A 3-year-old female child presents to sleep clinic with a concern of new onset of “deep breaths and gasps” during sleep followed by normal breathing followed by stopping breathing and repeating. Episodes happen about every 3 minutes when sleeping on her back, however these breathing changes do not happen when she sleeps on her right side. Both parents deny any night terrors, or nightmares. Both parents have noticed these apneic episodes during night sleep and naps for the last four months.
Patient has a history of late prematurity born at 36 weeks of gestation by normal vaginal delivery with history of in utero tobacco exposure. There have been no concerns with eating habits, GERD, delays in growth or development. There is no change in voice, difficulty swallowing, notable weakness of arms or abnormal arm movement. Parents have not noticed any truncal ataxia and no reported headaches.
On examination, patient is on the 20th percentile for weight, 22nd percentile for length and 26th percentile for BMI. Physical examination was positive for mildly enlarged nasal turbinates and tonsils 1-2+ with palpable thyroid. Ultrasound of thyroid showed likely fatty tissues with no compression of surrounding structures. Normal muscle strength and normal gait noted.
Initial polysomnogram study was done on room air (see figure 1) and showed severe mainly central sleep disordered breathing with a total apnea hypopnea index (AHI) of 27.4 events per hour (205 central apneas, 6 obstructive apneas, 3 mixed apneas and 7 hypopnea events), extensive pattern of periodic breathing noted during the study and occupied about 7.5% of total sleep time. Most of the periodic breathing occurred in NREM, specifically in stage 2 however periodic breathing still occurred but to less extent during REM.  No snoring was noted. The lowest oxygen saturation was 87% without any sleep related hypoxemia and no sleep related hypoventilation (peak PCO2 of 45.8mmHg). The sleep disordered breathing was slightly worse during REM sleep with REM related apnea-hypopnea index of 30.8 events per hour; the supine apnea-hypopnea index was 24.6 events per hour. The longest apnea event was obstructive in nature and lasted 21.3 seconds. The central apnea events varied from 9 to 17.2 seconds. Periodic limb movements (PLM) noted with PLM index of 4.3/hour. The sleep efficiency was normal at 94.3% and the sleep architecture was also normal for age. Gene sequence analysis of PHOX2B for congenital central hypoventilation syndrome was done due to the severe central apnea and the significant periodic breathing pattern and was negative.
Repeat Polysomnogram was performed on 1 LPM oxygen by simple nasal cannula 10 days after initial sleep study with improvement in central sleep disordered breathing noted on oxygen therapy. During the second polysomnogram, total AHI was 0.5 event per hour, the peak TCO2 was 49 mmHg and there was no sleep related hypoventilation. The lowest oxygen saturation was 93% without sleep related hypoxemia, no snoring noted, and the sleep efficiency and architecture were both normal for age. Based on this improvement with supplemental oxygen, patient was placed on oxygen during night sleep and naps with a pulse oximeter monitoring at home pending definitive intervention.
Due to the concern of the extensive pattern of periodic breathing in the setting of severe central sleep disordered breathing, MRI brain with and without contrast (see Figure 2) was performed. MRI -showed cerebellar tonsils extended below foramen magnum by 2cm with marked crowding of foramen magnum and severe restriction of CSF flow through foramen magnum. Neurosurgery was consulted and patient underwent Suboccipital Craniectomy, First and Second Cervical Laminectomies and Duraguard Duraplasty for Chiari I Decompression. Patient was observed in the PICU overnight and had appropriate oxygen saturations on room air. The surgery was uncomplicated, and patient had resolution of apneic events during sleep.
Repeat polysomnogram on room air was done about 3 months after surgical intervention and showed significant improvement in the sleep disordered breathing and periodic breathing pattern with a total AHI of 1.8 per hour (total of 15 central apnea events without any obstructive or mixed events), and periodic breathing for 2.5% of total sleep time. The lowest oxygen saturation was 94% without sleep related hypoxemia and the peak PCO2 was 48 mmHg without sleep related hypoventilation. Normal sleep efficiency and sleep architecture for age noted. Patient clinically continued to do well post-operatively and growing and developing appropriately for age.