates specific predictions as to the prevalence of different patterns of cerebral dominance and their distribution among right-handers and left-handers. Predictions differ between strict and generous criteria of sinistrality, as between left writers and non-right-handers. Tests of the predictions against reports in the literature reveal good fits for most data. New studies will test the RS theory if their design permits examination of the present predictions.

Pathological crying and laughing: treatment with sertraline

OBJECTIVE

To evaluate the efficacy of sertraline for treating pathological laughing and crying after stroke.

DESIGN

Case series.

SETTING

Inpatient rehabilitation units of a community and a tertiary-care hospital.

PATIENTS

One patient was a 62-year-old right-handed man who had two strokes approximately 2 years apart and had computed tomography consistent with a cerebral infarct involving the left middle cerebral artery branches in the left parietal lobe. A second patient was a 72-year-old right-handed man who had a right middle cerebral artery infarct. He had a questionable history of depression prior to the stroke.

INTERVENTION

Both patients had poststroke labile affect that was interfering with their rehabilitation. Sertraline was prescribed.

MAIN OUTCOME MEASURES

Pretreatment and posttreatment scores on the Pathological Crying and Laughing Scale and Functional Independent Measure.

RESULTS

Both patients showed significant improvement after taking sertraline-improvement that was reflected in their pretreatment and posttreatment scores on the Pathological Crying and Laughing Scale and Functional Independent Measure. The staff noted improvements in sleeping, eating, social interaction, and therapy participation. Both patients tolerated the sertraline well and had no significant side effects.

Illusory memories: a cognitive neuroscience analysis

Memory illusions and distortions have long been of interest to psychology researchers studying memory, but neuropsychologists and neuroscientists have paid relatively little attention to them. This article attempts to lay the foundation for a cognitive neuroscience analysis of memory illusions and distortions by reviewing relevant evidence from a patient with a right frontal lobe lesion, patients with amnesia produced by damage to the medial temporal lobes, normal aging, and healthy young volunteers studied with functional neuroimaging techniques. Particular attention is paid to the contrasting roles of prefrontal cortex and medial temporal lobe structures in accurate and illusory remembering. Converging evidence suggests that the study of illusory memories can provide a useful tool for delineating the brain processes and systems involved in constructive aspects of remembering.