The MOST common cause of anatomic megalencephaly is

Correct Answer: B

Rationale: Benign familial megalencephaly is the most common anatomic megalencephaly cause, a non-syndromic, inherited large head size without neurologic deficits. Sotos , Simpson-Golabi-Behmel , fragile X , and Weaver are rarer syndromic causwith additional features. Bs frequency and benign nature make it the correct answer.

Correct Answer: B

Rationale: Valproic acid causweight gain and alopecia via metabolic and hormonal effects (e.g., insulin resistance, hair follicle disruption). Primidone , oxcarbazepine , lamotrigine , and acetazolamide lack this profile rash or sedation dominate instead. Valproatunique side effects make B the correct answer.

Correct Answer: C

Rationale: Subtle seizure.g., eye deviation, apnea often lack EEG correlatin neonatdue to immature cortex and subcortical origins, per Volpe. Focal clonic , tonic , spasms , and myoclonic typically show discharges. Subtldissociation makes C the correct answer.

Correct Answer: D

Rationale: Phenytoins limited neonatal use stems from poor solubility , skin reactions , drug interactions , and cardiac risks . It can be mixed with saline (E is false), unlike stated, but other issupredominate. This exception mixability makes D the correct answer.

Correct Answer: D

Rationale: Migraine featurepisodic attacks , moderate-severe pain , often unilateral/focal , and nausea . Constant quality is false; migrainare throbbing, unlike steady tension headaches. This pulsatile nature (ICHD-3) makes D the exception and correct answer.