Neonatal-HypotoniaClinical-Approach-To-Floppy-Baby新生兒肌張力低下的臨床方法要軟盤嬰兒(-31)課件

1、Neonatal HypotoniaClinical Approach To Floppy BabyOsama Naga, M.D.,PGY27/23/09Neonatal HypotoniaClinical ApNeonatal HypotoniaCentral CausesCerebral palsyHypoxic ischemic encephalopathy Intracranial hemorrhage Cerebral malformations Chromosomal abnormalities (e.g.Trisomy 21, Prader-Willi syndrome) Co

2、ngenital infection TORCHAcquired infections Peroxisomal disorders Drug effects (e.g. benzodiazepines) Neonatal HypotoniaCentral CausNeonatal HypotoniaSpinal cord Birth trauma (especially Breech delivery) Syringomyelia Neonatal HypotoniaSpinal cord Neonatal HypotoniaAnterior Horn Cell Spinal Muscular

3、 Atrophy Traumatic myelopathy Neonatal HypotoniaAnterior HorNeonatal HypotoniaNeuromuscular junction Congenital myasthenia gravisTransient acquired neonatal myasthenia Infantile botulism Neonatal HypotoniaNeuromusculaNeonatal HypotoniaMuscle Muscular dystrophies (congenital myotonic dystrophy) Conge

4、nital myopathies (e.g. central core disease) Neonatal HypotoniaMuscle Neonatal HypotoniaPeripheral nerves Hereditary sensory motor neuropathiesCharcot-Marie-Tooth disease Neonatal HypotoniaPeripheral nNeonatal HypotoniaMetabolic myopathies Acid maltase deficiency Carnitine deficiency Cytochrome-c-ox

5、idase deficiency Neonatal HypotoniaMetabolic myNeonatal HypotoniaHistoryAny significant family historyAffected parentsSiblingsConsanguinityStillbirthsChildhood deaths Neonatal HypotoniaHistoryNeonatal HypotoniaHistoryMaternal diseaseDiabetesEpilepsyMyotonic dystrophy Pregnancy and delivery historyDr

6、ug or teratogen exposure Decreased fetal movements Abnormal presentation Polyhydramnios/ oligohydramnios Neonatal HypotoniaHistoryNeonatal HypotoniaHistoryApgar scores Resuscitation requirements Cord gases Neonatal HypotoniaHistoryNeonatal HypotoniaHistoryHistory since delivery Respiratory effort Ab

7、ility to feed Level of alertness Level of spontaneous activity Character of cryNeonatal HypotoniaHistoryNeonatal HypotoniaIdentification of hypotoniaHolding the infant under the armsThe legs will be extendedDecreased tone of the shoulder girdle allows the infant to slip through the examiners hands N

8、eonatal HypotoniaIdentificatiNeonatal HypotoniaIdentification of hypotoniaHolding the infant in horizontal suspensionThe back hangs over the examiners hand, and the limbs and head hang looselyPassive extension of the legs at the knees no resistance is met Pulling the infant from the supine to sittin

9、g position the head lags and continues to lag when the sitting position is reachedNeonatal HypotoniaIdentificatiNeonatal HypotoniaPhysical ExaminationCentralNormal strengthNormal or increased DTRsMay be SeizureMay be dysmorphic features Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical Examin

10、ationAnterior horn cellsGeneralized weakness Decreased/ absent DTRs FasciculationsOften described as alert Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical ExaminationNerveWeakness, distalproximal Decreased/ Absent DTRs +/- fasciculations Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysi

11、cal ExaminationNeuromuscular JunctionWeakness, face/ eyes/ bulbar Normal DTRs No fasciculations Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical ExaminationMusclesWeakness, proximaldistal Decreased DTRs Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical ExaminationClues and PitfallsPro

12、found central hypotonia may have absent DTRAbsent DTR in the first few DOL would not rule out a central cause for the hypotonia Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical ExaminationClues and PitfallsPresence of profound weakness and hypotonia suggest: Disorder of the lower motor neuro

13、nA sign of this may be a weak cryWeakness is uncommon in central hypotonia except in the acute stages Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical ExaminationClues and PitfallsArthrogryposis (the fixation of joints at birth)Associated with: Neonatal hypotoniaMore commonly with lower moto

14、r neuron unitMultisystem abnormalities Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical ExaminationCluesHepatosplenomegalyStorage disordersCongenital infections Renal cystsHigh foreheadWide fontanellesZellwegers syndrome Neonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical ExaminationClu

15、esAbnormal odor Metabolic disorders Hypopigmentation, undesceded testesPrader Willi HepatomegalyRetinitis pigmentosaNeonatal adrenoleukodystrophyNeonatal HypotoniaPhysical ExaNeonatal HypotoniaPhysical ExaminationCluesExamination of the motherCongenital myotonic dystrophyMyasthenia gravis Neonatal H

16、ypotoniaPhysical ExaNeonatal HypotoniaInvestigationHistory and examinationHypotonia and a degree of strengthCentral cause is most likely Hypotonic and weakPeripheral cause is possibleEarly review by the neurology service is warranted Neonatal HypotoniaInvestigatioNeonatal HypotoniaInvestigationCentr

17、al CausesNeuroimaging Ultrasound scan in the first instanceMRI for structural abnormalityEEG: if seizures suspected Neonatal HypotoniaInvestigatioNeonatal HypotoniaInvestigationCentral CausesGenetics review if any dysmorphic features present Karyotype (if dysmorphic features) TORCH screen DNA methyl

18、ation studies or FISH for Prader-Willi syndrome (if clinically indicated after a genetics review) Metabolic work upNeonatal HypotoniaInvestigatioNeonatal HypotoniaInvestigationPeripheral causesNeurology services review Molecular genetics CTG repeats, deletions in SMN gene Neonatal HypotoniaInvestigatioNeonatal HypotoniaInvestigationPeripheral causesCreatine kinase: If elevated in an early s