Hans Sjöholm

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Measurements in man of regional cerebral blood flow (rCBF) have demonstrated a number of cortical and subcortical events coupled to sensory stimulation or motor performance. It has also been shown that local activity changes take place in the cortex during 'pure' mental activity such as motor imagery (unaccompanied by sensory input or motor output). Thus,(More)
Our earlier findings of a cerebellar activation during motor imagery (Brain Res., 535 (1990) 313-317) were made with a technique with low regional resolution. Therefore we could not elucidate the distribution of the cerebellar activation. In the present study the cerebellar regional cerebral blood flow (rCBF) changes during motor imagery (MI) was measured(More)
OBJECTIVE The reason for longstanding fatigue following aneurysmal subarachnoidal hemorrhage (SAH) is still not clarified. The bleed from supratentorial aneurysms is often in the vicinity of the hypothalamus and pituitary gland making an endocrine dysfunction plausible. METHODS Ten patients with post-SAH fatigue were investigated with 3D-CBF (SPECT) and(More)
The quadriceps femoris muscles of nine volunteers were stimulated with intramuscular electrodes for 50 s. The stimulation frequency was 20 Hz and the voltage adjusted to produce an initial tension of 50-75% of the maximum voluntary contraction force. The force decreased after 25-30 s of contraction to reach a mean of 78% of the initial value after 50 s.(More)
It is proposed that glycolytic rate may be measured as lactate accumulation after electrical stimulation of the quadriceps femoris muscle under anaerobic conditions. The ratio of glucose 6-phosphate to lactate is an internal monitor of the glycolytic pathway. The phosphocreatine/lactate ratio links glycolysis and the creatine kinase reaction and could be(More)
Isometric contractions of single motor units were studied in the first deep lumbrical muscle of the cat's hind-foot. Motor units with short twitch contraction times (15-20 msec) generally differed from those with longer ones (23-50 msec; contraction time measured in unpotentiated twitches) in showing (1) a greater maximum tetanic tension, (2) a smaller(More)
OBJECTIVES This study evaluates the possible toxic effects on the peripheral nervous system of tunnel workers exposed to acrylamide and N-methylolacrylamide during grouting work. METHODS Symptoms and nerve conduction velocities (NCV) were recorded for 24 tunnel workers 4 and 16 months after the cessation of exposure during grouting operations. Fifty(More)
The influence of muscle contraction, induced by electrical stimulation, on the activity of glycogen phosphorylase, the contents of high-energy phosphates, hexose-monophosphates and lactate have been studied in isolated extensor digitorum longus (EDL) and soleus muscles from rats. The activity of phosphorylase a + b was about nine times higher in fast twitch(More)
Dihydroergotamine (DHE) is used in our recently introduced therapy of post-traumatic brain oedema and is suggested to reduce ICP through reduction in both cerebral blood volume and brain water content. This study aims at increasing our knowledge of the mechanisms behind the ICP reducing effect of DHE by analysing cerebrovascular effects of a bolus dose of(More)