Amyotrophic cervical myelopathy in adolescence.

Abstract

The clinical and radiological features in seven patients who had asymmetric muscular atrophy of the hand and forearm when young are reported and a new hypothesis for its aetiology is proposed. Investigation of body growth curves (a surrogate for velocity of arm growth) showed close relation between (a) the age when the body height increased most rapidly and the onset age of this disorder, and (b) the age when the rapid body growth period ended and the age when symptom progression ceased. Cervical radiological evidence is provided showing asymmetric anterior cord atrophy, disappearance of slackness of dorsal roots in neck extension, and anterior and lateral displacement of the lower cervical cord against the posterior aspects of the vertebral bodies during neck flexion. These results suggest that disproportionate shortening of the dorsal roots is further accentuated during the juvenile growth spurt, which determines the onset and self limited course of the condition, and that repeated neck flexion causes microtrauma and relative ischaemia of anterior horn cells, which finally results in atrophy of the muscles innervated by motoneurons with long axons.Predisposing anatomical factors are a straight neck due to lack of physiological cervical lordosis and the presence offoreshortened dorsal roots. (3 Neurol Neurosurg Psychiatry 1995;58:56-64)

Pathophysiology and treatment for cervical flexion myelopathy

“…Yada and colleagues have pointed out a rostral shift of the posterior root entry zone of the middle and lower cervical spinal cord on neck-flexed myelogram in nine cases of CFM. They hypothesized that the spinal cord could be stretched in an up-down direction due to growth imbalance between a long cervical spine and a short spinal cord (overstretch mechanism) [21,51,52]. Tachibana et al conducted an experimental study on a canine model of overstretching spinal cord [46,47].…”

Cervical dural sac and spinal cord in juvenile muscular atrophy of distal upper extremity

“…We and others have reported dynamic changes of the cervical dural sac and spinal cord during neck flexion in case series of this illness. [9][10][11][12][13] We further investigated if those dynamic changes are characteristic of this illness and contribute to the pathogenesis.…”

Autonomic changes with seizures correlate with postictal EEG suppression

“…3,4 Moreover, clinical studies have also shown that profound desaturations below 90% were significantly correlated with hemispheric lateralization in localization-related epilepsy (odds ratio right vs left 5 2.098; 95% confidence interval 1.078-4.085). 5 The knowledge about lateralization of the anatomy and pathophysiology of the central autonomic nervous system may contribute to a better understanding of SUDEP and has the potential to detect patients who may be particularly susceptible to this devastating clinical entity. …”