Hypotonia Presentation (case presentation)

Hypotonia

1. Case Presentation Norhan Khaled Ahmed Supervised by Dr. Ahmed Alhag

2. T able of Contents A bout the Patient D iagnosis and management 1 2 H ypotonia 3

3. A bout the Patient 1

4. H istory Female born at 39 weeks by NSVD to a 28yo G2P1 mom. Prenatal labs show HBsAg - ve , GBS - ve . Delivery was complicated by a short umbilical cord. The placenta was small and lobulated. The baby was delivered flat with Apgar score of 1, received bag ventilation, was intubated then transferred to NICU.

5. H istory NICU course: septic screening, chest X-ray, and ABGs were done. IV Abx, cooling were started, UVC & UAC were inserted, erythropoietin and morphine were given. The baby received 2 boluses of normal saline 15 ml / kg. H istory

6. Antenatal hx: last US done on 9 th of September showed; Single viable fetus with active movement and regular cardiac pulsation. EDD estimated to be 30 th of July, 2021 (20.7.2021). Nuchal translucency is 1.0 mm. Cervix was closed. Other history elements were insignificant H istory

7. P hysical examination General: The baby has dysmorphic features ; micrognathia, skeletal anomalies, severe hypotonia, and rocker-bottom heels. Weight 2.4 kg, temp 36.5 C, Pulse 128, RR 46, BP 68/45 Resp: intubated, connected to ventilator AC+VG CVS: normal S1-S2, systolic murmur Abdomen: soft and lax with normal bowel sounds

8. D iagnosis 2

9. D iagnosis Respiratory distress of the newborn Metabolic acidosis of the newborn Final diagnosis is pending, whole genome sequence was ordered.

10. H ypotonia 3

11. I ntroduction = Abnormally low resting muscle tone. It primarily manifests as decreased resistance to passive movement and abnormalities in resting posture.

12. D ifferential diagnoses S ystemic illness Infection, sepsis Electrolyte abnormalit y Congenital hypothyroidism hypoglycemia , ICH drug toxicity N eurological Central Peripheral O ther diagnoses Chromosomal Metabolic Genetic

13. D ifferential Diagnosis C entral hypotonia Infection (e.g., sepsis, meningitis, encephalitis) Genetic abnormalities (e.g., Down syndrome, Prader–Willi syndrome, fragile X) Metabolic disease (e.g., leukodystrophy, glycogen storage disease) Trauma (e.g., birth trauma, nonaccidental trauma) Hypoxic ischemic encephalopathy (e.g., decreased perinatal perfusion)

14. D ifferential Diagnosis P eriphral hypotonia Spinal muscular atrophy (SMA) Nerve injury (e.g., brachial plexus injury) Myasthenia gravis Medications/toxins (e.g., botulinum toxin, hypermagnesemia) Congenital myopathies Congenital myotonic dystrophy

15. A pproach to suspected hypotonia in infants Conditions that are amenable to rapid treatment (e.g., electrolyte imbalance, infection) must be excluded and treated first. Stabilization of the patient is the highest priority. After the patient is stable, detailed evaluation follows through Steps to diagnosis: careful Hx and PE confirming hypotonia, neurological vs. non-neurological etiologies, localization of the lesion in case of neurological etiology. A neurology consultation is generally necessary to help narrow the differential diagnosis after preliminary categorization is performed.

16. H istory O nset Acute; stroke, trauma Gradual; metabolic, degenerative P rogression Worsening over time vs. same L ocation Global vs. one limb A ssociated Sx Multisystem -> genetic Encephalopathy -> central Sensory deficit -> nerves P erinatal Hx Decreased fetal movements polyhydramnios Birth trauma Malrotation F amily Hx Hypotonia Nerve, or muscle diseases

17. P hysical examination M ental status Altered mental status strongly supports a central cause P osture of trunk and extremities. Infant is awake, relaxed, and head is at midline. F rog-leg position hips abducted, flexed, and externally rotated H ead lag when the infant is pulled from a supine to sitting position S uspension Vertical -> should be done for all infants Horizontal -> infant draping over the examiner’s hands D ifferentials Low muscle bulk -> primary muscle disease Fasciculations -> SMA DTR -> normal-brisk in C diminished-absent in P

18. A “frog-leg” position

19. L aboratory studies CBC & urinalysis Metabolic panel, TFT Bilirubin levels Creatinine phosphokinase If genetic disease is suspected Chromosomal analysis Congenital infection screen , CSF analysis, serum amino acids, urine organic acids, ammonia levels

20. D iagnostic modalities N CS and EMG For peripheral hypotonia M uscle US For myopathic changes M RI brain For central hypotonia structural abnormalities, vascular lesions

21. T reatment Depends on the underlying cause Supportive management Long-term programs of education, physical therapy, occupational therapy, and social skills training

22. D iscussion Summary Neonatal hypotonia is defined as abnormally low resting muscle tone A complete prenatal, birth and postnatal history is essential along with a through physical examination (esp. neurological examination and special tests for hypotonia) The differential diagnosis includes 3 main categories: Systemic illness Neurologic disease Genetic, chromosomal and metabolic abnormalities.

23. B ack to our patient On the 5 th of August, 9:17 am the baby was bradycardic at 30 BPM and desaturated down to 40. Coordinated PPV and chest compressions were done for 10 mins. Three doses of epinephrine 0.1ml / kg 1 : 10000 were given, HR was picking up slowly. The baby was on maximal ventilatory support and was declared dead at 1 PM on the same day. The parents were informed and counselled.

24. R esources Books: Schwartz’s Clinical Handbook of Pediatrics, 5 th edition First aid for the Pediatrics clerkship, 3 rd edition Online resources: Up to date Amboss