Serum from a Patient with GAD65 Antibody-Associated Limbic Encephalitis Did Not Alter GABAergic Neurotransmission in Cultured Hippocampal Networks.

BACKGROUND: Glutamate decarboxylase is an intracellular enzyme converting glutamate into GABA. Antibodies (abs) to its isoform GAD65 were described in limbic encephalitis and other neurological conditions. The significance of GAD65 abs for epilepsy is unclear, but alterations of inhibitory GABAergic neurotransmission may be involved. Here, we investigated the effects of the serum of a female patient suffering from GAD65 ab-associated LE on GABAA currents in cultured hippocampal networks. METHODS: Spontaneous or evoked post-synaptic GABAA currents were measured in cultured hippocampal neurons prepared from embryonic mice after 11-21 days in vitro using the patch-clamp technique in the whole-cell mode after incubation with serum of a healthy control or the LE-patient at a final concentration of 1% for 5-8 h. RESULTS: Properties of miniature inhibitory post-synaptic currents were not different in cultures treated with control and LE-serum. Likewise, paired-pulse ratio of evoked GABAA currents as a measure of release probability was not different in both conditions. Evoked GABAA currents were significantly depressed during 10 Hz stimulation without significant differences between control and LE-serum treated cultures. CONCLUSION: In our experimental paradigms, serum of a patient with confirmed GAD65 ab-associated LE had no apparent effect on GABAergic neurotransmission in murine-cultured hippocampal networks. These results challenge the view that the presence of GAD65 abs invariably compromise inhibitory network function.

Unusual pain due to unilateral facet degeneration at the C1-2 level.

AIM: Neck pain is a common problem that may result from abnormalities in the soft tissues, bones and joints of the spine. However, upper neck and occipital pain syndrome due to unilateral idiopathic arthrosis of a C1-2 lateral articulation is a very rare condition. MATERIAL AND METHODS: We describe two patients with unilateral arthrosis of a C1-2 lateral articulation who were successfully treated with C1-2 fusion. RESULTS: The patients presented with severe headache and/or neck pain. The diagnosis was made with a careful history and imaging studies, including X-ray films, CT scans, and MRI studies. Posterior atlanto-axial transfacet screw fixation was performed in both patients. There were no surgical complications. CONCLUSION: C1-2 fusion is necessary to relieve intractable pain after failure of conservative treatment and/or invasive pain procedures in unilateral C1-2 arthrosis.