AW may be originated from upper or lower motor neuron
lesions, spinal cord pathologies, neuromuscular junctions and muscle diseases1 (Table-I).
8) Electrophysiologic studies can be helpful in identifying active denervation of lower motor neurons
Neurogenic changes based on electromyography (EMG) of the rectus abdominis (RA) muscles are regarded as evidence of lesions in lower motor neurons
(LMNs) of the thoracic spinal cord in amyotrophic lateral sclerosis (ALS).
Pathologically, ALS is characterized by extensive loss of lower motor neurons
in the spinal cord and brain stem, atrophy of ventral roots, degeneration of upper motor neurons in the motor cortex and corticospinal tract, somatic and axonal inclusions of aberrant neurofilament proteins, and reactive astrocytosis.
Following a thoracolumbar disc herniation, this may clinically be characterized by systemic signs of toxemia, a flaccid abdomen, the level of 'cut-off' of the cutaneous trunci reflex response migrating cranially, a shift from upper motor neuron to lower motor neuron
signs in the rear limbs, progressive involvement of the forelimbs and eventually respiratory paralysis and death.
Trauma at these levels or disruption of the lower motor neurons
(LMNs) is contraindicated for phrenic nerve pacing.
The UMNs project to and synapse on lower motor neurons
in the spinal cord.
ALS is a neuro-degenerative disease that leads to muscle weakness and atrophy throughout the body as a result of the degeneration of both upper and lower motor neurons
, the nerve cells in the central nervous system responsible for voluntary muscle movement.
BBs have a predilection for the lumbar cord as opposed to thoracic and cervical sections and are present in greater numbers in the lower motor neurons
of patients with an associated dementia [10,11].
ALS is a neurodegenerative disease that usually attacks both upper and lower motor neurons
and causes degeneration throughout the brain and spinal cord, according to the ALS Association Web site.
The upper motor neurons originate in the brain and brainstem, and the lower motor neurons
arise from the spinal cord.
MNDs involving the upper and lower motor neurons
are heterogeneous group of syndromes with various clinical presentations, most with poor prognosis.