No abstract

ABSTRACT:Twelve fatal cases of encephalopathy associated with sepsis were examined in a ten-year retrospective study. The sources of infection and organisms isolated were variable. Six of the patients had focal neurologic signs; five had seizures. The level of consciousness varied from drowsiness to deep coma, and electroencephalograms revealed diffuse or multifocal abnormalities. Computed tomographic head scans and cerebrospinal fluid examinations were usually unremarkable. Eight patients had disseminated microabscesses in the brain at autopsy. Four patients had proliferation of astrocytes and microglia in the cerebral cortex, a feature associated with metabolic encephalopathies. Additional findings included cerebral infarcts, brain purpura, multiple small white matter hemorrhages, and central pontine myelinolysis. Although sepsis may cause encephalopathy by producing disturbances in cerebral synaptic transmission and cerebral energy production through a toxic mechanism, bacterial invasion of the brain with the formation of disseminated microabscesses is also an important cause.

SUMMARY The upper limbs of 10 healthy subjects were cooled and then warmed over physiological temperature ranges. The compound action potentials of median digital nerves, median sensory nerve at the wrist, radial sensory nerve at the wrist, and median thenar muscle, all showed progressive reduction in latency, amplitude, duration and area during rising temperature. Our tude, needle electrodes were used for recording, and there was concern that the equivocal results may have been due to inadvertent movement of the tip of the needle during the experiment.5 7 Surface electrodes, although recording lower voltage potentials, remain at an almost constant distance from the nerve, tending to eliminate this source of error. We therefore used surface electrodes in studying the effect of altering limb temperature, within physiological ranges, on the latency, amplitude, duration, and area of the CAP. Antidromic and orthodromic radial sensory conduction studies were performed in 10 healthy subjects. MethodsThe subjects were 23 to 31 years old, six males and four females. In each subject the temperature of the right hand and forearm was lowered by the application of icepacks. All subsequent studies were performed at 15 minute intervals while the limb gradually warmed over approximately two hours. In some subjects, warming was enhanced by the breeze from an electric hair-dryer. Cutaneous surface temperature was monitored at the proximal part of the second digit, centre of the palm and the mid-flexor surface of the forearm immediately after each nerve conduction study.One pair of recording and reference Beckman miniature electrodes were placed 3 cm apart over the superficial radial nerve at the wrist, and a second pair was placed over the median nerve at the wrist. Record-407 by copyright.

In antidromic sensory conduction studies, the nerves were stimulated by saline soaked pads spaced 2-5 cm. apart. A Disa 14E11 constant voltage stimulating unit delivered pulses 0-1 ms in duration. Supramaximal stimuli excited the median and ulnar nerves at the wrist, and the superficial branch of the radial nerve in the lower forearm. The median and ulnar nerve CAPs were recorded with Teca ring electrodes at the index and little fingers, respectively, the recording electrodes being at the level of the proximal crease of the digit. The CAP of the superficial branch of the radial nerve at the wrist was recorded with Beckman miniature electrodes. In orthodromic conduction studies, supramaximal stimuli were delivered to the index and little fingers through Teca ring electrodes and recordings were made with Beckman miniature electrodes placed at the wrist over median and ulnar nerves, respectively. Distances (mean (range) cm) between recording and stimulating electrodes were: for females -median antidromic and orthodromic conduction 13-7 (118-15-1), ulnar antidromic and orthodromic conduction 11-2 (9-9-12 5) and radial antidromic conduction 13-3 (12

Case II2 This 15 year old boy had always been clumsy. Since the age of 10, he had noticed generalised muscle stiffness which increased with physical activity such as walking upstairs, running and skating. For some time, he was aware of difficulty in releasing his grip and his fingers tended to cramp on writing. He had noticed involuntary twitching of his fingers, forearm muscles and thighs at rest and it was more pronounced after a forceful voluntary contraction. Muscle cramping and spontaneous muscle activity were particularly unpleasant when he re-entered the house in the winter, for example, after a game of hockey. Since the age of twelve, he had noticed a tendency to trip. Subsequently he developed bilateral foot drop and weakness of his hands. He denied sensory symptoms and perspired only with exertion.He was muscular with well-developed proximal muscles. This contrasted with moderate wasting and weakness of the wrist and finger extensors, the intrinsic hand muscles and also the peroneal and intrinsic fott muscles. Sensory examination was normal. Deep tendon reflexes were reduced and ankle jerks were absent. The plantar responses were flexor. When he was fully relaxed, brief, repetitive twitching of his fingers and myokymia and fasciculations in the proximal muscles were clearly apparent. After forceful flexion of the fingers, the grip release was slow and delayed, with the appearance of action myotonia, yet percussion of the thenar eminence produced no abnormal muscle contraction. Percussion of the tongue, however, resulted in a focal tonic contraction, lasting several seconds, which subsided into fasciculations. Strong voluntary contraction of his quadriceps was followed for 10 to 30 seconds by a persisting, involuntary contraction of the muscles, which subsided into myokymic activity and fasciculations. The Trousseau sign was positive. Within 10 seconds after inflation of a blood pressure cuff, the fingers began to twitch and by 35 seconds they were drawn into a carpal 1 2 Figure 1 Family tree, only II2 and II5 were affected. Detailed electrophysiological testing and biopsies were performed in I2.