Atormac
Neurology India
menu-bar5 Open access journal indexed with Index Medicus
  Users online: 2761  
 Home | Login 
About Editorial board Articlesmenu-bullet NSI Publicationsmenu-bullet Search Instructions Online Submission Subscribe Videos Etcetera Contact
  Navigate Here 
 Search
 
  
 Resource Links
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Article in PDF (660 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this Article
   References
   Article Figures

 Article Access Statistics
    Viewed1971    
    Printed64    
    Emailed0    
    PDF Downloaded74    
    Comments [Add]    
    Cited by others 1    

Recommend this journal

 


 
Table of Contents    
LETTER TO EDITOR
Year : 2012  |  Volume : 60  |  Issue : 5  |  Page : 533-534

Unusual clinical and imaging characteristics in a patient with voltage-gated potassium channel antibody-associated encephalitis


1 Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
2 Department of Neuroimaging and Interventional Neuroradiology (NIIR), National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India

Date of Web Publication3-Nov-2012

Correspondence Address:
Manjunath Netravathi
Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0028-3886.103213

Rights and Permissions



How to cite this article:
Jaychandran R, Patel MJ, Netravathi M, Saini J, Satishchandra P, Pal PK. Unusual clinical and imaging characteristics in a patient with voltage-gated potassium channel antibody-associated encephalitis. Neurol India 2012;60:533-4

How to cite this URL:
Jaychandran R, Patel MJ, Netravathi M, Saini J, Satishchandra P, Pal PK. Unusual clinical and imaging characteristics in a patient with voltage-gated potassium channel antibody-associated encephalitis. Neurol India [serial online] 2012 [cited 2019 Sep 19];60:533-4. Available from: http://www.neurologyindia.com/text.asp?2012/60/5/533/103213


Sir,

Antibodies reactive with neuronal voltage-gated potassium channel (VGKC-Abs) have emerged as a serologic marker of potentially reversible autoimmune encephalopathies. [1]

A 61-year-old college professor presented with one month history of seizures and recent memory loss. He was started on carbamazepine for complex partial seizures. Three weeks later, he developed disorientation to time, place and person; with frequent seizures (both myoclonic jerks and facio-brachial dystonic seizures). Initial evaluation revealed anti-thyroperoxidase antibody and hyponatremia (serum Na 115 mEq/L). Magnetic resonance imaging (MRI) of brain showed asymmetrical T1 isointense, T2 and FLAIR hyperintensities in caudate, putamen and hippocampus [Figure 1]. Electroencephalogram (EEG) showed diffuse background slowing. Work-up for paraneoplastic syndrome was negative. Cerebrospinal fluid (CSF) studies were normal. Carbamazepine was stopped and sodium valproate was started along with injectable steroids (methyl prednisolone), in view of possible Hashimoto's encephalopathy. However, there was only minimal improvement of his symptoms. At this stage, he was evaluated in our institute. He was disoriented, with impairment of recent memory, frequent seizures, and had myokymia in calf and right thumb and generalized hyporeflexia. MRI of brain showed asymmetrical T2 and FLAIR hyperintensities in caudate, putamen, hippocampus. T1 hyperintensities in the caudate and putamen were also seen as new changes compared to previous imaging findings [Figure 2]. Possibility of autoimmune encephalitis was considered. VGKC-Abs was positive. The patient was initially started on intravenous immunoglobulin, but showed no improvement, he was then started on plasmapheresis, following which he showed significant improvement. At follow-up (one year after onset of illness) the professor could go to the college alone; able to do few tasks with moderate memory improvement, and there were no seizures.

Autoimmune encephalitis is potentially reversible and the associated antibodies serve as diagnostic markers. [1],[2] These conditions are important to be recognized due to their etiological and prognostic implications. Encephalopathy associated with VGKC-Abs [1] responds to immunotherapy, and is usually not associated with neoplasm (except for few case reports) unlike other autoimmune encephalitis. It is typically accompanied by hyponatremia, which is resistant to correction but usually responds to immunosuppression. [3] Neuroradiological evidence of either unilateral or bilateral medial temporal lobe signal change is usually observed. MRI changes and hyponatremia are seen in about 60 percent of the cases. [4] There are isolated case reports of involvement of basal ganglia, thalamus and pons. [5] Our patient had recurrent hyponatremia, which provided a clue to the diagnosis. The unique feature in our patient, which has not been reported previously are: (i) Clinical findings of myokymia and hyporeflexia; (ii) MRI findings of involvement of bilateral basal ganglia in addition to the hippocampi and (iii) T1 hyperintensities of the basal ganglia. As this is a recently recognized entity, there may be varied presentations of the syndrome apart from those already reported. Autoimmune synaptic encephalopathy should be considered as a differential diagnosis in all cases of rapidly progressive cognitive impairment and seizures.
Figure 1: Brain MRI: (a) FLAIR hyper-intensities in bilateral hippocampus, caudate and putamen. (b) T1 sequences of the hippocampus and basal ganglia showing iso-intensities in the same areas (as indicated by the arrows)

Click here to view
Figure 2: Brain MRI: (a) FLAIR hyper-intensities in bilateral hippocampus, caudate and putamen. (b) T1 hyper-intensities in caudate and putamen (as indicated by the arrows)

Click here to view


 
  References Top

1.Vincent A, Buckley C, Schott JM, Baker I, Dewar BK, Detert N, et al. Potassium channel antibody-associated encephalopathy: A potentially immunotherapy-responsive form of limbic encephalitis. Brain 2004;127:701-12.  Back to cited text no. 1
    
2.Thieben MJ, Lennon VA, Boeve BF, Aksamit AJ, Keegan M, Vernino S. Potentially reversible autoimmune limbic encephalitis with neuronal potassium channel antibody. Neurology 2004;62:1177-82.  Back to cited text no. 2
    
3.Irani SR, Vincent A. Autoimmune encephalitis-new awareness, challenging questions. Discov Med 2011;11:449-58.  Back to cited text no. 3
    
4.Irani SR, Alexander S, Waters P, Kleopa KA, Pettingil P, Zuliani L, et al. Antibodies to kv1 potassium channel complex proteins leucine- rich, glioma inactivated 1 protein and contactin-associated protein-2 in limbic encephalitis, Morvan's syndrome and acquired neuromyotonia. Brain 2010;133:2734-48.  Back to cited text no. 4
    
5.Fujimori J, Endo M, Irino S, Shiga Y, Shiraishi H, Motomura M, et al. A recalcitrant case of encephalitis with voltage-gated potassium channel antibodies. Brain Nerve 2010;62:1252-7.  Back to cited text no. 5
    


    Figures

  [Figure 1], [Figure 2]

This article has been cited by
1 Basal ganglia T1 hyperintensity in LGI1-autoantibody faciobrachial dystonic seizures
E. P. Flanagan,A. L. Kotsenas,J. W. Britton,A. McKeon,R. E. Watson,C. J. Klein,B. F. Boeve,V. Lowe,J. E. Ahlskog,C. Shin,C. J. Boes,B. A. Crum,R. S. Laughlin,S. J. Pittock
Neurology: Neuroimmunology & Neuroinflammation. 2015; 2(6): e161
[Pubmed] | [DOI]



 

Top
Print this article  Email this article
   
Online since 20th March '04
Published by Wolters Kluwer - Medknow