Brain involvement in myotonic dystrophies: neuroimaging and neuropsychological comparative study in DM1 and DM2

The objective of this study was to determine the degree of brain involvement in a cohort of myotonic dystrophy type 1 and type 2 (DM1, DM2) patients by brain studies and functional tests and to compare the results of the two groups. DM1, DM2 are multisystemic disorders due to polynucleotide expansions. Previous studies on brain involvement by neuroimaging and functional methods have led to contradictory results. Fifty molecularly defined DM1 patients and 14 DM2 patients, were recruited for the study. Age at recruitment, age at disease onset, disease duration and educational level were recorded. Neuromuscular assessment was done by MIRS. An extensive neuropsychological battery was performed in 48/50 DM1 and in a control group of 44 healthy matched subjects. Forty six of 50 DM1 and 12/14 DM2 underwent brain MRI; 21/50 DM1 and 9/14 DM2 underwent brain perfusion SPECT, with semiquantitative analysis of the results. MRI images were classified by ARWMC (age-related white matter changes) score, in order to quantify recurrence, localization and patterns of distribution of white matter hyperintense lesions (WMHLs) in our two cohorts. MRI results were matched to SPECT and to neuropsychological results. Thirty-seven of 46 DM1 and 10/12 DM2 had abnormal MRI imaging, showing scattered supratentorial, bilateral, symmetrical focal or diffuse WMHLs. A typical temporo-insular diffuse subcortical pattern was seen in DM1 subjects only, with no correlation with cognitive involvement. Major cognitive involvement was seen in the case of diffuse frontal lesions. A relationship with CTG expansion size was documented for DM1 subjects. SPECT showed minimal hypoperfusion in the posterior cortex planes in DM1 and, to a lesser extent, in DM2. Very mild degrees of involvement in the DM2 cohort were seen. Neuroimaging and functional investigations confirmed a more severe involvement of the brain in DM1 compared to DM2. A temporo-insular diffuse lesional pattern, specific for DM1, was found on MRI. This confirms greater expansion size as a risk factor for more extensive brain involvement in DM1.     

Bickerstaff’s brainstem encephalitis: case report and Tc99m brain SPECT findings

A 21-year-old healthy female suffered from an upper respiratory tract infection and 2 days later developed diplopia, unsteady gait, dysarthria and a profound disturbance of consciousness with rapid development of coma. Brain MRI and Tc99m brain perfusion SPECT, EEG, neurophysiological tests and CSF analysis results were unspecific. The detection of serum anti-GQ1b IgG autoantibodies at high titre led to the diagnosis of Bickerstaff’s brainstem encephalitis (BBE). Clinical symptoms resolved after treatment with plasma exchange and the outcome was good. Brain MRI was normal, and Tc99m brain perfusion SPECT demonstrated hypoperfusion of the whole cerebral hemispheres and basal ganglia with relative sparing of the thalami and the brainstem. Similar to brain MRI, the sensitivity of Tc99m brain perfusion SPECT in detecting brainstem lesions in typical BBE patients seems to be low.     

Microvascular autonomic dysfunction may justify false-positive stress myocardial perfusion imaging in patients with liver cirrhosis undergoing liver transplantation

BACKGROUND: Up to 15% of liver transplant candidates have asymptomatic coronary artery diseases, which increase the risk of cardiac complications during and after transplantation. The aim of this study was to prospectively investigate the usefulness of an integrated cardiological approach in cirrhotic patients undergoing liver transplantation. METHODS: Twenty-four consecutive patients undergoing evaluation for liver transplantation were studied by assessing risk factors for coronary artery diseases, electrocardiogram with QTc interval determination, chest X-ray, echocardiography, 24-hour Holter monitor, myocardial perfusion scintigraphy (99mTc)MIBI-GSPECT at rest and after dipyridamole infusion. Cardiac (123)I-metaiodobenzylguanidine (MIBG) scan and coronarography were performed in patients with myocardial perfusion defects. Twenty three of 24 patients underwent successful liver transplantation; one patient died on the waiting list. RESULTS: Before liver transplantation, 29% of patients were diabetic and 41% were smokers. Eleven of 24 patients had a prolonged QTc interval, and 3/24 had positive myocardioscintigraphy after dipyridamole infusion: in two coronarography was negative, while the (123)I-MIBG washout was altered. No cardiac events were recorded during the short-and long-term follow-up after surgery. CONCLUSIONS: Predictive value of positive cardiac (99mTc)MIBI-GSPECT in patients with liver cirrhosis is low, and this may be due to alterations of cardiac microvascular tone as showed by cardiac (123)I-MIBG scan.     

High risk of malignancy in patients with incidentally discovered adrenal masses: accuracy of adrenal imaging and image-guided fine-needle aspiration cytology

AIMS AND BACKGROUND: The incidental finding of nonfunctioning adrenal masses (incidentalomas) is common, but no reliable criteria in differentiating between benign and malignant adrenal masses have been defined. The aim of this preliminary study was to assess the usefulness of adrenal imaging and image-guided fine-needle aspiration cytology in patients with nonfunctioning adrenal incidentalomas with the aim of excluding or confirming malignancy before surgery. METHODS: Forty-two consecutive patients (18 men and 24 women; median age, 54 years; range, 25-75 years) with incidentally discovered adrenal masses of 3 cm or more in the greatest diameter were prospectively enrolled in the study. All patients underwent helical computerized tomography scan and image-guided fine-needle aspiration cytology, 33 (78.6%) underwent magnetic resonance imaging, and 26 (61.9%) underwent norcholesterol scintigraphy before adrenalectomy. RESULTS: The revised final pathology showed 30 (71.4%) benign (26 adrenocortical adenomas, of which 3 were atypical, 2 ganglioneuromas, and 2 nonfunctioning benign pheochromocytomas) and 12 (28.6%, 95% CI = 15-42) adrenal malignancies (8 adrenocortical carcinomas and 4 unsuspected adrenal metastases). The definitive diagnosis of adrenocortical carcinoma was made according to Weiss criteria and confirmed on the basis of local invasion at surgery or metastases. The sensitivity, specificity and accuracy were 75%, 67% and 83% for computerized tomography scan, 92%, 95% and 94% for magnetic resonance imaging, 89%, 94% and 92% for norcholesterol scintigraphy, and 92%, 100% and 98% for fine-needle aspiration cytology. The sensitivity and accuracy of image-guided fine-needle aspiration cytology and magnetic resonance imaging together reached 100%. Immediate periprocedural complications of fine-needle aspiration cytology occurred in 2 (4.7%) patients: self-limited pneumothorax (n = 1), and severe pain (n = 1) requiring analgesic therapy. No postprocedural or late complications were observed. CONCLUSIONS: With the aim of selecting for surgery patients with a non-functioning adrenal incidentaloma of 3 cm or more in diameter, the combination of magnetic resonance imaging and fine-needle aspiration cytology should be considered the strategy of choice.