Language and memory disturbances from mesencephalothalamic infarcts. A clinical and computed tomography study

Impact of spontaneous intracerebral hemorrhage on cognitive functioning: An update

Intracerebral hemorrhage (ICH) accounts for 15% of all strokes and approximately 50% of stroke-related mortality and disability worldwide. Patients who have experienced ICH are at high risk of negative outcome, including stroke and cognitive disorders. Vascular cognitive impairment are frequently seen after brain hemorrhage, yet little is known about them, as most studies have focused on neuropsychological outcome in ischemic stroke survivors, using well-documented acute and chronic cognitive scores. However, recent evidence supports the notion that ICH and dementia are closely related and each increases the risk of the other. The location of the lesion also plays a significant role as regards the neuropsychological profile, while the pathophysiology of ICH can indicate a specific pattern of dysfunction. Several cognitive domains may be affected, such as language, memory, executive function, processing speed and gnosis.

Increasing surveillance and prevention efforts for elder self-neglect in clinical settings

Elder self-neglect is a growing public health problem characterized by a complex network of biopsychosocial risk factors and predictors. The lack of reliable and valid assessment criteria for identifying elder self-neglect during brief clinical visits often results in missed opportunities for reducing or preventing the negative health outcomes commonly associated with this geriatric syndrome. Knowing the most salient risk factors and predictors of self-neglect in older patients may help clinicians and other healthcare providers appropriately identify and prevent self-neglect and the associated negative health outcomes. This article discusses the salient factors that contribute to elder self-neglect and how they can be used to improve clinical surveillance and guide intervention and prevention efforts.

Cognitive, affective and behavioural disturbances following vascular thalamic lesions: a review

During the last decades, many studies have shown that the thalamus is crucially involved in language and cognition. We critically reviewed a study corpus of 465 patients with vascular thalamic lesions published in the literature since 1980. 42 out of 465 (9%) cases with isolated thalamic lesions allowed further neurocognitive analysis. On the neurolinguistic level, fluent output (=31/33; 93.9%), normal to mild impairment of repetition (=33/35; 94.3%), mild dysarthria (=8/9; 88.9%) and normal to mild impairment of auditory comprehension (=27/34; 79.4%) were most commonly found in the group of patients with left and bilateral thalamic lesions. The taxonomic label of thalamic aphasia applied to the majority of the patients with left thalamic damage (=7/11; 63.6%) and to one patient with bithalamic lesions (=1/1). On the neuropsychological level, almost 90% of the left thalamic and bithalamic patient group presented with amnestic problems, executive dysfunctions and behaviour and/or mood alterations. In addition, two thirds (2/3) of the patients with bilateral thalamic damage presented with a typical cluster of neurocognitive disturbances consisting of constructional apraxia, anosognosia, desorientation, global intellectual dysfunctioning, amnesia, and executive dysfunctions associated with behaviour and/or mood alterations. Our study supports the long-standing view of a 'lateralised linguistic thalamus' but restates the issue of a 'lateralised cognitive thalamus'. In addition, critical analysis of the available literature supports the view that aphasia following left or bithalamic damage constitutes a prototypical linguistic syndrome.

Elder Abuse at End of Life

CONTEXT

Advances in health care and changing demographics have led to an aging population whose care at the end of life has become complex. Patients at the end of life, by the nature of their clinical and social circumstances, are at high risk for elder abuse. Underreporting of elder abuse is a growing concern. The clinical presentation of abuse may overlap with the natural dying process, further compounding the problem.

EVIDENCE ACQUISITION

Articles were obtained through a PubMed search using the terms "elder abuse" and "elder mistreatment" and from the University of California, Irvine's Elder Abuse Forensic Center library. Additional references were followed through these first set of articles and also from colleagues expert in this field.

EVIDENCE SYNTHESIS

Multidisciplinary teams have been shown to be the most effective intervention for the assessment and prevention of abuse. Most abuse occurs at home by family members; the hospice team may be the only outside professionals coming into the home. Caregiver stress and victim dependency increase the risk for abuse. Although physical abuse is the most commonly envisioned, neglect is the most common form of abuse. Financial abuse is often the underlying motivation for other forms of abuse.

CONCLUSIONS

Health professionals have an ethical and legal responsibility to both report and work to prevent suspected abuse. The interdisciplinary team can make a significant impact on elder abuse, a major detriment on quality of life.

Elder mistreatment: dental assessment and intervention

Elder mistreatment has increasingly been recognized as a serious and complex health issue affecting large numbers of elders each year. Dependent elder populations are often at heightened risk for mistreatment by those individuals and institutions that care for them. Health professionals have been found to lack knowledge regarding assessment, diagnosis, intervention, and reporting criteria of elder mistreatment. This article reviews the types and prevalence of elder mistreatment, risk factors, signs and symptoms, preventive interventions, and ethical considerations.

Subcortical anarthria: a case report

A 56-year-old right-handed male with a history of hypertension and diabetes presented two episodes of stroke: The first affected territory was the left anterior coroidal artery (capsular and paracapsular infarcts at the level of the genu and posterior arm of the internal capsule) and the second was the right thalamus, due to a hematoma. Following the first stroke, the patient developed severe dysarthria and after the second stroke remained anarthric. The pathophysiology of the disorder is discussed, and the role of the left and right thalamus as far as speech is concerned is reviewed.

Elder abuse and neglect: detection, reporting, and intervention

Dental providers are in an excellent position to identify elder abuse and neglect (EAN), yet they are often reluctant to report or intervene in cases of suspected elder maltreatment. This problem is widespread, and the negative impact of this dilemma cannot be ignored. In 1999, the American Dental Association's House of Delegates, through Resolution 44H-1999, urged constituent dental societies to educate their members about abuse and neglect and individual states' legal reporting requirements. The American Society for Geriatric Dentistry (ASGD), responding to a need to inform its members about this issue, requested this literature review on elder abuse and neglect. This paper emphasizes the role of the dental profession in ameliorating EAN and offers ASGD members recommendations to aid individual practitioners and staff in educating and assisting the profession in recognizing and reporting EAN.

Abnormal vertical optokinetic nystagmus in infants and children

AIMS

To determine if testing vertical optokinetic nystagmus (VOKN) has a role in the clinical assessment of infants and children.

METHODS

A large field projection system was developed with which optokinetic nystagmus (OKN) could be stimulated in any direction. Gross abnormalities in the response were detected simply by observation.

RESULTS

VOKN was tested in 144 children using this OKN projection system. 26 of these children had abnormal VOKN; 13 had a vertical saccade initiation failure "ocular motor apraxia" (in either direction, up/down, or in both) and 13 had absent VOKN (in either direction, up/down, or in both). Nine of the children with an up and/or down vertical saccade initiation failure (VSIF) had a neurometabolic disease (two had Niemann-Pick disease type C, five had Gaucher disease type III, one had Gaucher disease type II, and one had Gaucher disease type I). Five children with a VSIF had an abnormality identified by a magnetic resonance imaging (MRI) scan of the brain. In two of these children there was a focal lesion of the rostral midbrain. In 11 of the children with absent up and/or down VOKN an MRI scan revealed an abnormality. This involved the brainstem and/or the cerebellum in 10. Absent up and/or down VOKN was found in association with Joubert syndrome, Leigh disease, and cerebral palsy.

CONCLUSION

VOKN testing has a useful role in detecting neurological abnormalities in infants and children. Detection of abnormal VOKN should indicate further investigations for a neurometabolic disease or an abnormality involving the cortex, brainstem, and/or cerebellum. Abnormal VOKN but normal horizontal OKN is highly suggestive of a rostral midbrain lesion.

Neuropsychology of infarctions in the thalamus: a review

From a review of the literature on the consequences of thalamic infarctions, it may be concluded that memory problems taking the form of an amnesic syndrome are dependent upon the integrity of the mammillo-thalamic tract (MTT). Memory problems incompatible with an amnesic syndrome however, appear to result from thalamic infarctions involving other areas of the thalamus but which leave MTT intact. In contrast, executive dysfunctions could not be shown so readily to depend upon a single structure of the thalamus. The results indicate that damage to the mediodorsal nucleus of the thalamus, the midline nuclei or the intralaminar nuclei, or a combined lesion of these structures may be responsible for deficits of executive functioning.

Effects of reversible inactivation of the primate mesencephalic reticular formation. II. Hypometric vertical saccades

Electrical microstimulation and single-unit recording have suggested that a group of long-lead burst neurons (LLBNs) in the mesencephalic reticular formation (MRF) just lateral to the interstitial nucleus of Cajal (INC) (the peri-INC MRF, piMRF) may play a role in the generation of vertical rapid eye movements. Inactivation of this region with muscimol (a GABA(A) agonist) rapidly produced vertical saccade hypometria (6 injections). In three of six injections, there was a marked reduction in the velocity of vertical saccades out of proportion to saccade amplitude (i.e., saccades fell below the main sequence). This was associated with a moderate increase in saccade duration. Inadvertent inactivation of the INC could not account for these observations because vertical, postsaccadic drift was not observed. Similarly, pure downward saccade hypometria, the hallmark of rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) inactivation, was always preceded by loss of upward saccades in our experiments. We also found a downward and ipsiversive displacement of initial eye position and evidence of a contraversive head tilt following piMRF injections. Saccade latency was shorter after two of six injections. Simulation of a local feedback model provided three possible explanations for vertical saccade hypometria: 1) a shift in the input to the model to request smaller saccades, 2) a reduction of LLBN input to the vertical saccade medium lead burst neurons (MLBNs), or 3) an increase in the gain of the feedback pathway. However, when the second hypothesis was coupled to a shortened duration of the saccade trigger (i.e., the discharge of the omnipause neurons), the physiological observations of piMRF inactivation could be replicated. This suggested that muscimol had targeted structures that provided both long-lead burst activity to the MLBNs in the riMLF and were critical for reactivation of the omnipause neurons. Evidence of markedly reduced vertical saccade amplitude, curved saccade trajectories, increased saccade duration, and saccades that fall below the amplitude/velocity main sequence in these monkeys closely parallels the oculomotor findings of patients with progressive supranuclear palsy (PSP).

Subcortical aphasia

We critically review the literature on subcortical aphasia, suggest that a number of traditional concepts regarding mechanisms of aphasia are inconsistent with now abundant data, and propose several new hypotheses. The absence of aphasia in 17 reported cases of dominant hemisphere striatocapsular infarction and the finding of nearly every conceivable pattern of language impairment in 33 different reported cases of striatocapsular infarction provide strong evidence against a major direct role of the basal ganglia in language and against disconnection or diaschisis as mechanisms of nonthalamic subcortical aphasia. However, detailed consideration of the vascular events leading to striatocapsular infarction strongly suggests that associated linguistic deficits are predominantly related to sustained cortical hypoperfusion and infarction not visible on structural imaging studies. Thalamic disconnection, as may occur with striatocapsular infarcts with extension to the temporal stem and putamenal hemorrhages, may also contribute to the language deficits in some patients. Review of the literature on thalamic infarction, in conjunction with previously unreported anatomic details of four cases, suggests that what infarcts in the tuberothalamic artery territory and the occasional infarcts in the paramedian artery territory associated with aphasia have in common is damage to the frontal lobe-inferior thalamic peduncle-nucleus reticularis-center median system that may be involved in regulating the thalamic gate in attentional processes. Disruption of attentional gating in the pulvinar and lateral posterior nuclei resulting from such lesions may impair selection of specific neuronal networks in the projection field of these nuclei that serve as the substrate for lexical-semantic function, which is in effect a disruption of a type of working memory, as defined by Goldman-Rakic. We define this as a defect of selective engagement.

Thalamic amnesia following venous infarction: evidence from a single case study

The present paper describes the case of a right-handed Italian-English bilingual male patient suffering from amnesia following a bilateral thalamic lesion due to venous infarction. Within a few months from the onset, the lesion gradually shrank and was finally confined to the left thalamus only, in particular to the antero-medial portion and the pulvinar. The mammillary bodies and the cortical areas of both hemispheres were spared. After the regression of a series of generalized cognitive deficits implying slow psychic activity confusion, and spatial and temporal disorientation, the patient presented a persistent amnesic syndrome with mild language disorders, both in Italian and in English. Major disorders of memory included a dissociation between verbal memory, which was severely impaired, and spatial memory, which was largely preserved.

Deep cerebral venous thrombosis and hereditary tissue plasminogen activator (t-PA) deficiency

We describe a patient with defective tissue plasminogen activator (t-PA) release who developed internal cerebral vein thrombosis. She recovered completely and, as shown by MRI, favourable outcome was probably related to vascular recanalisation. Other members of the pedigree had a similar fibrinolytic deficiency without clinical manifestations. The use of oral contraceptives may have contributed to the patient's hypercoagulable state.

Convex third ventricle: a possible sign for dementia using MRI

The shape and thickness of the third ventricles were studied with magnetic resonance imaging in 46 patients under evaluation for memory impairment. We compared this population with 23 subjects imaged for other reasons. The study group consisted of patients with diagnoses of probable dementia of the Alzheimer's type (DAT; 35.6%), multi-infarct dementia (MID; 22.2%), depression (8.9%), alcoholic dementia (6.7%), other dementias (OD; 13.2%) and no dementia (6.7%). Within the study group, there were no significant differences across diagnostic categories for duration of symptoms or level of education. Patients with DAT were, however, more impaired than others (Mini-Mental State Examination scores: DAT 14.6 [+/- 8.2] versus MID 17.4 [+/- 6.2] versus OD 21.2 [+/- 6.4]). Demented subjects were more likely than nondemented individuals to have a convex third ventricle and greater wall separation. The results suggest that the shape of the third ventricle may correlate with dementia. Possibly, the dorsal medial nucleus of the thalamus is involved in the dementia.

Unilateral amnesic stroke. Six new cases and a review of the literature

BACKGROUND AND PURPOSE

Although persistent amnesia due to bilateral limbic system infarction is well described, reports of amnesic syndromes due to unilateral stroke have appeared infrequently and unsystematically. We report six new cases and review previously published reports to expand and consolidate knowledge regarding amnesic stroke.

CASE DESCRIPTIONS

Six patients developed acute amnesia associated with unilateral stroke. Brain computed tomography or magnetic resonance imaging revealed lesions in limbic structures, which accounted for the memory deficit. Based on these as well as similar cases in the literature, we delineate three distinct syndromes of unilateral amnesic stroke involving the territories of the posterior cerebral, anterior choroidal, and thalamic penetrating arteries. Eighty-five percent of reported cases have involved the left hemisphere.

CONCLUSIONS

Persistent as well as transient amnesia may be the sole or primary manifestation of unilateral hemispheric stroke. The vascular mechanisms of amnesic stroke are diverse. Patients presenting with acute amnesia possibly related to cerebral ischemia should be classified by documented or presumed lesion site as well as the involved vascular territory. Left amygdalohippocampal or diencephalic dysfunction may produce a particular vulnerability to global amnesia.

Aphonia due to paramedian thalamo-subthalamic infarction. Remarks on two cases

We describe two patients in whom CT brain scans imaged paramedian thalamo-subthalamic infarcts in the territory of the thalamo-mesencephalic arteries. Such infarcts give rise to a complex syndrome marked by disturbances of consciousness and of eye movement and neuropsychological disorders, including attentional, memory and, more rarely, language deficits. A loss of voice volume may accompany aphasic disturbances but is exceedingly rare in isolation. In the cases described the aphonia, total but transient, was the only language disorder. The physiopathological mechanisms involved in aphonia are complex and controversial.

Language disturbances from mesencephalo-thalamic infarcts. Identification of thalamic nuclei by CT-reconstructions

The authors report the cases of two patients with CT-documented paramedian mesencephalo-thalamic infarcts, showing language disturbances. The first patient showed a non fluent, transcortical motor-like aphasia, the other had a fluent but severely paraphasic language disorder. The CT study disclosed that it was the dorso-median thalamic nucleus that was mostly involved in both cases. These findings agree with a few previous pathological studies suggesting that the paramedian thalamic nuclei, particularly the dorso-median nucleus may play some role in language disturbances. However the anatomical basis for thalamic aphasia remains speculative, taking into account the importance of cortical connections in the origin of subcortical neuropsychological disturbances.

Paramedian thalamic and midbrain infarcts associated with palilalia

A patient with paramedian thalamic and midbrain infarcts developed palilalia.