Three-dimensional transcranial Doppler in acute ischemic stroke in the territory of the middle cerebral artery: clinical and CT correlation.

We studied 34 patients with acute ischemic stroke in the territory of the middle cerebral artery (MCA) by three-dimensional transcranial Doppler (TCD-3D). The parameters analyzed were: mean blood flow velocity, systolic and diastolic velocities; indices of pulsatility, hemisphere asymmetry and pulsatility transmission. Of the 34 patients 11 presented marked slowing of flow velocity in the MCA on the infarct side with an asymmetry index (AI) of over 40%, 8 patients with slightly reduced flow velocity in the MCA and an AI of 25-40%, 2 patients in whom there was indirect evidence of collateral circulations in the anterior cerebral artery distribution together with slowing of MCA flow; 5 patients had stenosis of the MCA, 9 patients showed no alterations of the Doppler parameters.

Neurophysiological studies of L-acetylcarnitine administration in man.

Systemic administration of L-acetylcarnitine HCl (LAC) increases in human subjects the amplitude of visual evoked potentials (VEPs) obtained with patterned elements of 7.5 min of visual angle, of steady-state VEPs obtained with intermittent luminous stimulation, of EEG theta, alpha and beta bands. The latency of the "cognitive" P300 potential obtained with an auditory "oddball" paradigm was also reduced by LAC injection, while the amplitude of this potential was increased.

Effect of levo-acetylcarnitine on P300-like potentials of the normal monkey.

Endogenous components of evoked potentials resembling P300 in human beings were sequentially studied in four cynomolgus monkeys (Macaca fascicularis using an auditory "oddball" paradigm, after classical conditioning training. When robust P300-like signals were obtained, each animal underwent further recording sessions in which a placebo, L-carnitine or L-acetylcarnitine (LAC) was injected. Only LAC induced an amplitude increment of P300 waves in all the animals and a latency decrement in two animals.