Restorative Neurology and Neuroscience - Volume 9, issue 3

Authors: Thöne, Angelika I.T.

Article Type: Review Article

Abstract: Memory impairment is a frequent effect of different forms of brain injuries and may be even more handicapping than severe physical problems. The purpose of this article is to critically review empirical studies on the effectiveness of different procedures of memory rehabilitation. Traditionally memory rehabilitation has focused on direct training of memory functioning. The problem of these programs is that training effects hardly generalize to patients' everyday life memory problems. As a consequence of this transfer problem, strategies have been developed (method of vanishing cues, errorless learning) which are restricted to the aim of teaching patients domain specific knowledge. Another …aspect of memory rehabilitation concentrates on coping with memory impairment. This may be done by alleviating demands on the patient and by including external resources into the process of recovery. On the other hand, teaching the patient to actively cope with memory related difficulties, has recently become an essential objective of memory rehabilitation. In order to pursue this aim, traditional mnemonic techniques are embedded into training of problem solving abilities and metamemory knowledge. Future perspectives and questions open to research are outlined for each of the different procedures. Show more

Keywords: Memory rehabilitation, Memory impairment, Transfer, Generalization, Cognitive rehabilitation, Behavioral neuropsychology

DOI: 10.3233/RNN-1996-9301

Citation: Restorative Neurology and Neuroscience, vol. 9, no. 3, pp. 125-140, 1996

Authors: Dahlin, Lars B. | Miyauchi, Akira | Thomsen, Peter | Danielsen, Nils | Kanje, Martin

Article Type: Research Article

Abstract: The effects of granulation tissue exposure on regeneration of sensory axons after a test crush lesion in rat sciatic nerves were studied. Chromic catgut threads were applied subcutaneously in the back of rats. Three weeks later the surrounding granulation tissue was isolated and transposed to the sciatic or tibial nerve in the same rat. Immunocytochemical, light and electron microscopic evaluation of the isolated granulation tissue revealed numerous EDI and ED2 positive macrophages. After an additional three weeks the sciatic nerves were crushed and the axonal outgrowth lengths were measured by the pinch reflex test and by neurofilament staining 3 or …6 days later. The regeneration distances in the sciatic nerve exposed to granulation tissue were significantly longer compared with that of nerves to which only subcutaneous tissue was transposed. Thus, the nerve had become conditioned by the transposure of macrophage rich tissue. After the transposure macrophages were present close to the nerve at the time point of the test crush lesion, but no signs of degeneration or inflammation in the endoneurial space were observed. It was also found that the outgrowth lengths in the tibial nerve branch were consistently longer than in the peroneal branch of the sciatic nerve. It is concluded that granulation tissue, containing macrophages, can induce a conditioning effect in the sciatic nerve. We suggest that this effect is related to factors emanating from macrophages in the transposed tissue. Show more

Keywords: Nerve regeneration, Macrophages, Conditioning lesion, Sensory nerve fiber, Neurofilament, EDI, ED2

DOI: 10.3233/RNN-1996-9302

Citation: Restorative Neurology and Neuroscience, vol. 9, no. 3, pp. 141-149, 1996

Authors: Navarro, Xavier | Calvet, Santiago | Butí, Miquel | Gómez, Nuria | Cabruja, Enric | Garrido, Paco | Villa, Rosa | Valderrama, Elena

Article Type: Research Article

Abstract: This paper describes some developments, made to obtain a chronic neural interface to record signals from regenerated peripheral nerves. Microperforated silicon dices, fabricated by techniques compatible with CMOS processes, were coupled in silicone nerve chambers and implanted between the severed ends of peripheral nerves in rats. Three configurations of perforated dices with 25 via-holes of 100 μm diameter, 121 via-holes of 40 μm and 400 via-holes of 10 μm were assessed. The feasibility of axonal regeneration through the dices via-holes was proved by histological and physiological methods over 3 months post-implantation. The regenerated nerves were organized in fascicles corresponding to …the grid pattern of the via-holes. However, nerve regeneration was difficult and distal re-innervation delayed with respect to simple tubulization repair. The size of the via-holes and the total open area are determinants of the degree and quality of regeneration. Further improvements are needed in both the microelectrode dice design and in neurobiological stimulation of regeneration. Show more

Keywords: Nerve regeneration, Neural prosthesis, Peripheral nerve, Regenerating microelectrode, Tube repair

DOI: 10.3233/RNN-1996-9303

Citation: Restorative Neurology and Neuroscience, vol. 9, no. 3, pp. 151-160, 1996

Authors: Magnusson, Sofia | Kanje, Martin

Article Type: Research Article

Abstract: Invading and resident macrophages were studied in the regenerating rat vagus nerve in vivo and in vitro, using antibodies to invading (EDI) and resident (ED2) macrophages. Fresh vagus nerves contained no EDI positive macrophages as revealed by immunocytochemical staining. In crush lesioned nerves in vivo, the number of EDI positive cells around and distal to the crush lesion, increased dramatically with time. Interestingly, EDI positive cells, although few, appeared in the cultured vagus nerves subjected to a crush lesion. Resident ED2 positive macrophages were abundant in fresh nerves. In vivo, there was a small increase of ED2 positive macrophages at …the crush area as regeneration proceeded. In contrast, no increase was observed in vitro and after 3 days no ED2 stained macrophages were found. Immunocytochemical staining for low-affinity NGF-receptors showed a dramatic increase at the crush and distal to it in vivo, while in vitro, the receptors were upregulated along the entire nerve. The results suggest that invading macrophages may not be crucial for the initial and early outgrowth of sensory nerve fibres in peripheral nerves. Show more

Keywords: Peripheral nerve regeneration, Vagus nerve, Macrophages, Monoclonal antibodies, Immunohistochemistry

DOI: 10.3233/RNN-1996-9304

Citation: Restorative Neurology and Neuroscience, vol. 9, no. 3, pp. 161-166, 1996

Authors: Imai, Tomihiro | Aoki, Mamoru

Article Type: Research Article

Abstract: This study was performed to determine whether a correlation exists in the functional recovery of the longitudinal reflex systems and recovery of quadrupedal locomotion in chronic spinally-lesioned rats. Partial spinal lesions sparing only the right ventral quadrant (VQ) or dorsal quadrant (DQ) of the spinal cord at the lower thoracic (T9–10) levels were performed aseptically under Nembutal anesthesia. Quadrupedal locomotion reappeared within 2–3 weeks after the initial operations in VQ rats. However, no recovery of hindlimb movement was observed in DQ rats. In terminal experiments with VQ and DQ rats, the right brachial plexus (C6–T1) was dissected and mounted on …a bipolar stimulating electrode. Spino-bulbo-spinal and interlimb reflex potentials were recorded from bilateral hindlimb muscles under urethane-chloralose anesthesia and Nembutal anesthesia, respectively. In VQ rats, these longitudinal reflex potentials could not be evoked for several days post-operatively. However, the early threshold elevation for evoking the reflex potentials returned gradually to the normal range in accordance with locomotor recovery. In DQ rats, on the other hand, disappearance of the reflex potentials persisted over 1 month observation period. These results suggest that the functional recovery of these longitudinal reflex systems in the ventral quadrant parallels the quadrupedal locomotor recovery after partial spinal cord lesions in rats. Show more

Keywords: Locomotor recovery, Rat, Reticulospinal tract, Spinal lesion, Spino-bulbo-spinal reflex, Interlimb reflex

DOI: 10.3233/RNN-1996-9305

Citation: Restorative Neurology and Neuroscience, vol. 9, no. 3, pp. 167-176, 1996

Article Type: Research Article

DOI: 10.3233/RNN-1996-9306

Citation: Restorative Neurology and Neuroscience, vol. 9, no. 3, pp. 177-189, 1996