Early occurrence of brief potentially ictal rhythmic discharges [B(I)RDs], and subsequent emergence of asymmetric extreme delta brush (EDB) in Anti-NMDA receptors encephalitis

Ocorrência precoce de breves, rítmicas e potencialmente ictais descargas [B(I)RDS], e surgimento posterior de assimétrico extremo “delta brush” (EDB) num caso de encefalite Anti-NMDAr

A 12 years-old boy was admitted in coma without motor deficit, with normal CT scan, CSF with lymphocytosis, and EEG showing B(I)RDS (Figure A). Continuous EEG (24 hours) and subsequent serial intermittent EEGs were performed. Seizures were not documented. Patient developed orofacial diskynesia and coreoathetosis movements affecting superior limbs. Later, EEG showed asymmetric EDB pattern (Figure B). MRi was unremarkable. After immunotherapy, his level of consciousness improved. Anti-NMDAr antibodies were detected in serum and CSF.

Figure
(A) First electroencephalographic record showing frontocentral (F4, C4 electrodes) burst of rhythmic activity with a frequency of 12-14 Hz, during 06s, a Brief potentially ictal rhythmic discharges - B(I)RDS pattern. (B) EEG eight days after admission, showing asymmetric extreme delta brush (EDB) with delta activity more pronounced in right hemisphere. Parameters were as follows: sensitivity 7 μV/mm, time constant 0.3 s and high-frequency filter 70 Hz.

B(I)RDS were described in critically ill patients, often associated with brain injury and seizures, but no reported in Anti-NMDAr encephalitis¹. EDB has been described in Anti-NMDAr encephalitis; however, their clinical significance remains to be determined².

References

• ¹
  Yoo JY, Rampal N, Petroff OA, Hirsch LJ, Gaspard N. Brief potentially ictal rhythmic discharges in critically ill adults. JAMA Neurol. 2014;71(4):454-62. doi:10.1001/jamaneurol.2013.6238
• ²
  Schmitt SE, Pargeon K, Frechette ES, Hirsch LJ, Dalmau J, Friedman D. Extreme delta brush: a unique EEG pattern in adults with anti-NMDA receptor encephalitis. Neurology. 2012;79(11):1094-100. doi:10.1212/WNL.0b013e3182698cd8

Publication Dates

• Publication in this collection
  20 Oct 2015
• Date of issue
  Feb 2016

History

• Received
  08 July 2015
• Received
  13 Aug 2015
• Accepted
  02 Sept 2015