Etiopathology, Clinical and Imaging Characteristics of Border Zone Strokes

Introduction

A border zone infarct (BI) is defined as an infarction that is localized to watersheds or border zones in the brain. BI is further classified into cortical border zone infarct (CBZ) and internal border zone infarct (IBZ). This study was conducted to explore the clinical and radiological characteristics of BI.

Materials and Method

The study was conducted on eligible 400 acute ischemic stroke patients out of which 52 BI patients (diagnosed by the radiologist on DWI MRI images), patients >18 yrs of age were selected and divided into two groups of IBZ and CBZ infarct patients. The degree of intracranial and extracranial stenosis and characteristics on clinical presentation were assessed. The data were collected and analyzed using SPSS version 20.0 software at significance level p-value <0.05.

Results

25% and 75% of CBZ and IBZ patients, respectively, had history of presyncope or syncope before stroke. On vascular evaluation, 3.9% and 51.9% were in MCA and ICA stenosis group, respectively. Evidence of cardio embolism was found in 17.3% of patients. 53.3% of CBZ and 53.8% of IBZ patients were in ICA stenosis group, and 6.7% of CBZ and 7.7% of IBZ patients were in MCA stenosis group, with a statistically insignificant relation (p-value >0.05).

Conclusion

Association of BI with events causing hypotension or hypovolemia is well-established in our study, association of BI with large vessel atherosclerosis is common, and its contribution to CBZ and IBZ seems to be equal.

Myeloradiculitis with meningoencephalopathy and optic neuritis in a case of previous Chlamydia psittaci infection

We present a case of optic neuritis and myelo-radiculopathy as a late association following Chlamydia psittaci infection. A 45-year-old female patient with a prior history of C psittaci pneumonia and subsequent reactive arthritis presented to the neurology unit with severe headache, constitutional symptoms and monocular disturbance in vision. Clinical examination revealed focal signs with brisk upper limb reflexes compared to lower limbs and mild left-sided pyramidal signs. Systemic inflammatory markers were raised and serological studies showed no evidence of re-infection. MRI showed multiple high signal foci within the brain parenchyma and pachymeningeal thickening and enhancement. There was marked clinical and haematological improvement with high dose corticosteroids.

Accuracy of single-photon emission computed tomography in differentiating frontotemporal dementia from Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the commonest causes of presenile dementia. In the absence of a biological marker, diagnosis is reliant on clinical evaluation. Confirmation is often sought from neuroimaging, including single-photon emission computed tomography (SPECT). Most previous SPECT studies lack pathological validation.

AIM

To examine the accuracy of SPECT in differentiating FTD from AD in patients with subsequent pathological confirmation.

METHODS

Technetium-99-labelled hexamethyl propylene amine oxime SPECT images obtained at initial evaluation in 25 pathologically confirmed cases of FTD were examined. These images were visually rated by an experienced blinded nuclear medicine consultant and compared with those of 31 patients with AD, also with pathological validation.

RESULTS

A reduction in frontal cerebral blood flow (CBF) was more common in FTD and was of diagnostic value (sensitivity 0.8, specificity 0.65 and likelihood ratio (LR) 2.25; 95% CI 1.35 to 3.77). A pattern of bilateral frontal CBF reduction without the presence of associated bilateral parietal CBF change is diagnostically more accurate (sensitivity 0.80, specificity 0.81 and +LR 4.13, 95% CI 1.96 to 8.71). Diagnostic categorisation (FTD or AD) on the basis of SPECT alone was less accurate than clinical diagnosis (based on neurology and detailed neuropsychological evaluation). One patient with FTD was initially clinically misdiagnosed as AD, owing to the lack of availability of full neuropsychological assessment. However, SPECT correctly diagnosed this patient, providing a diagnostic gain of 4%.

CONCLUSION

Technetium-99-labelled hexamethyl propylene amine oxime SPECT CBF patterns provide valuable information in the diagnosis of FTD and AD. These data can be better used as an adjunct to clinical diagnosis if pathology is to be correctly predicted in life.

Qualitative performance characteristics differentiate dementia with Lewy bodies and Alzheimer's disease

OBJECTIVES

To determine whether dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) can be differentiated on the basis of qualitative performance characteristics during neuropsychological evaluation.

METHODS

Forty one patients with clinically defined DLB were matched with 26 patients with AD for age, illness duration, nature and severity of cognitive deficits, and regional blood flow distribution on SPECT. The presence or absence of a set of qualitative performance characteristics, observed and recorded during the patients' initial cognitive evaluation, was identified by retrospective analysis of patients' records and the groups compared.

RESULTS

Inattention, visual distractibility, impairments in establishing and shifting mental set, incoherence, confabulatory responses, perseveration, and intrusions were significantly more common in DLB than AD. Intrusions were particularly common in DLB, occurring in 78% of the group. They included externally cued intrusions arising from the visual environment, a feature never seen in AD. In a stepwise logistic regression analysis impaired mental set shifting, perseveration, and the presence of intrusions correctly classified 79% of patients.

CONCLUSION

It is possible to differentiate DLB and AD on the basis of qualitative features of performance. As many features are amenable to detection at clinical interview, they ought to contribute to clinicians' diagnostic armoury, leading to improved clinical recognition of DLB.

Diagnostic patterns of regional atrophy on MRI and regional cerebral blood flow change on SPECT in young onset patients with Alzheimer's disease, frontotemporal dementia and vascular dementia

OBJECTIVES

Alzheimer's disease (AD), frontotemporal dementia (FTD) and vascular dementia (VaD) are the three most common causes of young onset dementias. Most neuroimaging studies of these disorders have involved comparisons with normal controls. The aims of this study were to examine the clinical diagnostic value of magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) (in combination and in isolation) in the differentiation of one form of dementia from another from amongst a group of AD, FTD and VaD.

METHODS

T1 weighted MRI images and 99mTc-HMPAO SPECT images were obtained from consecutive patients with FTD (n=21), AD (n=23) and VaD (n=20) and rated visually by experienced neuroradiologists and nuclear medicine physicians.

RESULTS

Asymmetrical atrophy was seen only in FTD. Frontotemporal dementia patients were the most atrophic whereas severe atrophy was rarely observed in VaD. Severe frontal atrophy (unilaterally or bilaterally) and/or asymmetrical atrophy on MRI is highly diagnostic (sensitivity 0.71, specificity 0.93, LR 10.24) of FTD from within a group of FTD and non-FTD (AD, VaD) patients. Mild or severe parietal atrophy with severe reduction in parietal regional cerebral blood flow on SPECT is diagnostic (sensitivity 0.71, specificity 0.76, LR 3.02) of AD from within a group of AD and non-AD (VaD, FTD) patients.

CONCLUSION

Anatomical (MRI) and functional (SPECT) imaging provide different information and a combination of these modalities improves diagnostic specificity.

The electroencephalogram in dementia with Lewy bodies

OBJECTIVES

Dementia with Lewy bodies (DLB) is the second commonest neurodegenerative cause of dementia. While there is consensus on the clinical diagnostic criteria for DLB, the use of EEG to increase the diagnostic sensitivity has not been substantiated.

MATERIAL AND METHODS

We studied the resting EEG findings in 18 consecutive patients with DLB and compared them with a control group of 20 patients with "probable" Alzheimer's disease (AD). We aimed to evaluate the use of EEG in a representative sample of patients with DLB.

RESULTS

All patients with DLB fulfilled accepted clinical criteria for DLB. The DLB group had a more severe dementia than the AD group, as measured by the Mini-Mental State Examination (MMSE) test (DLB mean MMSE 9.4 and AD mean MMSE 17.2) despite a similar duration of overall severity of illness. The EEG was slow in both groups, predominantly in the 4-7 Hz range. Although there was no statistically significant difference in the EEG findings between the DLB and AD groups, there was a correlation between the EEG score and MMSE score (Spearman Rank correlation rs = -0.61, P < 0.001).

CONCLUSION

These findings suggest that although patients with DLB have a more aggressive course than AD, EEG abnormalities do not differ in the 2 groups. However, we believe the EEG provides important supporting diagnostic information in DLB.

Evaluation of the NINCDS-ADRDA criteria in the differentiation of Alzheimer's disease and frontotemporal dementia

OBJECTIVES

The diagnosis of Alzheimer's disease (AD) is now reliant on the use of NINCDS-ADRDA criteria. Other diseases causing dementia are being increasingly recognised--for example, frontotemporal dementia (FTD). Historically, these disorders have not been clearly demarcated from AD. This study assesses the capability of the NINCDS-ADRDA criteria to accurately distinguish AD from FTD in a series of pathologically proved cases.

METHODS

The case records of 56 patients (30 with AD, 26 with FTD) who had undergone neuropsychological evaluation, brain imaging, and ultimately postmortem, were assessed in terms of whether at initial diagnosis the NINCDS-ADRDA criteria were successful in diagnosing those patients who had AD and excluding those who did not.

RESULTS

(1) The overall sensitivity of the NINCDS-ADRDA criteria in diagnosing "probable" AD from 56 patients with cortical dementia (AD and FTD) was 0.93. However, the specificity was only 0.23; most patients with FTD also fulfilled NINCDS-ADRDA criteria for AD. (2) Cognitive deficits in the realms of orientation and praxis significantly increased the odds of a patient having AD compared with FTD, whereas deficits in problem solving significantly decreased the odds. Neuropsychological impairments in the domains of attention, language, perception, and memory as defined in the NINCDS-ADRDA statement did not contribute to the clinical differentiation of AD and FTD.

CONCLUSION

NINCDS-ADRDA criteria fail accurately to differentiate AD from FTD. Suggestions to improve the diagnostic specificity of the current criteria are made.

A volumetric MRI study of Gilles de la Tourette's syndrome

The neuroanatomic or neuropathologic basis of Gilles de la Tourette's syndrome (GTS) remains unknown. Recent studies have suggested abnormalities of cerebral asymmetry and basal ganglia volumes. We studied 17 patients with GTS and eight normal controls using volumetric MRI techniques for measuring the caudate nucleus, amygdala, and corpus callosum. One subject with GTS was subsequently excluded because he was left handed. No absolute differences in caudate nucleus volumes between patient and control groups were evident. There was an increase in corpus callosum (CC) cross-sectional area and a loss of the normal asymmetry of the caudate nucleus in the patient group. A loss of the normal correlation between cross-sectional area of the CC and whole brain index (WBI) in the patient group also was found. The amygdala measurements had a poor interrater reliability.

A 99mTc-HMPAO single-photon emission computed tomography study of Lewy body disease

The purpose of this study was to investigate patterns of 99mTc-HMPAO single-photon emission computed tomography (SPECT) abnormality in Lewy body disease (LBD) and to compare findings with those encountered in Alzheimer's disease (AD). The study group comprised 20 consecutive patient referrals fulfilling clinical criteria for LBD. All patients had fluctuating cognitive impairment and 'subcortical' dysfunction with or without perceptuospatial and/or linguistic impairment. Six patients had asymmetrical signs of parkinsonism (three left-sided and three right-sided), and 14 patients had symmetrical features of extrapyramidal involvement. 99mTc-HMPAO SPECT imaging was performed on LBD patients and findings compared with those of 57 patients with 'probable' AD and 11 normal age-matched controls. Within the LBD and AD groups, patterns of cortical and subcortical blood-flow abnormality were compared with patterns of cognitive and neurological breakdown. LBD was associated with bilateral posterior cortical blood flow abnormality, a pattern strikingly similar to that found in AD. Within the LBD group, cortical blood-flow abnormality was found to reflect patterns of neurological dysfunction (parkinsonism) indicative of subcortical involvement. In contrast, cortical blood-flow changes did not reflect patterns of neuropsychological impairment suggestive of cortical dysfunction. Within the AD group, cortical blood-flow changes were mirrored by the pattern of neuropsychological impairment. Findings support the notion that cortical blood-flow abnormality in LBD might reflect a combination of direct cortical pathology and cortical deafferentation secondary to subcortical Lewy body pathology. It would appear that 99mTc-HMPAO SPECT imaging is of limited value in the clinical differentiation of LBD and AD.

HMPAO SPECT in non-epileptic seizures: preliminary results

The diagnosis of non-epileptic seizures (NES) is problematic. Although diagnosis can be achieved by videotelemetry, these facilities are expensive and not widely available. HMPAO SPECT studies show focal hypoperfusion interictally in focal epilepsy. SPECT has not been studied in any detail in NES previously. Two groups (10 patients each) were studied, one with NES and one with complex partial seizures and localisation related epilepsy. SPECT scans were normal in 7 of 10 (70%) NES patients, while showing clear focal hypoperfusion in 8 of 10 patients (80%) with epilepsy. In the NES group, 1 patient showed hypoperfusion indistinguishable from that seen in epilepsy, while 2 patients in the epilepsy group showed only equivocal focal hypoperfusion. The remaining 2 patients in the NES group showed bifrontal and equivocal focal hypoperfusion. A normal HMPAO SPECT study supports the diagnosis of NES in patients with seizures of uncertain aetiology.

Multimodality evoked potentials in aortoarteritis

Brainstem auditory evoked potentials (BAEPs) have been used to detect early and even asymptomatic brain ischemia. There is a need to detect subclinical brain and/or spinal cord ischemia in patients with aortoarteritis so that ischemic deficits can be prevented by early intervention. We studied multimodality (Visual evoked potentials--VEPs, Somatosensory evoked potentials--SEPs and BAEPs) evoked potentials (EPs) in 10 neurologically asymptomatic subjects with aortoarteritis. EP latencies were normal in all the patients studied. The possible value of EP latencies in detection of early brain and/or spinal cord ischemia in patients with aortoarteritis is discussed.

Congenital afibrinogenaemia

A case of congenital afibrinogenaemia in a young female child is described. She had haemorrhagic tendency since birth in the form of markedly prolonged umbilical bleeding and easy bruising afterwards. Two of her brothers had bleeding tendencies, one died shortly after birth due to uncontrollable umbilical bleeding and other died at the age of 12 years from internal haemorrhage. The family study indicates the mode of inheritance to be probably autosomal recessive. The principal laboratory findings are complete non-coagulability of blood, grossly abnormal coagulation tests, zero ESR value, failure to detect fibrinogen by heat coagulation or chemical precipitation tests and biuret reaction and correction of thrombin time after fibrinogen infusion.

Diagnostic significance of pleural fluid eosinophilia during initial thoracocentesis

A prospective study of pleural fluid eosinophilia (PFE) during initial thoracocentesis in 162 patients of pleural effusion was undertaken to determine its value in establishing an etiological diagnosis. Eighteen of the 162 cases showed pleural fluid eosinophilia (PFE), twelve could not be labelled with any definitive etiology even after extensive investigations, four belonged to the para-pneumonic group and resolved with treatment. Of the 32 patients with malignancy, PFE was seen in a single case of pleural mesothelioma. None of the patients with tuberculosis, empyema, systemic lupus erythematosus or amoebiasis had PFE. These findings suggest that PFE seen at initial thoracocentesis favours a benign diagnosis, with a rare chance of malignancy. Tuberculosis is unlikely in such patients.

A case of subacute effusive constrictive pericarditis with a probable amoebic aetiology

A 48 year old man with amoebic pericarditis did not improve after pericardiocentesis. Facilities for echocardiography and haemodynamic studies were not available. Cardiac compression was suspected and at emergency pericardiectomy subacute effusive constrictive amoebic pericarditis was found. The patient recovered. This is believed to be the first report of a case of subacute effusive constrictive pericarditis caused by amoebiasis.