Central somatosensory conduction abnormalities after common peroneal nerve stimulation in lesions of the anterior cruciate ligament of the knee

Central somatosensory conduction abnormalities after common peroneal nerve stimulation in lesions of the anterior cruciate ligament of the knee

Society Proceedings be of no influence. Callosotomy was performed in 9 patients under 20 years of age and in 17 over 20. Better results were obtained ...

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Society Proceedings be of no influence. Callosotomy was performed in 9 patients under 20 years of age and in 17 over 20. Better results were obtained in the latter. ll.

Behavior of cerebral evoked potentials in infant-juvenile neurofibromatosis. - A. Ammendola ‘, G. Avino b, R. Cantore ‘, M. Majorana b, G. Ugolini ‘, M. Coletta b, G. Lama b and F. Bravaccio ’ ? Chair of Neurophysiopathology, and b Department of Pediatrics, 11 University of Naples, Naples)

In the attempt to search clinical signals of centra1 nerveus system dysfunction in type 1 neurofibromatosis (NFl) in infancy, multimodal evoked potentials were used. Fifteen infant patients suffering from NFl were subjected to visual, brain-stem auditory and somatosensory evoked potentials. Furthermore, electroencephalography and encephalic magnetic resonance were carried out in all patients. In two thirds of the cases at least one of the evoked potentials was altered, mostly the visual ones, sometimes without clinical or neuroradiologic (NMR) signs of related sensorial pathway dysfunction. In conclusion, because NFl is characterized by multiple and even potentially dangerous manifestations, multimodal evoked potentials can be an early detector of possible clinical dysfunctions of centra1 nerveus system structures and, therefore, of great practica1 utility. 12. Masticatory muscle contraction causes facilitation of spinal motoneurons: is it an equivalent of the Jendrassik maneuver? - G. Guerriero, R Risaliti and F. Sartori (Riabilitazione Mezzaselva di Roana, Vicenza) The opponent pollicis F wave area was significantly increased during maximal isometrie contraction of masticatory muscles (from 1.96 f 0.25 to 2.83 + 0.16% of M wave area, P < 0.01, Wilcoxon rank test). The same potentiation was obtained during isometrie contraction of neck muscles and it was bigger than that associated with the contraction of other muscles such as orbicularis oculi or contralateral hand muscles. A similar effect was observed on F wave from soleus muscle (162.7 + 24.2% of baseline value) and, to a lesser extent, from tibialis anterior (108.7 f 9.2%). The same increases were present during neck muscle contraction and Jendrassik maneuver even in edentulous subjects. Contraction of masticatory muscles causes a significant increase of H wave area (113 f 9.5%) and, to a bigger extent, of T reflex (146.9 f 26.5%) from soleus, like the Jendrassik maneuver. Our data suggest that contraction of masticatory muscles causes a facilitation of spinal motoneurons. For lower limbs, the effect is similar to the Jendrassik maneuver in terms of site and size. At leat for soleus muscle, this event can be mediated by gamma loop. 13. N30 amplitude reduction in Parkinson’s disease: a pathophysiologie study by means of pharmacological tools. - R. Traversa, M. Pierantozzi, R Semprini, A. Santilli, M, Loberti, A. Sabato and P. Stanzione (I.R.C.C.S. Clinica S. Lucia, Rome) The aim of this study was to perform pharmacological tests which might influence muscle tone, while recording the N30 in PD patients and normal subjects. Fifteen PD patients were recorded and clinically assessed on basic conditions and during continuous apomorphine infusion (3-4.5 mg/h) and L-DOPA stable therapy. They were compared with 14 normal age matched controls. Moreover, 10 normal subjects were recorded before and after administration of 0.05 mg/kg of haloperidol. NO extrapyramidal side effects were produced. Four young psychotic patients, showing extrapyramidal side effects as a consequente of prolonged neuroleptic treatment, were also recorded and clinically assessed before and during continuous apomorphine infusion (3-6 mg/h). Three PD patients were also studied during the preanaesthetic “priming” procedure, performed by means of 10% of a paralysing dose of atracurium besilate (a peripheral nicotinic antagonist of neuromuscular transmission). ANOVA analysis showed a significantly decreased N30 amplitude in PD

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patients in comparison with normal subjects. Apomorphine infusion abolished the decrement while L-DOPA did not. The clinical score showed a marked improvement of rigidity items following apomorphine infusion in comparison with stable L-DOPA therapy. 14. Central somatosensory conduction abnormalities after common peroneal nerve stimulation in lesions of the anterlor cruciate ligament of the knee. - M. Valeriani ‘, D. Restuccia ‘, V. Di Lazzaro ‘, C. Fabbriciani b, F. Franceschi b and P. Tonali ’ (Departments of ’ Neurology and b Orthopaedics, Catholic University, Rome) Early clinical studies demonstrated a decrease of proprioception in patients with deficiency of the anterior cruciate ligament (ACL) of the knee. It has been suggested that the reduction in number of the mechanoreceptors, normally present in ACL, could explain this finding. We studied 9 patients with an anterior cruciate deficient knee, using somatosensory evoked potentials (SEPs) after stimulation of the common peroneal nerve (CPN) that provides the sensory innervation to ACL. The recording electrodes were placed over the spinous process of the 12th dorsal vertebra (T12) and at Cz; we referred the TI2 electrode to the anterior abdomen (An0 to record the spinal potential (SP). We considered the latency and the amplitude of SP in order to assess the function of the peripheral fibers. To assess the centra1 conduction along the centra1 somatosensory pathways we also calculated the interpeak interval P27-SP. We found no significant differente in SP latency and amplitude between patients and normal subjects. 15. Adrenoleucodystrophy and BSERA. - G. Serafini ‘, S. Laureti b, F. Santeusanio b, C. Simoncelli ’ and G. Casucci b (” E.N.T. Clinic and b Institute of Internal Medicine, Endocrinal and Metabolic Sciences University of Perugia, Perugia) X-linked adrenoleucodystrophy (X-linked ALD), an abnormality in peroxisomal beta-oxidation, is a rare hereditary disease causing neurological disturbances, demyelination, endocrinal imbalance and cortico-adrenal dysfunction. Myelin sheath metabolism, cerebral and peripheral nette conduction are disturbed. This study used BSERA to assess electrophysiological damage in 14 patients and correlated the results with plasma very long chain fatty acid (VLCFA) levels and clinical findings. Interpeak I-V latency times were used to divide the BSERA responses into 4 groups. Abnormal plasma VLGFA levels, clinical findings and abnormal BSERA patterns overlapped in 4 patients who had already been diagnosed as affected by X-linked ALD. The BSERA response in 1 patient with Addison’s disease suggested the Addison-only form of X-linked ALD. This diagnosis was confirmed by other tests, Slight abnormalities in BSERA tracing were observed in 3 patients with no evidente of plasma mutation. They wil1 be monitored over time to see whether or not they develop X-linked ALD. 16. Evaluation of sleep during an altered rest-activity schedule. - S. Porcù and A. Bellatreccia (I.A.F., D.A.S.R.S., Aerospace Medical Department, Neuropsychophysiology Branch, “M. De Bernard? Air Force Base, Pomezia) The aim of this investigation was to study the effect of severe disruption of the normal rest-activity schedule, due to a particular kind of shift work, on the quantity and quality of sleep of 14 healthy male volunteers (mean age f S.D. = 20.2 + 1.7 years). Each subject slept a mean ( & S.D.) total sleep time and total sleep period of 231 ( f 69) and 257.4 ( f 68.7) min, respectively. Seven percent (1) of the subjects slept in A, 43% (6) in B, 86% (12) in C and 100% (14) in D. Slow wave sleep (SWS) of the 24 h mostly occurred in C (49.3%) and D (43.6%); during C each subject had an average SWS duration of 29.5 ( f 31.2) min, 31.8% of the total sleep of this cycle. REM sleep was mostly present in D, with a mean value of 37.7 ( F 21.4) min, 26% of the total sleep of this cycle. In