Neuroanatomy Draw It To Know It

120 Neuroanatomy: Draw It to Know It

Spinal Cord Disorders

Case I

Patient presents with years of progressive “lightning-like”
pain in the lower extremities. Exam reveals profound lower
extremity loss of vibration/proprioception sensation with
preserved pain/temperature sensation and preserved
strength in the lower extremities. Th ere is arefl exia in the
lower extremities. Th e upper extremities are normal.
Show that the loss of vibration/proprioception sensa-
tion with preserved pain/temperature sensation and pre-
served motor function suggests posterior column spinal

cord involvement. Th e lower extremity arefl exia suggests

lower motor neuron involvement, so also show that there

is dorsal root involvement. Th e dorsal root involvement

causes the lancinating pain — presumably from irritation

of the pain/temperature fi bers.

Indicate that this constellation of defi cits suggests a

diagnosis of tabes dorsalis (aka syphilitic myelopathy),

in which the posterior columns and dorsal roots are

aff ected.^15 – 21

Case II

Patient presents with an abrupt onset of interscapular
pain, lower extremity weakness, sensory disturbance,
and bowel and bladder incontinence. Exam reveals
arefl exia of the lower extremities; paraparesis; loss of
pain/temperature sensation with preserved vibration/
proprioception sensation in the lower extremities; anal
sphincter atonia; and a normal motor, sensory, and refl ex
exam in the upper extremities.
Show that the sudden weakness and arefl exia suggests
bilateral anterior motor horn cell involvement, and that

the longitudinal loss of pain/temperature sensation sug-

gests involvement of the anterolateral system with pres-

ervation of the posterior columns.

Indicate that this constellation of defi cits suggests

anterior spinal artery ischemia, in which the anterior

two thirds of the spinal cord are aff ected. Note that

this syndrome variably aff ects the lateral corticospinal

tracts. Th e most common site of anterior spinal artery

ischemia is at the T4 level.^18 – 22

Case III

Patient presents with sudden weakness on the right side
of the body and sensory disturbance. Exam reveals right-
side weakness, right-side loss of vibration/proprioception
sensation, and left -side loss of pain/temperature sensa-
tion. Refl exes are absent on the right side and normal on
the left.
Show that the right-side hemi-body weakness sug-
gests right-side corticospinal tract involvement; that
the right-side loss of vibration/proprioception suggests

right-side posterior column tract involvement; that the

left -side loss of pain/temperature sensation suggests

right-side anterolateral system involvement; and that

the right-side arefl exia suggests right-side lower motor

neuron involvement, which could occur from either

anterior or posterior horn injury.

Indicate that this constellation of defi cits suggests a

hemi-cord syndrome involving the right half of the spinal

cord, called Brown-Séquard syndrome.^18 – 21