The most common cause of neonatal seizuris

Correct Answer: D

Rationale: Hypoxic-ischemic encephalopathy (HIE) is the most common neonatal seizure cause (~50-60%), per Volpe, from perinatal asphyxia disrupting brain metabolism. Febrile seizuroccur later (6 months-5 years). Pre-eclampsia affects mothers, indirectly fetuses. Hypocalcemia is less frequent (~10%). Aicardi syndrome is rare. HIprevalence in term infants makes D the correct answer.

Correct Answer: A

Rationale: Caféau lait maculare flat, light brown spots defining NF1, per NIH criteria, with ≥6 (prepubertal >5 mm) signaling diagnosis. Adenoma sebaceum are angiofibromas in tuberous sclerosis. Ash-leaf spots are hypopigmented in tuberous sclerosis. Shagreen patch is a connective tissue nevus in tuberous sclerosis. Nail fibromas are unrelated. NF1s autosomal dominant (chromosome 17) pattern and macule specificity make A the correct answer, distinguishing it from other neurocutaneous syndromes.

Correct Answer: D

Rationale: The Gallant reflex , or trunk incurvation, occurs in neonatwhen stroking paravertebrally causspinal curvature toward the stimulus, present at birth to 2-6 months, per pediatric texts. Asymmetrical tonic neck reflex involvhead-turning and limb extension. Parachute is protective arm extension. Placing is leg lifting when dorsum toucha surface. Moro is startle. Gallants spinal response makes D the correct answer.

Correct Answer: C

Rationale: Smell can be reliably assessed in children over 3 years , per developmental neurology, when verbal cooperation allows testing with identifiable odors. Below 3 (A-B), language and attention limit reliability; 4-5 refine it further. Olfactory maturity at birth supports testing by 3, making C the correct answer.

Correct Answer: C

Rationale: Myotonia congenita causexcessive muscle bulk from persistent contraction, per myopathy literature. Neuropathiand SMA reduce bulk; Duchenne leads to pseudohypertrophy then atrophy; MS is unrelated. Myotonias hypertrophy makes C the correct answer.