An 8-month-old boy consistently reaches for toys only with his right hand. The left hand remains fisted much of the day and is not used for reaching. His parents are proud that he seems 'right-handed so early'. What is the correct interpretation?
- A Early right-handedness, a sign of advanced fine motor development
- B Abnormal handedness before 1 year, raising concern for weakness of the left side (left hemiplegia) ✓
- C Normal transient hand preference that resolves by 12 months
- D Left brachial plexus injury from birth trauma
Correct answer: B. Abnormal handedness before 1 year, raising concern for weakness of the left side (left hemiplegia)
Explanation
Handedness before 12 months of age is pathological. Established preference for one hand in infancy implies disuse of the other limb due to weakness, pointing toward contralateral hemiplegic cerebral palsy, often from a perinatal stroke. True hand dominance emerges only after 12 to 18 months. Brachial plexus injury causes flaccid weakness of the whole arm with poor spontaneous movement, not selective fisting with preserved reach on the preferred side.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.