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Biomedical subjects

F Mishkin

Publications and source records attributed to F Mishkin.

At least 19 recordsLinked to original sources
PubMed2006

Variations in regional SPECT hypoperfusion and clinical features in frontotemporal dementia.

OBJECTIVE: To characterize the presenting clinical features for frontotemporal dementia (FTD) and contrast them with the degree of frontal and temporal hypoperfusion on SPECT imaging. METHODS: The authors evaluated 74 patients who eventually met Consensus Criteria for the FTD form of frontotemporal lobar degeneration (excluding primary progressive aphasia and semantic dementia) on 2-year follow-up. On first presentation, these patients had undergone both an FTD Inventory for 12 features based on core and supportive Consensus Criteria and SPECT imaging. The initial clinical diagnostic features were contrasted with variations in regional SPECT hypoperfusion. RESULTS: The patients with FTD had more hypoperfusion in the right frontal lobe than in other regions; the subgroup of 25 patients who met Consensus Criteria from the first presentation had the most right frontal hypoperfusion. Frontal lobe involvement was associated with significant apathy, whereas temporal lobe involvement was associated with hypomania-like behavior. Right frontal lobe hypoperfusion further predicted loss of insight, environmental dependency, and stereotyped behaviors. Other associations included left frontal hypoperfusion with a decline in personal hygiene and left temporal hypoperfusion with compulsions and mental rigidity. CONCLUSIONS: On first presentation, frontotemporal dementia (FTD) is disproportionately a right frontal disease evident on behavioral measures and on SPECT. Nonetheless, patients with FTD can initially present with further regional differences in clinical diagnostic features, such as apathy with bifrontal hypoperfusion and hypomania-like behaviors with anterior temporal involvement.

Brain↗
PubMed2005

Functional neuroimaging and presenting psychiatric features in frontotemporal dementia.

BACKGROUND: Frontotemporal dementia (FTD) is a behavioural syndrome caused by degeneration of the frontal and anterior temporal lobes. Behavioural disturbances include psychiatric features. Whether patients with FTD present with psychiatric features varies with the initial neuroanatomical variability of FTD. OBJECTIVE: To identify presenting psychiatric changes not part of diagnostic criteria of FTD and contrast them with the degree of hemispheric asymmetry and frontal and temporal hypoperfusion on single photon emission computed tomography (SPECT) imaging. METHODS: 74 patients who met consensus criteria for FTD were evaluated at a two year follow up. All had brain SPECT on initial presentation. Results of an FTD psychiatric checklist were contrasted with ratings of regional hypoperfusion. RESULTS: The regions of predominant hypoperfusion did not correlate with differences on FTD demographic variables but were associated with presenting psychiatric features. Dysthymia and anxiety were associated with right temporal hypoperfusion. "Moria" or frivolous behaviour also occurred with temporal lobe changes, especially on the right. The only significant frontal lobe feature was the presence of a peculiar physical bearing in association with right frontal hypoperfusion. CONCLUSIONS: Patients with FTD may present with psychiatric changes distinct from the behavioural diagnostic criteria for this disorder. Early temporal involvement is associated with frivolous behaviour and right temporal involvement is associated with emotional disturbances. In contrast, those with right frontal disease may present with alterations in non-verbal behaviour.

Anxiety↗
PubMed2001

Effective renal plasma flow calculated from a single blood sample following Technetium-99m mercaptoacetyltriglycine renal scan can predict delayed graft function in renal transplantation.

PURPOSE: Effective renal plasma flow (ERPF) can be calculated by obtaining a single blood sample at a fixed time after injection in a patient undergoing a technetium-99m mercaptoacetyltriglycine (99mTc MAG3) renal scan. The purpose of this study was to determine whether the calculated ERPF following cadaveric renal transplantation could accurately predict the need fordialysis within the first 10 postoperative days or the serum creatinine at postoperative day 10. MATERIALS AND METHODS: Between February 1994 and September 1998, 41 patients underwent 45 99mTc MAG3 renal scans within the first 10 days following a cadaveric renal transplantation at Harbor-UCLA Medical Center. A blood sample was drawn 44 minutes after injection of 99mTc and was used to calculate ERPF. This calculated ERPF was compared to measures of early function, such as the need for dialysis and serum creatinine. RESULTS: Decreased ERPF strongly correlated with the need for dialysis within the first 10 postoperative days (p < .0001). No patient with ERPF >210 mL/min/1.7 M2 required dialysis, whereas 35% (6/17) of patients with ERPF < or =210 mL/min/1.7 M2 required dialysis within the first 10 postoperative days. For those patients who did not undergo dialysis, the calculated ERPF was significantly related to the serum creatinine on postoperative day 10 (p<.0001 ). CONCLUSIONS: ERPF can be calculated from a single blood sample when performing a 99mTc MAG3 renal scan following cadaveric renal transplantation. This calculated ERPF provides a useful clinical tool to identify patients at high risk for development of delayed graft function.

Cadaver↗
PubMed2000

Left frontotemporal hypoperfusion is associated with aggression in patients with dementia.

BACKGROUND: Aggressive behavior is common in patients with dementia. Temporolimbic and prefrontal cortical lesions can produce pathological aggression; however, involvement of these structures has not been established in aggressive patients with dementia. OBJECTIVE: To study the relation between regional brain perfusion and aggressive behavior in patients with dementia. METHODS: We compared the pattern of regional cerebral perfusion determined with technetium Tc 99m-labeled hexamethylpropelene amineoxime single photon emission computed tomography in 2 groups of 10 patients with dementia with and without aggression, that were comparable for demographic factors, severity of cognitive impairments, and other behavioral symptoms as measured by the Neuropsychiatric Inventory. RESULTS: Patients with aggression revealed significant (P<.001) hypoperfusion in the left anterior temporal cortex; additional bilateral dorsofrontal and right parietal cortex were also found to be significantly hypoperfused. CONCLUSION: These results indicated an association between aggression and decreased perfusion in the left anterior temporal cortex. Arch Neurol. 2000.

Aged↗
PubMed2000

Dipyridamole-thallium/sestamibi before vascular surgery: a prospective blinded study in moderate-risk patients.

PURPOSE: This study assessed in a prospective, blinded fashion whether a reversible defect on dipyridamole-thallium (DTHAL)/sestamibi (DMIBI) can predict adverse cardiac events after elective vascular surgery in patients with one or more clinical risk factors. METHODS: Consecutive patients with one or more clinical risk factors underwent a preoperative blinded DTHAL/DMIBI. Patients with recent congestive heart failure (CHF) or myocardial infarction (MI) or severe or unstable angina were excluded. RESULTS: Eighty patients (78% men; mean age, 65 years) completed the study. Diabetes mellitus was the most frequent clinical risk factor (73%), followed by age older than 70 years (41%), angina (29%), Q wave on electrocardiogram (26%), history of CHF (7%), and ventricular ectopy (3%). The results of DTHAL/DMIBI were normal in 36 patients (45%); a reversible plus or minus fixed defect was demonstrated in 28 patients (36%), and a fixed defect alone was demonstrated in 15 patients (19%). Nine adverse cardiac events (11%) occurred, including three cases of CHF, and one case each of unstable angina, Q wave MI, non-Q wave MI, and cardiac arrest (successfully resuscitated). Two cardiac deaths occurred (2% overall mortality), one after a Q wave MI and one after CHF and a non-Q wave MI. The cardiac event rate was 14% for reversible defect and 9.8% without reversible defect (P =.71). The cardiac event rate was 12.5% (one of eight cases) for two or more reversible defects, versus 11.1% (eight of 72 cases) for fewer than two reversible defects (P = 1.0). The sensitivity rate of two or more areas of redistribution was 11% (95% CI, 0.3%-48%), the specificity rate was 90%, and the positive and negative predictive values were 12.5% and 89%, respectively. CONCLUSION: Our study demonstrated no association between reversible defects on DTHAL/DMIBI and adverse cardiac events in moderate-risk patients undergoing elective vascular surgery.

Aged↗
PubMed2000

Cerebral correlates of psychotic symptoms in Alzheimer's disease.

BACKGROUND: Psychotic symptoms are produced by distributed neuronal dysfunction. Abnormalities of reality testing and false inference implicate frontal lobe abnormalities. OBJECTIVES: To identify the functional imaging profile of patients with Alzheimer's disease manifesting psychotic symptoms as measured by single photon emission computed tomography (SPECT). METHODS: Twenty patients with Alzheimer's disease who had SPECT and clinical evaluations were divided into two equal groups with similar mini mental status examination (MMSE), age, sex, and the range of behaviours documented by the neuropsychiatric inventory (NPI), except delusions and hallucinations. SPECT studies, registered to a probabilistic anatomical atlas, were normalised across the combined group mean intensity level, and subjected to a voxel by voxel subtraction of the non-psychotic minus psychotic groups. Subvolume thresholding (SVT) corrected random lobar noise to produce a three dimensional functional significance map. RESULTS: The significance map showed lower regional perfusion in the right and left dorsolateral frontal, left anterior cingulate, and left ventral striatal regions along with the left pulvinar and dorsolateral parietal cortex, in the psychotic versus non-psychotic group. CONCLUSION: Patients with Alzheimer's disease who manifest psychosis may have disproportionate dysfunction of frontal lobes and related subcortical and parietal structures.

Alzheimer Disease↗
PubMed2000

Orbital and dorsolateral frontal perfusion defect associated with behavioral response to cholinesterase inhibitor therapy in Alzheimer's disease.

The authors retrospectively explored the behavioral and functional imaging profile of Alzheimer's disease (AD) patients who respond to cholinesterase inhibitor therapy by using the Neuropsychiatric Inventory (NPI) and baseline [99mTc]HMPAO SPECT. Thirty AD patients were divided into three groups (Responders, Nonresponders, and Unchanged) based on their behavioral response to donepezil. Responders had significantly (P < or = 0.01) more pretreatment irritability, disinhibition (P < or = 0.05), and euphoria (P = 0.05) than Nonresponders and significantly lower lateral orbital frontal (P < 0.00001) and dorsolateral frontal (P < or = 0.0005) perfusion bilaterally. A pretreatment orbitofrontal syndrome may predict behavioral response to cholinesterase inhibitor therapy in AD.

Aged↗
PubMed2000

Functional correlates of musical and visual ability in frontotemporal dementia.

BACKGROUND: The emergence of new skills in the setting of dementia suggests that loss of function in one brain area can release new functions elsewhere. AIMS: To characterise 12 patients with frontotemporal dementia (FTD) who acquired, or sustained, new musical or visual abilities despite progression of their dementia. METHOD: Twelve patients with FTD who acquired or maintained musical or artistic ability were compared with 46 patients with FTD in whom new or sustained ability was absent. RESULTS: The group with musical or visual ability performed better on visual, but worse on verbal tasks than did the other patients with FTD. Nine had asymmetrical left anterior dysfunction. Nine showed the temporal lobe variant of FTD. CONCLUSION: Loss of function in the left anterior temporal lobe may lead to facilitation of artistic or musical skills. Patients with the left-sided temporal lobe variant of FTD offer an unexpected window into the neurological mediation of visual and musical talents.

Aged↗
PubMed1998

Emergence of artistic talent in frontotemporal dementia.

OBJECTIVE: To describe the clinical, neuropsychological, and imaging features of five patients with frontotemporal dementia (FTD) who acquired new artistic skills in the setting of dementia. BACKGROUND: Creativity in the setting of dementia has recently been reported. We describe five patients who became visual artists in the setting of FTD. METHODS: Sixty-nine FTD patients were interviewed regarding visual abilities. Five became artists in the early stages of FTD. Their history, artistic process, neuropsychology, and anatomy are described. RESULTS: On SPECT or pathology, four of the five patients had the temporal variant of FTD in which anterior temporal lobes are involved but the dorsolateral frontal cortex is spared. Visual skills were spared but language and social skills were devastated. CONCLUSIONS: Loss of function in the anterior temporal lobes may lead to the "facilitation" of artistic skills. Patients with the temporal lobe variant of FTD offer a window into creativity.

Aged↗
PubMed1997

Detection of axillary lymph node metastasis of breast carcinoma with technetium-99m sestamibi scintimammography.

Several investigators have advocated management of breast cancer patients without axillary dissection, obviating the morbidity associated with this procedure. Approximately 30-40 per cent of all patients with breast carcinoma will have lymph node metastasis. Axillary dissection offers no therapeutic benefit to node-negative patients, and it may lead to unnecessary morbidity. It is apparent that a noninvasive test to determine the presence of axillary metastases may obviate the need for axillary dissection. The aim of this study was to determine the role of scintimammography (SMM) with technetium-99m sestamibi in the detection of axillary node metastasis in breast carcinoma. Thirty-one women with the diagnosis of breast carcinoma who had SMM and axillary lymphadenectomy were included. SMM was done following an intravenous injection of 20 mCi of Tc-99m sestamibi. Planar scintigraphic imaging was acquired in a lateral prone and an anterior view of the breasts for the evaluation of the axilla. SMM scans were interpreted by two nuclear medicine physicians blinded to the clinical presentation and histologic results. The correlation of SMM with histologic assessment showed a sensitivity of 75 per cent, specificity of 82 per cent, positive predictive value of 88 per cent, and negative predictive value of 64 per cent. The interobserver correlation of SMM interpretation between the two nuclear medicine physicians showed good agreement, with kappa = 0.49. Consistency in the interpretation of Tc-99m SMM was obtained when two independent radiologists reviewed the studies. Based on these data, we are unable to show that SMM is a reliable test for the detection of axillary metastases in patients with breast cancer. However, a high positive value of 88 per cent is encouraging and deserves further study.

Adult↗
PubMed1983

Differentiation of posterior pararenal space infection from psoas abscess by gallium imaging.

Three of four patients whose cases fit the clinical description of psoas abscess proved on gallium imaging to have infection in the posterior pararenal space sparing the psoas muscle. This space provides a route for spread of infection connecting the spine, the anterior abdominal wall, the scrotum, the anterior thigh, and the gluteal region as demonstrated by the cases presented. Clinical differentiation between posterior pararenal space infection and psoas abscesses is difficult and CT studies may not demonstrate the process when the psoas space is not involved.

Abdomen↗
PubMed1979

In vitro assessment of Tc-99m labeled bovine thrombin and streptokinase-activated human plasmin: concise communication.

Bovine thrombin and streptokinase-activated human plasmin have been labeled with Tc-99m using stannous reduction of pertechnetate under physiological conditions (pH 7.4). The binding efficiency of radiotechnetium to these enzymes is greater than 94%, with less than 5% of reduced but unbound Tc-99m (Sn) complex as assayed by ascending paper radiochromatography using ITLC silica gel plate. Free or unbound pertechnetate is less than 1%. In vitro enzymatic analyses of the Tc-99m-labeled enzymes demonstrate no evidence of protein denaturation or significant loss of enzymatic activity after labeling. Both labeled enzymes are biochemically active in vitro with their respective substrates.

Animals↗