Introduction: Patients with multiple sclerosis (MS) often exhibit a brainstem (BS) involvement, which is sometimes undetected by conventional investigation. Recently, the vestibulocollic reflex (VCR) has been widely used in MS to assess vestibulospinal pathways. Besides VCR, other myogenic potentials can be used to explore BS circuits. Among these, the trigeminocollic reflex (TCR) has never been systematically studied in MS, while the vestibulomasseteric (VMR) and acousticmasseteric (AMR) reflexes have never been investigated in neurological diseases. Objectives: To perform a comprehensive evaluation of VMR, AMR, VCR and TCR in MS and compare frequency of abnormalities with those detected in controls; to correlate BSR data to those obtained from clinical examination, multimodal evoked potentials (EP) and conventional neuroimaging (MRI) assessment. Methods: Sixty patients (33.3±8.3 years old) with diagnosis of relapsing-remitting MS and 60 age- and sex matched controls were studied. All participants underwent clinical examination and BSR recording. MS underwent additional mEP and MRI assessment. Group differences were tested with χ² test and Mann-Whitney U test. Spearman’s rank correlation coefficient was used for correlation analysis. Results: Patients had a mean illness duration of 8.2±6.4 years and EDSS score of 1.78±1.10 (with EDSS=0 in 15.3%). Neurological examination showed symptoms and/or signs of BS involvement in 37.3% of cases. The frequency of altered BSR was significantly different (p=0.00001) between controls and patients. In patients, the false negative fraction was 10% and the true positive fraction of having at least one, two, three or four altered reflexes was 90.0%, 73.3%, 50.0% and 15.0% respectively. The distribution of reflex alteration in the “altered” group of patients was the following: VMR and AMR were altered in 66.7% of cases, TCR in 63.3% and VCR in 31.7% of patients. As for the pattern of alteration, ranked as absence, delay and delay plus absence, the most represented alteration was the reflex absence. Overall, mEPs revealed BS abnormalities in 82.8% of patients. As for the pattern of EP alterations, absence was significantly (p<0.01) more frequent than delay. MRI detected BS lesions in 71.7% of patients (midbrain 53.3%, pons 95.3% and medulla 60.5%). Alterations of the whole BSR set correlated with: global EDSS score (p=0006), pyramidal signs and/or symptoms (p=0.01); alterations of the III-IV peak interval of the Brainstem Auditory EP (BAEP) (p=0.003) and of the p14 wave of the median Somatosensory Potential (mSEP) (p=0.003); lesion load in the whole BS (0=0.0001), pons (p=0.004) and medulla (p=0.018). AMR and VMR significantly correlated with III-IV BAEP peak interval (p=0.001) and mSEP p14 wave (p=0.007). Conclusions: BSR-mEP correlations suggest that the combined use of this reflex battery may allow studying the BS level involved, with distinction of the medullo-spinal and medullo-pontine regions. The sensitivity of BSR set is comparable to that of mEP. The combination of these neurophysiological methods showed a high performance in spotting BS dysfunctions which were not clinically evident. The combined assessment of VMR, AMR, VCR and TCR may provide painless, easy to perform and low cost additional functional evaluation of BS integrity that may better assist conventional testing.
Brain stem reflex abnormalities in patients with multiple sclerosis / Deriu, Franca; Pilurzi, G; Magnano, I; Ginatempo, F; Cabboi, Mp; Pes, Giovanni Mario; Conti, Maurizio. - In: CLINICAL NEUROPHYSIOLOGY. - ISSN 1388-2457. - 124:10(2013), pp. 289-289. (Intervento presentato al convegno 5th International Conference on Non-Invasive Brain Stimulation tenutosi a Leipzig nel 19-21 marzo 2013) [10.1016/j.clinph.2013.04.273].
Brain stem reflex abnormalities in patients with multiple sclerosis
DERIU, Franca;Ginatempo F;PES, Giovanni Mario;CONTI, Maurizio
2013-01-01
Abstract
Introduction: Patients with multiple sclerosis (MS) often exhibit a brainstem (BS) involvement, which is sometimes undetected by conventional investigation. Recently, the vestibulocollic reflex (VCR) has been widely used in MS to assess vestibulospinal pathways. Besides VCR, other myogenic potentials can be used to explore BS circuits. Among these, the trigeminocollic reflex (TCR) has never been systematically studied in MS, while the vestibulomasseteric (VMR) and acousticmasseteric (AMR) reflexes have never been investigated in neurological diseases. Objectives: To perform a comprehensive evaluation of VMR, AMR, VCR and TCR in MS and compare frequency of abnormalities with those detected in controls; to correlate BSR data to those obtained from clinical examination, multimodal evoked potentials (EP) and conventional neuroimaging (MRI) assessment. Methods: Sixty patients (33.3±8.3 years old) with diagnosis of relapsing-remitting MS and 60 age- and sex matched controls were studied. All participants underwent clinical examination and BSR recording. MS underwent additional mEP and MRI assessment. Group differences were tested with χ² test and Mann-Whitney U test. Spearman’s rank correlation coefficient was used for correlation analysis. Results: Patients had a mean illness duration of 8.2±6.4 years and EDSS score of 1.78±1.10 (with EDSS=0 in 15.3%). Neurological examination showed symptoms and/or signs of BS involvement in 37.3% of cases. The frequency of altered BSR was significantly different (p=0.00001) between controls and patients. In patients, the false negative fraction was 10% and the true positive fraction of having at least one, two, three or four altered reflexes was 90.0%, 73.3%, 50.0% and 15.0% respectively. The distribution of reflex alteration in the “altered” group of patients was the following: VMR and AMR were altered in 66.7% of cases, TCR in 63.3% and VCR in 31.7% of patients. As for the pattern of alteration, ranked as absence, delay and delay plus absence, the most represented alteration was the reflex absence. Overall, mEPs revealed BS abnormalities in 82.8% of patients. As for the pattern of EP alterations, absence was significantly (p<0.01) more frequent than delay. MRI detected BS lesions in 71.7% of patients (midbrain 53.3%, pons 95.3% and medulla 60.5%). Alterations of the whole BSR set correlated with: global EDSS score (p=0006), pyramidal signs and/or symptoms (p=0.01); alterations of the III-IV peak interval of the Brainstem Auditory EP (BAEP) (p=0.003) and of the p14 wave of the median Somatosensory Potential (mSEP) (p=0.003); lesion load in the whole BS (0=0.0001), pons (p=0.004) and medulla (p=0.018). AMR and VMR significantly correlated with III-IV BAEP peak interval (p=0.001) and mSEP p14 wave (p=0.007). Conclusions: BSR-mEP correlations suggest that the combined use of this reflex battery may allow studying the BS level involved, with distinction of the medullo-spinal and medullo-pontine regions. The sensitivity of BSR set is comparable to that of mEP. The combination of these neurophysiological methods showed a high performance in spotting BS dysfunctions which were not clinically evident. The combined assessment of VMR, AMR, VCR and TCR may provide painless, easy to perform and low cost additional functional evaluation of BS integrity that may better assist conventional testing.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.