1. Spinal Cord Dysfunction
Neurology Rotation Lecture Series
Last Updated by Lindsay Pagano
Summer 2013

2. Case Presentation
The ED consults you on a 15 year old female with LE numbness and weakness.
Previously healthy
Symptoms began 4 days go with back pain
Subsequent development of numbness and weakness of both legs
Has lost control of urination and defecation
General exam: + for palpable suprapubic mass
Neuro Exam: normal except for
LE 0/5 throughout and symmetrically with hypotonia
Below the umbilicus, there is complete loss of light touch, temperature and pinprick
BLE with impaired vibration sense
Poor rectal tone
DTRs absent in BLE, toes mute
Differential?

3. Composition of the Spinal Cord

4. Localizing Spinal Cord Lesions
Upper Motor Neuron
Lower Motor Neuron
aka supranuclear, neuron is in CNS
weakness
spastic, increased tone
increased DTRs (muscle spindle threshold decreased)
clonus: contraction of one group mm  initiate monotactic reflexes in their antagonists
some atrophy- disuse
toes up
no fasciculations
aka infranuclear, nuclear; CNS neuron or PNS fibers
WEAKNESS
flaccid, decreased tone
decreased DTRs (efferent limb interrupted)
no clonus
ATROPHY
toes down
fasciculations present (exotoxicity)

5. Localizing the Lesion, continued
History
Onset of symptoms
Incontinence
Sexual dysfunction (depending on age)
Exam
Motor
tone
strength
Reflexes
DTRs
clonus
Sensory
pain and temperature
vibration, joint position sense
sensory level on the trunk
further dermatomes on the extremities

6. Spinal Cord Lesions Acutely: Spinal Shock
Initial injury with flaccid paralysis and mute reflexes, including plantar
Gradual recovery and development of UMN, LMN signs
Upgoing toes first to develop
Transverse myelitis: relate to level of lesion; gradual onset; MRI with contrast
MS: related to level of lesion; gradual onset; MRI with contrast
Mass: eg tumor, abscess: related to level of lesion; gradual onset; MRI with contrast
Stroke: typically anterior cord; MRI with diffusion and ADC map
Pain in a band around the abdomen
Symptoms related to level of lesion; sudden onset
Brown-Séquard Syndrome: cord hemisection
IL: weakness, loss of fine touch, vibration, proprioception distal to the lesion
CL: loss of pain and temperature 1-2 levels below the lesion
Atlantoaxial instability: C1-2 articulation
Down syndrome: transverse ligament instability; 10-30% of Down syn patients
Subluxation symptoms are those of cord dysfunction at those levels

7. PREP question
During the health supervision visit for a 6 week old boy, his father expresses concern that his son “doesn’t look like” his other children. Growth parameters are normal except for a head circumference of 35.5 cm (<5th percentile).
On PE, you note that the infant does not appear to fixate or track your face visually. There is a “slip through” on vertical suspension and “draping over” on horizontal suspension. DTRs are brisk. Moro reflex is present and brisk.
Of the following, the MOST likely cause of this infants hypotonia is:
Anterior horn cell disease
Congenital brain malformation
Congenital myasthenic syndrome
Congenital myopathy
Spinal cord disease

8. B. Congenital brain malformation
Hypotonia
Localize! UMN versus LMN signs, axial vs appendicular
Take into account growth parameters, especially HC, as well as features such as tracking
Regarding the other choices:
A. Anterior horn cell disease: wouldn’t cause microcephaly or increased reflexes
C. Congenital myasthenic syndrome: wouldn’t cause microcephaly or brisk reflexes
D. Congenital myopathy: no microcephaly or poor visual tracking
E. Spinal cord disease: wouldn’t cause microcephaly or poor visual tracking