The pulsatility index (PI) registreted by the transcranial doppler (TCD) was examined in relation to arterial pCO2 (paCO2) and epidural pressure (ICP). In 10 normal subjects PI was studied during variations in paCO2. In 10 neurosurgical patients with head injuries concomitant measurements of PI and ICP were obtained. The results showed a negative exponential correlation between PI and paCO2. PI changed with 3.2% pr mmHg paCO2. A positive exponential correlation between PI and ICP was observed. PI changed with 2.4% pr mmHg ICP. In the subgroup of patients with raised ICP (15 mmHg <) p

We assessed the diagnostic yield of adding quantitative sensory testing to the standard work-up for polyneuropathy in unselected patients. All patients aged 18 to 70 years referred to our department for electrodiagnosis with a tentative diagnosis of polyneuropathy and symptoms complying with predefined criteria were included in the study. We performed near nerve conduction studies in 4 nerves and determined heat and cold detection thresholds on hand and foot with a Thermotest (Somedic AB, Sweden). In order to uncover CNS diseases, somatosensory-evoked potentials were recorded in patients with abnormal quantitative sensory testing and normal nerve conduction studies. A total of 198 patients completed the study and 149 were considered to have polyneuropathy. Twenty-five patients remained undiagnosed and in 24 patients, other diseases were responsible for the symptoms. Of the patients with either polyneuropathy or no other diagnosis, 76% (n = 174) had abnormal nerve conduction. Abnormal cold sensation, heat sensation or abnormality in at least 1 of these and normal nerve conduction were found in 14, 12 and 17 patients. Of the 174 patients, 86% (95% CI 80-90%) had an abnormality in at least 1 of the tests (i.e. abnormal nerve conduction and/or abnormal quantitative testing of temperature sensation). In conclusion, quantitative testing of temperature sensation improves the diagnostic yield in patients examined for chronic polyneuropathy.