Utility of Clinical Assessment and Electrophysiological Study of The Respiratory Impairment in Egyptian Patients With Multiple Sclerosis

Background: The respiratory motor pathways may be involved because of the multi-focal nature of central nervous system affection in the Multiple sclerosis, leading to respiratory muscle weakness (predominately diaphragm involvement), producing a restrictive ventilatory defect.Materials &methods: Clinical pulmonary dysfunction index. An index comprised of four clinical signs: the patient's report of difficulty in clearing pulmonary secretions and his report of a weakened cough, the examiner's observation of the patient's cough, and ability to count on a single exhalation was devised for clinical assessment of respiratory muscle weakness..The index has acceptable validity and reliability for use in clinical practice to identify those neurological patients with respiratory muscle weakness, Kurtzke MS rating scales, fatigue severity scale (FSS), fatigue descriptive scale (FDS) and electrophysiological study of the diaphragm were used in 28 Egyptian patients with definite MS.Result: The clinical pulmonary dysfunction index was positive (abnormal) in 16 (57.1%) subjects [10 subjects (35.7%) with secondary progressive type and 6 subjects (21.4%) with relapsing remitting type]. MS patients were found to have a statistically highly significant prolongation of latency of motor evoked potential (MEP) as compared to controls following magnetic transcranial stimulation (MTS); following magnetic cervical stimulation at C7 level (MCS) and following electric stimulation of the phrenic nerve at the neck (EPS) (p<0.01). The central motor conduction time between the cortex and the cervical spine (CMCT1) was abnormal in 6 patients (21.4%), and the motor conduction time between the cortex and the neck (CMCT2), was abnormal in 4 patients (14.3%). Statistically significant positive correlations were found between cerebellar, brain stem, bladder, dysfunctions and pulmonary dysfunction index. Peripheral motor evoked potential latency correlated significantly positively with FSS scores and pulmonary dysfunction index (p=0.05; p=0.02) respectively .Cervical motor evoked potential latency correlated significantly positively with FSS scores (p=0.03).Conclusion: A systematic clinical assessment supplemented by electrophysiological assessment of the diaphragm can uncover subtle respiratory muscle weakness in patients with MS, rationalizing inclusion of assessment of respiratory muscle function in examination protocols of patients with MS to guide early intervention efforts.