ANTI-VOLTAGE GATED POTASSIUM CHANNEL (VGKC) ANTIBODY POSITIVE ENCEPHALOPATHY

Since autoimmune mediated encephalitis was recognised 15 years ago, several autoantibodies have been identified. We present 3 patients with positive VGKC antibodies to emphasise the spectrum of clinic presentation and value of antibody testing.A 61 yo male presented with cognitive decline and frequent right arm stiffening, which is recognised as faciobrachial dystonic seizure. VGKC/LGI1 antibody positive. Received IVIG treatment and rapidly recovered.A 69 yo women presented with acute personality change and poor short memory following a brief syncope. MRI showed bilateral hippocampus high T2/FLAIR signal. VGKC/LGI-1 antibody was 5800. She improved with IVIG and steroid treatment. However, seizures recurred when weaning from steroid at 4 months. Repeat titre of 1100. Steroid restarted until antibody negative.A 60 yo male presented with 8 months of personality change without myoclonus. VGKC antibody was positive with a titre of 169. Further testing LGI1 and CASPA2 were negative. He gradually recovered with 6 month steroid treatment. No specific cause was found with extensive investigations.The typical presentations of VGKC encephalitis have been widely recognised, however clinical vigilance is important for atypical presentations. Antibody titres are of great value following the treatment, while low positive cases prompt further investigations.

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THUR 153 Antibodies against the voltage-gated potassium channel complex

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp-2018-abn.65 ◽

2018 ◽

Vol 89 (10) ◽

pp. A18.2-A18

Author(s):

Joyutpal Das ◽

Vanisha Chauhan ◽

Ryan Keh ◽

Daniel Mills ◽

Johal Nicholas ◽

...

Keyword(s):

Potassium Channel ◽

Intravenous Immunoglobulins ◽

Voltage Gated ◽

Morvan’S Syndrome ◽

Classic Phenotype ◽

Antibody Titres ◽

Peripheral Nerve Hyperexcitability ◽

Clinical Phenotyping ◽

Positive Results ◽

Autoimmune Encephalopathy

Voltage-gated potassium channel (VGKC) complex antibodies have been associated with a spectrum of presentations including peripheral nerve hyperexcitability (PNH), Morvan’s syndrome, autoimmune encephalopathy, epilepsy and recently psychosis.We retrospectively reviewed the medical records of 70 patients from the Greater Manchester Neuroscience Centre, who had tested positive for VGKC-complex antibodies between 2012 and 2015 to identify the clinical relevance of positive results.The majority were diagnosed with autoimmune encephalopathy(19) followed by epilepsy(14), psychosis(10) and PNH(6). The remaining fifteen had other neurological presentations and six had no primary neurological disorder. 39/70 patients who had antibody titres>400 pM, were diagnosed with autoimmune encephalopathy(19), epilepsy(9), psychosis(4), PNH(3) and other disorders(4). 24/39 patients, who received treatment with one or a combination of corticosteroids, intravenous immunoglobulins, cyclophosphamide, plasma exchange, azathioprine or rituximab, had a diagnosis of autoimmune encephalopathy(18), epilepsy(2), psychosis(2) and malignancy(2). 16/24 were treatment responsive. 3/31 patients with lower titres were also treated, but only one with the classic phenotype (PNH) responded to treatment.The classic phenotype often had a titre >400 pM. PNH may have a titre ≤400 pM. The patients without classic presentations typically had titres≤400 pM. Consistent with previous studies, clinical phenotyping and antibody titre helped to determine the relevance of VGKC-complex antibodies.

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Voltage-gated potassium channel blanket testing in first-episode psychosis: Diagnostic nihilism?

Australian & New Zealand Journal of Psychiatry ◽

10.1177/0004867420983454 ◽

2021 ◽

pp. 000486742098345

Author(s):

Fiona Chan ◽

Cullen O’Gorman ◽

Andrew Swayne ◽

David Gillis ◽

Stefan Blum ◽

...

Keyword(s):

Potassium Channel ◽

Psychiatric Patients ◽

First Episode Psychosis ◽

Positive Case ◽

First Episode ◽

Voltage Gated ◽

Episode Psychosis ◽

Positive Voltage ◽

Antibody Titres

Objective: Voltage-gated potassium channel antibodies are implicated in limbic encephalitis and currently included in first-episode psychosis organic screening guidelines. Individuals with high-positive voltage-gated potassium channel titres most commonly present with neurological symptoms as well as sleep, cognitive, behaviour, psychosis and mood disturbance. The significance of low-positive voltage-gated potassium channel antibody titres in psychiatric patients is unclear and has not been previously examined. We aim to describe a statewide cohort of psychiatric patients with low- and high-positive voltage-gated potassium channel titres and explore if this finding influenced clinical management and patient outcomes. Methods: A retrospective review of all voltage-gated potassium channel antibodies testing performed in public psychiatric services in Queensland, Australia, with comparison of the clinical presentation and long-term outcomes of low- and high-positive voltage-gated potassium channel titre cases. Specific antigen targets (leucine-rich glioma-inactivated protein 1 and contactin-associated protein 2 antibodies) were also assessed. Results: The overall prevalence of voltage-gated potassium channel antibody positivity in Queensland, public, psychiatric service testing was 0.3% (14/4098), with 12 cases of low-positive voltage-gated potassium channel titre, 2 cases of high-positive (leucine-rich glioma-inactivated protein 1 antibody positive) cases and a voltage-gated potassium channel negative contactin-associated protein 2 antibody positive case. No low-positive case developed neurological abnormalities or had abnormal paraclinical investigations. In comparison, both high-positive voltage-gated potassium channel/leucine-rich glioma-inactivated protein 1 cases and the contactin-associated protein 2 antibody positive case rapidly developed neurological symptoms, had abnormal paraclinical testing and improved only with immunotherapy. There was no later development of encephalitic symptoms in the low-positive cases over an average of 1067 days follow-up. Conclusion: Voltage-gated potassium channel antibody–associated limbic encephalitis was rare, and always associated with high antibody titres. Low-positive titres were not associated with the development of encephalitis over a long period of follow-up. The value of universal voltage-gated potassium channel antibody screening is unclear, and further prospective studies in first-episode psychosis populations are required.

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Other Proven and Putative Autoimmune Disorders of the CNS

10.1093/med/9780199937837.003.0093 ◽

2017 ◽

Author(s):

Eoin P. Flanagan ◽

Richard J. Caselli

Keyword(s):

Cognitive Decline ◽

Potassium Channel ◽

Cancer Patients ◽

General Term ◽

Autoimmune Disorders ◽

Thyroid Antibodies ◽

Serological Evidence ◽

Voltage Gated ◽

Hashimoto’S Encephalopathy ◽

Autoimmune Encephalopathy

The historical term “Hashimoto’s encephalopathy” describes a serologically diverse spectrum of autoimmune encephalopathies that tend to be highly steroid responsive and unassociated with cancer. Patients typically present with subacute cognitive decline and serological evidence of autoimmunity that includes but is not limited to thyroid antibodies. An inflammatory spinal fluid and, in a subset of patients, MRI signal abnormalities are supportive. Patients often respond promptly to corticosteroids but relapses are typical. The continued discovery of novel neural-specific-autoantibodies such as voltage-gated-potassium-channel-autoantibodies associated with autoimmune encephalopathies highlights why the term “Hashimoto’s” is misleading. The authors advocate the more general term “autoimmune encephalopathy.”

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A RARE CASE OF PROGRESSIVE MYOCLONIC EPILEPSY DUE TO SSPE

10.36106/ijar/7301940 ◽

2021 ◽

pp. 54-55

Author(s):

Hari Sankar T ◽

Upasana Patra ◽

Hemanth Kumar Singh ◽

Sadhana Panda

Keyword(s):

Cognitive Decline ◽

Measles Virus ◽

Fatal Outcome ◽

The Body ◽

Lower Limbs ◽

Igg Antibody ◽

Antibody Titres ◽

History Of ◽

Progressive Myoclonic Epilepsy ◽

Atypical Presentations

SSPE is a chronic complication of measles with a delayed onset and nearly fatal outcome. This “slow virus infection” results from a persistent infection with an altered measles virus, that is harboured intracellularly in the CNS. Patients usually presents with cognitive decline and myoclonus but atypical presentations are also quite common. Our case is of a 9 year old male child , previously neurodevelopmentally normal, presented with 4 months history of frequent fall due to jerky movements of the left upper and lower limbs which progresses to involve left half of the body, reduced attention span, cognitive decline and loss of speech. During hospitalisation, despite treatment with antibiotics , steroids , and antiepileptics ,disease progressed with myoclonic jerks , altered sensorium and nally child became comatose. CSF study is normal but MRI and EEG shows abnormalities. Based on clinical features and history of exanthematous illness at 6 months of age, measles igG antibody titres in CSF were tested , which came to be highly elevated conrming SSPE.

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Limbic encephalitis with voltage gated potassium channel antibodies in a child

Neuropediatrics ◽

10.1055/s-2008-1079504 ◽

2008 ◽

Vol 39 (01) ◽

Author(s):

E Haberlandt ◽

CG Bien ◽

A Reiter ◽

B Simma ◽

R Crazzolara ◽

...

Keyword(s):

Potassium Channel ◽

Limbic Encephalitis ◽

Voltage Gated

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Post-treatment with a Hydrogen Sulfide Donor Limits Neuronal Injury and Modulates Potassium Voltage-gated Channel Subfamily D Member 2 (Kv4.2) and Potassium Channel Interacting Protein 3 (KChIP3) During Transient Global Cerebral Ischemia

Current Neurovascular Research ◽

10.2174/1567202614666171108113447 ◽

2018 ◽

Vol 14 (4) ◽

pp. 397-405 ◽

Cited By ~ 1

Author(s):

Cheng Ping Bai ◽

ChenLiang Zhao ◽

Lijuan Shen

Keyword(s):

Hydrogen Sulfide ◽

Cerebral Ischemia ◽

Potassium Channel ◽

Neuronal Injury ◽

Post Treatment ◽

Global Cerebral Ischemia ◽

Interacting Protein ◽

Voltage Gated ◽

Transient Global Cerebral Ischemia ◽

Gated Channel

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Voltage-gated potassium channel limbic encephalitis presenting as functional cognitive impairment

BMJ Case Reports ◽

10.1136/bcr-2019-233179 ◽

2020 ◽

Vol 13 (12) ◽

pp. e233179

Author(s):

Eric Garrels ◽

Fawziya Huq ◽

Gavin McKay

Keyword(s):

Cognitive Impairment ◽

Case Report ◽

Potassium Channel ◽

Limbic Encephalitis ◽

Psychiatric Symptoms ◽

Differential Diagnoses ◽

Visual Hallucinations ◽

Voltage Gated ◽

History Of ◽

Impaired Cognition

Limbic encephalitis is often reported to present as seizures and impaired cognition with little focus on psychiatric presentations. In this case report, we present a 49-year-old man who initially presented to the Psychiatric Liaison Service with a several month history of confusion with the additional emergence of visual hallucinations and delusions. Due to the inconsistent nature of the symptoms in the context of a major financial stressor, a provisional functional cognitive impairment diagnosis was made. Investigations later revealed a positive titre of voltage-gated potassium channel (VGKC) antibodies, subtype leucine-rich glioma inactivated 1 accounting for his symptoms which dramatically resolved with steroids and immunoglobulins. This case highlighted the need for maintaining broad differential diagnoses in a patient presenting with unusual psychiatric symptoms.

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