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Approach to floppy infant

Floppy Infant Aproach

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Approach to floppy infant

  1. 1. Approach To Floppy Infant Dr Anand Singh (DCH DNB)
  2. 2. OBJECTIVES  Define tone and how it is maintained  Distinguish b/w hypotonia and muscle weakness  Differences between central and peripheral causes of hypotonia.  Differential diagnosis of hypotonia in infants  Appropriate medical and genetic evaluation
  3. 3. MUSCLE TONE AND TYPES  Muscle tone is usually defined as the resistance to passive movement.  Muscle tone is most easily shown as movement of an extremity but certainly including the trunk, neck, back and the shoulder and pelvic girdles.  In the clinical setting we speak of 2 types of tone: phasic tone and postural tone  Phasic tone is passive resistance to movement of the extremities (appendicular structures)  Postural tone may be thought of as the resistance to passive movement of the axial muscles (neck, back, trunk )  There may be a discrepancy between phasic tone and postural tone in a given patient.  Best example is in the 3- or 4-month-old infant who has suffered an hypoxic-ischemic insult at birth and now has poor head and trunk control (postural hypotonia) but is beginning to become stiff (hypertonic) in the extremities (phasic tone) and will eventually develop increased reflexes and tone (spasticity) in the appendicular and axial muscles.
  4. 4. Control of Muscle Tone Supra Spinal ( CNS ) Motor Unit ( PNS )
  5. 5.  Motor signals are transmitted directly from cortex to spinal cord through cortico spinal tract  Indirectly from multiple accessory pathway involving basal ganglia, cerebelum and various nuclei of brain stem.  Direct pathways are more concerned with discrete and detailed movement, specially of distal segment of limbs.
  6. 6. MOTOR UNIT  Muscle tone is maintained at the peripheral level by participation of the fusimotor system  pathways involves the muscle spindles that promote muscle contraction in response to stretch  inverse myotactic reflex involving the Golgi tendon organ that provides a braking mechanism to the contraction of muscle.  A lesion interrupting the stretch reflexes at any level in the lower motor neuron (LMN) will result in a loss of muscle tone and stretch reflexes i.e. flaccidity
  7. 7. Hypotonia vs Weakness Hypotonia  Is decresed resistance to passive movement around a joint  Also defined as an impairment, of the ability to sustain postural control, and movement against gravity  Hypotonic infant may not have weakness  Central origin hypotonia – may or may not be associated with weakness  Hypotonia with pofound weakness suggest LMN cause Weakness  has reduction in maximum power that can be generated  Weak infant many times have hypotonia
  8. 8.  Because dysfunction at any level of the nervous system can cause hypotonia so D/D is extnsive  central causes account for 60% to 70% cases  peripheral causes occur in up to 30% cases.  Central conditions include hypoxic-ischemic encephalopathy, other encephalopathies, brain insult, intracranial hemorrhage, chromosomal disorders, congenital syndromes, inborn errors of metabolism, and neurometabolic diseases.  Peripheral disorders include abnormalities in the motor unit, specifically in the  anterior horn cell (ie spinal muscular atrophy),  peripheral nerve (ie, myasthenia)  neuromuscular junction (ie botulism)  muscle (ie, myopathy).  Both central and peripheral manifestations such as acid maltase deficiency (Pompe disease).
  9. 9. Differential Diagnosis of Floppy Infant Cerebral hypotonia  • Benign congenital hypotonia  • Chromosome disorders  • Prader-Willi syndrome  • Trisomy  • Chronic nonprogressive encephalopathy  • Cerebral malformation  • Perinatal distress  • Postnatal disorders  • Peroxisomal disorders  • Cerebrohepatorenal syndrome (Zellweger syndrome)  • Neonatal adrenoleukodystrophy  • Other genetic defects  • Familial dysautonomia  • Oculocerebrorenal syndrome (Lowe syndrome)  • Other metabolic defects  • Acid maltase deficiency (“Metabolic Myopathies”)  • Infantile GM gangliosidosis
  10. 10.  Anterior Horn Cell Disorders  ● Acute infantile spinal muscular atrophy  ● Traumatic myelopathy  ● Hypoxic-ischemic myelopathy  ● Neurogenic arthrogryposis  ● Infantile neuronal degeneration  Congenital Motor or Sensory Neuropathies  ● Hypomyelinating neuropathy  ● Congenital hypomyelinating neuropathy  ● Charcot-Marie-Tooth disease  ● Dejerine-Sottas disease  ● Hereditary sensory and autonomic neuropathy  Neuromuscular Junction Disorders  ● Transient acquired neonatal myasthenia  ● Congenital myasthenia  ● Magnesium toxicity  ● Aminoglycoside toxicity  ● Infantile botulism
  11. 11.  Congenital Myopathies  ● Nemaline myopathy  ● Central core disease  ● Myotubular myopathy  ● Congenital fiber type disproportion myopathy  ● Multicore myopathy  Muscular Dystrophies  ●  ● Congenital muscular dystrophy with merosin deficiency  ● Congenital muscular dystrophy without merosin deficiency  ● Congenital muscular dystrophy with brain malformations or intellectual disability  ● Walker-Warburg disease  ● Muscle-eye-brain disease  ● Fukuyama disease  ● Congenital muscular dystrophy with cerebellar atrophy/ hypoplasia  ● Congenital muscular dystrophy with occipital argyria  ● Early infantile facioscapulohumeral dystrophy  ● Congenital myotonic dystrophy
  12. 12.  Metabolic and Multisystem Diseases  ● Disorders of glycogen metabolism  ● Acid maltase deficiency  ● Severe neonatal phosphofructokinase deficiency  ● Severe neonatal phosphorylase deficiency  ● Debrancher deficiency  ● Primary carnitine deficiency  ● Peroxisomal disorders  ● Neonatal adrenoleukodystrophy  ● Cerebrohepatorenal syndrome (Zellweger)  ● Disorders of creatine metabolism  ● Mitochondrial myopathies  ● Cytochrome-c oxidase deficiency
  13. 13. classification ( based on anatomy )
  14. 14. Differentiating Central Versus Peripheral Causes Central  Hypotonia and do not track visually, fail to imitate facial gestures or appear lethargic  Dysmorphic  Motor delay +Social + cognitive delay  Hypotonia with normal strength  N to brisk DTR  h/s/o HIE or birth trauma  Seizure, abn eye movement, depressed level of consciousness  Predominant axial weakness  Fisting of hand  Persistent neonatal reflexes  brisk jaw jerk  crossed adductors / scissoring on ventral suspension  Infants who have experienced central injury usually develop increased tone and DTR but infants who have central developmental disorders do not Peripheral  Alert, respond well to surrounding & normal sleep wake cycle  Hypotonia + profound weakness & hyporeflexia DTR / areflexia  Motor delay  Normal social & cognitive  Family history of NMD or maternal myotonia  Reduced or absent antigravity movement with increased range of movement  Frogged leg posture  Fasciculations (SMA )  Muscle atrophy / pseudohypertrophy  Respiratory & feeding impairement
  15. 15. APPROACH  Name  Age of presentation :- SMA type 1- 0 to 6 mth SMA type 2 - 6 to 18 month SMA type 3 - after 18 month neonatal myasthenia soon after birth juvenile myasthenia - > 6 month  Term infant who born healthy but develops floppiness after 12 to 24 hours may have IEM
  16. 16. Chief complaints INFANT  floppy since birth  • Slips from hands  • Less movement of limbs  • Baby is alert but less motor activity.  • Delayed motor development  • Able to walk but with frequent falls  Difficult sucking, weak cry  Recurrent respiratory infection
  17. 17.  Sudden onset – IVH in preterm infants  Course – progressive ( SMA ) static fluctuating  Severity Apnea, aspiration ( gag reflex lost ) Respiratory difficulty ( inv of resp muscles ) h/o fatigue on continious sucking – myasthenia h/o constipation – botulinum  Distribution of weakness – Proximal ( unable to stand from sitting ) - myopathy Distal ( unable to hold things ) – neuropathy  Associate atrophy of muscle – myopathy, neuropathy  Muscle pain :- Myositis Metabolic cause
  18. 18.  Joint deformity –  Arthrogyropsis  zellwegar syndrome  chromosomal disorder  CMD  transitory neonatal myasthenia  Congenital dislocation of hip – frequent finding  CNS Cause – Seizure , abnormal movement Lack of response to visual, auditory stimuli MR , learning disability Poor state of alertness
  19. 19.  Antenatal history  h/o decreased fetal movements  Polyhydramnios  Drug exposure ( lithium, phenytoin, carbamzepine )  Breech delivery / prolonged labour  Post natal history  h/o birth asphyxia  Weak cry at birth  Resp distress with prolonged ventilatory support  Feeding difficulty  Convulsion  Neonatal hyperbillirubinemia  h/o honey consumption  h/o umbilical hernia, contractures , joint dislocation  Low Apgar scores may suggest floppiness from birth
  20. 20. Family History  History of consanginity – for inheritence  AD- myotonic dystrophic  AR – LGMD & metabolic myopathy  Maternal transmission – mitochondrial myopathy Family H/O wheelchair dependent, spinal / skeletal deformity, functional limitation, early death, cardiac disease
  21. 21. DEVELOPMENTAL HISTORY  Assesed in all four domains  Gross motor  Fine motor  Cognitive domain  Language domain Preserved cognition / language with Isolated motor delay – s/o NMD Cognitive delay / language/ speech delay with vision or hearing impairement with seizure – s/o CNS involvement
  22. 22. ANTHROPOMETRY  Obesity – Prader Willi syndrome  Microcephaly – cerebral palsy  Macrocephaly – myelomeningocele, congenital toxoplasma
  23. 23. Head TO Toe EXAMINATION  Assessment for dysmorphic features  Dysmorphic facies- Prader Willi syndrome  Doll like facies – Pompes disease  Downy facies – trisomy 21, Zelleweger syndrome  Anterior fontenalle - hypothyroidism  Eyes – cataract ( lowe syndrome )  Eye lid - drooping of lid ( myasthenia )  Tongue – fasciculation ( SMA )  large tongue – storage disorders ( acid maltase / pompes disease )  High arched Palate – Neuromuscular disorders  Neurocutaneous markers / facial dysmorphism – CNS involvement  Genitelia – hypogonadism ( prader willi syndrome ) undescended testis ( weakness of gubernaculum)  Limbs examination – contractures ( arthrogyropsis ).seen in both neurogenic and myopathic disorders.
  24. 24. TONE ASSESEMENT INSPECTION  Observe of posture of child in bed  Floppy child – frog like position ( hip abd, knee flex ) PALPATION Feel the muscle Normal muscle feels rubbery Hypotonic muscle feels soft and flabby
  25. 25.  Movement at joint  Freely moving joints suggest hypotonia  Examine all4 limbs, assymetry  Check trunk tone  RAG DOLL PHENOMENON  Shake limbs to & fro and observe movement of distal joint  Hypotonia – ease of movement at joint incresed  Distal limb have wooble around a joint like as ragged doll
  26. 26. Horizontal suspension an infant is suspended in the prone position with the examiner’s palm underneath the chest
  27. 27. vertical suspension  “slips through” at the shoulders when the examiner grasps him or her under the arms in an upright position
  28. 28. Head lag with Traction  Head lag or hyperextension is evident when the infant is pulled by the arms from a supine to sitting position
  29. 29. Amiel Tinson Angles
  30. 30. DTR  Central conditions :- DTR hyperactive clonus and primitive reflexes persist  Peripheral disorders DTRs are normal decreased or absent  Other pertinent findings  poor trunk extension  Astasias (inability to stand due to muscular incoordination) in supported standing  Decreased resistance to flexion and extension of the extremities.  Exaggerated hip abduction and exaggerated ankle dorsiflexion.  Abnormalities in stability and movement may manifest in an older infant as W-sitting a wide-based gait, genu recurvatum, and hyper pronation of the feet
  31. 31. ASSESEMENT OF WEAKNESS  Assessment for weakness includes evaluating for cry, suck, facial expressions, antigravity movements, resistance to strength testing, and respiratory effort.  1. cough test :- Ability to cough and clear airway secretions. Apply pressure to the trachea and wait for a single cough that clears secretions. If more than one cough is needed to clear secretions this is indicative of weakness.  2. Poor swallowing ability as indicated by drooling and oropharyngeal pooling of secretions.  3. Character of the cry — infants with consistent respiratory weakness have a weak cry  4. Paradoxical breathing pattern — intercostal muscles paralysed with intact diaphragm.  5. Frog-like posture and quality of spontaneous movements — poor spontaneous movements and the frog-like posture are characteristic of LMN conditions.  Infants who can generate a full motor response when aroused are more likely to be hypotonic than weak.
  32. 32. Spinal muscular atrophies  are a heterogeneous group of disorders, usually genetic in origin, characterized by the degeneration of anterior horn cells in the spinal cord and motor nuclei of the brainstem.  Presence of wasting, areflexia and fasciculation differentiates from primary muscle disease.  Diagnosis by (PCR RFLP )- exon 7 deletion  Muscle biopsy – group atrophy with small angulated fiber
  33. 33. Congenital Myasthenia syndromes PRESYNAPTIC ( 6 % ) SYNAPTIC (14 % ) POST SYNAPTIC ( 70 % ) Defect in ChAT -Floppy and weak -extraocular bulbar and respiratory muscle affected Episodic apnea is cardinal feature AR INHERITANCE AR INHERITANCE Primary AchR defeciency Slow channel/ fast channeL Group of disorders arise due to genetic mutation causing critical changes in presynaptic, synaptic or post synaptic proteins. These disorders are non immunologic so don’t respond with immune therapy as in MG
  34. 34. Transient neonatal myasthenic syndrome  is due to the passive placental transfer of antibodies against the acetylcholine receptor protein from the mother who has myasthenia to her unaffected fetus.  The severity of symptoms correlates with the newborn’s antibody concentration.  Ptosis, facial weakness, poor feeding, weak and respiratory insufficiency since birth.  Symptoms usually occur within hours of birth or up to 3 days later.  Although weakness initially worsens, dramatic resolution subsequently occurs.  The duration of symptoms averages 18 days and recovery is complete.  The transitory disorder is diagnosed by the presence of antibodies in the infant’s blood.
  35. 35. Congenital Myotonic dystrophy  Autosomal Dominant inheritance  caused by an unstable DNA trinucleotide repeat on chromosome 19 that can expand in successive generations.  Symptoms usually begin in young adult life and include weakness of the face and distal limb muscles, cataracts, multiple endocrinopathies, frontal baldness in males, and myotonia.  Congenital myotonic dystrophy (Steinert disease) can afflict infants born to affected mothers.  Polyhydramnios is common, labor is prolonged, and delivery usually requires mechanical assistance.   Severely affected infants have inadequate diaphragm and intercostal muscle function and require assisted mechanical ventilation.  Perinatal asphyxia can be a consequence of a prolonged and difficult delivery and resuscitation.  Facial paralysis, generalized muscular hypotonia, joint deformities, gastrointestinal dysfunction, and oral motor dysfunction can occur.  Affected infants have a characteristic facial appearance, with tenting of the upper lip, thin cheeks, and wasting of the temporalis muscles. They also tend to have dislocated hips, arthrogryposis, and club feet.  Limb weakness is proximal, tendon reflexes usually are absent and myotonia may not be elicited on electromyography (EMG).  The patients tend to have intellectual deficits.  Cardiomyopathy contributes to early death, and the long-term prognosis is poor.  Respiratory failure and an increased risk of aspiration also lead to early death.  If the infant survives the first 3 postnatal weeks, motor function may improve, although facial diplegia usually persists.
  36. 36. Severe weakness of face, jaw and elevated diaphragm with thin ribs on chest xray clues to diagnosis
  37. 37. - myotonia examined in mother during physical examination, myotonia may be demonstrated by asking the patient to make tight fists and then to quickly open the hands. - It may be induced by striking the thenar eminence with a rubber percussion hammer (percussion myotonia) and it may be detected by watching the involuntary drawing of the thumb across the palm. -Myotonia can also be demonstrated in the tongue by pressing the edge of a wooden tongue blade against its dorsal surface and by observing a deep furrow that disappears slowly.
  39. 39. Prader-Willi syndrome is characterized by hypotonia, hypogonadism, intellectual disability, short stature, and obesity.  Affected patients present at birth with profound hypotonia and feeding problems until 8 to 11 months of age, when they develop low-normal muscle tone and insatiable appetites.  Prominent physical features during childhood include a narrow bifrontal diameter, strabismus, almond-shaped eyes, enamel hypoplasia, and small hands and feet.  The genetic abnormality in 75% of patients is a deletion of the long arm of chromosome 15 at q11-q13.  Mostly the paternally derived chromosome has been deleted.
  40. 40. botulinum  Infantile botulism is an age-limited disorder in which C botulinum is ingested, colonizes the intestinal tract, and produces toxin in situ.  h/o ingestion of honey or corn syrup is present.  Historically, infants afflicted with botulism are between 2 and 26 weeks of age.  usually live in a dusty environment adjacent to construction or agricultural soil disruption, and become symptomatic between March and October.  A prodrome of constipation, lethargy, and poor feeding is followed in 4 to 5 days by progressive bulbar and skeletal muscle weakness and loss of DTRs.  Progressive muscle paralysis can lead to respiratory failure.  Symmetric bulbar nerve palsies manifested as ptosis, sluggish pupillary response to light, ophthalmoplegia, poor suck, difficulty swallowing, decreased gag reflex, and an expressionless face are primary features of infantile botulism.  Differential diagnosis includes sepsis, intoxication, dehydration, electrolyte imbalance, encephalitis, myasthenia gravis.  Spinal muscular atrophy type I and metabolic disorders can mimic infantile botulism. Patients who have spinal muscular atrophy type I generally have a longer history of generalized weakness, do not typically have ophthalmoplegia and have normal anal sphincter tone.  Treatment for infantile botulism should be instituted promptly with intravenous human botulism immune globulin, which neutralizes all circulating botulinum toxin, and supportive therapy for airway maintenance, ventilation, and nutrition.  Infantile botulism usually is a self-limited disease lasting 2 to 6 weeks, and recovery recovery generally is complete,although relapse can occur in up to 5% of infants.
  41. 41. benign congenital hypotonia  The most common clinical condition, although a diagnosis of exclusion.  presents with delays in achieving developmental milestones.  Benign congenital hypotonia improves with the maturity of the central nervous system.  Characteristics include generalized symmetric flaccidity of muscles and hypermobile joints.  Because this is a diagnosis of exclusion, the history does not suggest any neurologic or metabolic disorders.  Muscle stretch reflexes are normal or only slightly exaggerated and routine laboratory test results are within normal limits.  Patients must be counseled about the possibility of joint dislocations in the future.  An increased incidence of intellectual disability, learning disability, or other sequelae of cerebral abnormality often is evident later in life despite the recovery of normal muscle tone.  A high familial incidence also is reported.
  42. 42. Lab Evaluation Rule out sepsis Full blood count , C reactive protein, Erythrocyte sedimentation rate, Blood culture, Urine culture Cerebrospinal fluid culture and analysis  Serum electrolytes, calcium, magnesium  Serum glucose  Liver functions / Ammonia  Thyroid function test  TORCH titre & urine C/S for CMV(organomegaly & brain calcification)  Blood Gases  If acidosis is present, plasma amino acids and urine organic acids (aminoacidopathies and organic acidemias)  serum lactate (disorders of carbohydrate metabolism, mitochondrial disease)  Pyruvate & ammonia (urea cycle defects)  Acyl carnitine profile (organic acidemia, fatty acid oxidation disorder )
  43. 43. If central hypotonia is suspected  MRI brain/CT brain :- structural malformations, neuronal migrational defects Abnormal signals in the basal ganglia (mitochondrial abnormalities) Brain stem defects (Joubert syndrome) Deep white matter changes can be seen in Lowe syndrome Abnormalities in the corpus callosum may occur in Smith-Lemli-Opitz synd  Karyotyping  Molecular genetics  Very long chain fatty acids (VLCFA) – peroxisomal disorders  Serum/Urine amino acids  Urine organic acids  Blood/CSF lactate  Carnitine/acylcarnitine levels  Serum Ammonia
  44. 44. If peripheral hypotonia is suspected Creatine kinase level :- elvated in MD not in SMA  Electromyography (EMG)/Nerve conduction studies (NCS) – may be delayd till 6 months b’se neonatal results are difficult to interpret  Muscle biopsy – to diff b/w myopathy from muscle dystrophy, myopathy from neuropathy  Molecular genetics – CTG repeats, SMN deletion  Toxin assay i.e. Botulism  Auto antibody level  Specific DNA testing for myoyonic dystrophy & SMA (SMN gene )
  45. 45. Treatment  Treatment of the infant who has hypotonia must be tailored to the specific responsible condition.  In general therapy is supportive.  Rehabilitation with the aid of physical and occupational therapists.  Nutrition is of primary importance to maintain ideal body weight for the age and sex which is often achieved through the nasogastric route or percutaneous gastrostomy.  maximize muscle function and minimize secondary crippling anatomic deformities.  Regular orthopaedic review for scoliosis and hip subluxation / dislocation is an important aspect of management.  Vigorous therapy for respiratory tract infections and annual flu vaccinations are advised in affected patients.  In certain conditions (muscular dystrophies, central core disease) anaesthetic complications such as malignant hyperthermia and difficulty in reversing muscle paralysis may be an issue hence if these patients are undergoing anaesthesia, it is imperative that the anaesthetist is informed in advance.  Genetic counselling is an important adjunct for the family.  Once a definitive diagnosis is available discussing among professionals is of paramount importance and discussing with parents and family members about the disease and prognosis is an  important step.  Weaning off the ventilator may be an issue as there may be social and ethical considerations involved.  Counselling on family planning and future pregnancies with appropriate genetic diagnosis would be helpful.
  46. 46. SUMMARIZE
  47. 47. Clinical feature of floopy infant Frog like posture Abducted leg at hip, flexed at knee Pull to sit Excessive head lag and rounded back Vertical suspension Slipping through hand Ventral suspension Ragged doll like Drooling of secretions Poor swallowing ability Weak cry Respiratory weakness Paradoxical breathing Intercostal muscle paralysis with intact diaphragm Plagiocephaly, arthrogyropsis Seizure, apnea, feeding problem, abnormal posturing Decreased fetal movement f/s/o severe CNS abnormality
  48. 48. CLINICAL CLUES AND INVESTIGATIONS CONDITION CLINICAL CLUES INVESTIGATION Spinal cord transection Syringomyelia Spinal dysraphism Hemangioma or tuft of hair in midline Scoliosis Bowel / bladder dysfunctn Mixed DTR (- )abdominal / anal reflex MRI spinal cord Spinal Muscular Atrophy Tongue atrophy / fasciculations Severe proximal muscle weakness Absent DTR Preserved social interaction - EMG/ NCV – anterior horn cell involvement - PCR – deletion of SMN gene Perpipheral neuropathy Distal weakness Absent DTR Pes cavus - NCV study - nerve biopsy - DNA testing for specific demyelination disorder
  49. 49. CONDITION CLINICAL CLUES INVESTIGATION Myasthhenia gravis - Bulbar / oculomotor muscle involvement - True cong myasthenia is rare - Exclude transient neonatal from maternal history - Single fiber EMG - Serum antibodies to acetylcholine receptors -Response to acetylcholinesterase -inhibitors - Electrodiagnostic studies Infantile botulism Acute onset descending weakness Cranial neuropathies Ptosis Dysphagia Constipation - Isolation of organism from stool culture - Toxin in stool
  50. 50. CONDITION CLINICAL CLUES INVESTIGATION Cong myotonic dystrophy - Polyhydramnios - Decresed fetal movement - Inverted v apperance of mouth - Mother can have myotonia - Premature cataract surgery in mother - Slender stature Molecular DNA test ( CTG repest ) EMG in mother Cong muscular dystrophy ( merasinopathy / Fukuyama MD ) - Hypotonia, weakness, contracture - Associated brain / eye problem - Brain MRI - str / white matter abn - Raised CK - Muscle biopsy – merosin stain
  51. 51. CONDITION CLINICAL CLUES INVESTIGATIONS Cong structural myopathy Hypotonia with feeding problem at birth Non progressive weakness Central core – ass with malignant hyperthermia Myotubular myopathy – ptosis with extraocular palsies Nemaline myopathy – ass with feeding problem - Muscle biopsy for definitive diagnosis - ECG - Genetic mutation study Pompes disease Cardiomegaly Cardiac failue Enalrged tongue - Blood smear – vacuolated lymphocyte -Urine oligosacharides -ECG & ECHO changes - Acid maltase assay in cultured fibroblast
  52. 52. Sepsis Thyroid test ABG
  53. 53. TAKE HOME MESSAGE  Hypotonia is characterized by reduced resistance to passive range of motion in joints versus weakness which is a reduction in the maximum muscle power . (Dubowitz, 1985; Crawford,1992; Martin, 2005)  Central hypotonia accounts for 60% to 80% of cases of hypotonia whereas peripheral hypotonia is the cause in about 5% to 20% of cases.  Disorders causing central hypotonia often are associated with a depressed level of consciousness, predominantly axial weakness, normal strength accompanying the hypotonia, and hyperactive or normal reflexes. (Martin, 2005;Igarashi, 2004; Richer, 2001; Miller, 1992; Crawford, 1992; Bergen, 1985; Dubowitz, 1985)  50% of patients who have hypotonia are diagnosed by history and physical examination alone (Paro-Panjan, 2004)  An appropriate medical and genetic evaluation of hypotonia in infants includes a karyotype, DNA-based diagnostic tests, and cranial imaging. (Battaglia, 2008; Laugel, 2008; Birdi, 2005; Paro-Panjan, 2004; Prasad, 2003; Richer, 2001;)  Infant botulism should be suspected in an acute or subacute presentation of hypotonia in an infant younger than 6 months of age who has signs and symptoms such as constipation, listlessness, poor feeding, weak cry and a decreased gag reflex. (Francisco, 2007; Muensterer, 2000)