1/19. Two types of auditory neglect. Auditory neglect, defined as inattention to stimuli within the left hemispace, is mostly reported in association with left ear extinction in dichotic listening. However, it remains disputed as to how far dichotic extinction reflects a primary attentional deficit and is thus appropriate for the diagnosis of auditory neglect. We report here on four patients who presented left ear extinction in dichotic listening following right unilateral hemispheric lesions. Auditory spatial attention was assessed with two additional tasks: (i) diotic test by means of interaural time differences (ITDs), simulating bilateral simultaneous spatial presentation of the dichotic tasks without the inconvenience of interaural intensity or content difference; and (ii) sound localization. A hemispatial asymmetry on the ITD diotic test or a spatial bias on sound localization were found to be part of auditory neglect. Two patients (J.C.N. and M.B.) presented a marked hemispatial asymmetry favouring the ipsilesional hemispace in the ITD diotic test, but did not show any spatial bias in sound localization. Two other patients (A.J. and E.S.) had the reverse profile: no hemispatial asymmetry in the ITD diotic test, but a severe spatial bias directed to the ipsilesional side in sound localization. J.C.N. and M.B. had mainly subcortical lesions affecting the basal ganglia. A.J. and E.S. had cortical lesions in the prefrontal, superior temporal and inferior parietal areas. Thus, there are two behaviourally and anatomically distinct types of auditory neglect characterized by: (i) deficit in allocation of auditory spatial attention following lesions centred on basal ganglia; or (ii) distortion of auditory spatial representation following frontotemporoparietal lesions. ( info) |
2/19. Bilateral symmetrical basal ganglia infarction after intravenous use of cocaine and heroin. A case is reported of a young man who developed bilateral symmetrical basal ganglia infarcts after intravenous use of cocaine and heroin. Ischemic infarcts of the brain are a known complication of to cocaine use, alone or in combination with heroin (speed balling). This symmetrical occurrence of infarction, however, is unusual and has not been reported after cocaine use. ( info) |
3/19. A neurocytoma and an associated lenticulostriate artery aneurysm presenting with intraventricular hemorrhage: case report. OBJECTIVE AND IMPORTANCE: hemorrhage associated with central neurocytoma has been described previously, but never in association with an aneurysm originating from a feeding artery. We present the first reported case of a central neurocytoma in a patient with intraventricular hemorrhage caused by rupture of an aneurysm on a lenticulostriate artery that supplied the tumor. CLINICAL PRESENTATION: A 35-year-old man who presented with an intraventricular hemorrhage underwent magnetic resonance imaging and cerebral angiography that disclosed a right lateral intraventricular mass and a 7-mm fusiform aneurysm from a lateral lenticulostriate branch of the right middle cerebral artery. INTERVENTION: The patient underwent a contralateral transcallosal exploration and resection of the tumor, with excision of the adjacent lenticulostriate artery aneurysm. Pathological review demonstrated that the tumor was a neurocytoma. The aneurysm was discrete from the tumor but occurred on a vessel that supplied the tumor. CONCLUSION: Previous reports have demonstrated that intraventricular neurocytoma may present with tumor hemorrhage. In this case, an aneurysm separate and distinct from the tumor was the bleeding culprit, and the aneurysm was on an artery that fed into the tumor. Any such aneurysm must be identified and treated appropriately for therapy to be complete. ( info) |
4/19. Rule-abstraction deficits following a basal ganglia lesion. The cognitive profile of a patient, PM, who had damage to the right basal ganglia as the result of a stroke was investigated. Whilst most cognitive functions were intact, she showed specific neuropsychological deficits, most notably a difficulty in developing, through abstraction of the relevant information, a higher-level rule by which to guide behaviour. The types of rule affected were those based upon an attentional set (attending to a particular dimension of stimulus features, such as 'shape') or a response strategy (continuing to apply a previously successful pattern of responses). The learning of lower-level rules based on stimulus-reward values was spared, as was the ability to apply an instructed rule and to discontinue use of rules which were no longer appropriate. These data provide evidence for the dissociability of cognitive functions within the basal ganglia. ( info) |
5/19. Treatment of late-onset OCD following basal ganglia infarct. Current consensus on the treatment of obsessive-compulsive disorder (OCD) includes cognitive behavior therapy (CBT) in the form of exposure and response prevention (ERP). However, the generalizability of these methods to elderly populations remains largely undocumented. This clinical case study examines the effectiveness of medications and intensive, inpatient ERP in an elderly patient with onset of OCD following basal ganglia infarcts. There was a dramatic reduction from baseline to follow-up in both obsessions and compulsions with Yale-Brown Obsessive-Compulsive Scale [YBOCS; Goodman et al., 1989] total scores decreasing by over 20 points. These gains were maintained up to 1 year post-treatment. Age-specific issues and the application of standard therapeutic methods to elderly clients are discussed. ( info) |
6/19. Micrographia secondary to lenticular lesions. Four patients with a stroke developed micrographia. In two patients, the condition was pure and in the two other patients it was associated with signs of writer's cramp. We conclude that infarct of the left lenticular nucleus could either mimic pure micrographia similar to that of Parkinson's disease or micrographia associated with dystonia. ( info) |
7/19. Anti-beta2-glycoprotein I antibodies and ischemic stroke in a 20-month-old boy. antibodies to beta2-glycoprotein I (anti-beta2GPI) have been associated with recurrent thrombosis and pregnancy morbidity. However, the prevalence of anti-beta2GPI in children suffering from cerebral infarction is unknown. We report on a 20-month-old boy who had an ischemic stroke, secondary to antiphospholipid syndrome with high titers of immunoglobulin g anti-beta2GPI (first titer: 132 U; second titer 6 weeks later: 350 U; normal range: 0-100 U). Anticardiolipin antibodies and lupus anticoagulant tests were negative. All other causes of infarction were excluded. Laboratory studies showed anti-beta2GPI IgG levels of 164 U and 216 U at 6 months and 2 years, respectively, after the onset. The patient received treatment with low-dose aspirin. To our knowledge, this is the first reported case of childhood ischemic stroke with only anti-beta2GPI but no antibodies detectable in standard antiphospholipid assays. This case supports the recommendation of others to search for these antibodies in the presence of strong clinical suspicion of antiphospholipid syndrome, when anticardiolipin antibodies and lupus anticoagulant tests are negative. ( info) |
8/19. Severe bruxism following basal ganglia infarcts: insights into pathophysiology. bruxism characterized by clenching and grinding of teeth can lead to toothwear, headaches and depression. While bruxism has been associated with a number of neurological diseases, it has not been highlighted following cerebral infarction.An elderly man presented with an acute onset of tooth grinding and jaw clenching associated with dysarthria. His bruxism was worse during the day and resolved during sleep. He had frequent jaw aches, headaches and swallowing difficulty. Examination demonstrated the presence of dysarthria with jaw clenching and tooth grinding, producing persistent high pitch and loud squeaky sounds. A magnetic resonance imaging and angiography examination revealed a recent infarct in the right thalamus. In addition, chronic lacunar infarcts were present in the bilateral caudate nuclei with severe basilar artery stenosis. He was successfully treated with botulinum toxin.We discuss the pathophysiologic mechanisms of bruxism associated with basal ganglia infarcts. Dysfunction of the efferent and/or afferent thalamic or striatopallidal tracts may play a role in bruxism. Early recognition of bruxism following stroke could reduce unnecessary suffering since the condition can be effectively treated. ( info) |
9/19. Traumatic dissection of the internal carotid artery. We present the case of an 11-year-old male who had a dissection of his left internal carotid artery following a rather innocuous mechanism of injury. Although this phenomenon is documented in the medical literature, it remains a relatively rare event following blunt injury to the head and neck (0.3% occurrence rate in 1 study spanning 7 years). (Despite its rarity, it remains an important cause of cerebrovascular accidents in children. 2) Children presenting with gross neurologic abnormalities following blunt trauma to the head or neck should be considered to have sustained injury to the carotid arteries until proven otherwise. ( info) |
10/19. Misplaced peripherally inserted central catheter: an unusual cause of stroke. stroke in pediatric patients occurs with a frequency of 3 to 8 per 100,000. The postevent evaluation attempts to identify the etiology of ischemia whether anatomic, hematologic, or embolic, with the intention of preventing future events. We present the case of a previously healthy male who developed unilateral facial and extremity weakness 2 weeks after receiving an appendectomy. Once the usual etiologies of stroke in pediatric patients were excluded, an evaluation of the peripheral venous catheter (placed for postoperative antibiotic delivery) demonstrated arterial misplacement. This article presents the first reported case of such an occurrence in the literature and exhibits the need to pursue all avenues of evaluation if the etiology of a pediatric stroke is not initially identified. ( info) |