Examkin

Question

Difficulty: Very hardPediatric Neurologic Disorders

A 7-month-old boy is brought to the clinic by his parents due to "strange movements" that began two weeks ago. The parents report that the child has episodes where he suddenly bends his head and body forward while extending his arms stiffly. These episodes last for a few seconds, occur in clusters of 10 to 15, and typically happen just after he wakes up from a nap. Previously, the infant was able to sit with support and babble, but recently he has stopped vocalizing and seems less engaged with his surroundings. Vital signs are within normal limits for age. Physical examination reveals an infant who does not visually track objects well. Skin examination under a Wood lamp reveals three 2-cm elliptical hypopigmented macules on his trunk. An electroencephalogram (EEG) demonstrates a chaotic, high-voltage, asynchronous background with intermixed multifocal spikes and slow waves. Which of the following is the most appropriate initial pharmacotherapy for this patient's underlying condition?

  1. A
    Adrenocorticotropic hormone (ACTH)
  2. VigabatrinAnswer
  3. C
    Valproic acid
  4. D
    Reassurance and clinical observation
  5. E
    Topical clotrimazole

Answer

Vigabatrin
Vigabatrin is the first-line treatment for infantile spasms associated with Tuberous Sclerosis Complex (TSC). This patient's clinical presentation of clustered flexor/extensor spasms upon waking, developmental regression, and EEG findings of hypsarrhythmia are pathognomonic for infantile spasms (West syndrome). The presence of elliptical hypopigmented macules (ash-leaf spots) enhanced by a Wood lamp confirms the underlying diagnosis of TSC. In patients with TSC, vigabatrin is specifically targeted and more effective than other agents, acting via irreversible inhibition of GABA transaminase.

Step-by-Step Solution

1
Analyze the neurological presentation and EEG findings.
The patient has clustered flexor/extensor spasms upon waking, developmental regression, and hypsarrhythmia on EEG, which confirms the diagnosis of Infantile Spasms (West syndrome).
To establish the primary seizure syndrome before selecting therapy.
2
Evaluate the physical examination findings.
The presence of elliptical hypopigmented macules (ash-leaf spots) enhanced by a Wood lamp is identified.
To determine the underlying etiology of the infantile spasms, which in this case is Tuberous Sclerosis Complex (TSC).
3
Select the appropriate targeted pharmacotherapy.
Vigabatrin is chosen as the initial medication.
While ACTH or oral corticosteroids are used for idiopathic infantile spasms, vigabatrin is the specific first-line agent for infantile spasms associated with TSC.

Key Concept

Vigabatrin is the first-line pharmacotherapy for infantile spasms in patients with Tuberous Sclerosis Complex.
Estimated Time:1m 30s
Rate this question

Topics

Pediatric Neurologic Disorders

More questions from this topic