The degree and type of sensory loss will depend upon the extent of the involvement of the various sensory tracts, but there is often a "sensory level" at the spinal ganglion of the segmental spinal nerve, below which sensation to pain or light touch is impaired. Motor weakness occurs due to involvement of the pyramidal tracts and mainly affects the muscles that flex the legs and extend the arms.Disturbances in sensory nerves and motor nerves and dysfunction of the autonomic nervous system at the level of the lesion or below, are noted. Therefore, the signs and symptoms depend on the area of the spine involved. Back pain can occur at the level of any inflamed segment of the spinal cord.If the upper cervical segment of the spinal cord is involved, all four limbs may be affected and there is risk of respiratory failure – the phrenic nerve which is formed by the cervical spinal nerves C3, C4, and C5 innervates the main muscle of respiration, the diaphragm.Lesions of the lower cervical region (C5–T1) will cause a combination of upper and lower motor neuron signs in the upper limbs, and exclusively upper motor neuron signs in the lower limbs. Cervical lesions account for about 20% of cases.A lesion of the thoracic segment (T1–12) will produce upper motor neuron signs in the lower limbs, presenting as a spastic paraparesis.
Other symptoms
Breathing difficulties can occur, resulting from neuromyotonic activity of the laryngeal muscles. Laryngeal spasm possibly resulting from neuromyotonia has been described previously, and this highlights that, in patients with unexplained laryngospasm, neuromytonia should be added to the list of differential diagnoses.Studies have shown subtly decreased metabolism on positron emission tomography (PET) and single photon emission computed tomography (SPECT) in the left inferior frontal and left temporal lobes. and or basal ganglia hypermetabolism. Ancillary laboratory tests including MRI and brain biopsy have confirmed temporal lobe involvement. Cranial MRI shows increased signal in the hippocampus.Cerebral spinal fluid (CSF) shows normal protein, glucose, white blood cell, and immunoglobulin G (IgG) levels, but there are weak oligoclonal bands, which are absent in the blood serum. Marked changes in circadian serum levels of neurohormones and increased levels of peripheral neurotransmitters were also observed. The absence of morphological alterations of the brain pathology, the suggestion of diffusion of IgG into the thalamus and striatum, more marked than in the cortex (consistent with effects on the thalamolimbic system) the oligoclonal bands in the CSF and the amelioration after PE all strongly support an antibody-mediated basis for the condition. Raised CSF IgG concentrations and oligoclonal bands have been reported in patients with psychosis. Anti-acetylcholine receptors (anti-AChR) antibodies have also been detected in patients with thymoma, but without clinical manifestations of myasthenia gravis.