Hippocampal memory function as reflected by the intracarotid sodium methohexital Wada test.

The intracarotid amobarbital procedure (IAP) determines lateralization of memory function for predicting the risk of amnesia after epilepsy surgery. Shortages of amobarbital led to its substitution with sodium methohexital in the intracarotid methohexital procedure (IMP). We compared IAP scores (32 patients) with IMP scores (20 patients). Wada ipsilateral and contralateral memory scores were analyzed and compared, as was the relationship of these scores to the results of standard neuropsychological memory tests. There was no significant difference in Wada contralateral memory scores (first injection) between the IAP and IMP. Differences between the IAP and IMP in memory scores for the hemisphere ipsilateral to the epileptogenic focus (second injection) were significant (P=0.01), patients who underwent the IMP manifesting a higher ipsilateral memory reserve. IAP scores related better to standard neuropsychological memory test scores than did IMP scores. The anesthetic drug used in Wada testing may affect lateralized memory assessment and prediction of postsurgical memory changes.

MRI parameters of Alzheimer's disease in an Arab population of Wadi Ara, Israel.

Magnetic resonance imaging (MRI) findings are reported from 15 individuals in an Arab-Israeli community who were diagnosed with Alzheimer's disease (AD). The quantitative parameters that were used for MRI analyses included gradings (0-3) and linear measurements of different brain structures. Generalized tissue loss was assessed by combined measurements of the ventricles (ventricular score, VS) and sulcal grading and width (SG, SW, respectively). Loss of brain tissue in specific regions of interest, eg, temporal lobes, basal ganglia, and midbrain, was evaluated by precise measurements. We observed abnormal tissue characteristics, expressed as high intensity foci in white matter on T2W sequences, as well as tissue loss, both generalized and focal. Most notable were changes involving the head of the caudate nuclei, the midbrain, and to a lesser degree, medial temporal structures.

Quantitative imaging in late TBI. Part II: cognition and work after closed and penetrating head injury: a report of the Vietnam head injury study.

CONTEXT: Functional outcome in relation to CT findings in traumatic brain injured (TBI) patients is not well established in relation to cognitive and vocational outcome. OBJECTIVE: To investigate the possible correlation between relatively simple quantitative radiological measurements and cognitive and vocational outcome. DESIGN: Retrospective analysis of quantitative assessment of CT studies in relation to post-injury cognitive changes and vocational outcome. SETTING: US Army Medical Centre. PATIENTS: 74 penetrating head injured (PHI) and 37 closed head injured (CHI) Vietnam war veterans. OUTCOME MEASURES: The Armed Forces Qualification Test (AFQT); Disability score; Return to work. RESULTS: Total brain volume loss, third ventricle width (3VW), ventricular score (VS), and septum-caudate distance (SCD) were significantly related to cognitive change and return to work in PHI patients. Volume loss and 3VW were the most valuable radiologic predictors of outcome in multivariate linear and logistic regression models for both CHI and PHI. CONCLUSION: 3VW on late CT scans following traumatic brain injury is a powerful predictor of overall long-term cognitive outcomes and potential for return to work.

Quantitive imaging in late traumatic brain injury. Part I: late imaging parameters in closed and penetrating head injuries.

OBJECTIVE: To ascertain the value of relatively simple quantitative radiologic measurements after head injury. Despite major advances in neuroradiology, analysis and reporting of imaging studies is based primarily on individual subjective and local experience, rather than on reproducible, standardized parameters; reliance on newer technologies can improve care, but also raises diagnostic costs. DESIGN: Blinded, retrospective, quantitative assessment of computerized tomography studies done some 14 years post-injury. OUTCOME MEASURES: Frontal horn width (FHW); septum-caudate distance (SCD); temporal horn width (THW); interuncal distance (IUD); third ventricle width (3VW); ventricular score (VS); sulcal width (SW); gray-white matter discriminability (GWMD) and subjective assessment of atrophy (SAOA). RESULTS: Diffuse and frontal damage was noted in both closed (CHI) and penetrating (PHI) head injury groups. Enlargement of frontal lobe parameters (septum caudate distance and frontal horn width suggest frontal injury in both closed and penetrating traumatic brain injury (TBI). Temporal horn width and inter-uncal distance were related to VS, 3VW and FHW in closed, but not in penetrating head injury. CONCLUSIONS: Simple linear CSF space measurements are correlated with volumetric and parenchymal measures, and can represent valuable and reliable low-cost quantitative measures of long term brain damage after TBI.

Gray-white matter discrimination--a possible marker for brain damage in heat stroke?

INTRODUCTION/OBJECTIVE: Heat stroke (HS) is a common medical emergency which carries high morbidity and morality. This study was designed to describe the pattern of central nervous system (CNS) changes as detected by brain CT scan in a case series of six patients suffering from classical and exertional HS. METHODS AND PATIENTS: All the patients were admitted in critical condition during the heat wave in the summer of 1999 in Israel. Each was in deep coma with a measured core temperature of over 40 degrees C upon admission to the emergency department. RESULTS: Aggressive cooling measures decreased the core temperature to <38 degrees C within 30 min following admission. Two patients (33.3%) died. One of the survivors remained in a vegetative state. Brain CT studies carried out within 4 days of admission in all the patients revealed severe loss of gray-white matter discrimination (GWMD) without signs of acute bleed or significant focal lesion, findings that persisted in repeated brain CTs in one patient who remained in a vegetative state. DISCUSSION AND CONCLUSIONS: Loss of GWMD may represent an early and sensitive indication of severe brain damage in patients with severe HS. Further studies in larger groups of patients are warranted in order to determine whether the appearance of GWMD in brain CTs of patients with HS has prognostic value.