Impaired motor imagery in patients with essential tremor: a case control study.

Motor imagery (MI), which refers to the process of mental representation of movements, has not been studied in patients with essential tremor (ET). We investigated the presence of impaired MI in ET patients compared with healthy controls. A group of drug-naive and nondemented ET patients and age-matched controls were studied using transcranial magnetic stimulation, while they were specifically instructed to try and imagine themselves performing two motor tasks. The various clinical and electrophysiological variables were evaluated and compared. Repeated measures ANOVA demonstrated a significant difference between ET patients and controls with respect to mean motor-evoked potential (MEP) amplitudes (F(1,38) = 31.92, P < 0.005) during MI. The process of MI effectively facilitated MEP amplitude in controls but not in ET patients, regardless of side of stimulation or motor tasks. We provide evidence to demonstrate impairment of MI in a group of ET patients compared with healthy controls. The basis for this novel finding is unclear, and further studies are warranted to determine whether it is related to cerebellar or motor cortical dysfunction.     

Is focal task‐specific dystonia limited to the hand and face?

Focal task-specific dystonia (FTSD) of the hand and face have been well described; however, FTSD of the leg is exceedingly rare. We describe and demonstrate by videotape 2 patients with FTSD affecting the leg, in both cases triggered specifically by walking down steps. Walking on a level surface, up steps, and down steps backward, and sideways were normal. An interoceptive sensory trick (imagining walking in a different modality) led to temporary improvement. Our patients appear to demonstrated that task-specificity in focal dystonia may not be limited to skilled, rehearsed actions and that FTSD may occur in an activity that is relatively autonomic.     

EMG myokymia as a cause of ptosis in hypothyroidism

Ptosis is known to be associated with thyroid disorders. We describe two biochemically corrected hypothyroid patients presenting with isolated bilateral ptosis. EMG of the orbicularis oculi showed continuous grouped motor unit potentials. In the absence of obvious aetiology, it is hypothesised that focal demyelination of terminal branches to the orbicularis oculi may play a role in the generation of the discharges.     

Do house officers learn from their mistakes?*

Mistakes are inevitable in medicine. To learn how medical mistakes relate to subsequent changes in practice, we surveyed 254 internal medicine house officers. One hundred and fourteen house officers (45%) completed an anonymous questionnaire describing their most significant mistake and their response to it. Mistakes included errors in diagnosis (33%), prescribing (29%), evaluation (21%), and communication (5%) and procedural complications (11%). Patients had serious adverse outcomes in 90% of the cases, including death in 31% of cases. Only 54% of house officers discussed the mistake with their attending physicians, and only 24% told the patients or families. House officers who accepted responsibility for the mistake and discussed it were more likely to report constructive changes in practice. Residents were less likely to make constructive changes if they attributed the mistake to job overload. They were more likely to report defensive changes if they felt the institution was judgmental. Decreasing the work load and closer supervision may help prevent mistakes. To promote learning, faculty should encourage house officers to accept responsibility and to discuss their mistakes.     

Amoebae free-living. Report of the first Italian case of myelitis.

The AA. refer on the first Italian case of amoebae "Limax" primitive myelitis in a 25-year-old man. Microscopical observation showed amoebae free-living, but their cultivation and identification were not possible. The patient recovered because of the propriety of diagnosis and therapy with amphotericin B.     

Biological monitoring of toxic metals in urine by simultaneous inductively coupled plasma-atomic emission spectrometry

A simple and rapid method for the simultaneous determination of 11 metals (As, Be, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in urine by inductively coupled argon plasma-atomic emission spectrometry is presented. Acidification of the urine was the only sample preparation required. Background correction was applied to ensure accuracy. Analytical calibration was based on matrix matching using a "simulated urine" solution. Detection limits in the low mg/L range and linearity over three orders of magnitude were obtained for all 11 metals. In the Occupational Health Laboratory, this procedure has been applied for routine screening of workers for occupational exposure to toxic metals.