Chapter 4. Neurophysiology, Epilepsy, Evoked Potentials, and Sleep Disorders
A 6-month-old boy presents with episodes of rapid arm flexion followed by extension. Following the episodes, the child cries. The parents have noticed that these episodes typically happen repeatedly in rapid succession. The parents are also concerned that he cannot sit without assistance, roll over, or hold a rattle. Chemistry and complete blood count are normal. Lumbar puncture is performed, and cerebrospinal fluid (CSF) results are normal for age. An electroencephalogram (EEG) is obtained (Figure 4-1).
Figure 4-1 (Reproduced with permission from Laoprasert P. Atlas of Pediatric EEG. New York: McGraw-Hill; 2011.)
Based on the history and the EEG results, the patient most likely has
(A) Lennox–Gastaut syndrome
(D) benign idiopathic neonatal convulsions
(B) The patient in the vignette has West syndrome. West syndrome is a triad of infantile spasms, mental retardation, and hypsarrhythmia. Clinically, the patient has clusters of episodes of arm flexion/extension followed by crying, which is consistent with infantile spasms. His development is far behind what is expected of a 6-month-old and he has even regressed. This is consistent with baseline developmental delay with a superimposed developmental regression. The EEG, which demonstrates a chaotic, high-voltage pattern, is consistent with hypsarrhythmia. Therefore, the patient fits the triad of West syndrome.
The other answer choices are incorrect for a variety of reasons. Lennox–Gastaut syndrome does not occur until later in life, typically after the age of 3 years. The EEG in Lennox–Gastaut classically demonstrates slow (1–2 Hz) spike and wave with runs of fast activity during sleep. Clinically, the children have a multitude of seizure types (including tonic, atonic, and atypical absence seizures). Ohtahara syndrome is one of the early infantile epileptic encephalopathies (EIEE) and typically presents earlier in life. The EEG shows a burst suppression pattern. Benign idiopathic neonatal convulsions (“fifth-day fits”) typically occur within the first week of life and then completely resolve. Sandifer syndrome is a nonepileptic syndrome characterized by back arching and occasionally arm extension. It is caused by gastroesophageal reflux disease (GERD). (Laoprasert, 542; Menkes, 877–880, 884; Merritt, 561, 929)
Laoprasert P. Atlas of Pediatric EEG. New York, NY: McGraw-Hill, 2011.
Menkes JH, Sarnat HB, Maria BL. Child neurology, 7th ed. New York, NY: Lippincott Williams & Wilkins, 2000.
Merritt HH. Merritt's Neurology, 12th ed. New York, NY: Lippincott Williams & Wilkins, 2010.
A 9-year-old boy presents with progressive loss of developmental milestones. Over the ...