Evaluation of Paroxysmal Flexor Events in a 3-Month-Old Infant

Case at a Glance

A 3-month-old male with a history of gastroesophageal reflux disease (GERD) presented with a two-week history of new-onset, brief, clustered jerking movements. These events occurred primarily during the transition to sleep, prompting parental concern for infantile spasms.

Patient's Story

The patient is a 3-month-old male whose mother brought him for evaluation due to concerns about progressively frequent and intense motor events. She first noticed the movements approximately two weeks prior and initially believed them to be an exaggerated startle (Moro) reflex. However, she observed that the events were increasing in frequency rather than diminishing, which prompted her to seek further information. Her online research led her to information about infantile spasms, causing significant anxiety due to the similarity between video examples and her son's movements.

Initial Assessment

The mother provided a detailed description of the events. They occurred almost exclusively when the infant was lying supine in his bassinet or crib while drifting off to sleep (hypnagogic state). During these episodes, the infant would suddenly jerk, causing him to awaken. The movement was described as a synchronous flexion of the limbs, with arms flying out and knees being drawn up towards the chest. These movements would occur in clusters of four to five episodes before the infant would settle into a deeper sleep. Notably, the mother did not observe any eye rolling or deviation, only a widening of the eyes during the events. The episodes were not observed during contact naps. She had recorded several video clips, some of which captured the events while the infant was in a bouncer or a sleep sack.

The Diagnostic Journey

Upon initial consultation, the pediatrician acknowledged the mother's valid concerns and the importance of her detailed observations and video evidence. The primary diagnostic concern was to differentiate infantile spasms from other benign or less urgent conditions. The differential diagnosis included:

1. Infantile Spasms (West Syndrome): The clustering, flexor nature of the movements, and occurrence upon arousal from sleep were highly suspicious.
2. Benign Myoclonus of Early Infancy (BMEI): These movements can appear similar but are not associated with developmental regression or an abnormal EEG.
3. Exaggerated Moro Reflex: While initially considered, the increasing frequency and clustering made this less likely.
4. GERD-related movements (Sandifer Syndrome): Given the patient's history of GERD, movements related to discomfort were considered, though the described flexor jerks were not classic for Sandifer syndrome.

The pediatrician emphasized that a video recording is the most valuable tool for initial assessment but that definitive diagnosis required further neurological evaluation.

Final Diagnosis

Pending Neurological Evaluation. The primary differential diagnosis to urgently rule out is Infantile Spasms.

Treatment Plan

The immediate plan focused on achieving a definitive diagnosis.

1. Urgent Referral: An urgent referral to a pediatric neurologist was made.
2. Electroencephalogram (EEG): The patient was scheduled for an urgent video-EEG to assess for hypsarrhythmia, the characteristic chaotic brain wave pattern associated with infantile spasms, and to attempt to capture the clinical events on video simultaneously with EEG recording.
3. Parental Counseling: The physician counseled the mother on the importance of the diagnostic workup, validating her concerns while explaining the systematic approach to diagnosis.

Outcome and Follow-up

The patient was seen by pediatric neurology within 48 hours. The video-EEG was performed to confirm or rule out the diagnosis of infantile spasms. The outcome of the case and subsequent management would be dictated by the results of the EEG and the neurologist's comprehensive assessment. Close follow-up was scheduled to discuss the findings and initiate appropriate treatment promptly if a diagnosis of infantile spasms was confirmed.