Episodic Weakness and Irritability in a Child with Developmental Delay: History is the Key!

Abstract Background: We describe a 5-year-old girl with episodic weakness whose diagnosis was reached primarily with history and examination, later confirmed with genetic testing. Alternating hemiplegia of childhood (AHC) is a lesser-known entity whose diagnosis is mainly made on genetic testing; but what leads there is a systematic approach which is highlighted here. Clinical Description: The child had a 3-year history of episodic loosening of the body and irritability with episodes lasting for 4–5 days, after which the child would regain baseline state, occurring every 10-15 days. The mother observed that the loosening resolved during sleep and would reappear gradually within 1 hour of getting up without any triggering factors. Multiple consultations had not resulted in either a firm diagnosis or a sustained improvement. Management and Outcome: The child was admitted with us for observation of the episode, which helped in pointing out some unique features of the illness and ruling out other possibilities. Flunarizine was started keeping a possibility of AHC, the disease being confirmed by a response to treatment as well as genetic testing. Conclusion: We report this uncommon condition diagnosed clinically to underscore the importance of a diligent history taking, and also direct observation of episodic events, if feasible.