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Abstract
An 80-year-old woman presented with a 5-week history of increasing confusion. Examination was remarkable only for deficits in short-term memory and paranoid thoughts. Blood tests revealed hyponatraemia, and further biochemical testing was consistent with syndrome of inappropriate antidiuretic hormone (SIADH). After an exhaustive diagnostic workup for causes of SIADH, the only abnormal finding was a mildly raised antivoltage-gated potassium channel (VGKC) titre of 185 pmol/L (0-69) consistent with possible anti-VGKC autoimmune limbic encephalitis. However, other diagnostic features were absent. She is currently undergoing outpatient investigation for other causes of memory loss.
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Affiliation(s)
- Nicholas Black
- Department of General and Geriatric Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK
| | - Hazim Hamada
- Department of General and Geriatric Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK
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2
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Grain R, Lally J, Stubbs B, Malik S, LeMince A, Nicholson TR, Murray RM, Gaughran F. Autoantibodies against voltage-gated potassium channel and glutamic acid decarboxylase in psychosis: A systematic review, meta-analysis, and case series. Psychiatry Clin Neurosci 2017; 71:678-689. [PMID: 28573688 DOI: 10.1111/pcn.12543] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 01/21/2023]
Abstract
Antibodies to the voltage-gated potassium channel (VGKC) complex and glutamic acid decarboxylase (GAD) have been reported in some cases of psychosis. We conducted the first systematic review and meta-analysis to investigate their prevalence in people with psychosis and report a case series of VGKC-complex antibodies in refractory psychosis. Only five studies presenting prevalence rates of VGKC seropositivity in psychosis were identified, in addition to our case series, with an overall prevalence of 1.5% (25/1720) compared to 0.7% in healthy controls (12/1753). Meta-analysis established that the pooled prevalence of GAD65 autoantibodies was 5.8% (95% confidence interval [CI]: 2.0-15.6%; I2 = 91%; nine studies) in psychotic disorders, with a prevalence of 4.6% (95%CI: 1.2-15.9%; nine studies; I2 = 89%) and 6.2% (95%CI: 1.2-27.0%; two studies; I2 = 69%) in schizophrenia and bipolar disorder, respectively. People with psychosis were more likely to have GAD65 antibodies than controls (odds ratio [OR], 2.24; 95%CI: 1.28-3.92%; P = 0.005; eight studies; I2 = 0%). Among 21 participants with treatment-resistant psychosis, none had VGKC antibodies. The prevalence of VGKC antibodies is low in psychosis. Our preliminary meta-analysis suggests that GAD autoantibodies are more common in people with psychosis than in controls, although few studies accounted for the possibility of co-existing type 1 diabetes mellitus and the clinical significance of reported GAD titers remains unclear. The paucity of studies reporting thresholds for defining GAD abnormality and rates of comorbid type 1 diabetes mellitus precludes interpretations regarding the influence of GAD antibodies on the development of psychotic disorders and may have led to an overestimate of the prevalence of GAD. Our case series fails to support the hypothesis that VGKC antibodies are linked to treatment resistance in psychosis, but the literature to date is remarkably sparse.
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Affiliation(s)
- Rosemary Grain
- GKT School of Medicine, King's College London, London, UK
| | - John Lally
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,National Psychosis Service, South London and Maudsley NHS Foundation Trust, London, UK.,Department of Psychiatry, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland.,Department of Psychiatry, University College Dublin, Dublin, Ireland
| | - Brendon Stubbs
- Physiotherapy Department, South London and Maudsley NHS Foundation Trust, London, UK.,Health Service and Population Research Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Steffi Malik
- Medical School, University of Bristol, Bristol, UK
| | - Anne LeMince
- National Psychosis Service, South London and Maudsley NHS Foundation Trust, London, UK
| | - Timothy R Nicholson
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Robin M Murray
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,National Psychosis Service, South London and Maudsley NHS Foundation Trust, London, UK
| | - Fiona Gaughran
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,National Psychosis Service, South London and Maudsley NHS Foundation Trust, London, UK.,The Collaboration for Leadership in Applied Health Research and Care (CLAHRC), South London Psychosis Research Team, London, UK
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3
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Sipilä JO, Kauko T, Soilu-Hänninen M. Admission sodium level and prognosis in adult Guillain–Barré syndrome. Int J Neurosci 2016; 127:344-349. [DOI: 10.3109/00207454.2016.1163551] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Jussi O.T. Sipilä
- Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland
- 2Neurology, University of Turku, Turku, Finland
- 3Neurology clinic, North Karelia Central Hospital, Joensuu, Finland
| | - Tommi Kauko
- 4Department of Biostatistics, University of Turku, Turku, Finland
| | - Merja Soilu-Hänninen
- Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland
- 2Neurology, University of Turku, Turku, Finland
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A case study of voltage-gated potassium channel antibody-related limbic encephalitis with PET/MRI findings. EPILEPSY & BEHAVIOR CASE REPORTS 2015; 4:23-6. [PMID: 26106579 PMCID: PMC4475784 DOI: 10.1016/j.ebcr.2015.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 01/27/2015] [Accepted: 02/04/2015] [Indexed: 12/16/2022]
Abstract
Preclinical and clinical studies have demonstrated the significance of inflammation and autoantibodies in epilepsy, and the use of immunotherapies in certain situations has become an established practice. Temporal lobe epilepsy can follow paraneoplastic or nonparaneoplastic limbic encephalitis associated with antibodies directed against brain antigens. Here, we focus on a patient with worsening confusion and temporal lobe seizures despite treatment with antiepileptic medications. Serial brain MRIs did not conclusively reveal structural abnormalities, so the patient underwent brain PET/MRI to simultaneously evaluate brain structure and function, revealing bitemporal abnormalities. The patient was diagnosed with voltage-gated potassium channel antibody-related limbic encephalitis based on clinical presentation, imaging findings, and antibody testing. Treatment included the addition of a second antiepileptic agent and oral steroids. His seizures and cognitive deficits improved and stabilized.
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Abstract
We evaluated two different perspectives about the function of the human hippocampus--one that emphasizes the importance of memory and another that emphasizes the importance of spatial processing and scene construction. We gave tests of boundary extension, scene construction, and memory to patients with lesions limited to the hippocampus or large lesions of the medial temporal lobe. The patients were intact on all of the spatial tasks and impaired on all of the memory tasks. We discuss earlier studies that associated performance on these spatial tasks to hippocampal function. Our results demonstrate the importance of medial temporal lobe structures for memory and raise doubts about the idea that these structures have a prominent role in spatial cognition.
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Kim S, Borst G, Thompson WL, Hopkins RO, Kosslyn SM, Squire LR. Sparing of spatial mental imagery in patients with hippocampal lesions. Learn Mem 2013; 20:657-63. [PMID: 24136183 PMCID: PMC3799416 DOI: 10.1101/lm.031633.113] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In four experiments, we explored the capacity for spatial mental imagery in patients with hippocampal lesions, using tasks that minimized the role of learning and memory. On all four tasks, patients with hippocampal lesions performed as well as controls. Nonetheless, in separate tests, the patients were impaired at remembering the materials that had been used to assess mental imagery. The findings suggest that the hippocampus is not needed for constructing many forms of spatial imagery but is needed for the formation of long-term memory. In future studies of the neural organization of spatial mental imagery, it will be important to separate the contribution of spatial processing from the contribution of learning and memory.
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Affiliation(s)
- Soyun Kim
- Veterans Affairs San Diego Healthcare System, San Diego, California 92161, USA
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Pertzov Y, Miller TD, Gorgoraptis N, Caine D, Schott JM, Butler C, Husain M. Binding deficits in memory following medial temporal lobe damage in patients with voltage-gated potassium channel complex antibody-associated limbic encephalitis. ACTA ACUST UNITED AC 2013; 136:2474-85. [PMID: 23757763 PMCID: PMC3722347 DOI: 10.1093/brain/awt129] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Some prominent studies have claimed that the medial temporal lobe is not involved in retention of information over brief intervals of just a few seconds. However, in the last decade several investigations have reported that patients with medial temporal lobe damage exhibit an abnormally large number of errors when required to remember visual information over brief intervals. But the nature of the deficit and the type of error associated with medial temporal lobe lesions remains to be fully established. Voltage-gated potassium channel complex antibody-associated limbic encephalitis has recently been recognized as a form of treatable autoimmune encephalitis, frequently associated with imaging changes in the medial temporal lobe. Here, we tested a group of these patients using two newly developed visual short-term memory tasks with a sensitive, continuous measure of report. These tests enabled us to study the nature of reporting errors, rather than only their frequency. On both paradigms, voltage-gated potassium channel complex antibody patients exhibited larger errors specifically when several items had to be remembered, but not for a single item. Crucially, their errors were strongly associated with an increased tendency to report the property of the wrong item stored in memory, rather than simple degradation of memory precision. Thus, memory for isolated aspects of items was normal, but patients were impaired at binding together the different properties belonging to an item, e.g. spatial location and object identity, or colour and orientation. This occurred regardless of whether objects were shown simultaneously or sequentially. Binding errors support the view that the medial temporal lobe is involved in linking together different types of information, potentially represented in different parts of the brain, regardless of memory duration. Our novel behavioural measures also have the potential to assist in monitoring response to treatment in patients with memory disorders, such as those with voltage-gated potassium channel complex antibody limbic encephalitis.
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Affiliation(s)
- Yoni Pertzov
- Institute of Neurology, University College London, London, UK.
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Towards therapeutic applications of arthropod venom k(+)-channel blockers in CNS neurologic diseases involving memory acquisition and storage. J Toxicol 2012; 2012:756358. [PMID: 22701481 PMCID: PMC3373146 DOI: 10.1155/2012/756358] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 02/08/2012] [Indexed: 12/31/2022] Open
Abstract
Potassium channels are the most heterogeneous and widely distributed group of ion channels and play important functions in all cells, in both normal and pathological mechanisms, including learning and memory processes. Being fundamental for many diverse physiological processes, K+-channels are recognized as potential therapeutic targets in the treatment of several Central Nervous System (CNS) diseases, such as multiple sclerosis, Parkinson's and Alzheimer's diseases, schizophrenia, HIV-1-associated dementia, and epilepsy. Blockers of these channels are therefore potential candidates for the symptomatic treatment of these neuropathies, through their neurological effects. Venomous animals have evolved a wide set of toxins for prey capture and defense. These compounds, mainly peptides, act on various pharmacological targets, making them an innumerable source of ligands for answering experimental paradigms, as well as for therapeutic application. This paper provides an overview of CNS K+-channels involved in memory acquisition and storage and aims at evaluating the use of highly selective K+-channel blockers derived from arthropod venoms as potential therapeutic agents for CNS diseases involving learning and memory mechanisms.
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Kitten S, Gupta N, Bloch RM, Dunham CK. Voltage-gated potassium channel antibody associated mood disorder without paraneoplastic disease. Biol Psychiatry 2011; 70:e15-7. [PMID: 21531392 DOI: 10.1016/j.biopsych.2011.03.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 03/02/2011] [Indexed: 12/31/2022]
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Unusual amnesia in a patient with VGKC-Ab limbic encephalitis: A case study. Cortex 2011; 47:451-9. [DOI: 10.1016/j.cortex.2010.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2009] [Revised: 11/23/2009] [Accepted: 01/21/2010] [Indexed: 11/22/2022]
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Role of the hippocampus in remembering the past and imagining the future. Proc Natl Acad Sci U S A 2010; 107:19044-8. [PMID: 20956323 DOI: 10.1073/pnas.1014391107] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It has been proposed that a core network of brain regions, including the hippocampus, supports both past remembering and future imagining. We investigated the importance of the hippocampus for these functions. Five patients with bilateral hippocampal damage and one patient with large medial temporal lobe lesions were tested for their ability to recount autobiographical episodes from the remote past, the recent past, and to imagine plausible episodes in the near future. The patients with hippocampal damage had intact remote autobiographical memory, modestly impaired recent memory, and an intact ability to imagine the future. The patient with large medial temporal lobe lesions had intact remote memory, markedly impaired recent memory, and also had an intact ability to imagine the future. The findings suggest that the capacity for imagining the future, like the capacity for remembering the remote past, is independent of the hippocampus.
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Camerino DC, Desaphy JF, Tricarico D, Pierno S, Liantonio A. Therapeutic Approaches to Ion Channel Diseases. ADVANCES IN GENETICS 2008; 64:81-145. [DOI: 10.1016/s0065-2660(08)00804-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Reduplicative paramnesia in Morvan's syndrome. J Neurol Sci 2007; 267:154-7. [PMID: 17928004 DOI: 10.1016/j.jns.2007.09.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Revised: 08/30/2007] [Accepted: 09/20/2007] [Indexed: 01/24/2023]
Abstract
BACKGROUND Morvan's syndrome is characterized by peripheral nervous system hyperexcitibility (myokymia and neuromyotonia), hyperhydrosis, sleep disorder, limb paresthesias, and encephalopathy. Voltage gated potassium channel antibodies (VGKC abs) are frequently present. Reduplicative paramnesia (RP) has not been reported with this disorder. OBJECTIVE To describe a patient with Morvan's syndrome presenting with RP. DESIGN Single case study. PATIENT A 64-year-old man with several years of myokymia and myoclonus with escalating parasomnia and confusion developed the delusion that a replica of his house and its contents existed 40 mi away. RESULTS Serum VGKC ab titer was elevated. Neuropsychological testing disclosed executive function and memory deficits. Electromyography demonstrated diffuse myokymia. Treatment with intravenous immunoglobulin and prednisone produced improvement of RP and myoclonus, but not myokymia. CONCLUSION RP may occur in patients with VGKC ab-associated Morvan's syndrome. Both RP and nervous system hyperexcitability may respond to immunotherapy including intravenous immunoglobulin and corticosteroids.
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