NEURO Flashcards
Nervous System Development
Environmental influences: nutrition, hormones, O2 levels, maternal life-style, state of health
Neural tube: neural plate, groove, folds tube
Embryonic development of CNS: disruption in any stage causes disorders
5 important components of neurodevelopmental hx
health history
behaviorial assessment
psychosocial assessment
school performance
developmental history
Types of neuro exams
Neurological eval
Neuropsychological eval = looks at your brain and nervous system affect the way you think and behave
Neurodevelopment evaluation – takes into account developmental levels
Localization of the Problem and History
- If there is a problem with thinking or remembering, the problem may be localized in the hemispheres
- If there is a problem with coordination the cerebellum may be where the problem is
Problem with arms/legs with bladder control or bowel control the problem is…
spinal cord
speech problem
left hemisphere
The more problems that the child presents with that do not localize to one area, the more likely the problem involves
Psychosocial realms
Mechanism of injury
Episodic history
Key to developing an action plan for an acute head injury or acute neurological event
Get as much information as possible from people on the scene of an actual event
Overall inspection of the body
Look for… (5)
Neurocutaneous lesions
Muscle atrophy
Weakness in gait
Abnormal positioning
An infant who should not have handedness with marked favoring to one side
Ask about birthmarks
Skin = dermatologic clue to underlying diseases
Ash leaf spot
white mark on skin
cafe au lait
brown skin macule
Flammeus nevus
Flat red capillary skin stains
Large calf muscles (in comparison to thighs) may indicate
Muscular dystrophy especially if child has pelvic girdle weakness
Increase in lumbar curve…
Lumbar lordosis
Marie Charcot Tooth Syndrome
- Look for thin, stork like legs
- Neuropathy will be present with distal weakness therefore wasting, stork like legs is a sign of peroneal nerve disease
- Cuts that do not hurt
- High arched, toe nail fungus, decreased reflexes
Myopathies present with
central weakness
Neuropathy present with
distal weakness
Overall inspection
Watch for… (3)
Tremors of the hands when moving or tremors of the tongue when not crying
Hypermobility – can be confused with hypotonia (low muscle tone)
Look for asymmetry of the foot – DIASTEMATOMYELIA
What is Diastematomyelia
Spinal cord malfunction
Type of spinal dysraphism
Longitudinal split in the spinal cord
Diastematomyelia Epidemiology
Split cord malformations are a congenital abnormality and account for ~5% of all congenital spinal defects
Diastematomyelia
Clinical Presentation
May be minimally affected or entirely asymptomatic
Presenting symptoms include: leg weakness, low back pain, scoliosis, incontinence
Nevus flammeus along spinal cord – abnormality of gluteal fold
Watch Patient Gait
Thumb facing, looks normal, arm swing
Thumbs should face forward
General Cerebral Function (6)
- age adjusted and developmentally adjusted
- Child developmental level in terms of school performance
- The examiner must keep the child’s interest to gain full cooperation
- Interesting materials
- Do one thing at a time
- Environment facilitates testing and is not distracting
- Use stickers as reinforcement
- Positive reinforcement
JOMAC
Judgement, problem solving
Orientation to time and space
Memory
Affective disturbances
Calculation disturbances
Preschool Child (what they know)
- Does he recognize common objects – sesame street characters
- Know names of family members
- Know where you buy food
- Name one thing that you keep in the refrig
- Knows if he has a pet and name
- Count 3 objects
- Note behavioral characteristics
- Draw picture of himself
- Child can give 3 wishes
Cerebral Function – Affective
- Hyperactivity
- Decreased attention span
- Distractibility
- Disinhibition
- Emotional liability
- Impulsivity
- Hypoactivity
- Lack of spontaneity
- Low frustration level
- Low self-esteem
2 years (13)
- Gains 5-6 lbs and 5 inches HC 2cm
- Kicks ball forward
- Removes article of clothing (not hat)
- Combines two words
- mild lordosis with protuberant abdomen
- 8 more teeth to total 14-16
- Tower of 7 cubes
- Imitate circular strokes
- May draw a horizontal line
- Empties trash can and drawers
- Parallel play
- Speech should be understood
- Rotary chewing refined
3-5 years – preschool
POUNDS, INCHES
Initiative vs. Guilt
Gain 4-5 lbs and 2.5-3.5 inches
3 years (15)
- Throws ball overhand
- Names 4 animal pictures
- Pedals tricycle
- Puts on an article of clothing
- Names one animal picture
- Jumps up and down
- Draws a person upon request with sticks
- State age, sex
- Involve other in play
- Can count fingers
- Hand muscle developed
- Wants to do things by themselves
- Learning to shre
- Likes to help
- Brushes teeth
4 years (9)
- Lordosis and round abdomen starts to disappear
- Plays games with other children
- Says what to do when tired, cold, hungry
- Says first and last name when asked
- Copies circle
- Balances on each foot for 2 seconds
- Can copy a + with demonstration
- Finger muscles for tasks
- Balance on 1 foot for 5 seconds
5 year old (5)
- Dresses without supervision
- Copies a cross
- Draws a person
- Puts object on, under, in front of and behind when asked
- Hops on one foot 2 or more times
6-12 years
Industry vs. Inferiority
- Mastering skills that will be needed later as an adult
- Winning approval from other adults, peers
- Building self-esteem, positive self concept
- Taking place in a peer group
- Adopting moral standards
1st Grade
- Print 1st and last name
- Write #’s 1-10
- Draws a person with 6 parts
- Copies a square
- Heel to toe walk
- Knows the letters of the alphabet
- Walk on alternate heels
- Play sports
- Friends
- Peers
CN1 - Olfactory Nerve
– important to test for smell after a direct blow to the forehead above the nasal bridge which might involve a fracture of the cribriform plate
– Not done often
– Do not use 1-XII intact unless you test everything
CN 2 - Optic
- Test for vision
- Vision test after a head trauma. Note and refer if acuity now falls in the abnormal range
- Note shape of pupil
- Penny test:
- Follow it with their eyes.
- After this, use the cold coin to test for sensation of cold.
CN 2 - Optic
tests
- Examine the Optic Fundi
- Test Visual Acuity
- Test Pupillary Reactions to Light
- Dim the room lights as necessary.
- Ask the patient to look into the distance.
- Shine a bright light obliquely into each pupil in turn.
- Look for both the direct (same eye) and consensual (other eye) reactions.
- Record pupil size in mm and any asymmetry or irregularity.
- If abnormal, proceed with the test for accommodation.
- Test Pupillary Reactions to Accommodation
- Hold your finger about 10cm from the patient’s nose.
- Ask them to alternate looking into the distance and at your finger.
- Observe the pupillary response ineach eye.
Horner’s Syndrome
- Decreased sweating on the affected side of the face
- Ptosis
- Sinking of the eyeball into the face
- Constricted pupil
CN 3, 4, 6
Oculomotor, trochler, abducens
- Inspect eyelids for drooping
- Inspect pupils size for equality and reaction to light and accommodation
- Test eye movements in the 6 fields of cardinal gaze.
- Inspect pupils size for equality and reaction to light and accommodation
- Test eye movements in the 6 fields of cardinal gaze.
Abducens
- Dysfunction of the sixth cranial (abducens) nerve can result from lesions occurring anywhere along its course between the sixth nerve nucleus in the dorsal pons and the lateral rectus muscle within the orbit.
- The sixth nerve has the longest subarachnoid course of all cranial nerves and innervates the ipsilateral lateral rectus (LR) which abducts the eye
Increased ICP
Abducens
- Can result in downward displacement of the brainstem, causing stretching of the sixth cranial nerves which are tethered in Dorello’s canal.
- Can occur secondary to a variety of different causes
– Shunt failure
– Pseudotumor cerebri
– Posterior fossa tumors
– Neurosurgical trauma
– Venous sinus thrombosis – Meningitis
– Lyme disease.
Mimics of 6th Nerve Palsy
Thyroid eye diseases
Myasthenia gravis
Duane’s syndrome
Spasm of the near reflex
Delayed break in fusion
Old blowout fracture of the orbit
Papilledema
Optic nerve with mild swelling
Grade I papilledema
Pathologic C shaped halo of edema surrounding the optic disk
Grade II papilledema
The halo of edema now surrounds the optic disk
Grade IV papilledema
With more severe swelling in addition to a circumferential halo, the edema covers major blood vessels as they leave the optic disk (grade III) and vessels on the disk (grade IV)
The subretinal hemorrhage is present at 7 o clock
Nystagmus
Vertical, horizontal, medication
note direction, speed
- Horizontal nystagmus may be seen with labyrinthine, cerebellar, or brainstem pathology.
- Vertical nystagmus may be seen with cerebellar or brainstem pathology.
- Medication toxicity may cause both horizontal and vertical nystagmus
Abnormal pupils
Small, pinpoint, fixed, dilated, unequal
CN 3
Paralysis
Horizontal Nystagmus
Labyrinthine
Cerebellar
Brainstem pathology
Vertical nystagmus
Cellebellar or brainstem pathology
Medication toxicity
May cause both horizontal and vertical nystagmus
CN 5 or Trigeminal
- Inspect face for muscle atrophy and tremors
- Palpate the jaw muscles as child makes a “monster face” clenching their jaws together. show upper and lower teeth
- Test for touch and temperature sentation on either side of the face
- Corneal reflex is deferred
CN7 - Facial Nerve
While the child is doing the monster clenched teeth face for the trigeminal nerve, look for facial symmetry
When the monster face is over do a happy face
Smile and frown
Close eyes tight
Puff cheeks
CN 7-facial nerve
Central
Patient can elevate both eyebrows
Close both eyes
Loss of nasolabial folds
CN 7 - facial
Peripheral
Unable to elevate eyebrow on right
Right eye does not close and eyeball turns UP (Bell’s phenomenon)
CN 8 - Acoustic
- In the younger child, use of a tuning fork to determine which ear the sound is louder on can be very difficult
- Screen for hearing from 500-6000 or 8000 decibels to screen for higher frequency hearing loss that is found with mild sensorineural damage
- Equilibrium is also determine by the 8th CN
- Use of audioscope or audiometer for a routine hearing screen can test the 8th CN
Weber Test
- Placing a vibrating tuning fork on the middle of the forehead
- Does patient hear it equally or feels or hears it best on one side or the other
- Normal - same on both sides.
- Unilateral neurosensory hearing loss - best in
- the normal ear
- Patient with unilateral conductive hearing loss - best in the abnormal ear.
Rinne Test
- Comparing bone condution
- Placing the tuning fork on the mastoic process behind the ear
- Air conduction
- Assessed by holding the tuning for in air near the front of the ear
- AC is GREATER than BC
Hearing Screening
CONDUCIVE hearing loss
Eustachian tube dysfunction
Ear fluid
Hole in eardrum
Fixed middle ear bone
Sensorineural hearing loss (4)
Noise induced hearing loss
Presbycusis
Meniere’s disease
Tumors of the auditory nerve
CN 9
Glossopharyngeal
Test ability to swallow
Gag reflex is also part of the 9th CN but is not routinely done in school setting
Test for sweet/sour taste
CN 10 - VAGUS
- Listen to vocal quality
- Look for rise of soft palate as child says ah ah.
- Swallowing difficulties?
- Another way of getting the child to open his mouth is to have him say ha ha. Ha ha is funny and allows the child to be in control.
- Watch the child swallow without giving fluid if head injured.
CN 11 - Spinal Accessory
- Head rotation against resistance to test the strength of the sternocleidomastoid
- Upward shoulder movement that is stronger than examiners downward pressure tests the trapezius muscle strength.
CN 12 - hypoglossal
- Inspect tongue in the mouth. Look at symmetry, tremors, and atrophy
- Pressure the tongue against cheek and check for strength.
- Quality of lingual sounds like l, t, d, and n
- With a unilateral lesion, the protruded tongue deviates toward the affected weaker side
Reflex Pearls
- Patient must be relaxed and positioned properly
- Response depends on force of your stimulus
- Use no more force than you need to provoke a definite response
- Reflexes can be reinforced by having the patient perform isometric contraction of other muscles (clenched teeth)
- Must evaluate for equality
- Must make sure there is no spread if they are brisk
- Distraction
Tendon reflex grading scale
0 – absent
1 – hypoactive
2 – normal
3 – hyperactive without clonus
4 – hyperactive with clonus
BICEPS C5,6
- The patient’s arm should be partially flexed at the elbow with the palm down.
- Place your thumb or finger firmly on the biceps tendon.
- Strike your finger with the reflex hammer.
- You should feel the response even if you can’t see it.
Triceps C6,7
- Support the upper arm and let the patient’s forearm hang free.
- Strike the triceps tendon above the elbow with the broad side of the hammer.
- If the patient is sitting or lying down, flex the patient’s arm at the elbow and hold it close to the chest.
Clonus
- If the reflexes seem hyperactive, test for ankle clonus: ++
- Support the knee in a partly flexed position.
- With the patient relaxed, quickly dorsiflex the foot.
- Observe for rhythmic oscillations
Brachioradialis C5-C6
- Have the patient rest the forearm on the abdomen or lap
- Strike radius about 1-2 inches above the wrist
- Watch for flexion and supination of the forearm
Abdominal (T8, T9, T10, T11, T12)
- Use a blunt object such as a key or tongue blade.
- Stroke the abdomen lightly on each side in an inward and downward direction above (T8, T9, T10) and below the umbilicus (T10, T11, T12).
- Note the contraction of the abdominal muscles and deviation of the umbilicus towards the stimulus.
Knee (L2, L3, L4)
- Have the patient sit or lie down with the knee flexed.
- Strike the patellar tendon just below the patella.
- Note contraction of the quadraceps and extension of the knee.
Ankle
S1, S2
Dorsiflex the foot at the ankle
Strike the achilles tendon
Watch and feel for planter flexion at the ankle
Babinski
Should be upward until child walks
Once child walks then downward
Chaddock
Stroke with a blunt point around the side of the foot, from external malleolus to the small toe
In a positive test, there is dorsiflexion of the great toe
Oppenheimer
Firmly press down on the shin and run the thumb and knuckles along the anterior medial tibia toward the foot
In a positive test, there is a dorsiflexion of the great toe
Snouting Reflex
wrinkling of nose like giving a kiss
9 months
- Roll to both sides
- Sit well without support
- Demonstrate motor symmetry without established handedness
- Should be grasping and transferring objects hand to hand
18 month visit
- Sit, stand, and walk independently
- Grasp and manipulate small objects.
- Mild motor delays undetected at the 9-month screening visit may be apparent at 18 months.
30 month visit
- Most motor delays will have already been identified during previous visits.
- Subtle gross motor, fine motor, speech, and oral motor impairments may emerge at this visit.
- Progressive neuromuscular disorders may begin to emerge at this time and manifest as a loss of previously attained gross or fine motor skills.
48 month visit
- Early elementary school skills, with emerging fine motor, handwriting, gross motor, communication, and feeding abilities that promote participation with peers in group activities.
- Concerns about motor development is concerning.
- Loss of skills - progressive disorder.
High Normal or Low tone
Measure CK and TSH
Key elements of motor history
- Delayed acquisition of skill- Is parent concerned
- Involuntary movements or coordination impairments
- Is there anything your child is doing that concerns you?
- Regression of skill
- Is there anything your child used to be able to do that he or she can no longer do?
- Strength, coordination, and endurance issues
• Is there anything other children your child’s age can do that are difficult for your child?
Neuromuscular exam in the infant
- Postural tone is assessed by ventral suspension in the younger infant
- Postural tone is assessed by truncal positioning when sitting and standing in the older infant.
- Extremity tone can be monitored during maturation by documenting the scarf sign in infants and popliteal angles after the first year
- Persistence of primitive reflexes and asymmetry or absence ofprotective reflexes suggest neuromotor dysfunction.
- Unsteady gait or tremor can be a sign of muscle weakness.
- Diminution or absence of deep tendon reflexes can occur with lower motor neuron disorders, whereas increased reflexes
- Abnormal plantar reflex can be signs of upper motor neuron dysfunction.
- Neuromotor dysfunction can be accompanied by sensory deficits and should be assessed by testing touch and pain
Scarf sign tone assessment of shoulder girdle
With child supine or sitting (if able) pull arm across to the opposite shoulder until resistance occurs.
Note elbow position in relation to the bilateral midclavicular line and midline of the chest
Popliteal angle for hamstring tone assessment
With child supine, flex the hip to 90 degrees, with child’s torso supine on the table. Slowly extend leg at knee until resistance occurs.
Note the angle between the lower leg and vertical
Observe for Strength (5)
- Observe symmetry while tripod sitting with symmetrical posture
- Observe walking and then running, climbing, hopping, and skipping in the older child
- Use of a Gower maneuver, characterized by an ambulatory child’s inability to rise from the floor without pulling or pushing up with his arms.
- Muscle bulk and texture, joint flexibility, and presence or absence of atrophy should be observed.
- Quality and intensity of grasp is most easily assessed by observation during play.
PA Caveats
- Must divide into fine motor skills and gross motor skills
- Watching a child walk is important
- Children cannot tandem walk forward until age 4 at the earliest but as late as age 6 is acceptable
- Ask about milestones prior to coming into ed.
- Ask about school-regular versus special education
Motor function (7)
Body posture
Gait
Balance
Coordination – tap foot on floor; alternating finger with thumb rapidly
Gower’s sign
Tremors: resting, postural, intention
Gait abnormalities
Grading Motor Strength
0/5 = no muscle movement
1/5 = visible muscle movement, but no movement at the joint
2/5 = movement at the joint, but not against gravity
3/5 = movement against gravity, but not against added resistance
4/5 = movement against resistance, but less than normal
5/5 = normal strength
Myotonic vs. Neuropathy
Spinal muscular atrophy, muscular dystrophy, myotonic dystrophy = MYOTONIC
Marie charcot tooth disase = neuropathy
Duchenne Muscular Dystrophy
Boys
Difficulty climbing stairs
Running
Jumping from standing position
Frequent falls
DMD – slow motor milestones
18 months - walking
age 2-3 years = somewhat clumsy
3-5 years = difficulty keeping up with peers
DMD
Clinical Manifestations
Weakness
Consistent in pattern
Proximal muscles weaken before distal
Legs weaken before arms
Extensors weaken before flexors
Duchenne’s muscular dystrophy
Progression
Toe walking
Calf pseudohypertrophy (calf is as large as thigh)
Positive Gower’s maneuver
Lumbar Lordosis
Multifocal Contractures
Trendelenberg gait
Fatigue
Pronator Drift
- Ask the patient to stand for 20-30 seconds with both arms straight forward, palms up, and eyes closed.
- Instruct the patient to keep the arms still while you tap them briskly downward.
- The patient will not be able to maintain extension and supination (and “drift into pronation) with upper motor neuron disease.
Sensory
Pain
Light touch
Vibration
Proprioceptive and Cerebellar Function
Look at block stacking for intentional tremor
Look at tandem gait
Balance
Gait - wide based and ataxic
Coordination and gait
Rapid alternating movements
Point to point movements
Romberg
Gait
Rapid Alternating Movements
- Ask the patient to strike one hand on the thigh, raise the hand, turn it over, and then strike it back down as fast as possible.
- Ask the patient to tap the distal thumb with the tip of the index finger as fast as possible.
- Ask the patient to tap your hand with the ball of each foot as fast as possible.
Point to Point Movements
- Ask the patient to touch your index finger and their nose alternately several times. Move your finger about as the patient performs this task.
- Hold your finger still so that the patient can touch it with one arm and finger outstretched. Ask the patient to move their arm and return to your finger with their eyes closed.
- Ask the patient to place one heel on the opposite knee and run it down the shin to the big toe. Repeat with the patient’s eyes closed.
Two point discrimination
- Use in situations where more quantitative data are needed, such as following the progression of a cortical lesion. ++
- Use an opened paper clip to touch the patient’s finger pads in two places simultaneously.
- Alternate irregularly with one point touch.
- Ask the patient to identify “one” or “two.”
- Find the minimal distance at which the patient can discriminate.
Discrimination
Graphesthesia
With the blunt end of a pen or pencil, draw a large number in the patient’s palm.
Ask the patient to identify the number.
Discrimination
Stereognosis
- Use as an alternative to graphesthesia. ++
- Place a familiar object in the patient’s hand (coin, paper clip, pencil, etc.).
- Ask the patient to tell you what it is.
Neurodevelopmental Markers
Left to right confusion
Hand preference
Dystonic posturing
Proximal inhibition
Left-Right confusion
Most children can identify left and right by age 8.
Have the child touch his/her left ear with his right hand. Also ask the child to point to the examiners right hand with his/her left hand.
Hand Preference
- Hand preference is generally established by age 3. Left hand preference, or mixed hand preference are neurodevelopmental markers.
- Screen for hand preference by asking the child to demonstrate how s/he holds a pencil, throws a ball, and hammers in a nail.
Dystonic Posturing
Dystonic posturing is stiffening of the extremities during a stressed gait or ehythmic movements
The child hops in place or heel toe walk
Penny on the nose – hand goes up on weak side
Proximal Inhibition
The inability to inhibit proximal musculature while using distal muscles is a neurologic marker.
• Screen for proximal inhibition by having the child rapidly alternate opening and closing of fists with arms extended, or by rapidly rotating the wrist while holding the arm up and hand above the head.
Quick Neuro Check
- Level of Consciousness
- Motor function
- Pupillary response
- Vital signs
- Signs of increased intracranial pressure
- Glasgow coma scale
- Best eye opening response (1-4)
- Best motor response (1-6)
- Best verbal response (1-5)
Neurophychological Eval
Used for learning disabilities
Parents observations
Formal observation: watching the child copy designs, pronounce words, or figure out an arithmetic problem is also part of the assessment
Head Trauma
Simple - linear
SKULL FRACTURE = Depressed***
Hematoma at site
Piece of bone depressed into brain
Skull fracture
Compound
Laceration and depressed skull fracture
Dura usually pierced
Skull fragment may be displaced into the brain tissue
Skull fracture
Basilar
Break in the posteroinferior portion of the skull occurs
Produces dural tears that result in leakage of cerebrospinal fluid
Meningitis
Epidural Hematoma
- Blood is between the dural surface and the skull and is usually the result of a tearing of the meningeal artery.
- more common in older children than in toddlers and infants, because before age two, the middle meningeal artery is not yet embedded in the bony surface of the skull.
• May not have loss of consciousness.
Epidural Hematoma
Signs and Symptoms
Headache
Decreased LOC
Fever
Dilation of the pupil on the affected side of the brain
Early signs of basilar fracture
- Blood behind the tympanic membrane
- Nerve palsies (paralysis)
- Deafness, or ringing in the ears
- Dizziness; nausea; and vomiting.
- Delayed signs and symptoms
- Battle’s Sign
- Bruising over the temporal area
- Raccoon sign
- Bruising around the eyes
Meningitis
Incidence and Causes
4000-10000 cases per year
- Causes
- The childs age is the predominant determinants of the common bacteria causes
- Neonate
- Infant
- Child
- Streptococcus pneumoniae or pneumococcus
- Neisseria meningitidis or meningococcus
- The childs age is the predominant determinants of the common bacteria causes
History of Meningitis
- Progression of illness
- Exposure
- History of otitis media
- Underlying health problems – immunodeficiency
- Seizure
- FOCAL - more common as initial presentation
- GENERALIZED – febrile seizures
Presentation of meningitis
Newborn
- Fever
- Nonspecific symptoms (eg, poor feeding, vomiting, diarrhea, rash)
- Bulging fontanel
- Irritable, restless, or lethargic.
Presentation of Meningitis
Older Children
- Sudden fever
- Headache,
- Nausea, vomiting,
- Confusion, stiff neck, photophobia
Meningitis can cause seizures and decreased level of awareness
Meningeal sign
Brudzinski Sign
- Flexion of neck causes flexion of hips and knees
- Test for nuchal rigidity with head off table in your hands.
- Gently flex the head at the neck until the chin touches the chest
- Positive
- When both the knees and hips are flexed in response to passive flexion of the neck towards the chest.
- Reflex is due to exudate around the roots in the lumbar region
Meningeal signs
Kernig
Associated with meningeal irritation and hamstring spasm
Flex hip and knee, then straighten knee
Excessive pain and resistance bilaterlly suggest meningeal irritation
Patients with VP shunt = different presentation
Low grade ventriculitis
Headache
Nausea
Minimal fever
Malaise
Viral Meningitis
PA
Loss toxic and acute in presentation
More common in the summer – enteroviruses
Duchenne muscular dystrophy (DMD)
Clinical presentation, 10 years
- Life limiting
- Muscle wasting condition characterized by progressive muscle weakness and wasting
- Due to absence of the protein dystrophin in the muscles.
- Clinical presentation
- Delayed or disordered motor or speech development and muscle weakness.
• Over the last 10 years, improved standards of care have significantly increased the life expectancy in DMD.
DMD
Incidence and Prevalence
- DMD is the most common muscular dystrophy in children and affects approximately one in every 4000 male newborns
- No predilection for race or ethnic group
- 1 in 3500 live male births
- Estimated 8000 males in US with DMD
- If mother is a carrier
- 50% chance of affected male child & 50% chance of carrier female child
- “Carrier Female”
- ~8% of female carriers manifest mild proximal muscle weakness
- 10% develop cardiac failure – Cognitive effects
S & S of DMD
- Abnormal muscle function
- Delayed walking
- Falls
- Difficulty running and climbing stairs
- Calf pseudohypertrophy
- Progressive proximal musculature weakness
- Waddling gait 2 degree girdle muscle weakness
- Gower’s sign
- Increase in serum CK and transaminases (aspartate aminotransferase and alanine aminotransferase)
- Delayed in attainment of developmental milestones
DMD dx late
Negatively affects access to genetic counseling, standards of care and potentially recruitment into clinical trials
