Case Of the Week (COW) 02 June 2013
Answer:
Hirayama disease.
Findings:
There is suggestion of atrophy of lower cervical cord. There is anterior shifting of posterior dural sac ; prominence and enhancement of posterior epidural venous plexus on flexion studies causing marked flattening of lower cervical cord.
Discussion:
Hirayama disease, also called as juvenile muscular atrophy of the distal upper extremity, monomelic amyotrophy, benign focal amyotrophy, and juvenile asymmetric segmental spinal muscular atrophy is a benign disorder with a stationary stage after a progressive course. It occurs mainly in young males between the ages of 15 and 25 years.
Imbalanced growth between the patient's vertebral column and spinal canal contents has been suggested as the pathogenetic factor. This imbalanced growth cause disproportional length between the patient's vertebral column and the spinal canal contents causing a tight dural sac and anterior displacement of posterior dural wall when the neck is flexed with consequent compression of the cord.
This compression may cause microcirculatory disturbances in the territory of the anterior spinal artery or in the anterior portion of the spinal cord. The chronic circulatory disturbance resulting from repeated or sustained flexion of the neck may produce necrosis of the anterior horns, which are most vulnerable to ischemia.
Neuroimaging findings reported more frequently are asymmetrical/symmetrical atrophy of lower cervical cord, prominence and enhancement of posterior epidural venous plexus on flexion studies and anterior shifting of posterior dural sac on flexion. Loss of attachment between the posterior dural sac and subjacent lamina on neutral position, anterior shifting of the posterior wall of the cervical dural canal, enhancing epidural component in the lower cervical and thoracic region and prominent posterior epidural flow voids suggestive of dilated epidural venous plexus on flexion studies are reported as highly suggestive for the diagnosis of Hirayama disease.
Early diagnosis and therapeutic intervention in the form of cervical collar therapy to prevent neck flexion may minimize the functional disability of the young patients.
Contributed By:
Dr. Karunakaran M Kalathi MD, Dr. Arun Chelladurai MD
Consultant Radiologists, Aarthi Scans, Thirunelveli
Answer:
Hirayama disease.
Findings:
There is suggestion of atrophy of lower cervical cord. There is anterior shifting of posterior dural sac ; prominence and enhancement of posterior epidural venous plexus on flexion studies causing marked flattening of lower cervical cord.
Discussion:
Hirayama disease, also called as juvenile muscular atrophy of the distal upper extremity, monomelic amyotrophy, benign focal amyotrophy, and juvenile asymmetric segmental spinal muscular atrophy is a benign disorder with a stationary stage after a progressive course. It occurs mainly in young males between the ages of 15 and 25 years.
Imbalanced growth between the patient's vertebral column and spinal canal contents has been suggested as the pathogenetic factor. This imbalanced growth cause disproportional length between the patient's vertebral column and the spinal canal contents causing a tight dural sac and anterior displacement of posterior dural wall when the neck is flexed with consequent compression of the cord.
This compression may cause microcirculatory disturbances in the territory of the anterior spinal artery or in the anterior portion of the spinal cord. The chronic circulatory disturbance resulting from repeated or sustained flexion of the neck may produce necrosis of the anterior horns, which are most vulnerable to ischemia.
Neuroimaging findings reported more frequently are asymmetrical/symmetrical atrophy of lower cervical cord, prominence and enhancement of posterior epidural venous plexus on flexion studies and anterior shifting of posterior dural sac on flexion. Loss of attachment between the posterior dural sac and subjacent lamina on neutral position, anterior shifting of the posterior wall of the cervical dural canal, enhancing epidural component in the lower cervical and thoracic region and prominent posterior epidural flow voids suggestive of dilated epidural venous plexus on flexion studies are reported as highly suggestive for the diagnosis of Hirayama disease.
Early diagnosis and therapeutic intervention in the form of cervical collar therapy to prevent neck flexion may minimize the functional disability of the young patients.
Contributed By:
Dr. Karunakaran M Kalathi MD, Dr. Arun Chelladurai MD
Consultant Radiologists, Aarthi Scans, Thirunelveli