White-matter lesions on CT in Alzheimer patients: relation to clinical symptomatology and vascular factors

Fifty-four patients with Alzheimer's disease (AD) were examined for white-matter lesions (WMLs) using computerized tomography. WMLs were more frequent in late-onset AD (LAD) (26/34-76%) than in early-onset AD (EAD) (5/20-25%) (p less than 0.0001), in AD without parietal predominance (10/11-91%) (p less than 0.005) than in AD with parietal predominance (5/15-33%), and in AD with confusional symptoms (11/12-92%) than in AD without confusional symptoms (4/14-29%) (p less than 0.001). The supine systolic blood pressure was higher in AD with WMLs (151 +/- 20) than in AD without WML (139 +/- 22) (p less than 0.05). AD patients with WMLs, but not those without WMLs, had a higher mean albumin ratio (7.5 +/- 2.7) than healthy controls (5.7 +/- 2.1) (p +/- 0.005). The finding of less focal (= less parietal) symptomatology in AD with WMLs than without WMLs suggests clinical significance of WMLs in AD, while the relations between blood pressure, BBB function and WMLs support the hypothesis of a vascular pathogenesis.     

rCBF in brain tumours as measured by xenon enhanced CT

Heretofore, the rCBF of brain tumours has been measured by the 133Xe clearance method, but the resolving power of this method is limited and flow values measured by this method correlate poorly with the anatomical structure. On the other hand, our xenon-enhanced method has several advantages over the conventional isotope method and enables us to evaluate rCBF with a resolving power of 4 mm. With this method, we evaluated rCBF in 15 brain tumour cases and obtained the following results: Mean rCBF value of the tumour is a little lower than that of grey matter and higher than that of white matter with oedematous change. The xenon-enhanced method enables us to distinguish the demarcation between the tumour area and the surrounding oedematous area and offers useful information for determining the extent of resection in surgery. Mean lambda value of the tumour which is not obtainable in vivo by radionuclide scanning, was 1.02 +/- 0.06 for gliomas and 0.72 +/- 0.09 for metastatic tumours.     

Reappearing CT lesions: 4 cases.

An overwhelming majority of disappearing CT lesions in India have been aetiologically linked to cysticercosis. We report 4 patients with disappearing CT lesions in whom the lesion later reappeared at the same (3 patients) or different site (1 patient). One patient was a Taenia carrier. Serial MRI evaluation in one patient revealed a persisting lesion in the interval period. The contribution of these observations towards the understanding of the aetiology of disappearing CT lesions is discussed.     

Single small enhancing CT lesions in Indian patients with epilepsy: clinical, radiological and pathological considerations.

Thirty consecutive Indian patients with focal or generalised seizures and single, small (less than 10 mm), enhancing lesions on CT scans (SSECTL) were studied. Five patients (Group A) were treated with anticonvulsants alone and did not have a biopsy. In ten patients (Group B) a CT guided stereotaxic biopsy of the lesion was carried out and in the remainder (15-Group C) and excision biopsy of the lesion was carried out following CT guided stereotaxic localisation. In all patients in Group B the lesion were reported as "chronic nonspecific inflammation". In seven of 15 patients in Group C the lesions showed a cysticercus with a granuloma and in a further five the pathology was that of a "parasitic granuloma" but the parasite could not be identified. Biopsy did not reveal a tuberculoma or neoplasm in any of the patients. The lesions studied are the same as "disappearing" CT lesions reported in Indian patients, as in 12 of 15 patients in Groups A and B, who could be followed up for more than three months, the lesions had spontaneously disappeared or left calcific residues. It is concluded that in Indian epileptic patients with SSECTL cysticercosis is the commonest aetiology. A treatment protocol for these patients is suggested on the basis of the findings.     

Vanishing CT lesions in epilepsy.

Experience with computed tomography (CT) in patients with epilepsy has drawn attention to specific type of cerebral lesions widely prevalent in this part of the world. The lesions disappear spontaneously while patients receive only anticonvulsant therapy. The exact nature of these lesions is not yet understood. One-hundred and twenty-two such patients (M 77; F 45) were studied. Their age ranged from 3 to 57 (mean 21.8 +/- 12.7) years. Seizures were partial motor in 86 (70.5%), generalised tonic clonic in 31 (25.4%), complex partial in 4 and atonic in one case. Postictal hemiparesis was seen in 6 patients who completely recovered within 5 min to 7 days. One hundred patients underwent EEG examination. It was abnormal in 84 cases; 40 patients showed localisation which correlated with CT findings. Plain CT showed low attenuation lesions in all cases. Morphology on contrast enhancement was ring lesion in 50 (40.9%), disc lesion in 47 (38.5%), target lesion in 3 (2.5%), mixed lesion in 2 (0.8%), no enhancement in 18 (14.8%) and a speck with oedema in 2 (0.8%) cases. All lesions were cerebral, present at cortical-subcortical junction. The first follow-up scan was performed in 78 (63.9%) patients within 6-12 weeks. It showed complete disappearance of the lesion in 47 (60.3%) cases. Reduction in size of the lesion and surrounding oedema was observed in 24 (30.8%) cases. The follow-up scans in these 24 cases revealed disappearance of lesion in 11 cases and almost complete resolution of the lesion with a remaining speck in 13 cases. Cerebrospinal fluid (CSF) was normal in 95 out of 100 cases in which it was performed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Artificial intelligence for the detection of focal cortical dysplasia: Challenges in translating algorithms into clinical practice

Focal cortical dysplasias (FCDs) are malformations of cortical development and one of the most common pathologies causing pharmacoresistant focal epilepsy. Resective neurosurgery yields high success rates, especially if the full extent of the lesion is correctly identified and completely removed. The visual assessment of magnetic resonance imaging does not pinpoint the FCD in 30%–50% of cases, and half of all patients with FCD are not amenable to epilepsy surgery, partly because the FCD could not be sufficiently localized. Computational approaches to FCD detection are an active area of research, benefitting from advancements in computer vision. Automatic FCD detection is a significant challenge and one of the first clinical grounds where the application of artificial intelligence may translate into an advance for patients' health. The emergence of new methods from the combination of health and computer sciences creates novel challenges. Imaging data need to be organized into structured, well-annotated datasets and combined with other clinical information, such as histopathological subtypes or neuroimaging characteristics. Algorithmic output, that is, model prediction, requires a technically correct evaluation with adequate metrics that are understandable and usable for clinicians. Publication of code and data is necessary to make research accessible and reproducible. This critical review introduces the field of automatic FCD detection, explaining underlying medical and technical concepts, highlighting its challenges and current limitations, and providing a perspective for a novel research environment.     

Delirium detection in clinical practice and research: critique of current tools and suggestions for future development

Delirium is underrecognized clinically. Many tools have been developed to assist with the diagnosis of delirium, and they vary greatly in purpose, quality, and administration time. It is suggested that future development of delirium assessment instruments be guided by a dichotomization of raters into expert and nonexpert groups. Careful consideration of the needs of the two groups suggests that assessment instruments designed for nonexperts should be entirely objective, whereas those instruments developed for experts should include the full range of constructs associated with the syndrome. This conceptualization is explored in detail, and existing assessment instruments are considered briefly in light of this position.     

Single-enhancing CT lesions in Indian patients with seizures: a review

Single enhancing CT lesions are the commonest radiological abnormality in Indian patients with new-onset partial seizures. In few patients the lesions may be 'tuberculoma' (especially in presence of evidence of tuberculosis elsewhere). However, histopathological studies have proved that neurocysticercosis is the most frequent cause for these lesions. Acute inflammation in and around the cerebral lesions of cysticercosis manifests as acute seizure disorder. These cysticercal granulomas represent 'colloidal' and 'nodular-granular' stages of Escobar's pathological classification of natural evolution of a parenchymal cysticercus cyst. In 8-12 weeks time majority of these lesions spontaneously disappear, few may calcify. As albendazole therapy is of controversial value, these patients, possibly, need to be treated only with antiepileptic drugs. Associated seizure disorder is also benign in nature and remit in majority within 6-8 months, recurrences are usually infrequent. Antiepileptic drug may be withdrawn once follow-up CT scan shows resolution of the lesion. If seizures recur after resolution of the lesion, CT lesion persists or CT lesion calcified, a long-term (2-3 years) antiepileptic therapy may be required. The single enhancing CT lesions which persist despite anticysticercal or antituberculous therapy may need histopathological evaluation to establish the correct diagnosis.     

Significance of cerebral CT in neurological practice

The significance of cerebral CT in neurological diagnostic practice was analysed in this prospective study on 1191 consecutive patients investigated during a one-year period. CT abnormalities were detected in 601 cases (51%), local hemispheral lesions (22%) generalized atrophy (19%) and infratentorial lesions (5%) being the most common findings. In the cases which had presented at referral to CT with clinical indices suggesting cerebral pathology the CT was abnormal in 71% (379 of 537) while the percentage was 34 (222 of 654) in the cases in which CT was performed for exclusion criteria. The clinical diagnostic reviewed by CT accuracy was 88% in cerebral tumours, 69% in cerebral infarction and from 83% to 94% in various intracranial hemorrhages but only 51% in cerebral atrophy which was the most common CT finding without clinical correlates. Apart from atrophy, CT revealed other pathology than clinically suggested in 147 cases (e.g. cerebral infarct in 58, hemorrhage in 16, tumour in 8 and diverse abnormalities in 54 cases). Contrast medium enhancement (used in 45% of the scans) provided more information when compared with the plain scan in 16% (86 of 537), no more than 3 lesions (0.6% of the enhanced scans; 2 meningeomas and one vascular malformation) being visible with enhancement only.     

Optimizing the detection of bipolar II disorder in outpatient private practice: toward a systematization of clinical diagnostic wisdom

BACKGROUND: We review a clinical diagnostic approach to validate a redefinition of bipolar II disorder (BPII), which bypasses several conservative steps in the DSM-IV Mood Module of the Structured Clinical Interview for DSM-IV Axis I Disorders, Clinician Version (SCID-CV) to make detection of BPII more "clinician-friendly." METHOD: 563 consecutive private outpatients presenting with a DSM-IV-diagnosed major depressive episode (MDE) were included in the analyses. We used a modified SCID-CV in a semistructured way, used a duration of hypomania > or =2 days (rather than the 4-day floor cutoff recommended), did not follow the SCID-CV's stem (mood) skip-out instruction, focused more on past history of overactive behavior rather than mood change, and assessed hypomanic features both outside and during index MDE. Validation of BPII so-defined against major depressive disorder (MDD) was undertaken in the Washington University tradition. The study was conducted from June 1999 to December 2003. RESULTS: BPII occurred in 56.8% of patients. Compared with MDD, BPII had a significantly earlier index age and age at onset of first MDE and higher rates of atypical features, depressive recurrences, hypomanic symptoms during MDE, trait mood lability, and bipolar family history (p = .0000 for all variables). CONCLUSIONS: Our experience suggests that when probing history for past hypomanic episodes, behavioral activation should be inquired first, thereby facilitating the patient's subsequent recall of euphoria and/or irritability during such activated periods. Information from significant others or past records is also crucial. In light of these clinical procedures, BPII emerged as more prevalent than MDD. We submit that clinicians have the distinct advantage of intimate knowledge of their patients, which, coupled with the procedures outlined herein, can maximize the yield of BPII diagnoses.