Multitasking disorder from right temporoparietal stroke.

Acute behavioral syndromes after right hemisphere stroke (eg, hemi-inattention) resolve in most patients by 6 months. Less is known about the nature of chronic disorders after these lesions when the initial deficits are no longer apparent. We report the case of a woman who suffered a cerebral infarct in the right temporoparietal region and who, after the resolution of neglect, demonstrated a significant disorder of multitasking in her everyday life. Neuropsychologic tests failed to reveal the extent of disruption in her daily functioning. A journal of daily activities elucidates the nature of her deficits and demonstrates, from the patient's perspective, the impact of the lesion on her ability to multitask. Our findings are consistent with the concept of a right frontoparietal attentional axis that governs the ability to hold several tasks in working memory at the same time. We conclude that right hemisphere lesions can disrupt the cognitive system of multitasking through disruption of the attentional matrix.     

Autism and psychosis expressions diametrically modulate the right temporoparietal junction

The mentalizing network is atypically activated in autism and schizophrenia spectrum disorders. While these disorders are considered diagnostically independent, expressions of both can co-occur in the same individual. We examined the concurrent effect of autism traits and psychosis proneness on the activity of the mentalizing network in 24 neurotypical adults while performing a social competitive game. Activations were observed in the paracingulate cortex and the right temporoparietal junction (rTPJ). Autism traits and psychosis proneness did not modulate activity within the paracingulate or the dorsal component of the rTPJ. However, diametric modulations of autism traits and psychosis proneness were observed in the posterior (rvpTPJ) and anterior (rvaTPJ) subdivisions of the ventral rTPJ, which respectively constitute core regions within the mentalizing and attention-reorienting networks. Within the rvpTPJ, increasing autism tendencies decreased activity, and increasing psychosis proneness increased activity. This effect was reversed within the rvaTPJ. We suggest that this results from an interaction between regions responsible for higher level social cognitive processing (rvpTPJ) and regions responsible for domain-general attentional processes (rvaTPJ). The observed diametric modulation of autism tendencies and psychosis proneness of neuronal activity within the mentalizing network highlights the importance of assessing both autism and psychosis expressions within the individual.     

Motor deficits after left or right hemisphere damage due to stroke or tumor

The motor performance of 29 tumor and 43 stroke patients with unilateral left or right hemisphere damage and 40 non-brain-damaged control subjects was compared on six motor tasks. Grip strength, finger tapping, static and vertical groove steadiness, maze coordination and grooved pegboard tasks were administered. All brain-damaged groups performed more poorly than the control group on the hand contralateral to the lesion on all tasks and on the hand ipsilateral to the lesion on the tasks which required greater sensory-motor interaction (static and vertical groove steadiness, maze coordination and grooved pegboard). This pattern of results was the same for the patients with left or right hemisphere damage and was best explained by the hypothesis that the tasks which require greater sensory-motor interaction require more neural control and are more likely to be disrupted after brain damage, regardless of lateralization.     

Constructional apraxia after left or right unilateral stroke

The present study re-assesses the question whether deficits, after brain damage, in constructional tasks can be partitioned in different types of disorders of spatial cognition. Based on a current cognitive neuroscience account, originally proposed by Kosslyn [Kosslyn, S. M. (1987). Seeing and imagining in the cerebral hemispheres: A computational approach. Psychological Review, 94, 148-175], that posits two complementary lateralized systems for the encoding of (categorical and coordinate) spatial relations, it is here proposed that two qualitatively different types of "constructional apraxia" can occur and that the nature of the constructional impairment after unilateral lesions closely reflects the loss of lateralized components for the perceptual processing of differing types of spatial relations. New evidence is presented, based on the study of two groups of patients with unilateral posterior brain lesions, which supports such a bipartition of constructional apraxia. In addition, past evidence is reviewed in the light of this new cognitive neuroscience account.     

Acute atypical psychosis following a right hemisphere stroke

An acute atypical psychotic episode characterized by hallucinations and delusions suddenly developed in a 63-year-old right-handed male following an extensive right hemisphere infarction in the carotid artery distribution. While hallucinations were visual, tactile and auditory, delusions were associated with specific neurologic defects (anosognostic phenomenon, reduplication for place, body-parts and objects and confabulation). Distractibility, inappropriate sexual behavior, agitation or seizures were lacking. This case supports the presumption that the right hemisphere damage plays a major role in the genesis of organic psychotic episodes.     

Manic-like state after bilateral orbitofrontal and right temporoparietal injury: efficacy of clonidine

A manic-like state occurred in a 44-year-old right-handed woman with bilateral orbitofrontal and right temporoparietal traumatic contusions. In a brief trial, we assessed the effect of clonidine, carbamazepine, dopa therapy, and placebo on manic symptoms and cognitive functions. Clonidine rapidly reversed the manic syndrome. The patient's behavior did not change with carbamazepine and worsened with levodopa. We suggest that the manic-like syndrome was related to noradrenergic overactivity secondary to the fronto-orbital lesions.     

Partial and full own-body illusions of epileptic origin in a child with right temporoparietal epilepsy

Partial and full own-body illusions of neurological origin have been claimed crucial to understand the contribution of bodily experience and perception to self-consciousness. Whereas partial body illusions are relatively common and well defined, much less is known about full own-body illusions, and even less is known about these illusions in children. Here we describe a 10-year-old patient with the association of partial and full own-body illusions (somatoparaphrenia and out-of-body experience) that occurred sequentially during an epileptic seizure caused by right temporoparietal epilepsy. This report shows that partial and full own-body illusions share functional and neuroanatomical properties and highlights the importance of the right temporoparietal junction for bodily self-consciousness. This is the first report of out-of-body experiences in a child with focal epilepsy.     

Post-ictal psychosis after right temporal lobectomy.

Of 298 patients who had temporal lobectomies for intractable epilepsy, 4 (1.3%) developed post-ictal psychosis for the first time after surgery. All were males of normal intelligence with no pre-operative psychiatric disorder. Psychosis followed both complex partial and generalised seizures. The psychotic symptoms showed polymorphic features. Right temporal lobectomy may increase the susceptibility to post-ictal psychosis in patients who are not seizure free after surgery, particularly in the first post-operative year.     

Occurrence of psychosis in patients with epilepsy randomized to tiagabine or placebo treatment

PURPOSE: Patients with drug-resistant epilepsy have a higher incidence of psychiatric problems and possibly greater intolerance to antiepileptic drugs (AEDs) than do other patients with epilepsy. Concern has been raised that gamma-aminobutyric acid (GABA)ergic drugs may be associated with treatment-emergent psychosis. Tiagabine (TGB; Gabitril), a new AED that blocks synaptic GABA uptake, was developed in trials of drug-resistant patients with epilepsy. We conducted ad hoc analyses of adverse events, drug intolerance, and treatment response to evaluate the association between TGB treatment and psychosis and whether psychiatric history might be predictive of tolerance or effectiveness of this GABAergic drug. METHODS: Data were analyzed from two multicenter, randomized, double-blind, placebo-controlled trials of add-on TGB therapy (32 or 56 mg daily) in 554 adolescents and adults with complex partial seizures (CPSs). After an 8- or 12-week baseline phase, double-blind treatment consisted of a 4-week titration period (with TGB dose gradually increased to 32 or 56 mg daily) and an 8- or 12-week fixed-dose period. Adverse events commonly associated with psychosis were evaluated. Treatment intolerance and effectiveness (> or =50% reduction in CPS rate) were compared among patients with and without psychiatric histories. RESULTS: Psychotic symptoms (hallucinations) were observed in three (0.8%) of 356 TGB-treated patients and none of 198 placebo-treated patients (p = 0.556, NS). Statistical analysis showed no interaction between psychiatric history and drug intolerance or treatment outcome. CONCLUSIONS: TGB administration appears to carry no significant increased risk of treatment-emergent psychosis. Psychiatric history was not predictive of the tolerance or effectiveness of the drug.     

Acute aphasia after right hemisphere stroke

Right hemispheric stroke aphasia (RHSA) rarely occurs in right- or left-handed patients with their language representation in right hemisphere (RH). For right-handers, the term crossed aphasia is used. Single cases, multiple cases reports, and reviews suggest more variable anatomo-clinical correlations. We included retrospectively from our stroke data bank 16 patients (right- and left-handed, and ambidextrous) with aphasia after a single first-ever ischemic RH stroke. A control group was composed of 25 successive patients with left hemispheric stroke and aphasia (LHSA). For each patient, we analyzed four modalities of language (spontaneous fluency, naming, repetition, and comprehension) and recorded eventual impairment: (1) on admission (hyperacute) and (2) between day 3 and 14 (acute). Lesion volume and location as measured on computed tomography (CT) and magnetic resonance imaging (MRI) were transformed into Talairach stereotaxic space. Nonparametric statistics were used to compare impaired/nonimpaired patients. Comprehension and repetition were less frequently impaired after RHSA (respectively, 56% and 50%) than after LHSA (respectively, 84% and 80%, P = 0.05 and 0.04) only at hyperacute phase. Among RHSA, fewer left-handers/ambidextrous than right-handers had comprehension disorders at second evaluation (P = 0.013). Mean infarct size was similar in RHSA and LHSA with less posterior RHSA lesions (caudal to the posterior commissure). Comprehension and repetition impairments were more often associated with anterior lesions in RHSA (Fisher’s exact test, P < 0.05). Despite the small size of the cohort, our findings suggest increased atypical anatomo-functional correlations of RH language representation, particularly in non-right-handed patients.     

Depression and its relation to lesion location after stroke

The study of discrete organic cerebral lesions resulting inclearly definable psychiatric disorders may provide an understanding ofthe underlying patho-physiological basis of these disorders. However,the relation between lesion location and psychiatric illness afterstroke remains unclear. Fifty five patients referred to hospital wereidentified who had a single lesion on CT which was consistent withtheir neurological presentation and who did not have evidence of apersistent affective disorder at the time of the stroke. Six monthsafter stroke standardised psychiatric assessment disclosed that 26% ofthe patients met DSM-IV criteria for an anxiety or depressive disorder,with depression the most common diagnosis (20%). Pathologicalemotionalism was diagnosed in 18% of patients, particularly those whowere depressed (p<0.0001). Depression was significantly associatedwith larger lesions involving the right cerebral hemisphere (p=0.01).The importance of depression as a consequence of stroke has beenclarified by the studies in this area. However, wide confidenceintervals support the possibility that significant results may be dueto chance. A systematic review of these studies is now needed if aconsensus is to be reached.

     

Delayed complications after Gamma Knife surgery for intractable epilepsy

Despite the controversy concerning the clinical usefulness of Gamma Knife surgery (GKS; Elekta AB, Stockholm, Sweden) for intractable epilepsy, this treatment modality has attracted attention due to its low invasiveness. We report the long-term outcomes of four patients, focusing particularly on the efficacy and complications of GKS. We reviewed the data of four patients with medically intractable epilepsy who underwent GKS between 1998 and 2000 at our hospital. The marginal dose to the 50% isodose line was 24 Gy in one patient and 20 Gy in the remaining three patients. Two of the four patients were treated in the right temporal lobe, one was treated in the left parietal lobe, and one was treated in the right frontal lobe. The mean follow-up was 12.5 years (range 12–14 years). One patient was seizure free (Engel class IA) 24 months after GKS, and two patients failed to show any seizure reduction (Engel class IVA). However, a clear aggravation was evident in one patient (Engel class IVC). All four patients underwent resective surgery due to radiation necrosis (RN) 7, 10, 10 and 12 years after GKS. Three patients were seizure free (Engel class IA), and one was considered to have Engel class IB status following the resective surgery. GKS treatment resulted in insufficient seizure control and carried a significant risk of RN after several years. Drawbacks such as a delay in seizure control and the risk of RN should be considered when the clinical application of this treatment is evaluated.