Possible Involvement of Cerebral Hypoperfusion as a Trigger of Neurally-Mediated Vasovagal Syncope

It is well known that some patients with neurally mediated syncope have a feeling of aura before the onset of syncope. A case is reported in which cerebral dysfunction recorded by EEG was present before the onset of a vasovagal reaction. The vasovagal reaction, bradycardia and/or asystole, was preceded by abnormal EEG findings when the patient complained of feeling a headache, photophobia, and nausea. These findings suggest that cerebral hypoperfusion, such as with cerebral vasospasms, before the onset of bradycardia might be involved in the mechanism of neurally mediated syncope in patients with an aura.     

New Electrophysiologic Features and Catheter Ablation of Atrioventricular and Atriofascicular Accessory Pathways:

Catheter Ablation for Mahaim Pathways. Introduction : Several modalities of catheter ablation have been proposed to eliminate Mahaim pathway conduction. However, limited research has been reported on the electrophysiologic nature of this pathway in its entity.
Methods and Results : In seven patients, electrophysiologic study was performed, and radiofrequency energy was applied to investigate the electrophysiologic clues for successful ablation. In all seven patients, the Mahaim pathway was diagnosed as a right-sided atriofascicular or atrioventricular pathway with decremental properties. In two patients, two different kinds of electrograms were recorded through the ablation catheter positioned at the Mahaim pathway location: one was suggestive of conduction over the decremental portion, demonstrating a dulled potential; and the other of nondecremental conduction, demonstrating a spiked potential. All but one of the Mahaim pathways were eliminated successfully at the atrial origin where the spiked Mahaim potential was recorded. Radiofrequency energy application was performed at the slow potential site resulting in failure to eliminate the conduction over the Mahaim pathway. Conduction block at the site between the slow and fast potential recording sites was provoked by intravenous administration of adenosine, concomitant with a decrease in the amplitude of the Mahaim potential. In one patient, the clinical arrhythmia was a sustained monomorphic ventricular tachycardia originating from the ventricular end of the Mahaim fiber.
Conclusion : The identification of Mahaim spiked potentials may be the optimal method to permit their successful ablation. Detailed electrophysiologic assessment is indispensable for successful ablation of tachycardias associated with Mahaim fibers because tachycardias unassociated with Mahaim fibers can occur despite complete elimination of the Mahaim fiber.     

Human herpesvirus-6-associated exanthema in a patient with acute lymphocytic leukaemia

We report the first case of human herpesvirus-6 (HHV-6) associated exanthema in a patient with acute lymphocytic leukaemia (ALL). We analysed DNA extracted from an exanthematous lesion using the polymerase chain reaction (PCR). DNA was positive for HHV-6 but negative for herpes simplex virus, varicella zoster virus, and cytomegalovirus. Immunohistochemical staining of the skin with monoclonal antibody against HHV-6 confirmed the infection. The possibility of HHV-6 infection should be considered when an atypical skin rash is seen in patients with ALL.     

ELECTROENCEPHALOGRAPHIC EFFECTS OF LAUDANOSINE IN AN ANIMAL MODEL OF EPILEPSY

We examined the effects of laudanosine, one of the principalmetabolites of atracurium. on the electroencephalogram (EEG)in an animal model of induced epilepsy. Fourteen rabbits wereanaesthetized with 4% halothane in oxygen, the trachea intubatedand the lungs ventilated mechanically with 30% oxygen and 1%halothane in nitrogen. Animals were assigned randomly to receiveeither an in fusion of laudanosine (laudanosine group, n = 7)at a rate calculated to produce plasma concentrations similarto those found following the clinical use of atracurium, oran equal volume of normal saline (control group, n = 7). Toinduce an epileptogenic focus, gel-foam sponges soaked in apH-adjusted 4% cefazolin solution were applied bilaterally tothe parietal cortical surface. This resulted in the productionof spike and burst EEG activity in all animals. However, scoringthe frequency of the spikes and bursts revealed no significantdifferences between the laudanosine and control groups. We concludethat, in this animal model of epilepsy, no increased incidenceof seizure activity was produced by mean plasma laudanosineconcentrations as great as 0.8 µg ml^–1. These resultssuggest that the routine use of atracurium is unlikely to provokeseizures, even in the presence of an epileptogenic focus.     

Effect of Intraatrial Reentry on Initiation of Atrioventricular Reentrant Tachycardia

We studied the effect of intratrial reentry (IAE) on initiation of orthodromic reentrant tachycardia (ORT) in 150 patients with Wolff-Parkinson-White syndrome using His-bundle recording and the atrial extrastimulus technique. IAR was initiated by premature atrial stimulation in 44 patients (29%), and it was followed by ORT in 16 patients (11%). In 8 patients (5%), IAR promoted the initiation of ORT, whereas in 5 patients (3%), IAR inhibited the initiation of ORT. These findings suggest that ORT is frequently induced following IAR. IAR, which was frequently observed during electrophysiological studies, seems to play an important role in the initiation of ORT.     

Mucoid pseudocyst of the obturator nerve

A 71-year-old man visited the outpatients' clinic of National Saitama Hospital, Japan, complaining of pain in the right leg. Magnetic resonance imaging (MRI) revealed a cystic mass adjacent to the right side of the urinary bladder. He underwent the removal of the cystic mass and the pathological diagnosis was a mucoid pseudocyst of the obturator nerve. After tumor resection, the pain was diminished and he has been free of disease for 3 years.     

A case of familial thyroxine binding globulin excess associated with growth hormone deficiency

A 7 years 3 months old Japanese boy with familial thyroxine binding globulin (TBG) excess associated with growth hormone (GH) deficiency is reported. The patients height was 106.4 cm (- 2.86 s.d.) and his bone age was 5 years and 3 months. He had no goiter and his developmental milestones were normal. The serum thyroid stimulating hormone (TSH) was 2.8 μU/mL, triiodothyronine (T₃) 3.1 ng/mL, thyroxine (T₄) 23.4 μg/dL and free T₄ 1.8 ng/dL. The serum TBG level was beyond 80.0 μg/mL, with normal TSH response to the thyrotropin-releasing hormone (TRH) test. Familial study revealed that his grandmother, mother, uncle, younger sister and younger brother had high TBG and T₃ levels, thus an X-linked co-dominant transmission was suggested. The peak GH responses to insulin and clonidine hydrochloride were 5.8 and 8.2 ng/mL, respectively. The mean nocturnal GH concentration was 2.5 ng/mL. His growth velocity increased from 4.8 to 8.4 cm/year and his serum TBG levels decreased gradually after human growth hormone (hGH) treatment.     

Juvenile Secretory Carcinoma and Juvenile Papillomatosis

Two cases of juvenile secretory carcinoma associated with juvenilepapillomatosis are reported. One patient's disease was initiallydiagnosed at the age of 13 and she died 12 years later withextensive metastases. The contralateral breast at autopsy showedfindings indicative of juvenile papillomatosis. The second caseis that of an 18-year-old girl who had multiple juvenile secretorycarcinomas in the left breast associated with juvenile papillomatosis.