Auditory evoked potentials at 40 Hz (SSR40Hz) in post-trauma coma patients.

The authors evaluated auditory evoked steady state rest potentials at 40 Hz (SSR40Hz) in 21 post-trauma coma patients and compared their predictive value for prognosis of survival and quality of life with the results of the electroencephalogram (EEG), the computed tomography (CT) scan, and the Glasgow Coma Scale. SSR40Hz potentials recorded immediately after trauma had a maximum (100%) sensibility and specificity for a fetal prognosis and a high value for life prognosis. Consequently they appear to be a useful parameter for deciding on organ explant procedures. The EEG was more reliable in predicting a quality of life prognosis.

[The use and the potential of auditory electrophysiology in patients in posttraumatic coma]. / Uso y potencialidad de la electrofisiología auditiva en los pacientes en coma postraumático.

21 patients in post-traumatic coma status were submitted to a auditory electrophysiological valuation together with EEG, TC, and "Glasgow Coma Scale" (GCS) with the purpose to obtain the relative prognostic value quoad vitam and quoad valetudinem. In particular it was carried out the brainstem auditory evoked potentials (ABR) and the auditory middle latency potentials (MLR and SSR-40 Hz). 12 patients survived and their clinical conditions were classified according to the "Glasgow Outcome Scale"; 9 of 21 patients died. With the aim of quoad vitam prognosis, the ABR showed a good reliability whereas GCS, EEG, TC and MLR proved not much usefulness. On the contrary the absence of SSR-40 Hz always coincided with the subsequent patients death. With the aim of GOS a meaningful relationship was found between the clinical outcome conditions from coma and the improvement in MLR and EEG.

SSR-40Hz electrogenesis: results of clinical investigation.

This study attempts to provide clinical evidence on the origin of SSR-40Hz auditory evoked potential studying posttrauma coma patients. The SSR-40Hz present two types of morphology: an acute narrow wave, defined as "sharp", and a slow wide curve defined as "rounded". In constant recording of auditory brainstem responses (ABR) the "sharp" wave correlated with the absence of middle latency responses (MLR), and the "rounded" with their presence. In some patients the morphology changed passing grom a "sharp" to a "rounded" wave and a tendency towards widening preceded the appearance of middle latency responses. Perhaps the functional electrophysiologic block may have diminished in sub-cortical neuronal areas not involved in MLR genesis.

Microbial flora of nose and paranasal sinuses in chronic maxillary sinusitis.

Nasal secretions, maxillary sinus aspirates and specimens of the maxillary sinus mucosa were collected in 44 patients aged between 25 and 60 affected by mono- or bilateral chronic maxillary sinusitis, in order to establish the best sampling technique for microbiological purposes, the most frequently involved bacteria and the physiopathological mechanism underlying chronic maxillary disease. The sinusal mucosa resulted to be the most reliable sample as it reduces contamination and microbial variability. Anaerobic bacteria were isolated in nasal swab (15.6%), in maxillary sinus aspirates (30.4%) and in maxillary sinus mucosa (36.4%) of maxillary sinusitis patients. In controls anaerobic bacteria were isolated only in one nasal swab (2.3%), while they could not be isolated in maxillary sinus aspirates and in maxillary sinus mucosa. The presence of anaerobic bacteria in chronic maxillary sinusitis patients and their absence in controls seem to confirm that anaerobic microorganisms represent the main pathogenetic agents of chronic maxillary sinusitis. The possible physiopathological mechanisms underlying chronic maxillary sinus disease are finally discussed.