An unusual case of encephalomyeloradiculoneuropathy in a young woman.

Fulminant and progressive CNS disease developed in a young woman and was associated with bilateral deafness and sharply elevated CSF protein levels. Two months after onset, a severe sensorimotor neuropathy developed. Clinical improvement occurred with corticosteroid therapy.

Spinal cord regeneration in rats after immunosuppressive treatment. Theoretic considerations and histologic results.

Some species of animals and some early developmental stages of other species are capable of central nervous system (CNS) regeneration. These species and developmental stages also have reduced or absent allergic reaction to tissue homografts. Mammals are allergic to their own brain antigens, and experimental allergic encephalomyellitis (EAE) can be produced when they are exposed to parenterally administered brain antigen. Immunosuppressive treatment will delay or prevent the production of EAE in rats. In our experiments, immunosuppressive treatment made possible the electrophysiologic study of regeneration of long descending motor tracts of the spinal cord in rats six months after spinal cord transection. Histologic evaluation showed no comparative difference in scar at the site of transection when treated animals were compared with controls. Neither was any difference noted between animals in which regeneration was shown electrophysiologically and those without such regeneration. Perhaps humoral antibodies play a role in the prevention of functional regeneration in the rat.

AChE-positive fiber growth after hippocampal fimbria transection and peripheral nerve homogenate implantation.

Gelfoam treated with peripheral nerve homogenate was implanted into a site of hippocampal fimbria transection in the adult rat to assess whether the homogenate might enhance growth of AChE-positive fibers into the lesion site and whether the fiber growth might be directed to the implants. Homogenate was prepared from intact peripheral nerve and in a few cases from degenerated nerve. Some implants were encased in Silastic. Homogenate was also injected into the denervated hippocampus. The major finding was that AChE-positive fiber growth was associated with regions of high astroglial cell content in preference to the relatively hypocellular implants. No clear differences in AChE fiber sprouting into the lesion site, fiber growth into implants, or hippocampal reinnervation were noted between homogenate and saline-treated animals.

A long-term follow-up case study of crossed aphasia assessed by single-photon emission tomography (SPECT), language, and neuropsychological testing.

A 65-year-old man with well-defined crossed aphasia secondary to right cerebral infarction 10 years previously was studied for current language and cognitive abilities and regional cerebral blood flow (rCBF) during cognitive activation measured by single-photon emission tomography (SPECT). Reversed hemispheric lateralization was demonstrated by qualitative aspects of the patient's constructional deficits, dominant parietal lobe signs, and absence of the neglect syndrome. Language activation procedures during SPECT produced focal increases in rCBF to both frontal lobes with a phoneme detection task and to right temporal and parietal lobes with a math task. The authors stress the complexities of assessing brain/language mechanisms in vivo and demonstrate variabilities in rCBF during language activation dependent on task selection.

Is there regeneration of cholinergic axons through traumatic scar tissue in adult mammalian brain?

After a 2-mm coronal incision was made in the cerebral cortex of adult rats, cholinergic axonal reaction and growth were assessed by acetylcholinesterase histochemistry between 3 and 56 days postinjury. Early axonal reaction in the proximal stumps consisted of hypertrophy and terminal swellings, many with extended processes. Axonal fiber density rostral to the lesion remained constant throughout the observation period; caudally it was reduced but increased with time. Cholinergic fibers appeared to cross the lesion, although definitive tracing of individual fibers was not possible.

Regeneration of rat hippocampal fimbria fibers after fimbria transection and peripheral nerve or fetal hippocampal implantation.

After a unilateral hippocampal fornix-fimbria transection in adult rats, either autologous peripheral nerve or fetal hippocampus was implanted into the transection site. After 2 to 4 weeks, 2 to 3 months, and 6 to 8 months fimbria fiber regeneration was analyzed by acetylcholinesterase (AChE) histochemistry and retrograde transport of horseradish peroxidase after injection into the denervated host hippocampus. Prominent innervation of both types of implant by central AChE-staining axons occurred by 2 to 3 weeks postimplantation and was sustained to at least 8 months. Reinnervation of the adjacent host hippocampal terminal zone was also apparent, but was sparse compared with innervation of implants.