Early Clinical Course on a model of hemilesioned spinal rats:Relations among functional, electrophysiological and hystological data.

YORIO, A.; MANNARÁ, F.A.; COIRINI,H.; FIGURELLI, S.; PENNISI, P.; SEGURA, E.

Kobe International Conference Center and Kobe Portopia Hotel, Kobe, Japón

Congreso; 29th International Congress of Clinical Neurophysiology, ICCN2010; 2010

International Federation of Clinical Neurophysiology, Japanese Society of Clinical Neurophysiology, Science Council of Japan

Objectives: To evaluate by functional and electrophysiological methods the changes that follows hemispinal lesion in adult rats, investigating the earl y clinical effects in the time course of the spine lesion, and to evaluate the correlations between clinical, electrophysiological and histological data. Methods: In 12 Sprague Dawley rats (250-300 g) the spinal cord was exposed by laminectomy (T12-L1 vertebrae) under anesthesia, and a mechanical lesion was made in the left side. In other 12 rats only laminectomy was performed. Evaluations were made weekly up the 6th week after lesion. Muscle tone and motor activity of the hindlimbs and sides of the tail were scored using a clinical scale. The M/H waves were recorded in both legs and sides of the t ail. Finally, the lesion was verified by histopatology. Results: Once the lesion was done, all rats presented paresia and hypotonia of the ipsilateral hindlimb and side of the tail. After the second week clinical spasticity was evident on these body segments. None of them presented urinary disturbance s. At 15 days the amplitudes of compound muscle action potentials and of H reflex wave evoked by stimulation of the sciatic and caudal nerves were significantly lower in the lesioned side with respect to the non-lesioned side and the control rats. The latencies did not show significant differences in hemispinal rats with respect to controls. In hemispinal rats signifficant differences were seen between 15, 30 and 45 days for most functional and electro physiological parameters. A significant relation between the functional and electrophysiological impairments and with the area of spinal lesion was found. Conclusions: Early effects in the time course of spinal lesion tends to evolve in a multiphasic mode, and the grade of spasticity in the affected body parts correlates with the electrophysiological and histological data.