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.