Prevalence of benign epileptiform variants observed in an EEG laboratory from South India

No study has investigated the prevalence and pattern of benign epileptiform variants (BEVs) in the electroencephalograph (EEG) of subjects from a developing nation. We addressed this issue by ascertaining the BEVs among subjects referred for EEG to a comprehensive epilepsy program in South India. We identified BEVs in 326 out of 1778 subjects (18.3%) who had both awake and sleep EEG recordings. The frequency distribution of individual BEVs were as follows: benign sporadic sleep spikes 8.2%, wicket waves 1%, 14 and 6 Hz positive spikes 5.7%, 6 Hz spike-waves 2.8% and rhythmic temporal theta burst of drowsiness 0.8%. We conclude that the prevalence rates of BEVs among South Indian subjects are not different from those reported from developed countries. We have highlighted the consequences of misinterpretation of BEVs as epileptiform, which is more likely to occur in Third World countries because of the non-availability of qualified technologists and electroencephalographers.

[1]  R. Gumnit,et al.  Intensive neurodiagnostic monitoring , 1986, Neurology.

[2]  B. Westmoreland,et al.  Nonepileptogenic epileptiform electroencephalographic activity , 1985, Annals of neurology.

[3]  B. Westmoreland,et al.  Unusual variants of subclinical rhythmic electrographic discharge of adults (SREDA). , 1997, Electroencephalography and clinical neurophysiology.

[4]  T. Pedley,et al.  Benign epileptiform transients of sleep , 1977, Neurology.

[5]  A. S. Graaf,et al.  Influence of Ethnic and Geographic Factors on the Classic Photoparoxysmal Response in the Electroencephalogram of Epilepsy Patients , 1995, Epilepsia.

[6]  R Witzig,et al.  The Medicalization of Race: Scientific Legitimization of a Flawed Social Construct , 1996, Annals of Internal Medicine.

[7]  B. Westmoreland,et al.  Subclinical Rhythmic EEG Discharge of Adults (SREDA): Further Observations , 1985 .

[8]  F. Samaha.  Human striated muscle myofibrils and actomyosin , 1967, Neurology.

[9]  S. Jain,et al.  Incidence of photosensitive epilepsy in unselected Indian epileptic population , 1994, Acta neurologica Scandinavica.

[10]  D. Klass,et al.  Two common EEG patterns of doubtful clinical significance. , 1968, The Medical clinics of North America.

[11]  J. R. Hughes.  Two forms of the 6/sec spike and wave complex. , 1980, Electroencephalography and clinical neurophysiology.

[12]  T. Pedley.  Current Practice of Clinical Electroenceph‐alography , 1980, Neurology.

[13]  Richard C Lewontin,et al.  Not in Our Genes. Biology, Ideology and Human Nature. Harmondsworth (Penguin) 1984. , 1984 .

[14]  A. Beydoun,et al.  Pitfalls of EEG interpretation in epilepsy. , 1993, Neurologic clinics.

[15]  F. Gibbs,et al.  Psychomotor variant type of seizure discharge , 1963, Neurology.

[16]  I. Schwartz,et al.  Ctenoids in healthy youths , 1966, Neurology.

[17]  B. Tharp.  The 6-per-second spike and wave complex. The wave and spike phantom. , 1966, Archives of neurology.

[18]  J. Reiher,et al.  Wicket Spikes: Clinical Correlates of a Previously Undescribed EEG Pattern , 1977, Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques.

[19]  C. A. Marsan,et al.  Incidence and prognostic significance of "epileptiform" activity in the eeg of non-epileptic subjects. , 1968, Brain : a journal of neurology.

[20]  J. R. Hughes,et al.  An Investigation of Eight Different Types of Temporal Lobe Discharges , 1981, Epilepsia.

[21]  A. Gökyiğit,et al.  Diffuse Spike‐Wave Status of 9‐Year Duration Without Behavioral Change or Intellectual Decline , 1995, Epilepsia.

[22]  B. Westmoreland,et al.  A distinctive rhythmic EEG discharge of adults. , 1981, Electroencephalography and clinical neurophysiology.